05
.E55
0. 1062
op. 2
Special Report 1062
July 2005
Maiheur Experiment Station
Annual Report 2004
Oregon State I
UNIVERSITY
Agricultural
ExperimentStation
DOES NOT CIRCULATE
Oregon State University
Received on: 06—30—05
Special report
Ma
For additional copies of this publication
Clinton C. Shock, Superintendent
Maiheur Experiment Station
595 Onion Avenue
Ontario, OR 97914
For additional information, please
check our website
http://www.cropinfo.net/
Agricultural Experiment Station
Oregon State University
Special Report 1062
July 2005
Malheur Experiment Station
Annual Report 2004
The information in this report is for the purpose of informing cooperators in industry, colleagues
at other universitities, and others of the results of research in field crops. Reference to products and
companies in this publication is for specific information only and does not endorse or recommend
that product or company to the exclusion of others that may be suitable. Nor should information and
interpretation thereof be considered as recommendations for application of any pesticide. Pesticide
labels always should be consulted before any pesticide use.
Common names and manufacturers of chemical products used in the trials reported here are
contained in Appendices A and B. Common and scientific names of crops are listed in Appendix C.
Common and scientific names of weeds are listed in Appendix D. Common and scientific names
of diseases and insects are listed in Appendix E.
CONTRIBUTORS AND COOPERATORS
MALHEUR EXPERIMENT STATION SPECIAL REPORT
2004 RESEARCH
MALHEUR COUNTY OFFICE, OSU EXTENSION SERVICE PERSONNEL
Professor
Jensen, Lynn
Moore, Marilyn
Instructor
Porath, Marni
Assistant Professor
MALHEUR EXPERIMENT STATION
Eldredge, Eric
Faculty Research Assistant
Feibert, Erik
Senior Faculty Research Assistant
Ishida, Joey
Bioscience Research Technician
Jones, Janet
Office Specialist
Ransom, Corey V.
Assistant Professor of Weed Science
Rice, Charles
Faculty Research Assistant
Pereira, Andre
Visiting Professor
Saunders, Lamont
Bioscience Research Technician
Shock, Clinton C.
Professor, Superintendent
MALHEUR EXPERIMENT STATION, STUDENTS
Flock, Rebecca
Research Aide
Hoxie, Brandon
Research Aide
Ishida, Jessica
Research Aide
Linford, Christie
Research Aide
Nelson, Kelby
Research Aide
Saunders, Ashley
Research Aide
Shock, Cedric
Research Aide
Sullivan, Susan
Research Aide
OREGON STATE UNIVERSITY, CORVALLIS, AND OTHER STATIONS
Bafus, Rhonda
Faculty Research Assistant, Madras
Bassinette, John
Senior Faculty Research Assistant, Dept. of Crop and Soil Science
Charlton, Brian
Faculty Research Assistant, Kiamath Falls
Hane, Dan
Potato Specialist, Hermiston
James, Steven
Senior Research Assistant, Madras
Karow, Russell
Professor, Dept. of Crop and Soil Science
Locke, Kerry
Associate Professor, Klamath Falls
Mosley, Alvin
Associate Professor, Dept. of Crop and Soil Science
Rykbost, Ken
Professor, Superintendent, Klamath Falls
OTHER UNIVERSITIES
Brown, Bradford
Fraisse, Clyde
Gallian, John
Hoffman, Angela
Hutchinson, Pamela
Love, Steve
Mohan, Krishna
Morishita, Don
Neufeld, Jerry
Nissen, Scott
Novy, Rich
O'Neill, Mick
Reddy, Steven
Associate Professor, Univ. of Idaho, Parma, ID
Research Engineer, Washington State Univ., Prosser, WA
Professor, Univ. of Idaho, Twin Falls, ID
Professor, Univ. of Portland, Portland, OR
Assistant Professor, Univ. of Idaho, Aberdeen, ID
Professor, Univ. of Idaho, Aberdeen, ID
Professor, Univ. of Idaho, Parma, ID
Associate Professor, Univ. of Idaho, Twin Falls, ID
Associate Professor, Univ. of Idaho, Caldwell, ID
Associate Professor, Colorado State Univ., Ft. Collins, CO
Research Geneticist/Potato Breeder, USDA, Aberdeen, ID
Superintendent, New Mexico State Univ., Farmington, NM
Extension Educator, Univ. of Idaho, Weiser, ID
OTHER PERSONNEL COOPERATING ON SPECIAL PROJECTS
Anderson, Brian
Clearwater Supply, Inc., Othello, WA
Archuleta, Ray
Natural Resource Conservation Service, Ontario, OR
Bosshart, Perry
Professional Research Consultant, Farmington, ME
Calbo, Adonai G.
Embrapa, Brasilia, DF, Brazil
Camp, Stacey
Amalgamated Sugar Co., Paul, ID
Eaton, Jake
Potlatch, Boardman, OR
Erstrom, Jerry
Malheur Watershed Council, Ontario, OR
Feuer, Lenny
Automata, Inc., Nevada City, CA
Futter, Herb
Malheur Owyhee Watershed Council, Ontario, OR
Hansen, Mike
M.K. Hansen Co., East Wenatchee, WA
Hawkins, Al
Irrometer Co., Inc., Riverside, CA
Hill, Carl
Owyhee Watershed Council, Ontario, OR
Huffacker, Bob
Amalgamated Sugar, Nyssa, OR
Jones, Ron
Oregon Department of Agriculture, Ontario, OR
Kameshige, Brian
Cooperating Grower, Ontario, OR
Kameshige, Randy
Cooperating Grower, Ontario, OR
Klauzer, Jim
Clearwater Supply, Inc., Ontario, OR
Komoto, Bob
Ontario Produce, Ontario, OR
Leiendecker, Karen
Oregon Watershed Enhancement Board, La Grande, OR
Lund, Steve
Amalgamated Sugar Co., Twin FaIls, ID
Martin, Jennifer
Coordinator, Owyhee Watershed Council, Ontario, OR
Matson, Robin
Englehard Corp., Yakima, WA
McKeIIip, Robert
Cooperating Grower, Nampa, ID
Mittlestadt, Bob
Clearwater Supply, Inc., Othello, WA
Murata, Warren
Cooperating Grower, Ontario, OR
Nakada, Vernon
Cooperating Grower, Ontario, OR
Nakano, Jim
Malheur Watershed Council, Ontario, OR
Page, Gary
Malheur County Weed Supervisor, Vale, OR
Penning, Tom
Irrometer Co., Inc., Riverside, CA
Phillips, Lance
Soil and Water Conservation District, Ontario, OR
Pogue, Bill
Irrometer Co., Inc., Riverside, CA
Poihemus, Dave
Andrews Seed Co., Ontario, OR
Pratt, Kathy
Malheur Owyhee Watershed Council, Ontario, OR
TABLE OF CONTENTS (continued)
Soybean Performance in Ontario in 2004
124
POTATO
Potato Variety Trials 2004
128
Potato Tuber Bulking Rate and Processing Quality of Early Potato Selections ---
141
Planting Configuration and Plant Population Effects on Drip-irrigated Umatilla
Russet Potato Yield and Grade
156
A Single Episode of Water Stress Reduces the Yield and Grade of Ranger
Russet and Umatilla Russet Potato
166
Irrigation System Comparison for the Production of Ranger Russet and Umatilla
Russet Potato
173
Development of New Herbicide Options for Weed Control in Potato Production -
177
SUGAR BEETS
Sugar Beet Variety 2004 Testing Results
186
Kochia Control with Preemergence Nortron® in Standard and Micro-rate
Herbicide Programs in Sugar Beet
194
Timing of Dual Magnum® and Outlook® Applications for Weed Control in Sugar
Beet
199
Comparison of Calendar Days and Growing Degree-Days for Scheduling
Herbicide Applications in Sugar Beet
203
WHEAT AND SMALL GRAINS
2004 Winter Elite Wheat Trial
208
SOIL MOISTURE MONITORING
Automatic Collection, Radio Transmission, and Use of Soil Water Data
211
Use of Irrigas® for Irrigation Scheduling for Onion Under Furrow Irrigation
223
YELLOW NUTSEDGE BIOLOGY AND CONTROL
Factors Influencing Vapam® Efficacy on Yellow Nutsedge Tubers
230
Yellow Nutsedge Growth in Response to Environment
236
Yellow Nutsege Control in Corn and Dry Bean Crops
245
Chemical Fallow for Yellow Nutsedge Supression Following Wheat Harvest
250
OTHER PERSONNEL COOPERATING ON SPECIAL PROJECTS (continued)
Richardson, Phil
Oregon Dept. of Environmental Quality, Pendleton, OR
Simantel, Gerald
Novartis Seed, Longmont, CO
Stadick, Chuck
Simplot Grower Solutions, CaIdwell, ID
Stander, J. R.
Betaseed, Inc., Kimberly, ID
Stewart, Kevin
T-Systems International, Kennewick, WA
Taberna, John
Western Laboratories, Inc., Parma, ID
Vogt, Glenn
J. R. Simplot Co., Caldwell, ID
Wagstaff, Robert
Cooperating Grower, Nyssa, OR
Walhert, Bill
Amalgamated Sugar, Ontario, OR
Weidemann, Kelly
Malheur Watershed Council, Ontario, OR
Yoder, Ron
DuPont Crop Protection, Boise, ID
GROWERS ASSOCIATIONS SUPPORTING RESEARCH
Idaho Alfalfa Seed Growers Association
Idaho-Eastern Oregon Onion Committee
Idaho Mint Commission
Malheur County Potato Growers
Nyssa-Nampa Beet Growers Association
Oregon Alfalfa Seed Commission
Oregon Alfalfa Seed Growers Association
Oregon Potato Commission
Oregon Wheat Commission
PUBLIC AGENCIES SUPPORTING RESEARCH
Agricultural Research Foundation
Malheur County Soil and Water Conservation District
Natural Resource Conservation Service
Oregon Department of Environmental Quality
Oregon Department of Agriculture
Oregon Watershed Enhancement Board
U.S. Environmental Protection Agency 319 Program
USDA Cooperative State Research, Education, and Extension Service
Western Sustainable Agriculture Research and Extension
COMPANY CONTRIBUTORS
ABI Alfalfa, Inc.
Advanced Agri-Tech
Allied Seed Cooperative
American Crystal Sugar Co.
American Takii, Inc.
AMVAC
BASF
Bayer CropScience
Bejo Seeds, Inc.
Betaseed, Inc.
Clearwater Supply, Inc.
Crookham Co.
D. Palmer Seed Co., Inc.
Dairyland Research
DeKaIb Genetics Corp.
Dorsing Seeds, Inc.
Dow Agrosciences
DuPont
ESI Environmental Sensors
FMC Corp.
Forage Genetics
Fresno Valves & Castings, Inc.
Geertson Seed Co.
Global Genetics
Gooding Seed Co.
Gowan Co.
Hotly Sugar Corp.
Irrometer Co., Inc.
M.K. Hansen Co.
Monsanto
Nelson Irrigation
Netafim Irrigation, Inc.
Nichino America, Inc.
Novartis Seeds, Inc.
Nunhems USA, Inc.
Pioneer
Potlatch
Rispens Seeds, Inc.
Rohm and Haas
Seed Systems
Seed Works
Seedex, Inc.
Seminis Vegetable Seeds, Inc.
Simplot Co.
Streat Instruments, New Zealand
Summerdale, Inc.
Syngenta
T-Systems International
UAP Northwest
Valent
W-L Research
TABLE OF CONTENTS
WEATHER
2004 Weather Report
I
ALFALFA
Third Year Results of the 2002-2006 Drip-irrigated Alfalfa Forage Variety Trial ---
8
CORN
Weed Control and Crop Response with Option® Herbicide Applied in Field Corn
14
MINT
Evaluations of Spring Herbicide Applications to Dormant Mint
18
ONION
2004 Onion Variety Trials
21
Pungency of Selected Onion Varieties Before and After Storage
30
Effect of Short-duration Water Stress on Onion Single Centeredness and
Translucent Scale
33
Treatment of Onion Bulbs with Surround® to Reduce Temperature and Bulb
Sunscald
38
Effect of Onion Bulb Temperature and Handling on Bruising
45
Evaluation of Overwintering Onion for Production in the Treasure Valley,
2003-2004 Trial
50
Weed Control in Onion with Postemergence Herbicides
54
Soil-active Herbicide Applications for Weed Control in Onion
65
Insecticide Trials for Onion Thrips (Thrips tabaci) Control - 2004
71
A Two-year Study on Varietal Response to an Alternative Approach for
Controlling Onion Thrips (Thrips tabaci) in Spanish Onions
77
A One-year Study on the Effectiveness of Oxamyl (Vydate L®) to Control Thrips
in Onions When Injected into a Drip-irrigation System
89
Growers Use Less Nitrogen Fertilizer on Drip-irrigated Onion Than
Furrow-irrigated Onion
94
POPLARS AND ALTERNATIVE CROPS
Performance of Hybrid Poplar Clones on an Alkaline Soil
97
Micro-irrigation Alternatives for Hybrid Poplar Production 2004 Trial
106
Effect of Pruning Severity on the Annual Growth of Hybrid Poplar
118
TABLE OF CONTENTS (continued)
APPENDICES
A. Herbicides and Adjuvants
253
B. Insecticides, Fungicides, and Nematicides
254
C. Common and Scientific Names of Crops, Forages, and Forbs
255
D. Common and Scientific Names of Weeds
256
E. Common and Scientific Names of Diseases and Insects
256
2004 WEATHER REPORT
Erik B. G. Feibert and Clinton C. Shock
Malheur Experiment Station
Oregon State University
Ontario, OR
Introduction
Air temperature and precipitation have been recorded daily at the Malheur Experiment
Station since July 20, 1942. Installation of additional equipment in 1948 allowed for
evaporation and wind measurements. A soil thermometer at 4-inch depth was added in
1967. A biophenometer, to monitor degree days, and pyranometers, to monitor total
solar and photosynthetically active radiation, were added in 1985.
Since 1962, the Maiheur Experiment Station has participated in the Cooperative Weather
Station system of the National Weather Service. The daily readings from the station are
reported to the National Weather Service forecast office in Boise, Idaho.
Starting in June 1997, the daily weather data and the monthly weather summaries have
been posted on the Malheur Experiment Station web site on the internet at
www.cropinfo.net.
On June 1, 1992, in cooperation with the U.S. Department of the Interior, Bureau of
Reclamation, a fully automated weather station, linked by satellite to the Northwest
Cooperative Agricultural Weather Network (AgriMet) computer in Boise, Idaho, began
transmitting data from Malheur Experiment Station. The automated station continually
monitors air temperature, relative humidity, dew point temperature, precipitation, wind
run, wind speed, wind direction, solar radiation, and soil temperature at 8-inch and
20-inch depths. Data are transmitted via satellite to the Boise computer every 4 hours
and are used to calculate daily Malheur County crop water-use estimates. The AgriMet
database can be accessed through the internet at www.usbr.gov/pn/agrimet and is linked
to the Malheur Experiment Station web page at www.cropinfo.net.
Methods
The ground under and around the weather stations was bare until October 17, 1997,
when it was covered with turigrass. The grass is irrigated with subsurface drip irrigation.
The weather data are recorded each day at 8:00 a.m. Consequently, the data in the
tables of daily observations refer to the previous 24 hours.
Evaporation is measured from April through October as inches of water evaporated from
a standard 10-inch-deep by 4-ft-diameter pan over 24 hours. Evapotranspiration (ETa)
for each crop is calculated by the AgriMet computer using data from the AgriMet weather
1
station and the Kimberly-Penman equation (Wright 1 982). Reference evapotranspiration
(ET0) is calculated for a theoretical 12- to 20-inch-tall crop of alfalfa assuming full cover
for the whole season. Evapotranspiration for all crops is calculated using ET0 and crop
coefficients for each crop. These crop coefficients vary throughout the growing season
based on the plant growth stage. The crop coefficients are tied to the plant growth stage
by three dates: start, full cover, and termination dates. Start dates are the beginning of
vegetative growth in the spring for perennial crops or the emergence date for row crops.
Full cover dates are typically when plants reach full foliage. Termination dates are
defined by harvest, frost, or dormancy. Alfalfa mean
is calculated for an alfalfa crop
assuming a 15 percent reduction to account for cuttings.
Wind run is measured as total wind movement in miles over 24 hours at 24 inches above
the ground. Weather data averages in the tables refer to the years preceding and up to,
but not including, the current year.
2004 Weather
The total precipitation for 2004 (11.98 inches) was higher than the 10-year (10.19 inches)
and 60-year (10.16 inches) averages (Table 1). Precipitation in October was about three
times the 10-year and 60-year averages. Total snowfall for 2004 (24 inches) was higher
than the 10-year (14.0 inches) and 61-year averages (18.2 inches) (Table 2).
The highest temperature for 2004 was 104°F on July 18 (Table 3). The lowest temperature for the year was -1°F on January 5. The average maximum and minimum air
temperatures for March were substantially higher than the 10-year and 60-year
averages. March 31 reached 80°F.
March had the highest number of growing degree days (50° to 86°F) for that month since
1986, when measurements were started (Table 4, Fig. 1). The total number of degree
days in the above-optimal range in 2004 was close to the average (Table 5).
The months of May through December had total wind runs lower than the 10-year
average (Table 6). Total pan-evaporation for 2004 was close to the 10-year and 56-year
averages (Table 7). Total accumulated
for all crops in 2004 was close to the 10-year
average (Table 8).
The average monthly maximum and minimum 4-inch soil temperatures in 2004 were
close to the 10-year and 37-year averages (Table 9).
The last spring frost (32°F) occurred on April 16, 13 days earlier than the 28-year
average date of April 29; the first fall frost occurred on October 24, 19 days later than the
28-year average date of October 5 (Table 10). The 191 frost-free days was the longest
frost-free period over the last 14 years.
No other weather records were broken in 2004 (Table 11).
2
References
Wright, J.L. 1982. New evapotranspiration crop coefficients. J. Irrig. Drain. Div., ASCE
108:57-74.
Table 1. Monthly precipitation at the Maiheur Experiment Station, Oregon State
University, Ontario, OR, 1991-2004.
Year
Jan
Feb
Mar
Apr
May
Jun
0.59
0.58
2.35
1.20
2.67
0.97
2.13
2.26
1.64
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2.01
1.15
0.77
1.46
1.82
1.63
1.35
10-yravg
60-yravg
0.44
1.36
1.02
0.57
0.28
0.86
0.17
1.45
2.50
2.14
0.88
0.25
2.41
0.05
1.58
1.03
0.25
0.95
0.59
0.97
0.41
1.11
0.27
0.48
1.54
0.49
0.99
0.25
0.80
0.95
0.91
0.95
0.81
0.74
2.55
1.02
1.16
1.19
0.66
1.43
0.23
0.72
0.70
0.77
1.12
0.98
0.90
0.81
1.89
0.21
1.41
2.39
0.67
4.55
0.28
0.28
0.37
0.09
1.52
1.70
1.32
1.04
Sep
Oct
Nov
Dec
Total
0.01
0.04
101
0.95
0.80
0.43
0.01
0.35
0.09
0.00
0.15
0.07
0.59
0.40
1.00
0.00
0.39
0.10
0.36
0.15
0.56
0.32
0.48
1.71
0.36
0.18
0.19
1.10
0.32
1.40
1.15
0.64
2.46
0.88
1.18
1.02
1.07
0.49
0.38
1.33
0.44
0.86
0.93
1.04
1.15
1,51
9.25
8.64
13.30
10.05
nches
1.09
1.43
1.55
0.07
1.60
0.12
0.86
0.36
1.02
0.26
0.64
0.60
0.24
0.43
0.58
0.77
0.70
1.62
Aug
Jul
i
0.50
0.00
0.13
0.31
0.28
0.00
0.09
0.06
0.00
0.10
1.06
0.00
0.03
0.32
0.14
0.36
0.13
0.49
0.26
0.11
0.64
0.11
0.38
1.23
0.57
0.97
0.43
0.04
0.40
1.74
0.68
0.29
0.02
2.03
0.64
0.69
0.60
1.49
2.56
2.76
0.94
14.01
12.69
9.21
15.28
7.97
9.64
7.78
6.18
8.78
11.98
10.19
10.16
1.11
0.73
0.66
1.00
1.86
1.47
0.97
1.46
1.33
Table 2. Annual snowfall totals at the Maiheur Experiment Station, Oregon State
University, Ontario, OR, 1991-2004.
1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001
2002 2003
2004
10-yr
61-yr
avg
avg
14.0
18.2
inches
7.5
15.5
36.0
32.0
15.0
14.5
5.8
14.6
13.2
13.8
15.5
11.5
24.0
4.5
Table 3. Monthly air temperature, Malheur Experiment Station, Oregon State University,
Ontario, OR, 2004.
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Max Mm Max Mm Max Mm Max Mm Max Mm Max Mm Max Mm
Sep
Oct
Nov
Max Mm Max Mm Max Mm Max Mm
Highest
44 33
51
34
80 44 79 49 85 56 99 63 104 72 100 69 95 58 80 57 56 43
Lowest
13
29
11
43 25 52 32 56 37 70
2004 avg 31
-1
20 38 24 62 36 67 41
72 47
84
10-yr avg 38 25 46 27 56 32 64 37 72 45 81
60-yr avg 35 20 43 25 55 31 64 37 73 45 82
3
Dec
Max Mm
52
41
46
80 49 69 46 63 38 47 29 37
19
30
18
53
93 60
89
58
78 48 67 41
46
31
41
28
51
93
59
91
55
81
38
24
92
58
90
56
47 66 36 48
80 46 66 36 48
29
52
28
37
22
Average
"--- 2003
—•—-— 2004
1993
U-
3500
co
0
LC)
(I)
2500
2000
1500
10:0
74
148
295
221
369
Day of year
Figure 1. Cumulative growing degree days (50-86°F) over time for selected years
compared to 14-year average, Malheur Experiment Station, Oregon State University,
Ontario, OR.
Table 4. Monthly total growing degree days (50-86°F), Malheur Experiment Station,
Oregon State University, Ontario, OR, 1991-2004.
Year
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Total
1991
0
13
16
124
212
389
776
718
194
1
0
1992
0
13
106
202
482
574
704
174
4
0
0
23
81
423
358
639
464
436
385
252
6
0
1994
0
2
92
189
369
523
794
774
408
509
2,879
3,283
2,539
144
2
0
3,398
1995
0
29
32
106
293
433
680
588
472
101
3
1
2,747
1996
0
5
53
135
243
446
805
658
364
194
18
2
2,923
1997
4
0
81
117
419
509
661
706
481
157
20
0
3,154
1998
0
2
52
112
68
571
802
749
515
151
16
4
3,042
2
43
72
329
683
703
416
184
30
0
2,921
751
743
368
133
2
0
3,109
715
761
472
155
27
1993
1999
524
200
0
4
36
194
342
2001
tJ
0
63
126
401
459
536
488
2002
0
2
32
137
319
562
805
621
437
142
14
2
3,073
2003
0
4
72
112
319
594
846
754
448
281
11
2
3,443
2004
0
c
115
187
311
607
776
680
365
180
4
0
3,225
18-year avg
IJ
6
54
150
324
514
727
686
436
173
13
1
3,064
4
3,208
Table 5. Monthly total degree days in the above-ideal (86 -1 04°F) range, Malheur
Experiment Station, Oregon State University, Ontario, OR, 1991-2004.
Year
Apr
May
Jun
Jul
Aug
Sep
Oct
Total
1991
0
0
2
41
4
0
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
14-yr avg
0
5
20
23
36
54
2
0
0
4
4
2
11
5
0
0
2
16
4
7
0
0
0
5
54
22
32
0
0
4
0
0
4
0
68
23
54
27
63
7
0
31
5
0
45
14
0
83
104
26
147
56
95
67
122
0
0
0
0
1
2
21
16
1
0
41
0
0
7
41
5
7
4
4
0
0
43
45
95
86
0
0
14
11
5
0
36
5
0
31
2
0
34
6
0
0
5
9
0
0
18
25
54
74
43
0
2
7
41
0
85
130
94
90
Table 6. Wind-run daily totals and monthly totals, Malheur Experiment Station, Oregon
State University, Ontario, OR, 2004.
Daily
- Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
miles
Mean
54
74
67
75
43
45
35
34
46
31
32
24
Max.
170
201
175
164
118
120
90
64
137
124
136
120
Mm.
17
25
15
16
16
13
0
14
19
5
2
0
Annual total
2004
10-yraverage
56-yraverage
miles
1,659 2,143 2,092 2,261 1,320 1,336 1,087 1,039 1,389 972 947 739
1,573 1,942 2,500 2,512 2,293 1,932 1,723 1,685 1,554 1,798 1,616 1,912
2,150 1937 1,572 1,477 1,332 1,253 1,290
Table 7. Pan-evaporation totals, Malheur Experiment Station, Oregon State University,
Ontario, OR, 2004.
Totals
April
May
Jun
Jul
Aug
Sep
Oct
Total
Daily
inches
Mean
0.25
0.24
0.36
0.39
0.30
0.22
0.13
Max.
0.41
0.35
0.48
0.57
0.42
0.45
0.28
Mm.
0.10
0.12
0.23
0.12
0.07
0.08
0.00
Annual
inches
2004
7.25
7.51
10.66 12.09
9.23
6.55
3.82
57.11
10-yravg
6.05
8.45
9.75
11.61
7.38
10.70
4.43
58.27
56-yravg
5.61
7.72
8.94
11.15
9.64
6.32
51.78
3.28
5
Table 8. Total accumulated reference evapotranspiration (ETa) and crop
evapotranspiration (EL) (acre-inches/acre), Maiheur Experiment Station, Oregon State
University, Ontario, OR, 1992-2004.
Year
Reference Alfalfa Winter Spring
Sugar
beet
Onion
Potato
36.1
30.3
29.3
22.6
22.2
22.3
24.1
23.8
25.3
40.7
21.3
23.9
32.4
58.6
43.9
25.0
26.4
33.7
2000
58.7
45.5
26.0
25.7
2001
57.9
43,8
25.5
2002
58.8
41.7
2003
54.2
2004
52.8
10-year
average
55.8
28.8
Dry
bean
21.3
Field
corn
29.8
24.1
22.8
17.9
34.5
29.5
28.2
29.0
26.7
23.6
32.9
27.2
33.4
28.0
1st year 2nd year 3rd year
poplar
poplar
+ poplar
--
--
--
23.7
--
--
--
21.1
27.7
--
--
—
16.7
23.7
--
--
--
26.3
19.5
25.7
--
--
--
26.6
19.7
25.1
--
--
--
28.2
26.2
21.0
27.9
23.9
37.1
44.0
28.9
26.5
21.7
28.5
24.3
37.8
45.5
38.3
32.0
29.5
24.1
30.6
24.9
38.9
47.1
27.2
34.8
30.3
27.4
21.4
29.1
23.7
37.0
44.7
25.9
28.7
35.2
30.4
27.7
21.9
27.8
23.6
36.7
44.4
44.1
27.5
31.7
39.1
32.0
32.4
22.5
29.6
24.3
37.9
45.9
43.5
27.8
30.6
34.3
30.9
27.7
22.5
28.9
23.3
36.3
44.1
41.9
23.8
25.8
34.3
29.3
27.4
21.0
27.6
24.1
37.6
45.3
1992
ET
53.7
(mean)
44.4
grain
26.9
grain
27.9
1993
51.9
36.4
21.3
22.7
1994
57.6
40.6
21.3
1995
49.6
37.1
18.9
1996
52.8
39.8
1997
55.2
41.5
1998
55.0
1999
Table 9. Monthly soil temperature at 4-inch depth, Malheur Experiment Station, Oregon
State University, Ontario, OR, 2004.
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Max Mm Max Mm Max Mm Max Mm Max Mm Max Mm MaxMin Max Mm MaxMin Max Mm Max Mm Max Mm
°F
Highest
Lowest
2004 avg
10-yr avg
37-yr avg
37 34 38 34 52 47 59 52 65 60 77 69 81 72 81 71 72 66 64 59 46 45 46 45
31 30 32 29 37 36 47 43 55 50 61 56 69 63 66 62 59 55 48 45 34 33 32 32
33 32 33 32 45 41 54 48 61 55 70 62 76 68 74 68 65 60 56 52 42 40 37 36
35 34 38 35 46 41 55 47 65 56 73 64 80 70 78 70 70 63 57 52 44 41 36 35
33 32 38 34 49 40 59 47 71 57 80 66 87 73 85 72 75 63 59 51 44 40 35 33
6
Tab'e 10. Last and first frost (32°F) d ates and numbe r of frost-free days, Maiheur
Experiment Station, Oregon State Univ ersity, Ontario, OR, 1990-2004.
Total frost-free days
Date of last frost
Spring
Date of first frost
May8
Apr30
Apr24
Apr20
Apr15
Apr16
May6
May3
Oct7
Oct4
Sep14
152
Oct11
174
Oct6
Sep22
Sep23
Oct8
174
Oct17
182
1999
Apr18
May11
May12
Sep28
Sep24
140
2000
2001
Apr29
Oct10
164
2002
May8
May19
Oct12
157
Oct11
145
Year
1990
1991
1992
1993
1994
1995
1996
1997
1998
2003
Fall
157
143
159
140
158
135
2004
April16
Oct24
191
1976-2003 Avg
April 29
October 5
159
Table 11. Record weather events at the Malheur Experiment Station, Oregon State
University, Ontario, OR.
Record event
Measurement
Date
Greatest annual precipitation
16.87 inches
1983
Greatest monthly precipitation
4.55 inches
May 1998
Greatest 24-hour precipitation
1.52 inches
Sep 14, 1959
Greatest annual snowfall
40 inches
1955
Greatest 24-hour snowfall
10 inches
Nov 30, 1975
Earliest snowfall
1 inch
Oct 25, 1970
Highest air temperature
110°F
July 22, 2003
17 days
1971
-26°F
Jan 21 and 22, 1962
35 days
1985
12°F
Dec 24, 25, and 26, 1990
Highest yearly growing degree days
3,446 degree days
1988
Lowest yearly growing degree days
2,539 degree days
1993
Since 1943
Total days with maximum air temp. 100°F
Lowest air temperature
Total days with minimum air temp. 0°F
Since 1967
Lowest soil temperature at 4-inch depth
Since 1986
Since 1992
Highest reference evapotranspiration
58.8 inches
7
2002
THIRD YEAR RESULTS OF THE 2002-2006 DRIP-IRRIGATED ALFALFA FORAGE
VARIETY TRIAL
Eric P. Eldredge, Clinton C. Shock, and Lamont D. Saunders
Maiheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
The purpose of this trial is to compare the productivity and hay quality of alfalfa varieties
in the Treasure Valley area of Malheur County. The trial also provides information about
the adaptation of alfalfa hay production to drip irrigation. In this trial, over 5 years, 10
proprietary varieties are being compared to 2 public check varieties. This trial was
established with a portable sprinkler-irrigation system and then grown with a subsurface
drip-irrigation system.
Methods
The trial was established on Owyhee silt loam where winter wheat was the previous
crop and alfalfa had not been grown for more than 10 years. Pathfinder (Nelson
Irrigation Corp., Walla Walla, WA) drip tape (15 mil thick, 0.22 gal/mm/i 00-ft flow rate,
12-inch emitter spacing) was shanked in at a depth of 12 inches on 30-inch spacing
between the drip tapes. Plots were 5 ft wide by 20 ft long in a randomized complete
block design with each entry replicated five times. Further details of the establishment
of this trial were reported previously (Eldredge et al. 2003).
Gramoxone® at 2 pint/acre plus Sencor® at 1.5 pint/acre were applied for weed control
on March 11, 2004. No irrigations were applied before the first cutting in 2004. After the
first cutting, irrigations were semi-automated using a valve controller (DIG Corp. Vista,
CA) initially programmed to apply a 1-inch irrigation twice weekly, on Mondays and
Thursdays. Alfalfa crop evapotranspiration (ETa) was calculated based on data
collected by an AgriMet (U.S. Bureau of Reclamation, Boise, ID) weather station
located on the Malheur Experiment Station. Soil moisture was monitored by six
Watermark soil moisture sensors model 200SS (Irrometer Co. Inc., Riverside, CA)
installed at 12-inch depth in the center of six alfalfa plots, midway between drip tapes.
Sensors were connected to an AM400 data logger (M.K. Hansen, East Wenatchee,
WA) equipped with a thermistor to correct soil moisture calculations for soil
temperature. Water applied was measured by a totalizing water meter on the inlet of the
irrigation system. A rodenticide, Maki bromadiolone supercade bait (Liphatech, Inc.,
Milwaukee, WI), was applied in rodent tunnels on July 22 with a gopher probe (Eagle
Industries, Chatsworth, CA).
8
The alfalfa was harvested at bud stage on May 14, June 17, July 19, August 13, and
September 22, 2004. A 3-ft by 20-ft swath was cut from the center of each plot with a
flail mower, and the alfalfa was weighed. Ten samples of alfalfa were hand cut from
border areas of plots over the entire field on the same day just before each cutting,
quickly weighed, dried in a forage drier at 140°F with forced air, and reweighed to
determine the average alfalfa moisture content at each cutting. Yield was reported as
tons per acre of alfalfa hay at 88 percent dry matter.
Samples of alfalfa from approximately 1 ft of row per plot were taken June 16, before
the second cutting, to measure forage quality. The forage quality samples were dried,
ground in a Wiley mill (Thomas Scientific, Swedesboro, NJ) to pass through a 1-mm
screen, subsampled, and sent to the Oregon State University Forage Quality Lab at
Klamath Falls, Oregon, where they were reground in a UDY mill (UDY Corp., Ft. Collins,
CO) to pass through a 0.5-mm screen. Near infrared spectroscopy (N IRS) was used to
estimate percent dry matter, percent crude protein, percent acid detergent fiber (ADF),
percent neutral detergent fiber (NDF), percent fat, and percent ash. Relative forage
quality (RFQ) was calculated by the formula:
RFQ = (DM1 * TDNL)/ 1.23
where:
DM1 = dry matter intake (for alfalfa hay), and
DM1 = (((0.120 * 1350)! (NDF/100)) + (NDFD 45) * 0.374) / 1350 * 100, and
NDFD = dNDF48 / NDF * 100, and
dNDF48 = digestible NDF as a percentage of dry matter, as determined by a 48-hour in
vitro digestion test,
TDNL = total digestible nutrients [for legume (alfalfa hay)]
TDNL = (NFC * 0.98) + (protein * 0.93) + (fat * 0.97 * 2.25) + ((NDF-2) * (NDFD!100))
NFC 100- ((NDF -2) + protein + 2.5 + ash), and 1.23 was chosen as the
denominator to adjust the scale to match the RFV scale at 100 = full bloom alfalfa.
Quality standards based on REQ are: Supreme, REQ higherthan 185; Premium, REQ
170-184; Good, RFQ 150-169; Fair, RFQ 130-149, and Low, REQ below 129. RFQ
estimates voluntary energy intake when the hay is the only source of energy and
protein for ruminants. Hay with a higher RFQ requires less grain or feed concentrate to
formulate dairy rations.
Results and Discussion
Rodents chewed holes in the drip tape and continued to be a problem in this trial.
During the winter, voles burrowed down to the drip tape and chewed holes that were
found and repaired at the first irrigation. The rodenticide applied in the vole tunnels was
effective until the grain crop adjacent to the alfalfa trial was harvested. After the grain
harvest, a new population of voles gradually colonized the alfalfa trial. A gopher that
moved into the trial was promptly exterminated.
9
Soil moisture was monitored at the 12-inch depth after first cutting (Fig. 1). After June 8,
the soil remained uniformly moist in the —20 to —30 kPa (centibar) range for the rest of
the irrigation season.
The total irrigation water applied was less than the season-long accumulated alfalfa
crop evapotranspiration (Fig. 2). The irrigation system was turned off for harvest
operations and to repair leaks. Smaller irrigations, from 0.01 to 0.38 inch, were applied
on seven dates through the summer in order to check for leaks or following repairs to
the drip tape. Accumulated season-long alfalfa
from March 5 to October 10 totaled
43.38 inches, and the drip irrigation measured by the water meter, plus rain, totaled
31 .81 inches or 73.3 percent of accumulated season-long alfalfa ETC.
The average third-year total hay yield was 7.9 ton/acre (Table 1). The first-cutting
average yield was 2.5 ton/acre, with 'SX1002A' 'Masterpiece', and 'SX1001A' yielding
among the highest. In the second cutting 'Ruccus', Masterpiece, 'Tango', 'Orestan', and
'Somerset' were among the highest yielding varieties. In the third cutting, Ruccus,
'Lahontan', Masterpiece, Orestan, and Tango were among the highest yielding
varieties. In the fourth cutting, Ruccus, Tango, Orestan, and Lahontan were among the
highest yielding. In the fifth cutting, Ruccus, 'Plumas', and Somerset were among the
highest yielding varieties. In total yield of five cuttings, Ruccus, with 8.4 ton/acre,
Masterpiece, with 8.2 ton/acre, and Tango, SX1002A, and Orestan each with 8.0
ton/acre, were among the highest yielding.
The crude protein averaged 25.6 percent in the second cutting, and ranged from 24.3
percent for Orestan to 26.7 percent for Somerset. Acid detergent fiber, ADF, averaged
26.7 percent. Neutral detergent fiber, NDF, averaged 31.2 percent. Relative forage
quality averaged 245, with all varieties in the "Supreme" quality range. SX1005A,
Plumas, Somerset, and Masterpiece produced hay with RFQ scores higher than 247.
Total hay production in the first 3 years averaged 18.3 ton/acre (Table 2). The varieties
Ruccus, at 20.1 ton/acre; Tango, at 19.4 ton/acre; and Masterpiece, at 19.3 ton/acre
were among the highest yielding.
Information on the disease, nematode, and insect resistance of the varieties in this trial
was provided by the participating seed companies and/or the North American Alfalfa
Improvement Council (Table 3). Most alfalfa varieties have some resistance to the
diseases and pests that could limit hay production. Growers should choose varieties
that have stronger resistance ratings for disease or pest problems known to be present
in their fields. The yield potential of a variety should be evaluated based on
performance in replicated trials at multiple sites over multiple years.
References
Eldredge, E.P, C.C. Shock, and L. D. Saunders. 2003. First year results of the 2002 to
2006 alfalfa forage variety trial. Oregon State University Special Report 1048:14-17.
Available online at www.cropinfo.net/AnnualReports/2002/B5aDripAlf02.htm
10
Date, 2004
0)
CO
(0
(0
£3
(0
(0
CO
0)
C—
z
£3
£3
N-
N-
C)
C—
CO
CO
C—
Z
£3
£1
CO
CO
CO
£
0)
0
-10
0
0
Figure 1. Soil moisture in the drip-irrigated alfalfa variety trial during the 2004 growing
season, Maiheur Experiment Station, Oregon State University, Ontario, OR.
45
40
35
30
.C 25
C.)
20
15
10
0)
CO
CO
CO
0)
0)
(0
£3
CO
CO
£3
N£3
(0
Date, 2004
Figure 2. Accumulated irrigation applied plus rain compared to the AgriMet accumulated
evapotranspiration (ETa) for alfalfa grown for hay, Malheur Experiment Station, Oregon
State University, Ontario, OR 2004.
11
Table 1. Alfalfa variety hay yields and second-cutting crude protein*, ADF*, NDF*, and
relative forage quality for 2004, Malheur Experiment Station, Oregon State University,
Ontario, OR.
Cutting date
Relative
2004 Crude
Variety
5/14 6/17 7/19 8/13 9/22 total protein ADFt NDF forage quality
ton/acr&
% of
RFQ
Ruccus
2.4
1.4 2.0
1.2
27.0
31.5
239
1.3
8.4
26.0
Masterpiece 2.7 1.3 1.9
1.1
1.2
8.2
25.1
26.1
30.7
251
Tango
2.5
1.3
1.9
1.2
1.2
25.2
28.0
8.0
32.9
228
SX1002A
2.9
1.2
1.7
1.1
1.2
8.0
25.1
27.4
32.3
233
Orestan
2.4
1.3
1.9
1.2
1.2
29.0
8.0
24.3
34.2
213
Lahontan
2.3
1.2
2.0
1.2
1.2
7.9
25.8
26.7
31.3
243
Plumas
2.6
1.2
1.8
1.0
1.3
7.9
26.6
24.9
29.2
267
SX1001A
2.7
1.2
1.7
1.0
1.2
7.9
25.4
26.3
31.2
244
Somerset
2.4
1.3
1.8
1.1
1.3
7.9
26.7
26.1
30.3
253
SX1003A
2.5
1.2
1.6
1.0
1.2
7.5
25.5
26.5
31.0
246
SX1005A
2.5
1.1
1.7
1.0
1.1
7.4
26.4
25.1
29.1
271
SX1004A
2.3
1.2
1.5
1.0
1.2
7.4
25.5
26.8
31.2
247
Mean
2.5
1.2
1.8
1.1
1.2
7.9
25.6
26.7
31.2
245
LSD (0.05)
0.29 0.09 0.18 0.07 0.10 0.47 1.27
1.74
2.26
23.7
*Based on percent of dry weight. TADF: acid detergent fiber.
at 88 percent dry matter.
dry weight.
neutral detergent fiber.
Table 2. Alfalfa variety hay yields in the first 3 years of the 2002-2006
drip-irrigated alfalfa variety trial, Malheur Experiment Station, Oregon State University,
Ontario, OR, 2004
Variety
2002*
Yield
2003
2004
Cumulative
ton/acreT
Ruccus
2.6
9.1
8.4
20.1
Tango
2.5
9.0
8.0
19.4
Masterpiece
2.4
8.7
8.2
19.3
Somerset
2.4
8.5
7.9
18.8
Orestan
2.2
8.4
8.0
18.7
Plumas
2.6
8.1
7.9
18.5
Lahontan
2.0
8.1
7.9
18.1
SX1001A
2.1
8.0
7.9
18.0
SX1002A
1.9
7.7
8.0
17.7
SX1005A
2.4
7.7
7.4
17.5
SX1004A
2.1
7.5
7.4
16.9
SX1003A
2.0
7.0
7.5
16.5
Mean
2.3
8.2
7.9
18.3
LSD (0.05)
0.40
0.54
0.47
0.94
*Two cuttings, 8/6 and 9/5/2002. TYield at 88 percent dry matter.
12
Table 3. Variety source, year of release, fall dormancy, and level of resistance to pests
and diseases for 12 alfalfa varieties in the 2002-2006 drip-irrigated forage variety trial,
Maiheur Experiment Station, Oregon State University, Ontario, OR, 2004.
Pest Resistance ratingt
Release
FD* BW FW VW PRR AN SAA PA SN AP RKN
Variety
Source
year
Orestan
public
1934
Lahontan
public
1954
6
Tango
Eureka Seeds
1997
6
Plumas
Eureka Seeds
1997
4
Masterpiece Simplot
Agribusiness
Somerset
Croplan Genetics
2000
Ruccus
-
-
-
-
-
LR
-
-
HR
MR LR R
HR HR HR MR
HR
-
R
4
HR HR
HR HR
R
HR
HR
R
R
HR
R
MR
R
HR
HR
R
-
HR
R
R
2000
3
HR HR
HR
HR
HR
R
-
R
HR
-
2001
5
R
HR
R
HR
MR
R
R
R
-
MR
Seedex
-
-
-
-
-
-
-
-
-
-
-
-
SX1002A
Seedex
-
-
-
-
-
-
-
-
-
-
-
-
SX1003A
Seedex
-
-
-
-
-
-
-
-
-
-
-
-
SX1004A
Seedex
-
-
-
-
-
-
-
-
-
-
-
-
SX1005A
Seedex
-
-
-
-
-
-
-
-
-
-
-
-
Target Seed
R
-
MR LR
MR HR
-
-
-
-
-
*FD: fall dormancy, BW: bacterial wilt, FW: Fusarium wilt, VW: Verticillium wilt, PRR: Phytophthora root
rot, AN: Anthracnose, SAA: spotted alfalfa aphid, PA: pea aphid, SN: stem nematode, AP: Aphanomyces,
RKN: root knot nematode (northern).
tpest resistance rating: >50 percent = HR (high resistance), 31-50 percent = R (resistant),
15-30 percent = MR (moderate resistance), 6-14 percent = LR (low resistance).
tFall Dormancy: 1 = Norseman, 2 = Vernal, 3 = Ranger, 4 = Saranac, 5 = DuPuits, 6 = Lahontan,
7 = Mesilla, 8 = Moapa 69, 9 = CUF 101.
varieties, not released, pest resistance data not available.
13
WEED CONTROL AND CROP RESPONSE WITH OPTION® HERBICIDE
APPLIED IN FIELD CORN
Corey V. Ransom, Charles A. Rice, and Joey K. Ishida
Maiheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Weed control is important in field corn production to reduce competition with the crop
and to prevent the production of weed seed for future crops. Field trials were
conducted to evaluate Option® (foramsulfuron) herbicide applied alone and in various
combinations for weed control and crop tolerance in furrow-irrigated field corn. Option
is a new postemergence sulfonylurea herbicide that controls annual and perennial
grass and broadleaf weeds in field corn. Option contains a safener that is intended to
enhance the ability of corn to recover from any yellowing or stunting sometimes
associated with the application of sulfonylurea herbicides.
Materials and Methods
The soil was formed into 22-inch beds on May 10. Plots were sidedressed with 126 lb
nitrogen (N), 14 lb sulfates, 3 lb zinc, 1 lb boron, 1 lb manganese, and 38 lb elemental
sulfur/acre on May 11. Pioneer variety 'P-36N69' Roundup Ready® field corn was
planted with a John Deere model 71 Flexi Planter on May 17. Seed spacing was one
seed every 7 inches. Plots were 7.33 by 30 ft and herbicide treatments were arranged
in a randomized complete block with four replicates. Herbicide treatments were applied
with a C02-pressurized backpack sprayer calibrated to deliver 20 gal/acre at 30 psi.
Crop response and weed control were evaluated throughout the growing season. Corn
yields were determined by harvesting ears from 26-ft sections of the center 2 rows in
each 4-row plot on October 11. The harvested ears were shelled and grain weight and
percent moisture content were recorded. Grain yields were adjusted to 12 percent
moisture content. Data were analyzed using analysis of variance (ANOVA) and
treatment means were separated using Fisher's protected least significant difference
(LSD) at the 5 percent level (P = 0.05).
Postemergence treatments of Option, Clarion®, or Roundup® were applied alone and in
combinations with other herbicides and with or without preemergence (PRE) Dual
Magnum®. PRE applications were made May 21. Mid-postemergence (MP) treatments
were applied to corn at the V4 growth stage on June 11, and late postemergence
treatments (LP) were applied to corn at the V6 growth stage on June 19. Option was
applied with various additives as well as in combination with Distinct® or Callisto®.
Option combinations were compared to Clarion applied alone and in combination with
Distinct or to Roundup applied alone or following PRE Dual Magnum. The herbicide
rates and combinations are shown in Table 1.
14
Results and Discussion
Control of pigweed species (i.e., Powell amaranth and redroot pigweed) ranged from 91
to 100 percent on July23 and was similar among herbicide treatments. One exception
was the treatment with Option, Dyne-Amic®, and 32 percent N, which provided only 91
percent control (Table 1). When Option was applied with Dyne-Amic and 32 percent N
or Quest®, common lambsquarters control also was lower than all other treatments.
Clarion alone also provided less common lambsquarters control than all other
treatments except for Option applied with Dyne-Amic. Combinations of Option with
Distinct or Callisto, and the combination of Clarion and Distinct provided among the
best common lamsquarters control. Common lambsquarters control was improved
when Roundup was applied following PRE Dual Magnum compared to Roundup
applied alone. Clarion alone provided the least hairy nightshade control, and the
combination of Clarion and Distinct also provided less hairy nightshade control
compared to all other treatments except Option with Dyne-Amic and 32 percent N.
There were no significant differences in kochia and barnyardgrass control among
treatments.
Injury from herbicide treatments ranged from 0 to 14 percent on June 19 and was 4
percent or less on July 2 (Table 2). Corn yields ranged from a low of 103 bu/acre with
the untreated control to a high of 194 bu/acre with the combination of Option and
Callisto (Table 2). The treatment containing Option with Dyne-Amic and 32 percent N
had lower yields than many of the other Option treatments and was likely due to
reduced weed control with that treatment.
The selection of additives can significantly affect the efficacy of Option against pigweed
species, common lambsquarters, and hairy nightshade. The addition of Distinct or
Callisto to Option can significantly improve common lambsquarters control.
15
Table 1. Weed control with Optio n® herbi cide applied in field corn, Malheur Experiment
Station, Oregon State University, Ontario, OR, 2004.
Weed controP
I
Timingt
Pigweed
spp*
C, lambsquarters
H. nightshade
Kochia
Barnyardgrass
Option + MSO + 32% N
Rate*
lb al/acre
pt/acre
% v/v
0.033 + 1.5 + 3.0
MP
100
79
92
96
97
Option + MSO + AMS
0.033 + 1.5 + 3.0
MP
100
88
99
97
100
Option + DYNE-AMIC +
32% N
0.033 + 0.25% +
MP
91
45
76
95
94
Option + MSO + QUEST 0.033 + 1.5 ÷2.5%
MP
98
89
98
100
97
Clarion + MSO + 32% N
0.023 + 1.5+4
MP
98
61
52
98
99
Option + MSO + 32% N
0.033 + 1.5 +3.0
MP
99
89
94
100
97
Option + Distinct +
MSO + 32% N
0.033 + 0.088 +
1.5 + 3.0
MP
100
100
96
100
96
Option + Distinct +
MSO + 32% N
0.33 + 0.175 +
1.5 + 3.0
MP
100
100
99
100
97
Clarion + Distinct +
NlS + 32% N
0.023 + 0.088 +
0.5% + 4.0
MP
100
97
73
100
100
Option + Callisto +
MSO + 32% N
0.033 + 0.0625 +
1.5 + 3.0
MP
99
100
97
100
98
Dual II Magnum
Option + MSO + 32% N
1.6
PRE
97
90
85
100
100
0.033 + 1.5 + 3.0
LP
0.033 + 1.5 +3
MP
99
88
97
99
96
0.033 ÷ 0.25 % +
0.25%
MP
97
48
88
99
100
0.58
MP
99
81
95
100
97
1.6
PRE
100
92
90
100
99
0.58 + 3.0
LP
3
6
11
NS
NS
Treatment
Option + MSO + AMS
Option + DYNE-AMIC +
Quest
Roundup Ultramax
Dual II Magnum
Roundup Ultramax +
AMS
LSD (0.05)
3.0
*Herbicide rates are in lb ai/acre. Additive rates are in pt/acre or percent v/v.
tApplication timings were preemergence (PRE) on May 21, mid-postemergence (MP) applied to corn at the V4
rowth stage on June 11, and late postemergence (LP) to corn at the V6 growth stage on June 19.
Pigweed species were a mixture of Powell amaranth and redroot pigweed.
control was evaluated July 23. The untreated control was not included in the ANOVA for weed control.
16
Table 2. Injury and yield with Option® herbicide applied in field corn, Maiheur
Experiment Station, Orecion State University. Ontario, OR, 2004.
Field corn
Treatment
Untreated control
Rate*
lb al/acre
pt/acre
% v/v
Timingt
6-19
7-2
Yields
bu/acre
0/
--
--
--
--
103
Option + MSO + 32% N
0.033 + 1.5 + 3.0
MP
8
0
179
Option + MSO + AMS
0.033 + 1.5 + 3.0
MP
9
0
187
Option + DYNE-AMIC +
32% N
0.033 + 0.25% +
MP
5
0
157
Option + MSO + QUEST
0.033 + 1.5 +2.5%
MP
10
0
192
Clarion + MSO + 32% N
0.023 + 1.5+4
MP
3
0
178
Option + MSO + 32% N
0.033 + 1.5 +3.0
MP
9
3
174
Option + Distinct +
MSO + 32% N
0.033 + 0.088 +
1.5 + 3.0
MP
11
0
183
Option + Distinct +
MSO + 32% N
0.33 + 0.175 +
1.5 + 3.0
MP
14
4
178
Clarion + Distinct +
0.023 + 0.088 +
MP
6
1
189
NIS+32%N
3.0
0.5%+4.0
Option + Callisto +
MSO + 32% N
0.033 + 0.0625 +
1.5 + 3.0
MP
5
0
194
Dual II Magnum
Option + MSO + 32% N
1.6
PRE
9
3
184
0.033 + 1.5 + 3.0
LP
0.033 + 1.5 +3
MP
9
0
178
0.033 + 0.25% +
MP
1
0
178
0.58
MP
0
0
189
1.6
PRE
LP
0
0
173
4.5
2
21
Option + MSO + AMS dry
Option + DYNE-AMIC +
Quest
Roundup Ultramax
Dual II Magnum
Roundup Ultramax +
AMS
0.25%
0.58 + 3.0
LSD (0.05)
*Herbicide rates are in lb ai/acre. Additive rates are in pt/acre or percent v/v.
-tApplication timings were preemergence (PRE) on May 21 mid-postemergence (MP) applied to corn at the V4
9rowth stage on June 11, and late postemergence (LP) to corn at the V6 growth stage on June 19.
untreated control was not included in the ANOVA for percent injury.
SCorn was harvested October 11 and yields were adjusted to 12 percent moisture content.
-
17
EVALUATIONS OF SPRING HERBICIDE APPLICATIONS TO DORMANT MINT
Corey V. Ransom, Charles A. Rice, and Joey K. Ishida
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Weed control in mint is essential in order to maintain high mint oil yields and quality.
Reducing competition from weeds may prolong the productive life of a mint stand.
Herbicides are important tools for controlling weeds in mint. With the constant loss of
herbicides that are registered for use in mint, it is critical to identify replacements that
will provide similar weed control. Several new herbicides that have recently become
available or may be available in the near future have been tested in mint. This research
evaluated herbicides that have been used traditionally with new herbicide combinations
containing some recently registered herbicides including Spartan® (sulfentrazone),
Chateau (flumioxazin), and Command® (clomazone).
R
Materials and Methods
Two trials were established to evaluate spring herbicide applications to dormant mint for
mint tolerance and weed control efficacy. One trial was established near Nampa, Idaho
and the other near Nyssa, Oregon. Perennial weed problems and a poor mint stand
resulted in abandonment of the Oregon location. Herbicides that were evaluated
included a standard of Sinbar Karmex Stinger and Prowl compared to various
combinations that included Spartan, Chateau, and Command. Treatments were
applied March 3, 2004 when mint was still mostly dormant. Herbicide treatments were
arranged in a randomized block design with four replicates. Plots were 10 ft wide by 30
ft long. Herbicides were applied with a C02-pressurized backpack sprayer calibrated to
deliver 20 gal/acre at 30 psi. Visual evaluations of mint injury and weed control were
made throughout the season. Mint yield was determined by harvesting mint from 3
from the center of each plot. After the mint fresh weight was recorded, a 20-lb subsample was taken and allowed to dry in burlap bags. Once samples were dry, mint oil
was extracted at the University of Idaho mint research still. Distillation was done
according to the Mint Industry Research Council (MIRC) protocol.
,
,
,
Results and Discussion
Only the treatment containing Command, Spartan, and Stinger caused significant mint
injury on April 27 (Table 1). The same combination with Spartan at a lower rate caused
significantly less mint injury, as did the combination of Command, Spartan, and
Gramoxone®. By June 7, no significant injury was visible for any treatment. Prickly
lettuce populations were variable, and variability among prickly lettuce control
18
evaluations resulted in no statistical differences among herbicide treatments. Kochia
densities were too low for visual control evaluation, but counts of all the kochia in each
plot revealed that all but two treatments significantly reduced kochia numbers compared
to the untreated check. The combination of Sinbar, Karmex, Stinger, and Chateau and
the combination of Command, Chateau, and Gramoxone did not significantly reduce
kochia numbers. Mint fresh weight and oil yields were strongly correlated with prickly
lettuce control and kochia densities (Fig. 1). All treatments increased mint yield
compared to the untreated control. The combination of Command, Chateau, and
Gramoxone produced lower mint fresh weight and oil yields than all other treatments
except combinations of Command, Spartan, and Gramoxone, but had similar oil yields
compared to the combination of Sinbar, Karmex, Singer, and Prowl.
35
160
y=0.1558x+11.041
i
R2=0.7413
Y0.647X+28.888
1
5
20
0
0
Prickly lettuce control
A
30
40
60
80
100
Prickly lettuce control (%)
B
35
20
160
••
801x2 + 0.3547x + 25.16k
R2 = 0.5266
140
.
Y = -0.3947x2+2.0559x+ 86.721
R2 = 0.4563
20
C
Kochia (no./plot)
D
Kochia (no./plot)
Figure 1. Mint fresh hay and oil yield as influenced by prickly lettuce control (A and B) and
kochia density (C and D) in Nampa, ID, Malheur Experiment Station, Oregon State
University, Ontario, OR, 2004. For all regressions P < 0.0000.
19
120
Table 1. Mint injury and weed control from spring herbicide applications to dormant peppermint in Nampa, ID, Maiheur
Experiment Station, Oregon State University, Ontario, OR, 2004
Treatment*
Untreated control
Sinbar + Karmex +
Stinger + Prowl + NIS
Ratet
lb ai/acre
Mint injury
4-27
6-7
Weed control
Prickly lettuce
4-27
6-7
7-28
0/
Kochia
densityt
7-28
no/plot
Mint yield
Fresh Wt.
Oil
8-25
8-25
lb/3 yd2
lb/acre
--
-
-
-
-
-
13 a
8.7
28
0.6 + 0.8 +
0.124 + 1.5 + 0.25%
3
5
84
86
87
2b
19.5
82
Sinbar + Karmex +
Stinger + Spartan + NIS
0.6 + 0.8 +
0.124 + 0.188 + 0.25%
0
3
96
94
96
0b
21.0
95
Sinbar + Karmex +
Stinger + Chateau + NIS
0.6 + 0.8 +
0.124 ÷ 0.125 + 0.25%
5
4
94
94
98
5 ab
20.8
96
Command + Spartan +
Stinger + NIS
0.375 + 0.188 ÷
0.124 ÷ 0.25%
21
5
81
84
90
0b
21.0
103
Command + Chateau +
Stinger + NIS
0.375 + 0.125 +
0.124 + 0.25%
5
4
95
92
95
4b
21.6
84
Command + Spartan +
Gramoxone Extra + NIS
0.375 + 0.188 +
0.375 + 0.25%
8
4
70
66
83
4b
18.9
77
Command + Chateau +
Gramoxone Extra + NIS
0.375 + 0.125 +
0.375 + 0.25%
4
4
59
58
59
8 ab
15.1
58
Sinbar + Karmex +
Stinger + Spartan + NIS
0.6 + 0.8 +
0.124 + 0.125 + 0.25%
6
4
92
90
89
2b
19.4
92
Command + Spartan ÷
Stinger + NIS
0.375 + 0.125 +
0.124 + 0.25%
9
5
91
89
94
1
b
22.2
97
Command + Spartan +
Gramoxone Extra + NIS
0.375 + 0.125 +
0.375 + 0.25%
4
5
76
60
78
0b
19.0
74
Command + Spartan +
Stinger + Buctril + NIS
0.375 + 0.125 +
0.124 + 0.25 + 0.25%
3
5
83
86
93
1
b
20.6
96
10
NS
NS
NS
NS
4.1
24
LSD (0.05)
*Treatments were applied March 3, 2004 to dormant mint.
tHerbicide rates are lb ai/acre. NIS (nonionic surfactant, Activator 90) was applied at 0.25 percent V/V.
separation is based on transformed data. Raw data are presented.
-
2004 ONION VARIETY TRIALS
Clinton C. Shock, Erik B. G. Feibert, and Lamont D. Saunders
Maiheur Experiment Station
Lynn Jensen
Malheur County Extension Service
Oregon State University
Ontario, OR
Krishna Mohan
University of Idaho
Parma, ID
Introduction
The objective of the onion variety trials was to evaluate yellow, white, and red onion
varieties for bulb yield, quality, and single centers. Five early season yellow varieties
and one early season white variety were planted in March and were harvested and
graded in August. Forty-three full season varieties (33 yellow, 5 red, and 5 white) were
planted in March, harvested in September 2004, and evaluated in January 2005.
Methods
The onions were grown on an Owyhee silt loam previously planted to wheat. Soil
analysis indicated the need for 60 lb nitrogen (N)/acre, 100 lb phosphate (P2O5)Iacre,
70 lb sulfur/acre, 2 lb copper/acre, 7 lb zinc/acre, and 1 lb boron/acre, which was
broadcast in the fall. In the fall of 2003, the wheat stubble was shredded, and the field
was disked, irrigated, ripped, moldboard-plowed, roller-harrowed, fumigated with
Telone C-17® at 20 gal/acre, and bedded. A soil sample taken on May 20, 2004
showed a pH of 7.3, 2 percent organic matter, 8 ppm nitrate-N, 37 ppm phosphorus,
and 461 ppm potassium.
A full season trial and an early maturing trial were conducted adjacent to each other.
Both trials were planted on March 19 in plots four double rows wide and 27 ft long. The
early maturing trial had 6 varieties from 3 companies (Table 1) and the full season trial
had 43 varieties from 10 companies (Table 2). The experimental design for both trials
was a randomized complete block with five replicates. A sixth nonrandomized replicate
was planted for demonstrating onion variety performance to growers and seed
company representatives.
Seed was planted in double rows spaced 3 inches apart at 9 seeds/ft of single row.
Each double row was planted on beds spaced 22 inches apart with a customized
planter using John Deere Flexi Planter units equipped with disc openers. The onion
rows received 3.7 oz of Lorsban 1
per 1,000 ft of row (0.82 lb ai/acre), and the soil
surface was rolled on March 20. The field was irrigated on March 25. On March 31 the
21
field was sprayed with Roundup® at 24 oz/acre. Onion emergence started on April 5.
On May 4, alleys 4 ft wide were cut between plots, leaving plots 23 ft long. From May 5
through 8, the seedlings were hand thinned to a plant population of two plants/ft of
single row (6-inch spacing between individual onion plants, or 95,000 plants/acre). The
field was sidedressed with 100 lb of N/acre as urea and cultivated on May 12. On June
9 the field was sidedressed with 100 lb N/acre as urea.
The onions were managed to avoid yield reductions from weeds, pests, and diseases.
Weeds were controlled with an application of Prowl® at 0.75 lb ai/acre on April 12 and
on May 12, and an application of Goal® at 0.12 lb ai/acre, Buctril® at 0.12 lb ai/acre, and
Poast® at 0.28 lb ai/acre on May 25. After lay-by the field was hand weeded as
necessary. Thrips were controlled with aerial applications of Warrior® on June 12,
Warrior (0.03 lb ai/acre) plus Lannate® (0.4 lb ai/acre) on June 25, Warrior (0.03 lb
ai/acre) plus MSR®(0.5 lb ai/acre) on July 17, and Warrior (0.03 lb ai/acre) plus Lannate
(0.4 lb ai/acre) on July 31.
The trial was furrow irrigated when the soil water potential at 8-inch depth reached -25
kPa. Soil water potential was monitored by thirteen granular matrix sensors (GMS,
Watermark Soil Moisture Sensors Model 200SS, Irrometer Co. Inc., Riverside, CA)
installed in mid-June below the onion row at 8-inch depth. Six sensors were
automatically read three times a day with an AM-400 meter (Mike Hansen Co., East
Wenatchee, WA). Seven sensors were automatically read hourly with a Watermark
Monitor (Irrometer Co., Inc.). The last irrigation was on August 20.
Onions in each plot were evaluated subjectively for maturity by visually rating the
percentage of onions with the tops down and the percent dryness of the foliage. The
percent maturity was calculated as the average percentage of onions with tops down
and the percent dryness. The early maturing trial was evaluated for maturity on August
10 and the full season trial on August 24. The number of bolted onion plants in each
plot was counted.
Onions in each plot were evaluated subjectively for damage from iris yellow spot virus
on August 11. Each plot was rated according to the number of leaves with symptoms
per plant: 0 = no symptoms, 5 = at least 3 leaves with symptoms per plant.
Onions from the middle two rows in each plot in the early maturity trial were lifted on
August 13, and topped by hand and bagged on August 17. On August20 the onions
were graded. The onions in the full season trial were lifted on September 8 to field
cure. Onions from the middle two rows in each plot of the full season trial were topped
by hand and bagged on September 15. The bags were put in storage on September
22. The storage shed was managed to maintain an air temperature as close to 34°F as
possible. Onions from the full season trial were graded out of storage on January 11
and 12, 2005.
During grading, bulbs were separated according to quality: bulbs without blemishes (No.
is), split bulbs (No. 2s), neck rot (bulbs infected with the fungus Botiytis all/i in the neck
22
or side), plate rot (bulbs infected with the fungus Fusarium oxysporum), and black mold
(bulbs infected with the fungus Aspergillus niger). The No. I bulbs were graded
according to diameter: small (<2.25 inches), medium (2.25-3 inches), jumbo (3-4
inches), colossal (4-4.25 inches), and supercolossal (>4.25 inches). Bulb counts per 50
lb of supercolossal onions were determined for each plot of every variety by weighing
and counting all supercolossal bulbs during grading. The red varieties were evaluated
subjectively during grading for exterior thrips damage during storage. The bulbs from
each red variety plot were rated on a scale from 0 (no damage) to 10 (most damage)
for the damage that was apparent on the bulb surface, without removing the outer
scales.
In early September bulbs from one of the border rows in each plot of both trials were
rated for single centers. Twenty-five consecutive onions ranging in diameter from 3.5 to
4.25 inches were rated. The onions were cut equatorially through the bulb middle and,
if multiple centered, the long axis of the inside diameter of the first single ring was
measured. These multiple-centered onions were ranked according to the diameter of
the first single ring: "small double" had diameters less than 1 .5 inches, "intermediate
double" had diameters from 1 .5 to 2.25 inches, and "blowout" had diameters greater
than 2.25 inches. Single-centered onions were classed as a "bullet". Onions were
considered functionally single centered for processing if they were a "bullet" or "small
double."
Varietal differences were compared using ANOVA and least significant differences at
the 5 percent probability level, LSD (0.05).
Results
Varieties are listed by company in alphabetical order. The LSD (0.05) values at the
bottom of each table should be considered when comparisons are made between
varieties for significant differences in performance characteristics. Differences between
varieties equal to or greater than the LSD value for a characteristic should exist before
any variety is considered different from any other variety in that characteristic.
A few experimental varieties were named in 2004. Nunhems' 'SX 70000N' and 'SX
70020N' were named 'Bandolero' and 'Montero', respectively. Seedworks' '6001' was
named 'Maverick'. Varieties are all listed by name in the results. The experimental
numbers are useful for comparing results from previous years.
Iris Yellow Spot Virus Rating
Subjective rating of damage from iris yellow spot virus for the early maturing varieties
ranged from 0.68 for 'Renegade' to 1.84 for 'XON-0101' (Table 1). Subjective rating of
damage from iris yellow spot virus for the full season varieties ranged from 0.82 for
'T-433', 'Delgado', and 'PX 5299' to 1.92 for 'Export 151' (Table 3).
23
Early Maturity Trial, Five Yellow Varieties, One White Variety
The percentage of "bullet" single centers averaged 20.6 percent and ranged from 0
percent for 'XON-209W', a white variety, to 76.4 percent for Montero (Table 1). The
percentage of onions that were functionally single centered averaged 45 percent and
ranged from 14.7 percent for XON-0101 to 95.2 percent for Montero. Montero had the
highest percentage of bullet and functionally single-centered bulbs in this trial.
Total yield averaged 849 cwtlacre and ranged from 721 cwtlacre for Montero to 971.4
cwt/acre for 'Exacta' (Table 2). Exacta, XON-0101, and Renegade were among the
highest in total yield. Supercolossal-size onion yield averaged 25.6 cwtlacre and
ranged from 9.2 cwt/acre for XON-209W to 47.2 cwt/acre for Exacta. Exacta and
XON-0101 were among the highest in yield of supercolossal bulbs. Not considering
supercolossals, colossal-size onion yield averaged 235 cwt/acre and ranged from 109.5
cwt/acre for Montero to 371 cwt/acre for Exacta. Exacta and XON-0101 had the
highest colossal bulb yields.
Full Season Trial, 33 Yellow Varieties
The percentage of "bullet" single centers averaged 33.7 percent and ranged from 4
percent for Delgado to 82 percent for '6011' (Table 3). Varieties 6011, Bandolero, 'SX
7004 ON', and 'Sabroso' were among the highest in percentage of onions with "bullet"
single centers. Varieties 6011, SX 7004 ON, Montero, Bandolero, Sabroso, 'Granero',
'Varsity', 'Vaquero', '4001', and 'SVR 5819' were among the highest in percentage of
onions that were functionally single centered.
Marketable yield out of storage in January 2005 ranged from 439.9 cwtlacre for Export
151 to 1,025.7 cwt/acre for 'Ranchero' (Table 4). Ranchero, 'Sweet Perfection', and
'OLYS97-24' were among the varieties with the highest marketable yield.
Supercolossal-size onion yield ranged from 2.3 cwtlacre for Sabroso to 245.6 cwt/acre
for 6001. 6001, 'PX 2599', 'PX 5299', 'Harmony', 'Harvest Moon', and Ranchero were
among the varieties with the highest supercolossal yield. The number of bulbs per 50
lb of super colossal onions ranged from 29.8 for 'XPH95345' to 58.0 for Sabroso. Eight
yellow varieties had supercolossal bulb counts above the acceptable range (average
size too small, because almost all bulbs are at the small end of the size range) for
marketing as super colossals (28-36 count per 50 Ib). None of the varieties had
supercolossal counts below the acceptable range (averaged too big) for marketing as
supercolossal. Not counting supercolossals, colossal-size onion yield ranged from 48.5
cwt/acre for Export 151 to 500.8 cwt/acre for Ranchero. Ranchero, 'Torero', PX 5299,
PX 2599, 0LY597-24, Harmony, and Sweet Perfection were among the highest in
colossal bulb yields.
Decomposition in storage ranged from 1.5 percent for 'Daytona' to 9 percent for
'Tequila'. No. 2 bulbs ranged from 5 cwt/acre for SX 70040N to 100.3 cwt/acre for
Harvest Moon. Bolting averaged 0.04 bolted onions per plot and occurred in only seven
varieties.
24
Full Season Trial, Five Red Varieties
The percentage of "bullet" single centers averaged 25 percent and ranged from 10.8
percent for 'Mercury' to 46.4 percent for 'Salsa' (Table 2). The percentage of
functionally single-centered onions averaged 44.6 percent and ranged from 24.2
percent for Mercury to 64.8 percent for Salsa.
Total marketable yield ranged from 389.4 cwt/acre for 'Red Fortress' to 538.8 cwtlacre
for Mercury (Table 4). Colossal-size onion yield ranged from 19.4 cwtlacre for 'Red
Zeppelin' to 71.7 cwt/acre for Mercury. Decomposition in storage ranged from 1.5
percent for 'Redwing' to 13.9 percent for Salsa. No. 2 bulbs ranged from 10.6 cwt/acre
for Redwing to 146.1 cwt/acre for Red Fortress.
Subjective evaluation of thrips damage to red onions in storage ranged from a rating of
1.4 for Red Fortress to 3.8 for Salsa.
Full Season Trial, Five White Varieties
The percentage of "bullet" single centers averaged 22.9 percent and ranged from 15.3
percent for 'Gladstone' to 33.3 percent for 'SVR 7106' (Table 2). The percentage of
functionally single-centered onions averaged 55.7 percent and ranged from 44.7
percent for 'Oro Blanco' to 76.0 percent for SVR 7106.
Total marketable yield ranged from 441.7 cwt/acre for Oro Blanco to 578.4 cwt/acre for
'SVR 5646' (Table 4). Colossal-size onion yield ranged from 80.4 cwtlacre for Oro
Blanco to 217.5 cwt/acre for SVR 5646. Decomposition in storage ranged from 6.4
percent for 'Brite Knight' to 21.6 percent for Oro Blanco. No. 2 bulbs ranged from 16.0
cwt/acre for SVR 7106 to 109.6 cwt/acre for Brite Knight.
Table 1. Onion multiple-center rating and iris yellow spot virus rating for early maturing
varieties, Malheur Experiment Station, Oregon State University, Ontario, OR, 2004.
Seed
company
Variety
Bulb
Intermediate Small
color Blowout
double
double
Functionally
single centered Iris yellow
"bullet + small spot virus
rating*
Bullet
double"
0-5
0/
Sakata
Sakata
Seminis
Seminis
Nunhems
Nunhems
Average
LSD (0.05)
XON-0101
XON-209W
Exacta
Golden Spike
Renegade
Montero
Y
61.3
W
55.1
Y
Y
Y
Y
18.7
23.3
37.3
0.5
32.7
13.7
24.0
26.2
21.3
18.0
40.0
4.3
22.3
15.2
13.3
18.8
39.3
38.0
18.0
18.8
24.4
16.3
*subjective rating: 0 = no da mage, 5 = total damage.
25
1.3
0.0
20.7
20.7
4.7
76.4
20.6
8.3
14.7
18.8
60.0
58.7
22.7
95.2
45.0
16.0
1.84
1.06
1.26
1.06
0.68
1.26
1.19
0.55
Table 2. Performan ce data for early maturing onion varieties harvested on August 17 and graded on Aug ust 20, Malheur
Experiment Station, Oregon State University, Ontario, OR, 2004.
Marketable yield by grade
Non-marketable yield
Bulb
color
Company Entry name
Bulb
Total
yield
Total
>41/4 in
cwtlacre --Sakata
Seminis
Average
LSD (0.05)
N.)
a)
3-4 in
in
>4V4 in
739.7
818.6
589.4
37.0
9.2
Y
Y
971.4
841.5
865.6
727.3
47.2
24.7
370.9
196.4
426.6
484.3
21.0
21.9
31.8
32.6
Y
Y
904.9
721.3
848.5
126.0
823.5
662.4
747.8
140.0
24.2
11.7
255.7
109.5
521.2
519.4
22.5
21.9
25.6
20.2
234.8
68.7
464.4
23.0
NS
NS
31.9
40.3
32.6
3.8
Y
912.1
W
Exacta
Golden Spike
Montero
4-4Y4 in
cwtlacre
344.6
420.4
131.7
414.4
XON-0101
XON-209W
Nunhems Renegade
counts
Maturity
Total
rot
Sun
scald
on
No. 2s Small Aug. 10 Bolters
#/50 lb
%
16.7
34.1
30.8
28.3
0.6
6.6
34.1
0.7
0.8
35.1
53.0
10.5
49.2
47.1
11.1
1.7
31.6
25.3
27.0
2.9
7.5
14.0
35.3
NS
37.1
11.9
21.5
NS
2.4
2.1
1.9
---- cwt/acre ---44.5
8.9
36.6
48.3
19.2
%
#/plot
53.0
67.0
0.0
0.2
32.0
36.0
0.2
0.0
46.0
33.0
44.5
8.8
1.2
0.0
0.3
NS
Table 3. Onion multiple-center rating and iris yellow spot virus rating for long season
varieties, Malheur ExDeriment Station, Orecion State University, Ontario, OR, 2004.
Bulb
Seed
company
Variety
color Blowout
Intermediate Small
double
double
Functionally
single centered Iris yellow
"bullet + small spot virus
rating*
double"
Bullet
0-5
0/
T-433
T-439
9003G
Daytona
Delgado
Gladstone
Redwing
R
24.7
38.0
20.0
20.0
26.0
20.0
8.0
BGS 196 Fl
Crookham Harmony
Sweet Perfection
OLYS97-24
OLYS97-27
XPH95345
Y
Y
Y
17.3
18.7
15.3
Y
Y
Y
21.3
21.3
30.0
28.0
29.3
40.0
33.3
15.3
480
D. Palmer Mesquite
Y
Y
22.5
20.0
24.7
46.3
21.3
29.3
38.7
29.3
29.3
A. Takii
Bejo
Tequila
Rispens
Brite Knight
Export 151
Red Fortress
Scottseed Oro Blanco
Seedworks Varsity
4001
Maverick
6011
Seminis
Mercury
Red Zepelin
Santa Fe
PX 2599
PX5299
Nunhems
Average
LSD (0.05)
SVR 7106
SVR 5646
SVR 5819
Bandolero
Grariero
Pandero
Ranchero
Sabroso
Salsa
Tesoro
Torero
Vaquero
Montero
SX7004 ON
Y
Y
Y
Y
Y
W
W
Y
R
18.7
30.0
26.0
4.0
4.0
8.7
0.7
54.3
R
46.7
Y
Y
Y
11.3
6.0
7.3
2.0
14.7
5.3
3.2
1.3
9.3
0.8
3.2
22.4
R
W
Y
Y
Y
Y
W
W
Y
Y
Y
Y
Y
Y
R
Y
Y
Y
Y
Y
47.3
25.3
35.3
59.3
30.7
31.3
32.0
13.3
37.3
8.0
14.7
31.3
4.7
21.5
20.0
34.7
30.7
31.3
22.0
22.0
13.3
3.2
8.7
26.7
35.2
1.3
3.2
12.8
18.0
32.7
13.3
1.1
5.1
2.0
15.7
9.2
25.6
20.0
8.0
3.3
16.8
20.0
26.7
26.7
15.3
39.3
33.3
28.0
43.3
3.3
15.3
24.0
14.7
24.0
10.8
16.3
0.42
18]
15.3
18.7
27.3
29.3
20.7
24.7
32.0
34.0
22.7
12.7
13.4
17.3
24.0
36.7
38.7
42.7
36.0
39.3
12.8
27.3
26.0
27.2
19.2
18.4
28.7
35.3
18.0
26.9
15.3
24.9
14.6
*subjective rating: 0 = no damage, 5 = total damage.
27
0.82
0.88
0.88
1.06
0.82
0.94
1.06
0.88
1.40
1.00
1.32
1.26
1.32
42.0
80.8
62.7
38.0
36.8
74.4
46.4
33.3
24.0
67.3
66.9
79.3
33.7
28.0
36.7
44.7
20.7
43.3
48.7
60.0
69.3
44.0
56.7
49.3
38.7
36.7
36.7
31.2
58.7
46.0
42.7
40.7
44.7
88.0
81.3
60.0
94.7
24.2
33.3
54.0
63.3
61.3
76.0
63.3
81.3
93.6
90.0
64.0
64.0
93.6
64.8
62.0
59.3
85.3
93.7
94.7
58.7
8.0
10.0
18.0
5.3
4.0
15.3
32.0
26.0
40.7
41.3
25.3
24.0
12.7
16.0
40.0
18.7
13.3
20.0
20.0
56.0
47.3
37.3
82.0
10.8
16.0
30.0
26.7
22.7
33.3
27.3
1.
1.38
1.12
1.18
1.92
1.66
1.20
1.00
0.94
1.66
1.20
0.94
1.12
1.34
0.88
0.82
1.26
1.12
1.00
0.94
0.94
1.06
1.18
0.88
1.00
0.94
0.94
0.94
0.94
1.34
1.11
Table 4. 2004 performance data for experimental and commercial onion varieties graded out of storage in January 2005, Malheur Experiment Station, Oregon State
University. Ontario. OR.
Marketa ble yield by grade
Bulb
Non -marke table yield
Maturity
on
Thrips
Bulb
Total
counts Total Neck Plate Black No.
damage*
Aug.
24
Bolters
>41/4
in
>41/4
in
Company Entry name
color yield
Total
4-4¼ in 3-4 in 2Y4-3 in
rot
rot
rot mold
2s Small
cwtl acre
cwtlacre
#/50 lb
%oftotal yield
cwtlacre-#/plot
%
A. Takii
T-433
Y
984.2
821.3
167.9 421.7 216.4
15.3
30.4
7.6
3.2
4.1
6.7
24.0
0.3 82.3
0
T-439
Y
780.4
717.3
31.5
323.8 351.3
10.7
33.7
3.5
0.3
3.2
0.0 30.8
5.0
59.0
0
9003G
Y
684.1
627.0
7.8
138.1
454.6
26.6
41.2
3.5
1.0
2.5
56.0
0.0 18.5 15.3
0
Bejo
Crookham
Dorsing
D. Palmer
Rispens
Daytona
Delgado
Y
624.5
8.3
139.5
444.3
32.4
38.0
1.5
0.3
1.0
0.2
32.2
12.8
43.0
0.2
Y
680.0
717.4
631.5
9.2
176.9
436.4
9.1
43.4
3.0
0.8
2.2
0.0
59.7
5.8
55.0
0
Gladstone
W
709.8
548.2
10.1
127.6
391.0
19.5
36.4
12.1
10.1
1.6
0.4
71.8
4.1
46.0
0.4
Redwing
R
562.2
536.6
1.1
45.2
468.0
22.4
48.3
1.5
0.7
0.8
0.0
10.6
6.7
37.0
0
BGS 196 Fl
Y
832.3
761.8
43.1
288.1
411.6
19.1
35.5
2.6
0.3
2.3
0.0
41.6
7.5
58.0
0
Harmony
Y
1040.6
902.9
221.1
447.9
223.7
10.3
30.9
5.4
3.5
1.8
0.0
77.0
5.2
37.0
0.2
Sweet Perfection
Y
1072.6
969.8
169.9
439.9
339.9
20.1
30.8
4.6
1.8
2.1
0.8
46.1
7.1
39.0
0
OLYS97-24
Y
1082.9
927.9
173.9
453.5
281.9
18.6
33.6
6.0
3.7
1.9
0.3
80.7
10.1
25.0
0
OLYS97-27
Y
964.9
835.6
144.7
397.9
272.7
20.1
32.1
5.7
2.6
2.6
0.5
64.4
9.8
28.0
0
XPH95345
Y
795.6
613.8
59.3
215.1
321.1
18.4
29.8
10.6
8.9
1.7
0.0
94.7
4.8
33.0
0
Harvest Moon
Y
941.2
786.2
220.8
350.6
206.2
8.7
31.5
5.7
3.4
2.1
0.2
100.3
5.3
29.0
0.2
Mesquite
Tequila
Y
932.3
810.7
176.2
369.3
246.1
19.2
31.6
4.0
1.6
2.4
0.0
81.8
4.6
20.0
0
Y
1004.4
812.7
184.0
403.3
216.4
9.0
31.3
9.3
4.9
2.9
1.5
93.2
3.5
23.0
0.2
Export 151
Y
552.3
439.9
5.2
48.5
369.8
16.4
40.5
3.1
0.7
2.4
0.0
92.8
3.6
43.0
0
Brite Knight
W
662.7
501.4
4.5
98.3
367.8
30.7
34.8
6.4
5.6
0.8
0.0
109.6
9.3
44.0
0
0.0
25.1
321.8
42.6
1.9
0.6
1.4
0.0
146.1
11.8
47.0
0
Red Fortress
R
557.8
389.4
Scottseed
Oro Blanco
W
672.8
441.7
2.8
80.4
337.3
21.2
38.4
21.6
20.5
1.2
0.0
75.0
7.0
55.0
0
Global
Genetics
Varsity
Y
655.5
616.0
30.3
195.5
378.6
11.7
35.9
3.9
0.7
3.2
0.0
10.1
5.5
4001
Y
683.6
638.9
10.7
140.0
464.9
23.3
42.2
3.4
0.3
3.2
0.0
15.0
7.6
68.0
69.0
0.2
Maverick
Y
961.0
869.0
245.6
413.9
195.5
13.9
31.3
6.2
3.1
3.1
0.0
28.6
4.1
30.0
0
0
2.0
1.4
Table 4. 2004 performance data for experimental and commercial onion varieties graded out of storage in January 2005, Malheur Experiment Station, Oregon State
University. Ontario. OR.
Marketable yield by grade
Maturity
Bulb
Non-marketable yield
Thrips
011
counts Total Neck Plate Black No.
Bulb
Total
damage*
Small
Aug.
24
Bolters
>41/4
in
>41/4
in
Company Entry name
yield
color
Total
in 3-4 in
rot
rot
2s
in
rot
mold
cwt/acre --cwtiacre
cwt/acre -% of total yield
#/plot
#/50 lb
%
6011
Y
867.7
803.0 130.3
418.0 237.1
2.0
15.2 4.7
52.0
0
17.5
31.6
5.3
3.2
0.1
Mercury
Santa Fe
R
593.1
538.8
2.6
71.7
437.3
27.2
40.5
5.9
2.7
2.9
0.2
12.8
7.4
80.0
0
Y
904.6
798.4
171.1
374.8
240.8
11.7
30.3
5.9
2.4
3.6
0.0
47.0
6.0
29.0
0
Red Zepelin
R
518.1
428.2
2.7
19.4
373.8
32.2
56.9
3.3
2.0
1.3
0.0
67.3
5.5
78.0
0
PX 2599
Y
945.8
900.7
244.2
464.7
182.3
9.4
31.5
2.5
0.8
1.7
0.0
16.1
5.4
21.0
0
PX 5299
Y
954.3
895.5
227.9
467.3
193.8
6.4
30.9
2.4
0.8
1.6
0.1
31.8
3.8
33.0
0
SVR 7106
660.8
504.9
8.9
136.7
343.4
15.9
34.4
19.9
15.2
4.7
0.1
16.0
8.1
63.0
0
SVR 5646
W
W
767.1
578.4
19.3
217.5
331.1
10.5
37.2
21.1
14.6
6.1
0.4
19.5
6.4
58.0
0
SVR 5819
Y
950.3
895.3
130.0
440.9
309.5
15.0
31.8
3.6
0.9
2.7
0.0
14.7
7.1
31.0
0
Bandolero
Granero
Y
674.7
3.7
71.8
45.5
2.5
0.1
8.0
10.6
73.0
0
20.8
34.3
4.3
3.2
1.7
429.1
536.4
339.4
34.6
913.1
626.9
861.1
52.2
Y
1.5
1.6
0.1
14.8
8.8
35.0
0
Pandero
Y
928.8
884.5
132.7
428.6
310.6
12.6
32.3
1.7
0.2
1.5
0.0
22.0
6.2
23.0
0.2
Ranchero
Y
1115.0
1025.7
205.8
500.8
302.6
16.5
30.7
5.7
3.2
1.7
0.8
19.1
7.3
49.0
0
Sabroso
Y
620.5
571.7
2.3
69.6
478.6
21.2
58.0
5.4
2.0
3.4
0.0
6.8
8.7
58.0
0
Salsa
R
529.7
404.9
0.0
62.4
320.1
22.3
70.0
0
Tesoro
Y
749.3
686.3
7.8
202.1
457.8
18.6
Torero
Y
952.4
889.2
170.5
483.3
223.5
Vaquero
Y
930.1
861.6
65.6
403.4
Montero
Y
848.1
798.9
45.2
SX7004 ON
Y
904.1
856.7
68.3
Average
810.6
712.4
LSD(0.05)
86.0
101.2
Seminis
Nunhems
3.4
2.6
13.9
8.5
5.4
0.0
46.0
6.4
39.7
2.5
0.7
1.8
0.0
34.5
10.5
59.0
0.2
11.9
32.2
4.1
2.3
1.6
0.1
19.1
5.5
40.0
0
373.4
19.2
34.2
5.3
2.5
2.8
0.0
11.9
7.4
46.0
0
337.3
398.2
18.2
35.7
4.2
2.2
2.0
0.0
7.8
7.7
75.0
0
424.0
356.5
7.8
32.7
4.6
3.1
1.6
0.0
5.0
3.1
50.0
0
84.6
273.1
336.4
18.3
36.1
6.0
3.4
2.4
0.1
44.1
7.0
46.3
0.04
2.6
46.1
68.9
81.1
16.2
5.5
5.6
'4.3
2.2
NS
23.0
NS
8.0
NS
1.2
* Thrips damage: 0 = least damage, 10 = most damage.
3.8
PUNGENCY OF SELECTED ONION VARIETIES BEFORE AND AFTER STORAGE
Clinton C. Shock, Erik B. G. Feibert, and Lamont D. Saunders
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
The objective of this trial was to evaluate the pungency of 12 onion varieties commonly
grown in the Treasure Valley.
Methods
Varieties for pungency analysis were selected based on information provided by the
seed companies on their probability of being mild (Tables 1 and 2). 'Vaquero' was
included as the industry standard variety of the Treasure Valley.
The onions were grown on a Owyhee silt loam previously planted to wheat. Onion seed
was planted on March 19, 2004. The procedures for growing the onions can be found
in the "2004 Onion Variety Trials" report by Shock et al. in this report. Onions in the
early maturity trial were lifted on August 13, topped by hand and bagged on August 17,
and graded on August 20. The onions in the full-season trial were lifted on September
8 to field cure. Onions in the full season trial were topped by hand and bagged on
September 15. The bags were put in storage on September 22. The storage shed was
managed to maintain an air temperature of approximately 34°F. Onions from the full
season trial were graded out of storage in early January 2005.
On August 25, 10 bulbs from each of 5 plots of each of 3 varieties of the early maturing
trial were sent to Vidalia Labs International (Collins, GA), by UPS ground, for pyruvate
and sugars analysis. On October 5, 10 bulbs from each of 5 plots of each of 9 varieties
of the full season trial were sent to Vidalia Labs International for pyruvate analysis.
After storage, a second sample of 10 bulbs from each plot of the 9 full season varieties
was sent to Vidalia Labs on January 14, 2005.
Bulb pyruvic acid content is related to onion pungency, with the units of measurement
being micromoles pyruvic acid per gram of fresh weight (pmoles/g FVV). Onions with
low pungency can taste sweet, because the sugar can be tasted. Onion bulbs having a
pyruvate concentration of 5.5 or less are considered "sweet" according to Vidalia Labs
sweet onion certification specifications. Sugars were analyzed by the Brix method.
30
Results
None of the early maturing varieties evaluated for pyruvate in 2004 had concentrations
low enough to be considered sweet (Table 1). Of these, 'Renegade' was among the
varieties with the lowest pyruvate concentration. 'Exacta' had the lowest sugar content.
In 2003, variety Renegade, grown from transplants and harvested in July, had an
average pyruvate concentration of 5.5 pmoles/g FW (Shock et al. 2004a).
On October 15, 2004 and January 24, 2005, none of the full season varieties had
pyruvate concentrations low enough to be considered sweet (Table 2). There was no
significant difference in either pyruvate concentration or sugar content between
sampling dates. Varieties 'Harmony' and 'PX 5299' were among the varieties with the
lowest pyruvate concentration. Varieties 'SVR 5819' and Vaquero were among the
varieties with the highest sugar content. In 2003, the average pyruvate concentration of
selected full season varieties was 5.3 pmoles/g FW in October and 7.9 pmoles/g FW in
January, 2004 (Shock et al. 2004b).
References
Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 2004a. Onion production from
transplants in the Treasure Valley. Oregon State University Agricultural Experiment
Station Special Report 1055:47-52.
Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 2004b. Pungency of selected onion
varieties before and after storage. Oregon State University Agricultural Experiment
Station Special Report 1055:45-46.
Table 1. Pyruvate concentration and estimated sugar concentration of selected early
maturing onion varieties on September 2, 2004, Malheur Experiment Station, Ontario,
OR.
Seed
company Variety
Seminis
Exacta
Golden Spike
Nunhems Renegade
Average
LSD (0.05)
Pyruvate
concentration
pmoles/g FW
6.36
6.84
5.83
6.34
0.60
31
Sugars
% Brix
8.88
9.92
9.75
9.52
0.60
Table 2. Pyruvate con centration and estimated su gar concentration of selected full
season onion varieties in 2003 and 2004, Malheur Experiment Station, Ontario, OR.
2004
2003
Date
October
Company
A. Takii
T-439
Pyruvate
concentration
pmoles/g FW
4.66
Sugars
% Brix
8.08
Pyruvate
Sugars
concentration
pmoles/g FW
% Brix
- 8.44 8.38
- - - 8.80 - -
Crookham
Harmony
6.08
8.88
7.24
Seedworks
6011
4.90
9.04
8.04
8.64
Seminis
Santa Fe
PX 5299
SVR 5819
5.66
8.80
8.62
8.64
6.63
9.88
8.25
Ranchero
Vaquero
SX7002 ON
5.60
5.62
4.70
8.56
8.80
8.04
9.00
9.10
7.52
9.00
8.56
Nunhems
January
Variety
9.48
8.16
Average
A. Takii
5.32
8.70
8.25
8.61
T-439
7.54
7.56
8.50
8.48
Crookham
Harmony
6.40
8.72
6.60
8.56
Seedworks
6011
8.12
8.56
8.02
8.64
Seminis
Santa Fe
PX 5299
SVR 5819
8.22
8.28
7.96
8.33
8.84
9.00
8.40
9.04
Ranchero
Vaquero
SX7002 ON
8.34
8.90
7.84
8.12
8.34
8.24
8.64
8.92
8.80
7.48
8.40
8.12
7.91
8.19
8.21
8.59
8.46
Nunhems
Average
A. Takii
T-439
6.10
7.82
8.44
Crookham
Harmony
6.24
8.80
6.92
8.68
Seedworks
6011
6.51
8.80
8.03
8.64
Seminis
Santa Fe
PX 5299
SVR 5819
6.94
8.54
8.29
7.48
9.36
8.82
Ranchero
Vaquero
SX7002 ON
6.97
7.26
6.27
8.34
8.57
8.14
8.82
9.01
8.02
7.96
8.90
8.14
Average
6.61
8.45
8.23
8.60
LSD (0.05) Date
LSD (0.05) Variety
LSD (0.05) Date X variety
0.08
0.17
NS
NS
0.56
0.79
0.35
0.71
NS
1.00
0.43
NS
Average
Nunhems
32
8.32
9.26
-
EFFECT OF SHORT-DURATION WATER STRESS ON ONION SINGLE
CENTEREDNESS AND TRANSLUCENT SCALE
Clinton C. Shock, Erik Feibert, and Lamont Saunders
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
In earlier trials we have shown that onion yield and grade are very responsive to careful
irrigation scheduling and maintenance of soil moisture (Shock et at. 1 998b, 2000).
Using a high-frequency automated drip-irrigation system, the soil water potential at
8-inch depth that resulted in maximum onion yield, grade, and quality after storage was
determined to be no drier than -20 kPa. It is not known whether short-term water
stress, caused by irrigation errors, could result in internal bulb defects such as multiple
centers and translucent scale. This trial tested the effects of short-duration water stress
at different times during the season on onion single centeredness and translucent
scale.
Materials and Methods
The onions were grown at the Malheur Experiment Station, Ontario, Oregon on an
Owyhee silt loam previously planted to wheat. Soil analysis indicated the need for 60 lb
Nitrogen (N)/acre, 100 lb phosphorus/acre, 100 lb Potassium/acre, 70 lb sulfur/acre, 2
lb copper/acre, and 1 lb boron/acre, which was broadcast in the fall. Onion (cv.
'Vaquero', Nunhems, Parma, ID) was planted in 2 double rows, spaced 22 inches apart
(center of double row to center of double row) on 44-inch beds on March 17, 2004. The
2 rows in the double row were spaced 3 inches apart. Onion was planted at 150,000
seeds/acre. Drip tape (T-tape, T-systems International, San Diego, CA) was laid at
4-inch depth between the 2 double onion rows at the same time as planting. The
distance between the tape and the double row was 11 inches. The drip tape had
emitters spaced 12 inches apart and a flow rate of 0.22 gal/min/100 ft.
Immediately after planting the onion rows received 3.7 oz of Lorsban 1 5G® per 1,000 ft
of row (0.82 lb ai/acre), and the soil surface was rolled. Onion emergence started on
April 2. The trial was irrigated on April 5 with a minisprinkler system (RIO Turbo
Rotator, Nelson Irrigation Corp., Walla Walla, WA) for even stand establishment.
Risers were spaced 25 ft apart along the flexible polyethylene hose laterals that were
spaced 30 ft apart, and the water application rate was 0.10 inch/hour.
The experimental design was a randomized complete block with five replicates. There
were six drip-irrigated treatments that consisted of five timings of short-duration water
stress and an unstressed check. Each plot was 4 rows by 50 ft. Each plot had a ball
33
valve allowing manual control of irrigations. The water stress was applied by turning the
water off manually to all plots in a treatment until the average soil water potential at
8-inch depth for the treatment reached -60 kPa; at this point, the water to all plots in
that treatment was turned on again. Each treatment was stressed once during the
season. The four timings for the stress treatments were: two-leaf stage (water off May
5, water back on June 2), four-leaf stage (water off May 25, water back on June 4),
early six-leaf stage (water off June 2, water back on June 11), late six-leaf stage (water
off June 11, water back on June 16), and eight-leaf stage (water off June 18, water
back on June 24).
Soil water potential (SWP) was measured in each plot with four granular matrix sensors
(GMS, Watermark Soil Moisture Sensors Model 200SS, Irrometer Co. Inc., Riverside,
CA) installed at 8-inch depth in the center of the double row. Sensors were calibrated
to SWP (Shock et al. 1 998a). The GMS were connected to the datalogger with three
multiplexers (AM 410 multiplexer, Campbell Scientific, Logan, UT). The datalogger
read the sensors and recorded the SWP every hour. The irrigations were controlled by
the datalogger using a relay driver (A21 REL, Campbell Scientific, Logan, UT)
connected to a solenoid valve. Irrigation decisions were made every 12 hours by the
datalogger: if the average SWP at 8-inch depth in the unstressed treatment plots was
-20 kPa or less the field was irrigated for 4 hours. The pressure in the drip lines was
maintained at 10 psi by a pressure regulator. Irrigations were terminated on September
2.
Onion tissue was sampled for nutrient content on June 13. The roots from four onion
plants in each check plot were washed with deionized water and analyzed for nutrient
content by Western Labs, Parma, ID. The onions in all treatments were fertilized
according to the plant nutrient analyses. Urea ammonium nitrate solution at 50 lb
N/acre was applied through the drip tape on May 27 and on June 17.
Prior to onion emergence, Roundup® at 24 oz/acre was sprayed on March 29. The field
had Prowl®(llb ai/acre) broadcast on April 12 for postemergence weed control.
Approximately 0.45 inch of water was applied through the minisprinkler system on April
12 to incorporate the Prowl. The field had Goal® at 0.12 lb al/acre, Buctril® at 0.12 lb
ai/acre, and Poast® at 0.28 lb ai/acre applied on May 25. Thrips were controlled with
one aerial application of Warrior® on June 12, one aerial application of Warrior (0.03 lb
ai/acre) plus Lannate® (0.4 lb al/acre) on June 25, one aerial application of Warrior
(0.03 lb al/acre) plus MSR®(0.5 lb al/acre) on July 17, and one aerial application of
Warrior (0.03 lb ai/acre) plus Lannate (0.4 lb al/acre) on July 31.
On September 9 the onions were lifted to cure. On September 15, onions in the central
40 ft of the middle 2 double rows in each plot were topped and bagged. The bags were
placed into storage on September 29. The storage shed was managed to maintain an
air temperature of approximately 34°F. The onions were graded on December 9.
Bulbs were separated according to quality: bulbs without blemishes (No. Is), double
bulbs (No. 2s), neck rot (bulbs infected with the fungus Botiytis al/li in the neck or side),
plate rot (bulbs infected with the fungus Fusarium oxysporum), and black mold (bulbs
34
infected with the fungus Aspergillus niger). The No. I bulbs were graded according to
diameter: small (<2.25 inch), medium (2.25-3 inches), jumbo (3-4 inches), colossal
(4-4.25 inches), and supercolossal (>4.25 inches). Bulb counts per 50 lb of
supercolossal onions were determined for each plot of every variety by weighing and
counting all supercolossal bulbs during grading.
After grading, 50 bulbs ranging in diameter from 3.5 to 4.25 inches from each plot were
rated for single centers and translucent scale. The onions were cut equatorially through
the bulb middle and, if multiple centered, the long axis of the inside diameter of the first
single ring was measured. These multiple-centered onions were ranked according to
the diameter of the first single ring: "small doubles" have diameters less than 1 .5 inch,
"intermediate doubles" have diameters from 1 .5 to 2.25 inches, and "blowouts" have
diameters greater than 2.25 inches. Single-centered onions are classed as a "bullet".
Onions are considered functionally single centered for processing if they are a "bullet"
or "small double." The number and location of translucent scales in each bulb was also
recorded.
Results and Discussion
The SWP at 8-inch depth during the stress treatments reached values lower than the
planned -60 kPa (Fig. 1). Irrigations for the plots being stressed were restarted as soon
as the SWP reached -60 kPa. In addition to being difficult to catch the SWP when it
first reaches -60 kPa, the drip tape was located 11 inches from the soil moisture
sensors, which caused a short delay between the onset of irrigations and when the
wetting front reached the sensors, so that they would begin responding to the
irrigations.
At no stage did water stress affect onion single centeredness or the incidence of bulbs
with translucent scale in 2004 (Table 1). Single-centered "bullet" and functionally
single-centered bulbs averaged 80.5 and 93.8 percent, respectively. Bulbs with
translucent scale averaged 1.1 percent. In 2003, water stress at the four-leaf and
six-leaf stages resulted in significantly lower single-centered and functionally
single-centered bulbs than the unstressed check (Shock et al. 2004). In 2004 there
were relatively few other sources of stress than those imposed by the trial treatments,
suggesting a possible role of multiple sources of stress influencing multiple-centered
bulbs.
The short-duration water stress in this trial did not affect onion yield or grade. The
average onion yields in this trial were: 1,016.4 cwt/acre total yield, 980.5 cwt/acre
marketable yield, 7.0 cwtlacre supercolossal yield, 164.3 cwt/acre colossal yield, and
786.4 cwt/acre jumbo yield. In contrast, in a previous study by Hegde (1986), onion
yield and size were reduced by short-duration water stress to -85 kPa, with the onions
otherwise irrigated at -45 kPa. In that study, the SWP at which the onions were
irrigated was drier (-45 kPa) than in our study (-20 kPa) and the irrigation frequency was
much lower, possibly causing the difference in results.
35
References
Hegde, D.M. 1986. Effect of irrigation regimes on dry matter production, yield, nutrient
uptake and water use of onion. Indian J. Agronomy 31:343-348.
Shock, C.C., J.M. Barnum, and M. Seddigh. 1998a. Calibration of Watermark Soil
Moisture Sensors for irrigation management. Pages 139-146 in Proceedings of the
International Irrigation Show, Irrigation Association, San Diego, CA.
Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 1998b. Onion yield and quality
affected by soil water potential as irrigation threshold. HortScience 33:188-191.
Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 2000. Irrigation criteria for
drip-irrigated onions. HortScience 35:63-66.
Shock, C.C., E. Feibert, and L. Saunders. 2004. Effect of short duration water stress on
onion single centeredness and translucent scale. Oregon State University Agricultural
Experiment Station Special Report 1055:53-56.
Table 1. Onion multiple-center rating and translucent scale response to timing of water
stress, Malheur Experiment Station, Oregon State University, Ontario, OR, 2004.
Functionally
single
centered
Water stress timing
Blowout*
Intermediate Small
Bullet + small Translucent
doublet
doublet Bullets
double
scale
%
Check, no stress
1.6
4.8
12.0
81.6
2-leaf stage, early May
2.0
2.8
11.2
84.0
4-leaf stage, late May
2.4
5.2
11.2
81.2
6-leaf stage, early June
2.4
4.0
14.4
79.2
6-leaf stage, mid-June
2.0
4.1
15.5
78.3
8-leaf stage, late June
1.6
4.4
15.2
78.8
LSD (0.05)
NS
NS
NS
NS
*Blowout: diameter of the first single ring >21/4 inches.
intermediate double: diameter of the first single ring 1 %-21h inches.
tSmall double: diameter of the first single ring <1 1/2 inch.
single-centered.
36
93.6
95.2
92.4
93.6
93.8
94.0
NS
2.0
0.0
2.4
0.8
1.6
0.0
NS
0
-20
-40
check, no stress
-60
-80
0
-20
-40
-60
0
0
-20
-40
mid June stress
-60
-80
0
-20
late June stress
-60
-80
126
150
175
199
224
248
Day of year
Figure 1. Soil water potential for onions irrigated at -20 kPa with an automated
drip-irrigation system and submitted to short-duration water stress, Maiheur Experiment
Station, Oregon State University, Ontario, OR, 2004.
37
TREATMENT OF ONION BULBS WITH SURROUND® TO
REDUCE TEMPERATURE AND BULB SUNSCALD
Clinton C. Shock, Erik B. G. Feibert, and Lamont D. Saunders
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Onion prices generally decrease starting in September when harvest intensifies.
Harvesting earlier from overwintered, transplanted, or normally planted full season
onions could increase profits, but mechanized early harvest runs the risk of increased
losses to sunscald. Sunscald occurs when the side of the bulb exposed to afternoon
sun becomes excessively hot. Sunscald results in a flattened and shrunken area on
the bulb surface. The 59-year-average maximum air temperature at the Malheur
Experiment Station is 91, 90, and 80°F for July, August, and September, respectively.
Maximum air temperatures in July and August often exceed 100°F, which can result in
very high unprotected bulb temperatures and sunscald. Surround® (Engelhard Corp.,
Iselin, NJ) is a product made from kaolinite clay and works by forming a white coating
on surfaces, thus reflecting solar radiation. Surround is a wettable powder that is
labeled for reduction of sunscald in fruits and vegetables. Application of Surround after
onions are lifted could reduce sunscald and make early mechanized harvests more
feasible.
Methods
Trials were conducted in two fields in 2004.
Procedures for Growing Onions in Field I
The onions were grown with subsurface drip irrigation at the Malheur Experiment
Station, Ontario, Oregon on an Owyhee silt loam previously planted to wheat. Onion
(cv. 'Vaquero', Nunhems, Parma, ID) was planted on March 17, 2004. The procedures
can be found in "Effect of Short-duration Water Stress on Onion Single Centeredness
and Translucent Scale" by Shock et al. in this report.
Procedures for Growing Onions in Field 2
The onions were grown with furrow irrigation on an Owyhee silt loam previously planted
to wheat. Onion seed ('Vaquero') was planted on March 19, 2004. The procedures
can be found in "2004 Onion Variety Trials" by Shock et al. in this report.
Procedures for Surround Treatments
Onions in each field were lifted on August 9. The lifted onions were divided into plots
23 ft long. The experimental designs were randomized complete blocks with four
38
replicates in each field. There were seven treatments: treatment 1 was untreated; 2
received one Surround application after lifting; 3 received one Surround application
after lifting and one after windrowing; and 4 was treated after windrowing (Table 1).
Treatments 2-4 had an application rate of 25 lb Surround/acre. Treatments 5-7 were
the same as treatments 2-4, except that the application rate was 50 lb Surround/acre.
The Surround was applied after lifting on August 9 with a ground sprayer and a boom
with 9 nozzles spaced 10 inches apart. The Surround was applied in 102 gal
water/acre with 8004 nozzles at 40 psi.
Prior to the Surround application, temperature probes were installed in bulbs at 0.5-cm
depth. The temperature probes in the monitored bulbs were placed so that they faced
to the south-southeast in a position receiving direct sun. Three replicates in the
drip-irrigated field and two replicates in the furrow-irrigated field each had one bulb
monitored for temperature. The temperature probes were read hourly by a datalogger
(Hobo datalogger, Onset Computer Corp., Bourne, MA).
On August 12 the temperature probes and probed onions were removed and the onions
were topped and wind rowed by hand. After wind rowing the temperature probes were
reinserted in different onions as before. The onion wind row was sprayed with Surround
using a ground sprayer with 3 nozzles spaced 10 inches apart. Application rates and
specifications were the same as the initial Surround application. Since only the
windrow was sprayed (one-third of the field), the application rates were reduced to 8.3
lb Surround/acre for treatments 2-4 and to 17 lb Surround/acre for treatments 5-7.
The onions were bagged on August 16 and hauled to a shed. On August 19 the onions
were graded. Bulbs were separated according to quality: bulbs without blemishes (No.
is), bulbs with sunscald damage, double bulbs (No. 2s), neck rot (bulbs infected with
the fungus Bottytis al/il in the neck or side), plate rot (bulbs infected with the fungus
Fusarium oxysporum), and black mold (bulbs infected with the fungus Aspergi//us
niger). The No. 1 bulbs were graded according to diameter: small (<2.25 inches),
medium (2.25-3 inches), jumbo (3-4 inches), colossal (4-4.25 inches), and
supercolossal (>4.25 inches). Bulb counts per 50 lb of supercolossal onions were
determined for each plot by weighing and counting all supercolossal bulbs during
grading.
To reduce the influence on the statistical analysis of the variability in onion yield and
size between plots, the data for each field were normalized in relation to the average
total yield for that field. Normalized data were subjected to analysis of variance.
Results and Discussion
The highest air temperature reached after lifting of the onions and before topping and
windrowing was 100°F on August 11 (Table 2). The highest average bulb temperature
reached after onions were lifted and before they were topped and windrowed was
129.5°F. Following the application of Surround after lifting on August 9, average
maximum bulb temperatures were reduced 6-7°F compared to the untreated bulbs, but
39
the temperature differences were statistically significant only on August 9 (Table 2, Fig.
1). Bulb temperatures for the 50-lb/acre Surround rate were slightly lower than for the
25 lb/acre rate, but the differences were not statistically significant.
The highest air temperature reached after topping and windrowing on August 12 was
99°F on August 13 (Table 3). The highest average bulb temperature reached after
topping and windrowing was 129.2°F. For the onions treated with Surround after
topping and windrowing, average maximum bulb temperatures were reduced by 5-6°F
compared to the untreated check (Table 3, Fig. 1). After topping and windrowing, the
bulb temperature differences between treatments were statistically significant for all
days measured (August 12-15). After topping and windrowing, bulb temperatures for
the 50-lb/acre Surround rate were slightly lower than for the 25-lb/acre rate and the
differences were statistically significant on August 13, August 15, and on average.
The furrow-irrigated field (field 2) had lower marketable yield and higher yield of onions
with sunscald than the drip-irrigated field (field 1, Table 4). There were no significant
differences in onion yield or grade between treatments. However, in Field 2 there was
a small but significant reduction in rot with increasing total amount of Surround applied
(Fig. 2). In 2003, application of Surround resulted in statistically significant reductions in
bulb sunscald and in increases in marketable yield (Shock et al. 2004). In 2003, the
highest bulb temperature reached after lifting was 123°F and the highest bulb
temperature after topping and windrowing was 121°F. These bulb temperatures were
6.5 and 8.2°F lower than the highest bulb temperatures in 2004. The higher bulb
temperatures in 2004 could be related to the higher average bulb sunscald in 2004 (152
cwt/acre) compared to the average sunscald in 2003 (37 cwt/acre). The higher bulb
temperatures in 2004 might also be related to the higher air temperatures reached
during the 2004 trial (average of 97°F) than during the 2003 trial (average of 94°F).
References
Shock, CC., E.B.G. Feibert, and L.D. Saunders. 2004. Treatment of onion bulbs with
"Surround" to reduce temperature and bulb sunscald. Malheur Experiment Station
Annual Report, Oregon State University Agricultural Experiment Station Special Report
1055:75-79.
40
Table 1. Treatments applied to onion s to evaluate two application rates of Surround®,
Maiheur Experiment Station, Oregon State University, Ontario, OR, 2003.
Post topping and
Treatment Surround
Post lifting
windrowing Surround
rate
Surround
application
lb/acre
application
1
none
No
No
2
25
No
Yes
3
25
Yes
Yes
4
25
Yes
No
5
No
50
Yes
6
50
Yes
Yes
7
50
No
Yes
Table 2. Maximum daily air temperature and maximum bulb temperature (°F) at 0.5-cm
depth for onions treated with two rates of Surround® after lifting, Malheur Experiment
Station, Oregon State University, Ontario, OR, 2004.
Date
Maximum air
Solar radiation
Surround rate lb/acre
LSD
temperature
(0.05)
none
25
50
°F
24-hr total watt hr/m2
°F
9Aug
92
7,531
123.6
116.2
114.2
5.4
10 Aug
97
7,340
127.4
122.6 120.7
NS
11 Aug
100
7,204
129.5
124.2 123.7
NS
Average
126.8
121.0 119.5
NS
Table 3. Maximum daily air temperature, solar radiation, and maximum bulb temperature (°F) at 0.5-cm depth for onions treated with two rates of Surround® after topping
and windrowing, Malheur Experiment Station, Oregon State University, Ontario, OR,
2004
Date
Maximum air
Solar radiation
Surround rate lb/acre
LSD
temperature
none
25
(0.05)
50
°F
24-hr total watt hr/m2
12 Aug
l3Aug
l4Aug
15 Aug
98
99
97
96
7,081
128.4
126.5
125.8
129.2
127.5
6,830
4,769
6,656
Average
41
123.0
121.2
120.5
125.5
122.5
121.5
119.7
119.5
123.6
121.1
3.4
1.4
1.5
1.4
1.2
Check - no Surround
130
U-
0
U)
120
110
C',
100
U)
90
80
70
E
U)
-Q
60
50
Surround at 25 lb/acre
130
120
A
A
U)
C',
L.
U)
E
U)
70
50
Surround at 50 tb/acre
130
U-
0
120
U)
110
C',
100
U)
90
F
U)
80
-Q
70
-
60
50
221
222
223
224
225
Day
of year
226
227
228
1. Onion bulb temperature over time for untreated bulbs and bulbs treated with
two rates of Surround, Maiheur Experiment Station, Oregon State University, Ontario,
OR, 2004.
Figure
42
Table 4. Onion yield and grade response to application of two rates of Surround® in a
drip-irrigated field (field 1) and in a furrow-irrigated field (field 2), Malheur Experiment
Station, Oregon State University, Ontario, OR, 2004.
Surround
—
rate
1st applic. 2nd applic.
lb/acre
Marketa ble yield
cwt/acre % of total
Small
Non-marketable yield
Doubles
Scald
cwt/acre
Rot
Field 1
none
25
25
25
No
Yes
Yes
No
50
Yes
Yes
50
No
50
average
Field 2
none
25
25
25
50
No
Yes
Yes
No
50
Yes
Yes
50
No
average
Fields 1 and 2 average
none
No
25
Yes
25
Yes
25
No
50
50
Yes
Yes
50
No
LSD (0.05) Trt
LSD (0.05) Field
LSD (0.05) Trt X Fid
No
No
Yes
Yes
No
Yes
Yes
No
No
Yes
Yes
No
Yes
Yes
No
No
Yes
Yes
No
Yes
Yes
NS
NS
NS
674.0
697.8
718.7
703.5
667.2
712.7
712.9
79.2
82.0
84.5
82.7
78.4
83.8
83.8
7.9
698.1
82.1
641.3
664.7
672.5
676.0
673.3
679.9
651.5
665.6
8.1
0.4
2.8
6.7
0.8
8.8
1.7
9.4
9.5
0.0
0.4
0.6
165.3
140.2
121.8
132.5
172.2
126.2
125.2
8.3
1.0
140.5
2.4
2.7
76.4
3.8
189.1
4.6
79.2
4.4
168.6
1.2
80.1
5.1
159.1
2.1
80.5
80.2
81.0
77.6
79.3
3.8
0.7
0.7
0.8
2.2
155.5
2.1
2.7
4.6
3.2
1.5
161.1
1.1
2.3
3.0
2.2
3.9
1.6
150.9
179.7
166.3
657.7
681.3
695.6
689.7
670.2
696.3
682.2
77.8
80.6
82.3
81.6
79.3
82.4
80.7
5.9
0.6
6.2
5.9
6.3
6.0
1.8
6.3
6.4
1.4
177.2
154.4
140.4
144.0
166.7
138.6
1.8
152.4
2.3
NS
NS
NS
NS
2.7
NS
NS
NS
NS
NS
NS
NS
NS
22.6
NS
NS
NS
43
8.0
0.8
1.9
0.7
NS
3.0
1.6
2.6
4.2
1.8
3.2
1.8
2.1
3.8
1.4
2.3
3.1
1.4
2.5
_
8
7.
0
C',
6
Y = 5.13- 0.115X + 0.000713X2
•
•
R2 = 0.50, P = 0.001
5
0
4
C/)
0
0
0
0
I
3
2
.
10
-0
20
40
60
80
100
Surround rate, lb/acre
Figure 2. Effect of total amount of Surround® applied on onion decomposition in a
furrow-irrigated field, Malheur Experiment Station, Oregon State University, Ontario,
OR, 2004.
44
EFFECT OF ONION BULB TEMPERATURE AND HANDLING ON BRUISING
Clinton C. Shock and Erik Feibert
Malheur Experiment Station
Oregon State University
Ontario, OR, 2005
Introduction
There is some evidence that onion handling after harvest can bruise bulbs and cause
symptoms similar in appearance to translucent scale. Several shippers have suggested
that the effect of handling on bruise may be influenced by bulb temperature during
handling and by length of time after handling before the onions are checked. This trial
tested the effect of handling 4 onion varieties at 2 temperatures on bruise and on bulb
recovery after 3 days storage at 38°F.
Methods
Trial I
Prior to evaluating variety susceptibility to bruise in January 2004, a preliminary test of
the effect of drop height on bruise was conducted. Fifteen onions from mixed varieties
were each dropped on their sides onto a concrete floor from heights of 0.8 m (2 ft, 7
inches), 1 m (3 ft, 4 inches), 1.2 m (3 ft, 11 inches), or 1.4 m (4 ft, 7 inches). The
onions were cut equatorially and rated for damage. During rating we noted where in the
bulb the damage occurred and whether the appearance was of translucent or watery,
mushy rings. The damaged or bruised area had the form of a triangle (Fig. 1) which
extended from the surface to the center of the bulb. When the affected scales were
translucent, the damage was different from typical translucent scale in that the scales
were only translucent in the bruised area.
bruised area
width of damage
N
Figure 1. Diagram of onion bulb damage or bruising resulting from a drop of I m (3 ft, 4
inches).
45
All drop heights resulted in bulb damage (Table 1). The lowest drop height of 0.8 m (2
ft, 7 inches) resulted in less pronounced damage.
Table 1. Number of onions out of 15 with visible damage or translucent scale
being dropped on a concrete floor from different heights.
Drop height
meters
Onions with damage
(ft, inches)
0.0
0
Oofl5
10*ofl5
0.8
2'7"
10
3'4"
8of15
12
3'll"
10 of 15
1.4
4'7"
*damage was less pronounced.
llofl5
Trial 2
Onions of four varieties were randomly placed in nylon mesh bags (24 bags per
variety). Given the availability of bulbs, there were 24 bulbs/bag of 'Delgado' (Bejo
Seeds), 28 bulbs/bag of 'Granero', 27 bulbs/bag of 'Vaquero', and 30 bulbs/bag of
'Bandolero' (all three Nunhems). On January 13, 2005 the 24 bags of each variety
were placed in 2 coolers: 12 at 32°F and 12 at 38°F. Three days later the bags were
removed a few at a time from the coolers and were either not handled or handled by
dropping each bulb from each bag individually on its side onto a concrete floor from a
height of I m (3 ft, 4 inches). The spot of impact was marked on the onion bulb. After
the handling treatments, half of the bags were put in a cooler at 38°F and the bulbs in
the other half of the bags were immediately cut equatorially and rated for bruising.
Three days after dropping, the onions in the bags stored in the cooler were rated
individually for bruising. The number of bruised bulbs and the number of bruised rings
in bruised bulbs was recorded. The width of the bruised area (Fig. 1) was also
recorded. Rings with a watery appearance were judged to be bruised. Each treatment
was replicated three times (three bags) for each variety (Table 2).
Table 2. Treatments applied to four onion varieties in January 2005.
Treatment
Pretreatment
Handling
Post-treatment
storage
treatment
storage
1
32°F
Drop
no storage
2
storage at 38°F
3
No Drop
no storage
4
storage at 38°F
5
38°F
Drop
no storage
6
storage at 38°F
7
No Drop
no storage
8
storage at 38°F
46
Results
Averaged over varieties and pretreatment storage temperatures, 82.2 percent of the
dropped bulbs showed bruise damage compared to 1.6 percent of the bulbs that were
not dropped (Table 3). There was no significant difference in the percentage of bruised
bulbs before or after storage. In 2004, the percentage of bruised bulbs was higher after
storage, because the affected rings became more translucent and hence more
detectable. In 2005, the damage before storage, in the form of mushy, watery rings,
was easy to detect. Averaged over varieties, the percentage of dropped bulbs that
showed bruise damage after storage was similar in 2004 (80.4) and in 2005 (81.6).
Averaged over varieties, there was no significant difference in percentage of bruised
bulbs that were at 32°F (81 percent) when dropped compared to bulbs that were at
38°F (83.2 percent). In 2004, there was a small but significant difference between the
percentage of bruised bulbs that were at 32°F (75.6 percent) when dropped and bulbs
that were at 38°F (70.8 percent). Averaged over varieties, the percentage of rings that
showed bruising in bruised bulbs was higher in bulbs stored at 38°F (69.9 percent) than
at 32°F (64.9 percent). In 2004, the percentage of rings that showed bruising in
bruised bulbs was higher in bulbs stored at 32°F (91 .8 percent) than at 38°F (89.4
percent).
Averaged over temperature, variety, and handling treatment, the percentage of rings
that showed bruising in bruised bulbs was lower after 3 days of storage (53.1 percent)
than immediately after dropping (81.6 percent). In 2004, averaged over temperature
and variety, the percentage of rings that showed bruising in bruised bulbs was also
lower after 3 days of storage (82.4 percent) than immediately after dropping (98.8
percent), but the difference was smaller than in 2005. Averaged over temperature and
variety, the width of the bruised area was narrower after 3 days of storage than
immediately after dropping.
There was no significant difference between varieties in the percentage of bruised
bulbs. Averaged over temperature and time, Granero had the highest percentage of
bruised rings in bruised bulbs, and Vaquero had among the lowest percentage of
bruised rings. The width of damage in bruised bulbs was widest for Granero. Granero
was the only variety that did not have a lower percentage of rings that showed bruising
in bruised bulbs after storage. In 2004, Vaquero had the highest percentage of bruised
bulbs and Bandolero was among the lowest in percentage of bruised bulbs. In 2004,
Bandolero and Vaquero were among the lowest in percentage of bruised rings in
bruised bulbs.
Discussion
Onions are clearly very sensitive to bruise injury during handling, which could contribute
to undesirable bulb quality at arrival for retail sales and processing. The influence of
bulb temperature at dropping on bruising was small in 2004 and 2005. Bruising
damage can become more evident over time after dropping, as in 2004. However, both
in 2004 and 2005 a healing process started, as shown by the lower percentage of
47
bruised rings in bruised bulbs after 3 days of storage. It would be desirable to explore
the recovery time necessary for bruising injury to disappear.
There were differences between the varieties in susceptibility to bruising injury, but the
differences were small and not consistent between years. The full range of variability in
variety susceptibility to bruising injury is not known. Observations were made only on
four varieties in this preliminary trial.
48
Table 3. Effect of prehandling temperature, handling, and time after handling on onion
bulb bruising, Malheur Experiment Station, Oregon State University, Ontario, OR, 2005.
Variety
Prehandling
storage
temperature
Delgado
°F
32
Bandolero
Before After Avg.
storage storage
Before After Avg.
storage storage
0/
0/
87.5
89.6
92.1
51.9
72.0
5.4
cm
4.8
5.1
No Drop
Drop
No Drop
Drop
No Drop
4.2
76.4
0.0
90.3
2.1
18.2
9.1
1.4
0.0
0.7
83.3
84.8
0.0
58.1
71.5
5.8
5.0
5.4
0.0
0.0
0.0
5.3
0.0
0.0
0.0
0.0
32
Drop
No Drop
85.7
75.6
83.6
2.4
38
Drop
81.0
65.5
3.6
97.6
89.3
25.0
80.4
6.0
1.2
3.6
41.7
Avg
No Drop
Drop
No Drop
83.3
81.5
2.4
82.4
82.0
3.6
3.0
33.4
Drop
No Drop
84.0
72.8
78.4
80.4
0.0
0.0
0.0
0.0
38
Drop
81.5
69.1
75.3
78.9
No Drop
Drop
No Drop
6.0
1.2
3.6
82.7
71.0
0.0
76.8
41.7
79.6
19.4
Avg
0.0
0.0
80.5
76.3
0.0
42.8
1.1
0.0
32
32
38
Avg
0.0
0.0
0.0
0.0
0.0
0.0
84.0
88.9
86.5
88.4
55.0
71.7
5.6
4.9
0.0
0.0
0.0
0.0
0.0
51.3
17.9
67.5
21.4
5.9
3.9
4.9
1.0
1.2
1.1
78.8
79.6
5.2
5.7
5.5
19.4
2.5
2.0
2.3
65.1
30.6
73.5
5.6
4.8
5.2
18.7
26.1
1.8
1.6
1.7
40.8
60.6
5.6
5.0
5.3
0.0
0.0
0.0
0.0
0.0
34.1
56.5
5.6
3.3
4.5
30.6
58.5
2.5
2.0
2.3
5.6
4.2
4.9
0.0
1.2
0.0
Drop
No Drop
77.8
0.0
83.3
2.2
Drop
83.3
86.7
85.0
0.0
0.0
0.0
No Drop
Overall
Width of damage in
bruised bulbs
91.7
Avg
Vaquero
Handling Before After Avg.
treatment storage storage
Affected rings in
bruised bulbs
Drop
38
Granero
Bruised bulbs
Drop
37.4
0.0
0.0
0.0
5.0
76.6
67.2
71.9
5.1
4.9
2.0
5.0
5.0
12.8
59.5
6.4
0.0
0.0
0.0
0.0
0.0
0.0
0.0
1.0
5.0
80.6
85.0
82.8
76.4
55.0
65.7
5.1
4.9
5.0
No Drop
0.0
1.1
0.6
0.0
6.4
3.2
0.0
1.0
0.5
Drop
No Drop
84.8
81.6
81.0
83.1
46.7
4.7
5.1
1.4
1.4
10.8
7.7
0.6
0.8
0.7
38
Drop
80.5
85.9
83.2
80.2
59.6
64.9
9.3
69.9
5.5
1.3
5.5
4.8
5.2
No Drop
Drop
No Drop
3.0
0.6
1.8
20.9
9.7
15.3
1.3
1.0
1.1
Avg
82.7
81.6
82.2
81.6
53.1
67.3
5.5
4.7
5.1
2.2
1.0
1.6
15.8
8.7
12.3
0.9
0.9
0.9
32
averages
LSD (0.05) Handling
Temperature
3.9
5.1
0.3
NS
1.7
NS
Time
NS
1.7
0.1
Temp. X Time
Variety
Temp. X Variety
Time X Variety
Temp. X Time X Variety
NS
2.4
NS
NS
0.2
NS
2.4
3.3
NS
3.3
0.2
NS
4.7
0.3
49
0.2
EVALUATION OF OVERWINTERING ONION FOR
PRODUCTION IN THE TREASURE VALLEY, 2003-2004 TRIAL
Clinton C. Shock, Erik B. G. Feibert, and Lamont D. Saunders
Maiheur Experiment Station
Oregon State University
Ontario, OR
Introduction
The objective of this trial was to evaluate yellow and red onion varieties for overwintering
production in the Treasure Valley. Bulb yield, grade, and pungency were evaluated. Seven
yellow varieties and three red varieties were planted in August 2003 and were harvested
and graded in June 2004.
Methods
The onions were grown on a field of Owyhee silt loam located northeast of the Maiheur
Experiment Station on Railroad Ave. between Highway 201 and Alameda Drive. Seed of
10 varieties was planted in double rows spaced 3 inches apart at 9 seeds/ft of single row on
August 25, 2003. Each double row was planted on beds spaced 20 inches apart with a
customized planter using John Deere Flexi Planter units equipped with disc openers. On
October 21, 2003, alleys 4 ft wide were cut between plots, leaving plots 23 ft long. On
October 22 the seedlings were hand thinned to a plant population of 95,000 plants/acre
(6.6-inch spacing between individual onion plants). All cultural practices were performed by
the grower. The experimental design was a randomized complete block with five replicates.
Onions in each plot were evaluated subjectively for maturity on June 14, 2004 by visually
rating the percentage of onions with the tops down and the percent dryness of the foliage.
The percent maturity was calculated as the average of the percentage of onion with tops
down and the percent dryness. The number of bolted onion plants in each plot was
counted.
Onions from the middle two rows in each plot were lifted, topped by hand, and bagged on
June 21, 2004. The onion bags were transported to a shed at the Maiheur Experiment
Station. On June 23 the onions were graded.
Before grading, all bulbs from each plot were counted to determine actual plant populations
at harvest. During grading, bulbs were separated according to quality: bulbs without
blemishes (No. is), split bulbs (No. 2s), neck rot (bulbs infected with the fungus Boti'ytis all/i
in the neck or side), plate rot (bulbs infected with the fungus Fusarium oxysporum), and
black mold (bulbs infected with the fungus Aspergillus niger). The No. 1 bulbs were graded
according to diameter: small (<2.25 inch), medium (2.25-3 inch),
(3-4 inch), colossal
(4-4.25 inch), and supercolossal (>4.25 inch). Bulb counts/50 lb of supercolossal onions
50
were determined for each plot of every variety by weighing and counting all supercolossal
bulbs during grading.
Ten randomly chosen bulbs from each plot were shipped on June 25 via UPS ground to
Vidalia Labs International (Collins, GA). The bulb samples were analyzed for pyruvic acid
content on July 2. Bulb pyruvic acid content is a measure of pungency with the unit being
micromoles pyruvic acid/g of fresh weight (pmole/g FW). Onion bulbs having a pyruvate
concentration of 5.5 or less are considered sweet according to Vidalia Labs sweet onion
certification specifications.
On July 6, bulbs from each plot were rated subjectively for exterior quality. Bulbs were
rated for skin retention, exterior thrips damage, and rot.
Varietal differences were compared using ANOVA and least significant differences at the 5
percent probability level, LSD (0.05). Varieties were listed by company in alphabetical
order. The LSD (0.05) values should be considered when comparisons are made between
varieties for significant differences in performance characteristics. Differences between
varieties equal to or greater than the LSD (0.05) value for a characteristic should exist
before any variety is considered different from any other variety in that characteristic.
Results
Grower practices adequately controlled thrips during seedling emergence and early plant
growth, critical phases for successful overwintering onion production in the Treasure Valley.
The winter of 2003-2004 in the Treasure Valley was mild, with the lowest temperature of
-1°F on January 5, 2004. In spite of that, plant populations were below the target of 95,000
plants/acre for all varieties, suggesting that a higher population should have been left after
thinning. Plant populations ranged from 38,863 plants/acre for 'Musica' to 71,362
plants/acre for 'T-420' (Table 1).
Total yield averaged 440 cwt/acre and ranged from 360 cwt/acre for 'Electric' to 606
cwt/acre for 'Stansa' (Table 1). Stansa and T-420 had the highest total yield. Marketable
yield averaged 391 cwt/acre and ranged from 291 cwt/acre for 'XON-305Y' to 545 cwt/acre
for Stansa. Supercolossal-size onion yield averaged 18 cwtlacre and ranged from 2
cwt/acre for 'MKS-816' to 79 cwtlacre for Stansa. Stansa had the highest yield of
supercolossal bulbs. Not counting supercolossals, colossal-size onion yield averaged 179
cwt/acre and ranged from 14.4 cwt/acre for 'Desert Sunrise' to 179 cwtlacre for Stansa.
Stansa had the highest colossal bulb yields.
Maturity on June 14 ranged from 0 percent for 'Garnet' to 79 percent for 'MKS-801' (Table
2). Varieties 1-420, XON-305Y, MKS-801, and MKS-816 had bulb pyruvate concentrations
low enough (<5.5 pmoles/g FW) to be classified as sweet onions. MKS-801 had the lowest
pyruvate concentration. Subjective evaluation of skin retention ranged from 1.6 (worst = 0)
for MKS-801 to 4.4 (best = 10) for T-420. Subjective evaluation of thrips damage ranged
from 5.8 (most thrips = 10) for Desert Sunrise to 1.4 (fewest thrips = 0) for 'Hi Keeper'.
51
Table 1. Performance data for onion varieties planted in August 2003 and harvested in June 2004, Malheur Experiment Station,
Oregon State University, Ontario, OR.
Marketable yield by grade
Company Entry name
A. Takii
Hi Keeper
T-420
Bejo
Electric
Musica
Stansa
D. Palmer Desert Sunrise
Sakata
XON-305Y
Scottseed Garnet
MKS-801
MKS-816
LSD (0.05)
Bulb
color
Y
Y
R
Y
Y
R
Y
R
Y
Y
Plant
population
plants/acre
67,044
71,362
54,204
38,863
64,431
58,294
46,817
56,249
58,522
65,453
13,182
Total
yield
Total
--- cwt/acre
518.5
562.2
359.8
366.2
605.7
440.6
482.6
515.3
341.3
320.9
545.3
326.9
376.5290.8
377.5
373.1
417.5
63.6
352.8
344.8
387.6
63.5
>41/4
in 4-4% in 3-4
in
cwt/acre
4.7
109.1
334.2
13.1
107.5
41.9
107.9
179.4
14.4
59.6
43.8
27.8
19.0
30.0
365.1
3.3
39.8
78.9
3.5
18.4
12.1
5.1
1.7
17.3
270.7
165.4
273.6
271.3
187.6
267.7
265.4
322.9
64.0
SuperNon-marketable yield
colossal
2%-3 in counts Total rot No. 2s Small
#/50 lb % of total -- cwt/acre -yield
34.6
37
0.0
29.8
5.9
29.6
35
0.2
40.5 5.0
25.4
0.7
60
8.2
7.5
7.6
44
0.6
4.4
38.6
13.3
37
0.3
54.9
3.4
37.8
33
0.0
105.9 7.8
25.1
33
0.8
76.3
6.4
29.2
54
0.4
17.1
6.2
46.6
35
1.2
16.3
7.6
43.8
0.3
21.9
33
6.5
17.4
NS
NS
25.4
5.1
Table 2. M aturity, pyruvate concentration, and subjective rating of exte nor bulb quality: 0 = fewest and 10 = most for thrips damage
and rot, 0 = worst and 10 = best for skin retenti on, Maiheur Experiment Station, Oregon State University, Ontario, OR, 2004.
Bulb
Company
Entry name
Hi Keeper
T-420
Bejo
Electric
Musica
Stansa
D. Palmer Desert Sunrise
Sakata
XON-305Y
Scottseed Garnet
MKS-801
MKS-816
LSD (0.05)
A. Takii
Matur ity
Pyruvate
color 14 June Bolters concentration
%
#/plot pmoles/g FW
Y
66
0
6.38
Y
67
0
5.18
R
0
0
7.60
Y
1.2
6.26
6
Y
8
1.2
6.80
R
47
5.70
0.2
Y
44
5.34
2.8
7.08
R
0
0.4
Y
79
4.36
0
Y
78
4.64
0
6
0.7
0.61
Exterior bulb quality
Skin retention Thrips damage
3.2
4.4
5.0
3.6
3.8
2.6
2.4
3.4
1.6
1.8
1.7
1.4
3.6
4.0
2.4
3.2
5.8
2.6
4.4
2.0
2.4
1.8
Rot
1.2
1.4
1.0
1.4
2.2
2.4
1.6
1.0
4.0
2.6
NS
WEED CONTROL IN ONION WITH POSTEMERGENCE HERBICIDES
Corey V. Ransom, Charles A. Rice, and Joey K. Ishida
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Weed control is essential for the production of marketable onions. Weed control in
onions is difficult compared to many crops because of the lack of a complete crop
canopy and limited herbicide options. Chateau® (flumioxazin), formerly called Valor®,
and Nortron® (ethofumesate) are two experimental herbicides that have been evaluated
for use in onions in past research trials. Trials were conducted this year to determine
the benefits of using these experimental herbicides in postemergence herbicide
combinations and compare their performance to registered herbicide combinations.
Methods
General Procedures
Trials were conducted at the Malheur Experiment Station to evaluate experimental and
registered herbicides for weed control and onion tolerance. Trials were conducted
under furrow irrigation. On March 25, onions (cv. Vaquero', Nunhems, Parma, ID) were
planted at 3.7-inch spacing in double rows on 22-inch beds. Plots were 4 rows wide
and 27 ft long and arranged in a randomized complete block design with four
replications. Lorsban® was applied in a 6-inch band over each double row at 3.7
oz/1,000 ft of row. Onions were sidedressed with 175 lb nitrogen (N), 30 lb phosphorus
(P), 35 lb sulfate, 38 lb sulfur (S), 2 lb Zinc (Zn), 3 lb manganese (Mn), and 1 lb boron
(B)/acre on June 3. Registered insecticides and fungicides were applied for thrips and
downy mildew control.
Herbicide treatments were applied with a CO2-pressurized backpack sprayer.
Preemergence applications and postemergence grass herbicides were applied at 20
gal/acre at 30 psi and postemergence treatments were applied at 40 gal/acre at 30 psi.
All plots were treated with a preemergence application of Roundup® (glyphosate) at
0.75 lb ai/acre plus Prow®l (pendimethalin) at 1.0 lb ai/acre on April 5 and a
postemergence application of Poast® (sethoxydim) at 0.19 lb ai/acre plus crop oil
concentrate (COC) (1.0% v/v) on June 16. Postemergence treatments were applied to
two-leaf onions on May 6, two- to three-leaf onions on May 14, and to five-leaf onions
on June 2. In the Chateau application timing trial, a separate application of Chateau
was made to three-leaf onions on May 18. Weed control and onion injury were
evaluated throughout the season. Onions were harvested September 16 and 17 and
graded by size on October 1-4.
54
Data were analyzed using analysis of variance and means were separated using a
protected least significant difference (LSD) at the 5 percent level (0.05).
Comparison of Postemergence Chateau or Goal Combinations
Chateau and Goal® (oxyflurofen) were applied in combinations with Buctril
(bromoxynil) to evaluate weed control and onion tolerance. Buctril, Goal, and Chateau
were evaluated at two rates. Comparisons of Goal or Chateau with Buctril included
several combinations of herbicides and rates. Additional treatments included a split
application of Chateau applied to two-leaf and again to three-leaf onions, and a
comparison of Buctril plus Chateau treatments following preemergence applications of
Roundup, Prowl, and Dacthal® (DCPA).
Application Timings for Chateau
Chateau was applied at two rates in combination with Buctril to two-leaf or three-leaf
onions. Chateau treatments were compared to Goal plus Buctril. Additional treatments
included Chateau in a separate application 4 days after the Buctril application at the
three-leaf application timing.
Addition of Nortron to Postemergence Treatments
This trial was conducted to determine if the addition of Nortron to postemergence
herbicide applications would improve weed control. Each treatment was applied with or
without Nortron added to the two-leaf and three-leaf applications at either 0.25 or 0.5 lb
ai/acre. One treatment evaluated Outlook® (dimethenamid-P) added to the two-leaf
application and Nortron added to the three-leaf application.
Results and Discussion
Preemergence herbicides worked fairly well due to rainfall in April. Adequate rainfall
also ensured that weeds were actively growing when postemergence treatments were
applied.
Comparison of Postemergence Chateau or Goal Combinations
Because the preemergence application of Prowl was so effective, there were no
differences in weed control between any of the postemergence herbicide treatments
(Table 1). Control of all species was 85 percent or greater. There were also no
differences in onion injury among treatments. This is surprising as there were large
differences in the herbicide rates applied for different treatments. There were a few
differences in onion yields, with higher yields resulting from treatments with additional
soil-active herbicides applied or with higher rates (Table 2).
Application Timings for Chateau
Treatment with Chateau combined with Buctril when applied either to two-leaf or threeleaf onions did not cause greater injury than combinations of Goal plus Buctril (Table 3).
When Chateau was applied alone 4 days after Buctril was applied to three-leaf onions,
injury increased significantly. By July 21 there were no differences in onion injury
55
among treatments. The injury caused by the delayed application of Chateau was
probably related to wet cool weather that occurred after the Buctril application and prior
to the Chateau application. Pigweed (red root pigweed and Powell amaranth), common
lambsquarters, hairy nightshade, and barnyardgrass control was not different among
herbicide treatments and was 88 percent control or greater. Kochia control was
significantly greater with treatments that contained Chateau tank-mixed with Buctril and
applied at either the two-leaf or three-leaf timing compared to Buctril plus Goal.
Treatments where Chateau was applied alone following the Buctril application to threeleaf onions did not control weeds better than Buctril plus Goal.
There were few significant differences in onion yields between herbicide treatments,
with marketable yields ranging from 1,107 to 1,459 cwtlacre.
Addition of Nortron to Postemergence Treatments
Onion injury was not different among treatments on either evaluation date (Table 5).
Pigweed, hairy nightshade, and barnyardgrass control was similar among herbicide
treatments and was 89 percent or higher. The addition of Nortron at either rate to
Buctril significantly increased common lambsquarters control, but control was similar to
that provided by Goal plus Buctril. There was no improvement in common
lambsquarters control when Nortron was added to Buctril plus Goal. Kochia control
was less when Buctril was applied alone compared to treatments containing Buctril plus
Nortron or Goal or both. A few of the treatments containing Nortron produced more
supercolossal onions than did Buctril alone, but yields were similar to the other
herbicide treatments (Table 6). Nortron is useful for improving weed control in onion
but in this trial did not provide greater benefits than the currently registered herbicides.
56
Table 1. Onion injury and weed control from Goal® or Chateau® combinations with Buctril®, Maiheur Experiment Station,
Oregon State University, Ontario, OR, 2004.
Weed controlt
Injury
Treatment
Rate
lb
ai/acre
Timing*
5-24
6-9
Pigweed
Common
Iambsguarters
Hairy
nightshade
Kochia
Barnyardgrass
0/
Leaf
Untreated
Roundup + Prowl
Buctril
Buctril + Goal
Goal
0.75 + 1.0
0.125
0.25 + 0.125
0.25
PRE
2-leaf
3-leaf
5-leaf
24
28
86
90
96
95
100
PRE
24
20
88
85
97
95
98
25
18
96
95
96
100
100
29
22
93
98
100
96
98
21
16
93
98
96
100
99
Roundup + Prowl
Buctril
Buctril + Goal
Goal
0.75 + 1.0
0.125
0.25 + 0.125
Roundup+Prowl
0.75+ 1.0
PRE
Buctril + Chateau
Buctril + Goal
Goal
0.125 + 0.063
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Chateau
Buctril + Goal
Goal
0.75 + 1.0
0.125 + 0.094
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
Roundup+ Prowl
Buctril + Chateau
Buctril + Goal
0.25 + 0.063
0.25 + 0.125
0.25
0.75+ 1.0
2-leaf
3-leaf
5-leaf
PRE
0.25
PRE
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Chateau
Buctril + Goal
Goal
0.75 + 1.0
0.25 + 0.094
0.25 + 0.125
0.25
PRE
2-leaf
3-leaf
5-leaf
26
21
94
99
97
100
100
Roundup + Prowl
Buctril + Goal
Buctril + Goal
Goal
0.75 + 1.0
0.125 + 0.125
0.25 + 0.125
0.25
PRE
2-leaf
3-leaf
5-leaf
20
19
96
90
99
94
100
Roundup + Prowl
Buctril + Goal
Buctril + Goal
Goal
0.75 + 1.0
0.125 + 0.25
0.25 + 0.125
0.25
PRE
24
17
94
90
95
96
100
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal
Buctril + Goal
Goal
0.75 + 1.0
0.25 + 0.125
0.25 + 0.125
28
16
91
88
99
98
93
Goal
0.25
PRE
2-leaf
3-leaf
5-leaf
Table I (continued). Onion injury and weed control from Goal® or Chateau® combinations with Buctril®, Maiheur
Experiment Station, Oregon State University, Ontario, OR, 2004.
Weed controlt
Injury
Treatment
Roundup + Prowl
Buctril + Goal
Buctril + Goal
Goal
Rate
Timing*
5-24
6-9
Pigweedt
Common
lambsguarters
Ibal/acre
Leaf
PRE
28
19
90
25
18
27
0.75 + 1.0
0.25 + 0.25
0.25 + 0.125
0.25
Kochia
Barnyardgrass
93
94
100
95
95
97
97
88
100
21
97
92
100
96
100
27
18
96
98
100
100
100
24
20
96
100
98
100
95
NS
NS
NS
NS
NS
NS
NS
0/
2-leaf
3-leaf
5-leaf
Roundup+Prowl
0.75+ 1.0
PRE
Buctril + Chateau
Buctril + Chateau
Goal
0.125 + 0.047
0.25 + 0.047
0.25
2-leaf
3-leaf
5-leaf
Roundup + Dacthal + Prowl
Buctril + Chateau
Buctril + Goal
Goal
0.75 +
7.5 + 0.6
0.25 + 0.094
0.125 + 0.25
2-leaf
3-leaf
5-leaf
Roundup + Dacthal + Prowl
Buctril + Chateau
Buctril + Goal
Goal
0.75+7.5 + 0.6
PRE
0.125 + 0.094
0.125 + 0.25
0.25
2-leaf
3-leaf
5-leaf
Roundup + Dacthal + Prowl
Buctril + Chateau
Buctril + Goal
Goal
0.75 + 7.5 + 0.6
0.25 + 0.094
0.125 + 0.125
0.25
2-leaf
3-leaf
5-leaf
--
--
LSD (P = 0.05)
Hairy
nightshade
PRE
PRE
*Preemergence (PRE) treatments were applied on April 5, two-leaf (2-leaf) on May 6, three-leaf (3-leaf) on May 14, and five-leaf (5-leaf) on June 2.
tweedcontrol ratings were taken September 2.
tPigweed is a combination of redroot pigweed and Powell amaranth.
Table 2. Onion yield in response to Goal® or Chateau® combinations with Buctril®, Malheur Experiment Station, Oregon
State University, Ontario, OR, 2004
Onion
Treatment
Rate
Timing*
Ibal/acre
Leaf
Untreated
0.75 + 1.0
0.125
0.25 + 0.125
0.25
Roundup + Prowl
Buctril
Buctril + Goal
Goal
0.75 + 1.0
0.125
0.25 + 0.125
Roundup+Prowl
0.75+ 1.0
PRE
Buctril + Chateau
Buctril + Goal
Goal
0.125 + 0.063
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Chateau
Buctril + Goal
Goal
0.75 + 1.0
0.125 + 0.094
0.25 + 0.125
0.25
Roundup + Prowl
Buctril + Chateau
Buctril + Goal
Goal
Roundup + Prowl
Buctril + Chateau
Buctril + Goal
Goal
Jumbo
Colossal
S. Colossal
Marketable
0
0
0
0
0
1029
5
28
626
345
30
4
13
527
540
150
1,229
7
16
481
522
141
1,160
PRE
2-leaf
3-leaf
5-leaf
6
17
559
510
123
1,208
0.75 + 1.0
0.25 + 0.063
0.25 + 0.125
0.25
PRE
2-leaf
3-leaf
5-leaf
4
18
580
453
115
1,167
0.75 + 1.0
0.25 + 0.094
0.25 + 0.125
0.25
PRE
5
17
562
490
207
1,275
2-leaf
3-leaf
5-leaf
7
48
595
348
111
1,101
3
13
497
524
181
1,216
8
20
583
361
78
1,041
0.25
PRE
2-leaf
3-leaf
5-leaf
PRE
2-leaf
3-leaf
5-leaf
0.75+ 1.0
PRE
0.125 + 0.125
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal
Buctril + Goal
Goal
0.75 + 1.0
0.125 + 0.25
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal
Buctril + Goal
Goal
0.75 + 1.0
0.25 + 0.125
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
Buctril + Goal
Buctril + Goal
Goal
Medium
cwtlacre
0
Roundup + Prowl
Buctril
Buctril + Goal
Goal
Roundup+Prowl
Small
PRE
PRE
Table 2 (continued). Onion yield in response to Goal® or Chateau® combinations with Buctril®, Malheur Experiment
Station, Oregon State University, Ontario, OR, 2004.
Onion yieldt
Treatment
Roundup + Prowl
Buctril + Goal
Buctril + Goal
Goal
Rate
Timing*
lbai/acre
Leaf
0.75 + 1.0
0.25 + 0.25
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
PRE
1,277
5
23
600
441
128
1,192
PRE
2-leaf
3-leaf
5-leaf
3
18
461
552
207
1,238
PRE
4
15
450
596
225
1,285
4
18
484
552
168
1,222
0.25
PRE
2-leaf
3-leaf
5-leaf
--
--
5
18
185
180
122
193
PRE
Roundup + Dacthal + Prowl
Buctril + Chateau
Buctril + Goal
Goal
LSD(P=0.05)
Marketable
167
2-leaf
3-leaf
5-leaf
Goal
S. Colossal
592
0.75+1.0
Roundup + Dacthal + Prowl
Buctril + Chateau
Buctril + Goal
Colossal
cwt/acre
502
0.125 + 0.047
0.25 + 0.047
Goal
Jumbo
16
Buctril + Chateau
Buctril + Chateau
Roundup + Dacthal + Prowl
Buctril + Chateau
Buctril + Goal
Medium
5
Roundup+Prowl
Goal
Small
0.25
0.75 + 7.5 + 0.6
0.25 + 0.094
0.125 + 0.25
0.25
0.75 + 7.5 + 0.6
0.125 + 0.094
0.125 + 0.25
0.25
0.75 + 7.5 + 0.6
0.25 + 0.094
0.125 + 0.125
2-leaf
3-leaf
5-leaf
*preemergence (PRE) treatment applied on April 5, two-leaf (2-leaf) on May 6, three-le af (3-leaf) on May 1 4, and five-leaf (5-leaf) on June 2.
tonions were harvested on September 16 and 17.
Table 3. Weed control and onion injury in response to Chateau® application timings, Malheur Experiment Station,
Oregon State University, Ontario, OR, 2004.
Weed controlt
Injury
Treatment
Untreated
Roundup + Prowl
Buctril + Goal
Buctril + Goal
Goal
Roundup + Prowl
Buctril + Chateau
Buctril + Goal
Goal
Barnyardgrass
-97
-72
-100
90
100
96
99
94
89
100
96
100
21
97
88
100
99
98
29
21
91
91
99
93
100
PRE
2-leaf
3-leaf
3-leaf (S)
5-leaf
34
20
92
89
100
77
100
36
21
92
91
98
82
100
0.25
0.094
0.25
PRE
2-leaf
3-leaf
3-leaf (S)
5-leaf
--
--
5
NS
NS
NS
NS
15
NS
Ibal/acre
Leaf
--
--
0.75 + 1.0
0.125 + 0.125
0.25 + 0.125
PRE
0.25
0.75 + 1.0
0.125 + 0.063
0.25 + 0125
0.25
5-24
6-21
-.
24
-16
--
89
-90
26
19
96
26
21
PRE
29
0/
PRE
2-leaf
3-leaf
5-leaf
0.25
PRE
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal
Buctril + Chateau
Goal
0.75 + 1.0
0.125 + 0.125
0.25 + 0.063
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal
Buctril + Chateau
Goal
0.75 + 1.0
0.125 + 0.125
0.25 + 0.094
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal
Buctril
Chateau
Goal
0.75 + 1.0
0.125 + 0.125
Roundup + Prowl
Buctril + Goal
Buctril
Chateau
Goal
0.75 + 1.0
0.125 + 0.125
0.05)
Hairy
nightshade
2-leaf
3-leaf
5-leaf
0.75 + 1.0
0.125 + 0.094
0.25 + 0.125
0.25
0.063
0.25
Common
lambsquarters
Pigweedt
Roundup + Prowl
Buctril + Chateau
Buctril ÷ Goal
Goal
LSD (P
.
Kochia
Rate
Timing*
PRE
*preemergence (PRE) treatments were applied on April 5, two-leaf (2-leaf) on May 6, three-leaf (3-leaf) on May 14, th ree-leaf separate (3-leaf (S)) on May 18, and five-leaf (5-leaf)
on June 2.
tWeed control ratings were taken September 2.
tpigweed is a combination of redroot pigweed and Powell amaranth.
Table 4. Onion yield in response to Chateau® application timings, Maiheur Experiment Station, Oregon State University,
Ontario, OR, 2004
Onion
Treatment
Untreated
Roundup+ Prowl
Buctril + Goal
Buctrit + Goal
Goal
Roundup+ Prowl
Buctril + Chateau
Buctril + Goal
Rate
Timing*
lbailacre
Leaf
Small
Medium
Jumbo
Colossal
S. Colossal
Marketable
cwtlacre
--
--
0
0
0
0
0
0
0.75+1.0
PRE
2-leaf
3-leaf
5-leaf
4
18
639
385
75
1,117
4
16
519
535
110
1,179
4
28
592
386
87
1,093
4
22
602
501
90
1,215
0.125 + 0.125
0.25 + 0.125
0.25
0.75+1.0
PRE
Goal
0.125 + 0.063
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Chateau
Buctril + Goal
Goal
0.75 + 1.0
0.125 + 0.094
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal
Buctril + Chateau
Goal
0.75 + 1.0
0.125 + 0.125
0.25 + 0.063
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal
Buctril + Chateau
Goal
0.75 + 1.0
0.125 + 0.125
0.25 + 0.094
0.25
PRE
2-leaf
3-leaf
5-leaf
2
21
640
713
86
1,459
Roundup + Prowl
Buctrit + Goal
Buctril
Chateau
Goal
0.75 + 1.0
0.125 + 0.125
0.25
0.063
0.25
PRE
6
30
661
345
70
2-leaf
3-leaf
3-leaf (5)
5-leaf
1,107
Roundup + Prowl
Buctril + Goal
Buctril
Chateau
Goal
0.75 + 1.0
0.125 + 0.125
0.25
0.094
0.25
6
30
584
423
109
1,145
3-leaf(S)
5-leaf
--
--
2
18
99
302
64
333
LSD (P = 0.05)
PRE
PRE
PRE
2-teaf
3-leaf
*Preemergence (PRE) treatments were applied on Aprit 5, two-leaf (2-leaf) on May 6, three-leaf (3-leaf) on May 14, three-leaf separate (3-leaf(S)) on May 18, and five-leaf (5-leaf)
on June 2.
were harvested on September16 and 17.
Table 5. Onion injury and weed control in response to the addition of Nortron® to postemergence applications of Buctril®
and Goal®, Maiheur Experiment Station, Oregon State University, Ontario, OR, 2004.
Weed
Injury
Treatment
Untreated
Rate
Timing*
lbai/acre
Leaf
--
--
Roundup + Prowl
Buctril
Buctril + Goal
Goal
0.75 + 1.0
0.125
0.25 + 0.125
Roundup + Prowl
Buctril + Goal
Buctril + Goal
Goal
0.75 + 1.0
0.125 + 0.125
0.25 + 0.125
0.25
0.25
5-24
6-9
Pigweedt
Common
lambsquarters
Hairy
nightshade
Kochia
Barnyardgrass
0/
--
--
--
--
--
--
--
20
18
89
89
100
76
100
25
21
93
95
100
89
100
23
16
100
100
97
95
100
27
22
90
100
100
97
100
28
23
93
93
100
94
100
25
18
100
100
100
98
100
PRE
2-leaf
3-leaf
5-leaf
PRE
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Nortron
Buctril + Goal + Nortron
Goal
0.75 + 1.0
0.125 + 0.25
0.25 + 0.125 + 0.25
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Nortron
Buctril + Goal + Nortron
Goal
0.75 + 1.0
0.125 + 0.5
0.25 + 0.125 + 0.5
0.25
PRE
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal + Nortron
Buctril + Goal + Nortron
Goal
0.75 + 1.0
0.125 + 0.125 + 0.25
0.25 + 0.125 + 0.25
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal + Outlook
Buctril + Goal + Nortron
Goal
0.75 + 1.0
0.125 + 0.125 + 0.84
0.25 + 0.125 + 0.25
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal + Nortron
Buctril + Goal + Nortron
Buctril + Goal
0.75 + 1.0
0.125 + 0.125 + 0.5
0.25 + 0.125 + 0.5
0.125 + 0.25
2-leaf
3-leaf
5-leaf
28
24
97
99
97
100
97
--
--
NS
NS
NS
7
NS
13
NS
LSD (P = 0.05)
PRE
PRE
PRE
PRE
*preemergence (PRE) treatments were applied on April 5, two-leaf (2-I eaf) on May 6, three-leaf (3-leaf) on May 14, and five-leaf (5-leaf) on June 2.
tWeed control ratings were taken September 2.
tPigweed is a combination of redroot pigweed and Powell amaranth.
Table 6. Onion yield in response to the addition of Nortron® to postemergence applications of Buctril® and Goal®, Malheur
Experiment Station, Oregon State University, Ontario, OR, 2004.
Onion vieldt
Treatment
Rate
Timing*
lb al/acre
Leaf
Untreated
Roundup + Prowl
Buctril
Buctril + Goal
Goal
Roundup + Prowl
Buctril + Goal
Buctril + Goal
Goal
Roundup + Prowl
Buctril + Nortron
Buctril + Goal + Nortron
Goal
Roundup + Prowl
Buctril + Nortron
Buctril + Goal + Nortron
Goal
Roundup + Prowl
Buctril + Goal + Nortron
Buctril + Goal + Nortron
0.75 + 1.0
0.125
0.25 + 0.125
PRE
0.25
2-leaf
3-leaf
5-leaf
0.75 + 1.0
0.125 + 0.125
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
0.75 + 1.0
0.125 + 0.25
0.25 + 0.125 + 0.25
0.25
PRE
PRE
PRE
0.125+ 0.5
0.25 + 0.125 + 0.5
2-leaf
3-leaf
5-leaf
0.25
PRE
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal + Outlook
Buctril + Goal + Nortron
Goal
0.75 + 1.0
0.125 + 0.125 + 0.84
0.25 + 0.125 + 0.25
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal + Nortron
Buctril + Goal + Nortron
Buctril + Goal
0.75 + 1.0
0.125 + 0.125 + 0.5
0.25 + 0.125 + 0.5
0.125 + 0.25
2-leaf
3-leaf
5-leaf
Goal
LSD (P = 0.05)
Medium
Jumbo
Colossal
S. Colossal
Marketable
0
0
0
0
0
0
S
45
689
225
12
971
7
37
609
354
65
1,066
6
29
693
349
60
1,130
3
18
597
424
111
1,150
4
33
640
363
72
1,107
4
17
614
475
117
1,223
8
21
662
440
97
1,219
4
16
113
237
66
278
2-leaf
3-leaf
5-leaf
0.75 + 1.0
0.75 + 1.0
0.125 + 0.125 + 0.25
0.25 + 0.125 + 0.25
Small
PRE
PRE
*preemergence (PRE) treatment applied on April 5, two-leaf (2-leaf) on May 14, three-leaf (3-leaf) on May 18, and five-leaf (5-leaf) on June 2.
tOnions were harvested on September 16 and 17.
SOIL-ACTIVE HERBICIDE APPLICATIONS FOR WEED CONTROL IN ONION
Corey V. Ransom, Charles A. Rice, and Joey K. Ishida
Maiheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Weed control is essential for the production of marketable onions. Only a few
herbicides are registered for preemergence application in onion. Effective
preemergence herbicides can control weeds as they germinate and reduce the size and
number of weeds that are present when onions are large enough to tolerate
postemergence herbicide applications. This research evaluated registered and
experimental herbicides for preemergence weed control in onion.
Methods
General Procedures
A trial was conducted at the Malheur Experiment Station under furrow irrigation. On
March 25, onions (cv. 'Vaquero', Nunhems, Parma, ID) were planted at 3.7-inch
spacing in double rows on 22-inch beds. Plots were 4 rows wide and 27 ft long and
arranged in a randomized complete block design with 4 replicates. Lorsban® was
applied in a 6-inch band over each double row at 3.7 oz/1 ,000 ft of row. Onions were
sidedressed with 175 lb nitrogen, 30 lb phosphorus, 35 lb sulfate, 38 lb elemental
sulfur, 2 lb zinc, 3 lb manganese, and 1 lb boron/acre on June 3. Registered
insecticides and fungicides were applied for thrips and downy mildew control.
Preemergence (PRE) applications of Prowl® (pendimethalin), Nortron® (ethofumesate),
and Outlook® (dimethenamid-P) in combination with Roundup (glyphosate) were
evaluated for weed control and onion tolerance. Each product was evaluated at two
rates. Combinations of Prowl with Nortron or Outlook were also evaluated. Prowl and
Prowl H20® (a new water-based formulation) were also applied to onions at the flag leaf
stage following Roundup applied PRE. Prowl H20 was also combined with Outlook
applied at the flag leaf stage following a PRE application of Roundup. Preemergence
treatments and other applications of soil-active herbicides were compared to plots
where only Roundup was applied preemergence.
Herbicide treatments were applied with a C02-pressurized backpack sprayer.
Preemergence applications were applied at 20 gal/acre at 30 psi. Postemergence
applications were applied at 40 gal/acre at 30 psi. Preemergence treatments were
applied on April 5, two-leaf on May 6, three-leaf on May 14, and five-leaf on June 2.
65
All plots received Poast® (sethoxydim) at 0.19 lbs ai/acre plus crop oil concentrate
(COC) (1 qt/acre) on June 16 to control grasses. Weed control and onion injury were
evaluated throughout the season. Onions were harvested September 16 and 17 and
graded by size on October 1-4.
Data were analyzed using analysis of variance and means were separated using a
protected least significant difference (LSD) at the 5 percent level (0.05).
Results and Discussion
Preemergence and postemergence treatments were effective because of rain and
actively growing weeds at the time herbicides were applied. Injury was similar among
treatments except for plots treated with a tank mixture of Buctril, Outlook, and Chateau,
which had significantly more injury than all other treatments on May 24 and at the later
evaluation on June 9 (Table 1). Pigweed (redroot pigweed and Powell amaranth)
control was similar among herbicide treatments and ranged from 84 to 99 percent.
Common lambsquarters control was improved with preemergence applications of Prowl
compared to plots treated only with Roundup PRE. Outlook and Nortron did not
significantly increase common lambsquarters control compared to Roundup alone.
Hairy nightshade control was greater than 90 percent and barnyardgrass greater than
96 percent for all herbicides. Kochia control was significantly greater with PRE Prowl or
Nortron compared to Outlook. However, the high rate of Outlook improved kochia
control compared to Roundup alone PRE. This year, delaying Prowl or Prowl plus
Outlook combinations until the flag leaf stage provided similar control to preemergence
applications. If these treatments are as effective as the PRE applications, then
applications to flag leaf onions provide an increased level of crop safety compared to
PRE applications. Treatments with Prowl applied PRE or to flag leaf onions followed by
applications of Outlook to two-leaf onions also effectively controlled all weeds. The
Prowl label allows applications to flag leaf onions and the Outlook label allows
applications to two-leaf onions.
Roundup alone PRE and Roundup plus Outlook (0.66 lb ai/acre) produced higher
medium onion yields and lower colossal, total, and marketable onion yields compared
to all the other treatments (Table 2). The combination of Prowl plus Outlook PRE had
among the lowest number of onion bulbs per acre and was less than plots with
Roundup alone PRE or applications of Prowl made to flag leaf onions. This result
illustrates the potential to reduce onion stand with PRE applications of soil-active
herbicides. Even with the reduced number of onion bulbs, this treatment produced
yields similar to all other treatments. Only plots with reduced weed control had
significantly lower yields. The increased weed control and subsequent increase in
onion yields from plots receiving a PRE or flag leaf application of a soil-active herbicide
demonstrates the importance of soil-active herbicides for reducing weed germination
and growth prior to when postemergence herbicide applications can be made.
66
Table 1. Onion injury and weed control in response to applications of Outlook®, Nortron®, and Prowl®, Maiheur
Experiment Station, Oregon State University, Ontario, OR, 2004.
Injury
•
Treatment
Rate
lbai/acre
Timing
5-24
6-9
Pigweedt
Common
lambsquarters
Weed
Hairy
nightshade
Kochia
Barnyardgrass
0/
Leaf
Untreated
PRE
25
16
87
77
100
73
100
2-leaf
3-leaf
5-leaf
PRE
2-leaf
3-leaf
5-leaf
25
17
95
88
100
85
100
PRE
26
19
88
85
91
96
98
27
16
93
90
100
100
100
PRE
2-leaf
3-leaf
5-leaf
25
16
98
96
100
95
98
PRE
26
17
95
98
100
99
100
25
16
84
77
98
69
99
26
16
99
100
100
99
97
26
18
97
100
95
98
100
Roundup + Outlook
Buctril + Goal
Buctril + Goal
Goal
Roundup + Outlook
Buctril + Goal
Buctril + Goal
Goal
0.75 + 0.656
0.125 + 0.125
0.25 + 0.125
Roundup + Nortron
Buctril + Goal
Buctril + Goal
Goal
0.75 + 1.0
0.125 + 0.125
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
Roundup + Nortron
Buctril + Goal
Buctril + Goal
Goal
0.75 + 2.0
0.125 + 0.125
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal
Buctril + Goal
Goal
0.75 + 1.0
0.125 + 0.125
0.25 + 0.125
Roundup + Prowl
Buctril + Goal
Buctril + Goal
Goal
0.75 + 1.5
0.125 + 0.125
0.25 + 0.125
Roundup
Buctril + Goal
Buctril + Goal
Goal
Roundup + Prowl + Nortron
Buctril + Goal
Buctril + Goal
Goal
Roundup + Prowl + Outlook
Buctril + Goal
Buctril + Goal
Goal
0.25
0.75 + 0.843
0.125 + 0.125
0.25 + 0.125
0.25
0.25
0.25
PRE
2-leaf
3-leaf
5-leaf
0.75
PRE
0.125 + 0.125
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
0.75 + 1.0 + 1.0
0.125 + 0.125
0.25 + 0.125
0.25
0.75 + 1.0 + 0.843
0.125 + 0.125
0.25 + 0.125
0.25
PRE
2-leaf
3-leaf
5-leaf
PRE
2-leaf
3-leaf
5-leaf
Table 1 (continued). Onion injury and weed control in response to applications of Outlook®, Nortron®, and Prowl®,
Maiheur Exreriment Station, Oregon State University, Ontario, OR, 2004.
Weed controlt
Iniury
Treatment
Roudup
Prowl + Outlook
Buctril + Goal
Buctril + Goal
Goal
Roundup
Prowl H20 + Outlook
Buctril + Goal
Buctril + Goal
Goal
Roundup
Prowl
Buctril + Goal + Outlook
Buctril + Goal
Goal
Roundup
Prowl H2O
Buctril + Goal + Outlook
Buctril + Goal
Goal
Roundup+ Prowl
Buctril + Goal + Outlook
Buctril + Goal
Goal
Roundup+ Prowl
Buctril + Chateau + Outlook
Buctril + Goal
Goal
LSD (0.05)
Rate
Timing
lbai/acre
Leaf
0.75
1.0 + 0.843
0.125 + 0.125
0.25 + 0.125
0.25
PRE
flag
0.75
1.0 + 0.843
0.125 + 0.125
0.25 + 0.125
0.25
0.75
PRE
flag
0.125 + 0.125 + 0.843
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
0.75
PRE
flag
0.25
0.75+ 1.0
0.125 + 0.125 + 0.843
0.25 + 0.125
0.25
0.75+ 1.0
0.125 + 0.063 + 0.843
0.25 + 0.125
6-9
tPigweed
Common
lambsguarters
Hairy
nightshade
Kochia
Barnyardgrass
0/
26
17
96
93
99
97
100
26
18
95
92
100
88
100
25
16
88
83
97
100
100
26
17
92
92
100
100
100
24
17
97
98
100
100
99
39
27
98
100
100
100
96
2
3
12
12
6
10
3
2-leaf
3-leaf
5-leaf
PRE
flag
0.125 + 0.125 + 0.843
0.25 + 0.125
5-24
2-leaf
3-leaf
5-leaf
1.0
1.0
.
2-leaf
3-leaf
5-leaf
PRE
2-leaf
3-leaf
5-leaf
PRE
0.25
2-leaf
3-leaf
5-leaf
--
--
*preemergence (PRE) treatments were applied on April 5, two-leaf (2-le af) on May 6, three-leaf (3-leaf) on May 14, and five-leaf (5-leaf) on June 2.
tWeed control was evaluated on September 2.
is a combination of redroot pigweed and Powell amaranth.
Table 2. Onion yield in response to applications of Outlook®, Nortron®, and Prowl®, Maiheur Experiment Station, Oregon
State University, Ontario, OR, 2004
Onion yieldt
Treatment
Rate
Timing*
Small
Medium
Jumbo
Colossal
S. Colossal
Marketable
cwtlacre
lbai/acre
Leaf
Roundup + Outlook
Buctril + Goal
Buctril + Goal
Goal
0.75 + 0.656
0.125 + 0.125
0.25 + 0.125
0.25
PRE
2-leaf
3-leaf
5-leaf
8
59
650
151
25
884
Roundup + Outlook
Buctril + Goal
Buctril + Goal
Goal
Roundup + Nortron
Buctril + Goal
Buctril + Goal
Goal
Roundup + Nortron
Buctril ÷ Goal
Buctril + Goal
Goal
0.75 + 0.843
0.125 + 0.125
0.25 + 0.125
PRE
9
23
726
340
22
1111
9
31
624
369
60
1085
5
32
633
379
61
1105
9
22
695
412
70
1199
Untreated
0.25
0.75 + 1.0
0.125 + 0.125
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
Buctril + Goal
Buctril + Goal
Goal
0.125 + 0.125
0.25 + 0.125
0.25
PRE
2-leaf
3-leaf
5-leaf
PRE
2-leaf
3-leaf
5-leaf
PRE
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal
Buctril + Goal
Goal
0.75 + 1.5
0.125 + 0.125
0.25 + 0.125
0.25
PRE
2-leaf
3-leaf
5-leaf
7
23
640
357
73
1092
Roundup
Buctril + Goal
Buctril + Goal
Goal
0.75
0.125 + 0.125
0.25 + 0.125
0.25
PRE
2-leaf
3-leaf
5-leaf
11
59
678
128
10
874
Roundup + Prowl + Nortron
Buctril + Goal
Buctril + Goal
Goal
0.75 + 1.0 + 1.0
0.125 + 0.125
0.25 + 0.125
11
23
555
498
101
1176
0.25
PRE
2-leaf
3-leaf
5-leaf
Roundup + Prowl + Outlook
Buctril + Goal
Buctril + Goal
Goal
0.75 + 1.0 + 0.843
0.125 + 0.125
0.25 + 0.125
0.25
PRE
4
20
543
423
110
1095
2-leaf
3-leaf
5-leaf
Roundup+Prowl
0.75 + 2.0
0.125 + 0.125
0.25 + 0.125
0.25
0.75+ 1.0
Table 2 (continued). Onion yield in response to applications of Outlook®, Nortron®, and Prowl®, Maiheur Experiment
Station, Oreqon State University, Ontario, OR, 2004.
Onion yieldt
Treatment
Rate
Small
lb ai/acre
Leaf
PRE
flag
Goal
0.75
1.0 + 0.843
0.125 + 0.125
0.25 + 0.125
0.25
Roundup
Prowl H2O + Outlook
Buctril + Goal
Buctril + Goal
Goal
0.75
1.0 + 0.843
0.125 + 0.125
0.25 + 0.125
0.25
Medium
Jumbo
Colossal
S. Colossal
Marketable
cwt/acre
Untreated
Roundup
Prowl + Outlook
Buctril + Goal
Buctri! + Goal
Roundup
Prowl
Buctril + Goal +
Outlook
Buctril + Goal
Goal
0.75
1.0
0.125 + 0.125 + 0.843
0.25 + 0.125
0.25
7
33
599
382
83
1097
7
28
676
348
70
1122
10
31
647
391
64
1132
6
30
683
370
61
1144
2-leaf
3-leaf
5-leaf
PRE
flag
2-leaf
3-leaf
5-leaf
PRE
flag
2-leaf
3-leaf
5-leaf
Roundup
Prowl H2O
Buctril + Goal + Outlook
Buctril + Goal
Goal
1.0
PRE
flag
0.125 + 0.125 + 0.843
0.25 + 0.125
0.25
2-leaf
3-leaf
5-leaf
Roundup + Prowl
Buctril + Goal + Outlook
Buctril + Goal
0.75+ 1.0
0.125 + 0.125 + 0.843
0.25 + 0.125
PRE
2-leaf
3-leaf
5-leaf
6
23
582
491
126
1221
0.75+1.0
PRE
5
28
594
433
67
0.125 + 0.063 + 0.843
0.25 + 0.125
2-leaf
3-leaf
5-leaf
1122
6
20
111
181
57
188
Goal
Roundup + Prowl
Buctril + Chateau + Outlook
Buctril + Goal
Goal
LSD (0.05)
0.75
0.25
0.25
*preemergence (PRE) treatments were applied on April 5, two-leaf (2-leaf) on May 6, three-leaf (3-leaf) on May 14, and five-leaf (5-leaf) on June 2.
were harvested on September 16 and 17.
INSECTICIDE TRIALS FOR ONION THRIPS (THRIPS TABACI)
CONTROL — 2004
Lynn Jensen
Malheur County Extension Service
Oregon State University
Ontario, OR
Introduction
During the past 4 years alternative insecticides have demonstrated superior
control of onion thrips when compared to conventional insecticides. Alternative
insecticides in this trial are azadirachtin
and Ecozin®) an extract
from the neem tree (Azadirachia md/ca, A. Juss.), and spinosad (Success®), a
bacterial fermentation product. Conventional insecticides are the currently
registered products in the synthetic pyrethroid (Warrior®, Mustang®), organophosphate (parathion, malathion, Guthion®, Diazinon), and carbamate (Lannate®,
Vydate®) classes. Different rates and combinations of these insecticides were
tested for efficacy against onion thrips.
Materials and Methods
A 36.7-ft-wide by 500-ft long block was planted to onion (cv. 'Vaquero',
Nunhems, Parma, ID) on March 23, 2004. The onions were planted as 2 double
rows on a 44-inch bed. The double rows were spaced 2 inches apart. The
seeding rate was 137,000 seeds/acre. Lorsban 1 5G® was applied in a 6-inch
band over each double row at planting at a rate of 3.7 oz/1 ,000 ft of row for onion
maggot control. Water was applied by furrow irrigation. The plots were 7.3 ft wide
(2 beds) by 25 ft long and were replicated 4 times.
There were 14 treatments as outlined in Table 1. Acephate is an older insecticide
that is now manufactured by several companies. It is not currently registered for
use on onions.
Insecticide applications were made with a CO2-pressurized plot sprayer with 4
nozzles spaced 19 inches apart. All treatments were made with water as a carrier
at 38.9 gal/acre. Thrips counts were made weekly through the growing season by
counting the total number of thrips on 20 plants.
The onion bulbs were harvested by hand on September 10 and graded on
October 11. The plot area harvested was 20 ft of the center 2 double rows.
71
Treatment differences were compared using ANOVA and least significant
differences at the 5 percent probability level, LSD (0.05). Means were also
compared using Duncan's multiple range test.
Results and Discussion
Thrips populations in June were fairly high (Fig.1). The acephate treatments
provided the best thrips control. Table 2 contains yield and grade information. All
of the yield classes had significant differences except for medium-size onions.
Acephate treatments had the highest yield of supercolossal plus colossal bulbs at
both the 8.0-oz and 16.0-oz rate, and the 6.0 oz rate had the highest yield of
colossal bulbs. The Aza Direct plus Success (10.0 oz) had the overall highest
yield followed by treatment 13, which was a combination of Penncap M plus
MSR® and Warrior plus MSR. Acephate at the 6.0-oz rate also produced high
yields.
Aza-Direct by itself produced the lowest yields, followed by the late June and
mid-July applications of Warrior plus MSR and Warrior plus Lannate (treatment
2). Compost tea by itself was not better than the untreated check. Aza-Direct plus
the 6.0-oz rate of Success was not better than the untreated check, whether
applied as a weekly spray mix or alternated weekly.
The iris yellow spot virus infected the plot area late in the season. The treatments
were evaluated for resistance to disease expression and the data are shown in
Table 3. Generally, the treatments with the highest yields had less incidence of
the disease although the correlation was not very strong.
Conclusions
Azadirect(20 oz) plus Success applied at the 10.0-oz rate (treatment 14) and
acephate at the 8.0-oz rate (treatment 12) were the best treatments. Neither
Success or acephate is currently registered for use on onions although a section
18 emergency registration for Success was granted in 2004 and is anticipated
again in 2005.
There were significant differences between treatments in all onion size classes
except mediums.
72
Table 1. Insecticides evaluated for thrips control, Maiheur Experiment Station,
Oregon State University, Ontario, OR, 2004.
Treatment
Insecticide applied
Formulated product
Aza-Direct
Rate/acre
20.Ooz
Warrior+
3.8oz
Warrior +
Lannate
Untreated check
Aza-Direct
Success
Compost Tea
Warrior
Warrior +
Lannate
Aza-Direct +
Success
Acephate
Success
Success
Warrior
Warrior ÷
3.8 oz
3.0 pt
Treatment date
no.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Warrior +
Lannate
Acephate
20.0 oz
6.Ooz
4.0 gal
3.8 oz
3.8 oz
3.0 pt
20.0 oz
6.Ooz
16.Ooz
6.Ooz
6.Ooz
3.8oz
6/7
X
6/28
X
7/16
X
7/29
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
3.8 oz
PenncapM+
3.8 oz
3.0 pt
8.Ooz
2.0 pt
Warrior +
MSR
Aza-Direct +
Success
3.8 oz
2.Opt
20.0 oz
10.Ooz
73
X
X
X
X
X
X
Table 2. Effects of different thrips treatments on onion yield and grade, Malheur
Experiment Station, Oregon State University, Ontario, OR, 2004.
Treatment
Medium Jumbo Colossal
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
LSD
(0.05)
18.2
13.2
11.5
12.4
9.9
13.0
7.4
7.7
13.3
13.2
11.0
6.2
14.1
13.3
ns
464.2
394.0
475.3
399.8
501.5
432.0
351.0
296.5
435.8
388.8
398.0
260.0
486.3
431.4
133.6
220.2
278.9
241.9
322.1
263.3
318.9
351.1
379.3
346.2
398.9
411.4
489.2
382.3
392.5
110.8
74
Super- Colossal Jumbo + Ccl.
colossal + 5-Col.
+ S-Col.
cwt/acre
10.7
230.9
695.1
39.4
318.3
712.3
44.2
286.1
761.4
43.7
365.8
765.6
36.4
299.7
801.2
50.7
369.6
801.6
107.3
458.5
809.5
160.0
539.2
835.7
87.2
433.3
869.1
89.6
488.4
877.2
85.9
497.2
895.2
165.2
654.4
914.4
42.4
424.7
911.1
105.6
498.1
929.6
65.7
142.0
133.6
Total
Yield
713.3
725.5
773.0
778.0
811.1
814.6
816.9
843.4
882.4
890.3
906.3
920.6
925.2
942.9
132.1
Table 3. Evaluation of iris yellow spot virus disease severity with different
insecticide treatments for the thrips vector, Malheur Experiment Station, Oregon
State University, Ontario, OR, 2004.
Treatment
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
LSD (0.05)
Iris ye how spot virus severity
0 = dead; 5 = no injury
2.8
2.0
2.3
2.3
2.3
2.3
4.0
4.0
2.8
3.8
3.2
4.0
3.0
3.8
0.6
75
a
30
a-b
25-
d-e
c-e
e
15
a)
>
10-
0-
--
--
—
d-e
b-e c-e1
d-e
d-e
---—
1234567891011121314
Treatment no.
Figure 1. Treatment effects on thrips populations during June, Malheur
Experiment Station, Oregon State University, Ontario, OR, 2004.
76
A TWO-YEAR STUDY ON VARIETAL RESPONSE TO AN ALTERNATIVE
APPROACH FOR CONTROLLING ONION THRIPS (THRIPS TABACI) IN
SPANISH ONIONS
Lynn Jensen
Malheur County Extension Service
Clinton Shock and Lamont Saunders
Malheur Experiment Station
Oregon State University
Ontario, OR, 2003-2004
Introduction
Onion (A/hum cepa L.) is a major economic crop in the Treasure Valley of eastern
Oregon and western Idaho. Annually about 20,000 acres of onion are grown in the
valley. Typically Spanish hybrids are grown for their large size, high yield, and mild
flavor.
The principal onion pest in this region is onion thrips (Thrips tabaci, Lindeman). Thrips
cause yield reduction by feeding on the epidermal cells of the plant. Onion thrips can
reduce total yields from 4 to 27 percent, depending on the onion variety, but can reduce
yields of colossal-sized bulbs from 27 to 73 percent. The larger sized colossal bulbs are
difficult to grow and demand a premium in the marketplace. Growers typically spray
three to six times per season to control onion thrips. Treatments include the use of
synthetic pyrethroid, organophosphate, and carbamate insecticides. The ability of these
products to control thrips has decreased from over 90 percent control in 1995 to less
than 70 percent control in 2000. Onion growers are applying insecticides more
frequently in order to keep thrips populations low.
New biological insecticides with low toxicity to beneficial predators have been
developed, including neem tree (Azadirachta md/ca A. Juss.) extracts (azadirachtin) and
bacterial fermentation products (spinosad). Both of these materials have previously
been evaluated for thrips control and have performed poorly compared to conventional
insecticides. Studies during the past 2 years have shown that applications of spinosad
and azadirachtin coupled with straw mulch are superior to conventional insecticide
programs for controlling onion thrips in 'Vaquero' onions. Vaquero was used in the study
because of its vigorous growth characteristics and resistance to thrips injury compared
to slower growing varieties. The objective of this study was to test this program on
varieties that are highly susceptible to thrips injury.
Materials and Methods
A 1.5-acre field was planted to the onion varieties Vaquero, 'Flamenco', and 'Redwing'
(cv. Vaquero, Flamenco, Nunhems, Parma, ID; Redwing, Bejo Seeds, Oceano, CA) in a
77
split plot design on March 14, 2003 and March 23, 2004. Vaquero is a yellow variety
while Redwing and Flamenco are red varieties. Red varieties are generally assumed to
be more attractive to thrips than yellow varieties. The onion varieties were planted as 2
double rows on a 44-inch bed. The double rows were spaced 2 inches apart. The
seeding rate was 137,000 seeds/acre. Lorsban 15G® was applied in a 6-inch band over
each row at planting at a rate of 3.7 oz/1 000 ft of row for onion maggot control. Water
was applied by furrow irrigation. The field was divided into plots 37 ft wide by 100 ft
long. There were three treatments with six replications.
The three treatments were a grower standard treatment, an untreated check, and the
alternative treatment as described previously (Jensen et al. 2003a, 2003b). The grower
standard treatment included Warrior® (lambda-cyhalothrin), MSR® (oxydemeton-methyl),
and Lannate® (methomyl). The untreated check did not receive any treatments for thrips
control. The alternative treatment included straw mulch applied to the center of the bed
plus Success® (spinosad), and
(azadirachtin).
Insecticide treatments were applied 7-10 days apart during the growing season (Table
1). All insecticides were sprayed in water at 31 gal/acre in 2003 and 39 gal/acre in 2004.
Straw was applied only between the irrigation furrows on top of the beds to avoid
confounding irrigation effects with thrips effects. The straw was applied on May 1, 2003
at a rate of 1,080 lb/acre. Straw was not applied in 2004 because results in 2003
suggested it was not enhancing thrips control.
Thrips populations were sampled by two methods. The first was by visually counting the
number of thrips on 20 plants. The second method was by cutting 10 plants at ground
level and inserting the plants into a berlese funnel. Turpentine used in the berlese
funnel dislodged the thrips from the plant into a jar containing 90 percent isopropyl
alcohol. The collected thrips were then counted through a binocular microscope. Thrips
populations were monitored weekly through the growing season.
The predator populations were monitored using pitfall traps that contained ethylene
glycol. They were evaluated three times per week. The berlese funnel was also used to
monitor predators foraging on the plants. The onions were harvested in September and
graded in October of each year.
Treatment differences were compared using ANOVA and least significant differences at
the 5 percent probability level, LSD (0.05). Means were also compared using Duncan's
multiple range test.
Results and Discussion
Weekly thrips populations are compared in Figure 1. The alternative program had a
significantly lower average thrips population than the untreated check in both years (Fig.
2). Visual damage to the foliage was observed with the variety Vaquero in 2004 but not
in 2003. Flamenco showed severe foliage damage from thrips feeding. The visual thrips
78
damage to Redwing appeared intermediate between Vaquero and Flamenco. Flamenco
is less vigorous than Redwing and more thrips damage would be expected.
There were no yield differences between any of the treatments with Vaquero in 2003
but the alternative treatment produced significantly more colossal- and super-colossalsized bulbs in 2004 (Table 2).
Redwing significantly increased yield of colossal-sized bulbs with the alternative
treatment both years compared to both the standard and untreated check and
significantly increased in total yield in 2003 compared to the untreated check (Table 3).
Flamenco responded to the alternative treatments with significantly less medium-size
yield and higher jumbo and colossal yield compared to the untreated check in 2003
(Table 4). There was a trend towards higher total yield and larger bulb size compared to
the standard treatment but this was only significant in the colossal size class in 2003.
The alternative plus standard treatments produced higher total yields than the untreated
control in 2004.
Predator populations (Fig. 3) were significantly higher in the alternative and untreated
check treatments than in the standard treatment. The predator population consisted
mostly of spiders, big-eyed bugs, minute pirate bugs, damsel bugs, lacewings and lady
bird beetles.
The 2004 season experienced an epidemic of iris yellow spot virus (IYSV) in the trial
area and surrounding fields. The IYSV is a new disease currently spreading to most
production areas of the United States and the world. Onion thrips are the vector, so this
trial gave the opportunity to evaluate the alternative program for IYSV control (Table 5).
The treatments grown under the alternative treatment were healthier and showed
significantly less virus damage than the standard insecticide treatment or the untreated
check.
Red onions often exhibit thrips scarring when placed in storage due to continued
feeding by the insects. The alternative treatment produced significantly fewer damaged
bulbs compared to the untreated check with the Redwing variety, and a similar though
not significant trend with Flamenco (Table 6). Averaged over treatment, Redwing had
less thrips injury than Flamenco.
Conclusion
The alternative treatments were equal to or in some cases significantly better than the
standard insecticide program. There was a general trend towards higher yields in the
larger bulb classes, which gives a higher return to the grower. The alternative program
produced less thrips damage to red onions in storage and reduced the incidence of iris
yellow spot virus.
79
References
Jensen, L., B. Simko, C. Shock, and L. Saunders 2002. Alternative methods for
controfling onion thrips (Thrips tabaci) in Spanish onions. Pages 65-72 in Proceedings
of the 2002 AIlium Research National Conference.
Jensen, L., B. Simko, C. Shock and L. Saunders. 2003. Alternative methods for
controlling thrips. Pages 895-900 in British Crop Protection Council: Crop Science and
Technology 2003 Congress Proceedings. Vol. 2.
Jensen, L., B. Simko, C. Shock, and L. Saunders 2003a. Alternative methods for
controlling onion thrips (Thrips tabaci) in Spanish onions. Proceedings of the 2003
Idaho-Maiheur County Onion Growers Annual Meeting Feb. 2003. 7 pages.
Jensen, L., C. Shock, B. Simko, and L. Saunders 2003b. Straw mulch and insecticide to
control onion thrips (Thrips tabaci) in dry bulb onions. Pages 19-30 in Proceedings of
the Pacific Northwest Vegetable Association 17th Annual Meeting.
80
Table 1. Application dates for thrips control on two red and one yellow onion variety,
Malheur Experiment Station, Oregon State University, Ontario, OR, 2003-2004.
Standard insecticide treatment
Application date Insecticides applied Rate/acre
2003
Warrior
June 7
3.84 oz.
June14
June 25
Warrior
Lannate
Warrior
MSR
Warrior
Lannate
June 16
June 23
July 1
July 8
July 19
July 29
Warrior
MSR
Warrior
MSR
Warrior
Lannate
Warrior
Lannate
Warrior
MSR
Warrior
Lannate
Warrior
Mustang
Lannate
Aza-Direct
Success
20.0 oz.
10.Ooz.
Aza-Direct
Success
20.Ooz.
10.Ooz
Aza-Direct
Success
20.0 oz
10.Ooz.
Aza-Direct
Success
Aza-Direct
Success
Aza-Direct
Success
Aza-Direct
Success
Aza-Direct
Success
Aza-Direct
Success
Aza-Direct
Success
20.0 oz.
10.0 oz.
20.0 oz.
10.Ooz.
20.0 oz.
10.0 oz.
20.0 oz.
3.84 oz.
3.0 pt.
July 29
June 6
20.0 oz.
10.Ooz.
20.Ooz.
10.Ooz.
3.84 oz.
2.0 pt.
July11
July 25
Aza-Direct
Success
Aza-Direct
Success
3.84 oz.
3.Ooz.
July 3
July 7
Alternative insecticide treatment
Rate/acre
Insecticides applied
2004
3.84 oz.
2.0 pt.
3.84 oz.
2.0 pt.
3.84 oz.
3.0 pt.
3.84 oz.
3.0 pt.
3.84 oz.
2.0 pt.
3.84 oz.
3.0 pt.
3.84 oz.
4.0 oz.
3.0 pt.
81
1O.Ooz.
20.0 oz.
10.Ooz.
20.0 oz.
10.Ooz.
20.0 oz.
10.Ooz.
Table 2. Yield and grade of Vaquero onion with different strategies for controlling onion
thrips, Maiheur Experiment Station, Oregon State University, Ontario, OR.
2003
Treatment
Medium
Jumbo
Untreated
check
Standard
Alternative
LSD (0.05)
9.7
9.8
10.9
ns
459.7
451.0
Supercolossal
Total
yield
489.6
484.2
124.0
140.9
145.2
1057.5
1091.3
1086.4
ns
ns
ns
Supercolossal
Total
yield
29.8
52.3
126.9
71.9
888.0
882.4
928.4
Colossal
cwt/acre
464.1
446.1
ns
2004
Treatment
Medium
Jumbo
Untreated
check
Standard
Alternative
LSD (0.05)
17.6
11.9
14.8
ns
586.1
Colossal
cwt/acre
254.5
306.9
377.4
76.9
511.3
409.3
ns
82
ns
Table 3. Yield and grade of Redwing onion with different strategies for controlling onion
thrips, Maiheur Experiment Station, Oregon State University, Ontario, OR.
2003
Treatment
Medium
Jumbo
Untreated
check
Standard
Alternative
LSD (0.05)
12.0
14.2
11.6
ns
726.4
724.2
701.2
Colossal
cwt/acre
107.4
174.3
240.2
62.2
ns
Supercolossal
Total
yield
4.0
2.2
6.9
849.8
914.9
959.9
56.3
ns
2004
Treatment
Untreated
check
Standard
Alternative
LSD (0.05)
SuperColossal
colossal
cwt/acre
Total
yield
Medium
Jumbo
57.6
50.8
395.1
9.1
0
509.0
445.6
15.4
36.9
16.5
0
0
461.8
575.2
534.6
ns
ns
52.1
ns
ns
83
Table 4. Yield and grade of Flamenco onions with different strategies for controlling
onion thrips, Malheur Experiment Station, Oregon State University, Ontario, OR.
2003
Treatments
Medium
Jumbo
Colossal
Total
yield
cwt/acre
Untreated
check
Standard
Alternative
LSD (0.05)
121.5
380.5
442.3
486.1
55.5
107.1
94.0
16.9
7.8
512.4
565.5
606.9
51.8
Colossal
Total
yield
1.0
9.2
19.1
2004
Treatments
Medium
Jumbo
cwtlacre
Untreated
check
Standard
Alternative
LSD (0.05)
128.1
175.1
0.3
101.0
82.2
ns
275.3
305.9
1.0
10.7
ns
ns
512.4
565.5
606.9
51.8
Table 5. Average iris yellow spot virus injury for insecticide treatments, Maiheur
Experiment Station, Oregon State University, Ontario, OR, 2004.
Treatment
IYSV*
Untreated
1.5
Standard
1.7
Alternative
2.2
LSD (0.05)
0.4
*Scale: 0 = dead, 5 = healthy, no lesions.
84
Table 6. Thrips injury on two stored red onion varieties, Maiheur Experiment Station,
Oregon State University, Ontario, OR, 2003.
Thrips injury
Flamenco
Redwing
10
=
severe
injury)
=
no
injury,
(0
Treatment
Alternative
Standard
Untreated check
LSD (0.05)
1
1 .3
1.3
1.5
1.6
2.1
ns
0.3
Varietal differences
Redwing
Flamenco
LSD (0.05)
1.27
1.68
0.39
85
2003
25
20
U)
a.
I..
-C
15
th
>
10
5
0
13-Jun
24-Jun
30-Jun
9-Jul
23-Jul
31-Jul
7-Aug
14-Aug
—.-— Untreated check —u—Standard —a—Alternative
2004
25
a.
U) 15
a-
I-
-C
110
0
8-Jun
I
I
15-Jun
22-Jun
29-Jun
6-Jul
13-Jul
20-Jul
27-Jul
3-Aug
10-Aug
—.-— Standard —i-— Untreated
Figure 1. Thrips populations with different treatments in an alternative thrips control
program, Maiheur Experiment Station, Oregon State University, Ontario, OR.
86
2003
I
4-.
C-
I-
.z
4
C)
>
2
0
Untreated check
Standard
Alternative
2004
7
6
5
5.
Cl)
C.
.c
4
3
2
C)
1
0
Untreated
Standard
Alternative
Figure 2. Average season-long thrips populations in an alternative thrips control
program, Malheur Experiment Station, Oregon State University, Ontario, OR.
87
01
0
2
25
20
0
Untreated check
Standard
Alternative
Figure 3. Predator populations in the alternative thrips trial, Maiheur Experiment Station,
Oregon State University, Ontario, OR, 2003.
88
A ONE-YEAR STUDY ON THE EFFECTIVENESS OF OXAMYL
(VYDATE L®) TO CONTROL THRIPS IN ONIONS WHEN INJECTED INTO A
DRIP-IRRIGATION SYSTEM
Lynn Jensen
Maiheur County Extension Office
Eric Feibert, Clint Shock, and Lamont Saunders
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Onion thrips and western flower thrips are the main insect pests on onions grown in the
Treasure Valley of Idaho and eastern Oregon. In this region about 3,000 acres of onions
are grown under drip irrigation. Because of the increased yield and quality of onions
grown under drip irrigation, this management practice is increasing on lands that were
formerly marginal for onion production. It is a common practice to inject the systemic
insecticide oxamyl (Vydate L®) into the drip lines on a weekly or biweekly basis to
control thrips. Most growers also apply two to six foliar insecticide applications in
addition to the oxamyl applications. Growers using conventional furrow irrigation
commonly use four to six foliar insecticide applications for thrips control. The drip
irrigation growers feel there is an economic advantage to the additional oxamyl
applications even though the additional cost is about $150/acre. This trial was designed
to determine the effectiveness of oxamyl at two different application rates and in
combination with two foliar insecticide programs.
Materials and Methods
The trial was conducted at the Malheur Experiment Station on an Owyhee silt loam soil
previously planted to wheat. Onion (cv: 'Vaquero'; Nunhems, Parma, ID) was planted on
March 23 in 2 double rows on a 44-inch bed. The double rows were spaced 2 inches
apart. The seeding rate was 150,000 seeds/acre. Lorsban 1 5G® was applied in a 6-inch
band over each double row at a rate of 3.7oz/1 ,000 ft of row for maggot control. The
drip tape was placed in the center of the bed between the double rows. The drip tape
(T-tape, T-Systems International, Inc., San Diego, CA) had a flow rate of 0.22
gal/mm/i 00 ft of tape. Irrigation water was applied when the soil water potential reached
—20 kPA. Water potential was determined by granular matrix sensors (GMS, Watermark
Soil Moisture Sensors Model 200ss, Irrometer Co. Inc., Riverside, CA) installed at 8inch depth in the center of the double row.
The experimental design was a randomized complete block design with four
replications. The plot size was 8 double rows wide (37.5 ft) by 34 ft in length.
89
Oxamyl was injected into the main irrigation line by a positive displacement injector
(Dosmatic Model A30, Dosmatic USA, Inc., Carollton, TX). Prior to injecting oxamyl, 95
percent sulfuric acid was diluted at a ratio of 1:6,248 acid to water to buffer the water in
the soil solution to a pH of 5.0. The oxamyl was added to water buffered at the same
ratio and injected immediately after the initial buffer treatment. The buffered water and
buffered oxamyl treatments required 20 minutes each to inject into the treated plots.
This process applied slightly more water to the treated plots compared to the untreated,
but the additional water was minor compared to the overall applied water and probably
did not have an overall impact on the final yield.
Each plot had four drip tapes supplying water to the eight double rows. Each plot was
equipped with an on/off valve so that oxamyl could be applied to individual plots as
needed. There were 6 treatments including an untreated check, a standard insecticide
program, oxamyl at 1.0 qt/acre applied weekly, oxamyl at 2.0 qt/acre applied every
other week, oxamyl at 1.0 qt/acre plus a standard insecticide program and oxamyl at 1.0
qt/acre plus the bio-insecticides azadirachtin
and spinosad (Success®)
(alternative program). Azadirachtin and spinosad have shown promise under
conventional systems by suppressing thrips and allowing predatory insect populations
to build to the point where they control thrips. Systemically applied through the drip
system, oxamyl has the potential to enhance this program. The application dates of the
treatments are shown in Tables 1 and 2.
Thrips counts were made weekly by counting the total number of thrips on 15 plants in
each plot. Onions were harvested on September 9 and 10 and graded on October 5. A
visual evaluation for iris yellow spot virus was taken on August 19.
Treatment differences were compared using ANOVA and least significant differences at
the 5 percent probability level, LSD (0.05).
Results and Discussion
Figure 1 shows the weekly thrips populations found in the different treatments
throughout the growing season. There was a tendency for the oxamyl plus alternative
treatments to have lower thrips pressure than the other treatments. The season average
thrips populations are shown in Table 3. The oxamyl at 1.0 qt every week plus the
alternative bio-insecticides had significantly lower total thrips populations than the other
treatments. There were no significant differences in thrips populations between the
other treatments, including the untreated check.
Table 4 shows the breakdown in yield and quality between the different treatments.
There was a significant increase in colossal-sized bulbs with the three foliar-applied
insecticide treatments versus the untreated check or the oxamyl alone treatments.
Iris yellow spot virus (IYSV), which is thrips transmitted, appeared in the trial during
August. A visual evaluation of the onions for IYSV showed significantly less infection in
90
the oxamyl plus azadirachtin plus spinosad treatment compared to the oxamyl alone
treatments or the untreated check (Table 5).
Conclusion
The oxamyl plus alternative insecticides (azadirachtin plus spinosad) treatment
significantly controlled thrips better than any other treatment and had the highest yield
of colossal, super-colossal, and total yield. All of the treatments with foliar insecticides
gave significantly higher colossal yields compared to the oxamyl only and the untreated
check. Oxamyl treatments applied as 1.0 qt/acre weekly or 2.0 qt/acre every other week
were no better than the untreated check. The lack of thrips control by oxamyl may be
due to the late initial application on June 3. This application was about 2 weeks later
than growers would typically start. There was also the possibility that the oxamyl was
not applied with enough irrigation water to allow movement to the onion roots during the
early onion growth period when the root zone was small.
Table 1. Application dates for the different treatments in the drip-irrigation/oxamyl trial,
Maiheur Experiment Station, Oreqon State University, Ontario, OR, 2004.
Oxamyl 2.0 qt every
Standard
Alternative
Date
Oxamyl 1.0 qt/wk
other week
insecticide
insecticide
6/03
X
X
6/04
X
X
6/11
6/16
6/23
6/25
7/02
7/08
7/19
7/20
7/29
8/06
X
X
X
X
X
X
X
X
X
X
91
X
X
X
X
X
X
X
X
X
X
X
Table 2. Application dates for foliar insecticide applications for thrips control on dripirrigated onions, Malheur Experiment Station, Oregon State University, Ontario, OR, 2004.
Product
Rate/acre
Product
Rate/acre
June 6
Warrior
3.84 oz.
Aza-Direct
20.0 oz.
MSR
2.0 pt.
Success
10.0 oz.
June 16
Warrior
3.84 oz.
Aza-Direct
20.0 oz.
MSR
2.0 pt.
Success
10.0 oz.
June 23
Warrior
3.84 oz.
Aza-Direct
20.0 oz.
Lannate
3.0 pt.
Success
10.0 oz.
July 1
Warrior
3.84 oz.
Aza-Direct
20.0 oz.
Lannate
3.0 pt.
Success
10.Ooz.
July 8
Warrior
3.84 oz.
Aza-Direct
20.0 oz.
MSR
2.0 pt.
Success
10.0 oz.
July 19
Warrior
3.84 oz.
Aza-Direct
20.0 oz.
Lannate
3.0 pt.
Success
10.Ooz.
July 29
Warrior
3.84 oz.
Aza-Direct
20.0 oz.
Mustang
4.0 oz.
Success
10.0 oz.
Lannate
3.0 pt.
Table 3. Average thrips counts for the 2004 season, Malheur Experiment Station, Oregon
State University, Ontario, OR, 2004
Treatment
Average thrips/plant
Untreated
47.9
oxamyl 2.0 qt - every other week
51.8
oxamyl 1.0 qt - every week
50.7
oxamyl 1.0 qt + alternative
36.2
oxamyl 1.0 qt + standard
49.6
Standard treatment
50.1
LSD (0.05)
9.6
Table 4. Total yield of oxamyl-treated onions grown under drip irrigation, Malheur
Experiment Station, Oregon State University, Ontario, OR, 2004.
Onion Yield
Medium
Jumbo
Colossal
Treatment
Supercolossal
Total yield
cwtf acre
Untreated
oxamyl 2.0 qt (every other week)
oxamyl 1.0 qt (every Week)
oxamyl 1.0 + Alternative
oxamyl 1.0 + Standard
Standard only
LSD (0.05)
26.4
30.4
22.8
19.6
17.4
21.3
ns
676.3
642.3
630.5
633.7
655.6
198.3
210.8
193.5
326.4
307.4
310.9
11.9
22.8
13.3
46.1
34.7
912.9
906.3
937.7
1022.6
993.2
28.0
1015.8
ns
91.3
ns
ns
708.1
92
Table 5. Iris yellow spot virus (IYSV) e valuation in oxamyl-treated onions grown under drip
irrigation, Maiheur Experiment Station, Oregon State University, Ontario, OR, 2004.
IYSV rating 1 = no virus, 5 = severe virus
Treatment
Untreated
oxamyl 2.0 qt (every other week)
oxamyl 1.0 qt (every Week)
oxamyl 1.0 + Alternative
oxamyl 1.0 + Standard
Standard only
LSD (0.05)
U)
ci
>
3.3
1.8
2.5
2.5
0.9
•
I
16
S.-
3
—-.-— Untreated
18
C
3
Vydate2.0
—-*-— Vydate 1.0
14
12
Vydate + Alt
L
10
-
Vydate+St.
8
•
Standard
6
4
2
0
0
o
0
o
(0
0
0
0
0
o
o
0
0
0
0
0
(N
S.-
co
(N
(0
(N
C)
r
(0
(0
(0
S.-
N-
N-
CD
(N
N-
o
o
o
0
co
co
Figure 1. Weekly thrips populations, 2004 oxamyl/drip trial, Malheur Experiment Station,
Oregon State University, Ontario, OR, 2004.
93
GROWERS USE LESS NITROGEN FERTILIZER ON DRIP-IRRIGATED
ONION THAN FURROW-IRRIGATED ONION
Jim Klauzer and Clinton Shock
Malheur Experiment Station
Oregon State University and Clearwater Supply
Ontario, OR, 2004
Sum mary
Over previous years, research at the Malheur Experiment Station has shown that
nitrogen (N) needs of drip-irrigated onion can be modest (Shock et al. 2004). In 2002,
surveys of two growers' furrow-irrigated and drip-irrigated onion fields showed that N
fertilizer use efficiency was substantially better in drip-irrigated fields than in
furrow-irrigated fields (Shock and Klauzer 2003). In 2004 we repeated this survey with
various growers' fields.
Introduction
Drip irrigation is generally used on fields with imperfect topography, lower soil fertility,
and histories of lower productivity compared to the fields used for furrow irrigation.
From 1992 to 1994 we demonstrated that drip irrigation is an effective irrigation practice
compared to furrow and sprinkler irrigation for onion production on Treasure Valley soils
that were difficult to irrigate (Feibert et al. 1995). While 320 lb N/acre is commonly
used in furrow-irrigated onion production, drip-irrigated onion is not very responsive to N
fertilizer (Shock et al. 2004). The lower response of drip-irrigated onion could be
because less irrigation water is applied using drip. With less irrigation, water is less apt
to leach away residual soil nitrate and N from mineralization, allowing these N sources
to supply the crop much of its N needs. Here we report growers' 2004 nitrogen fertilization practices using drip- and furrow-irrigation systems and the corresponding crop
yields.
Materials and Methods
Growers were asked to keep records of all fertilizer and water supplied to their onion
fields. Yield was recorded for each field. The soil water potential was monitored in
selected fields. The bulb yield was recorded. This report covers the yield, N applied,
and yield per unit of applied N fertilizer for onions grown using drip and furrow irrigation.
Some of the drip-irrigated fields were of poorer soil quality than the corresponding
furrow-irrigated fields.
Although root tissue testing for nitrate is a proven method to assure adequate supplies
of N for onion, to improve yields, and save on N fertilizer costs, none of the growers
surveyed conducted root tissue testing.
94
Results and Discussion
For the growers and fields surveyed in 2004, growers applied on average 279 lb N/acre
when growing onions with furrow irrigation, while only 173 lb N/acre was applied with
drip irrigation (Table 1). These N rates include all N applied during the fall prior to the
crop year, spring preplant fertilizer, sidedressed N, and N applied by fertigation in the
irrigation water.
Drip irrigation out-yielded furrow irrigation by an average of 68 cwt/acre for 4 growers
and furrow irrigation out-yielded drip by 300 cwt/acre for 1 grower (Table 1). The low
yielding drip-irrigated onion was from a very unfavorable field. The 2004 Treasure
Valley growing season was favorable for high onion yields and excellent onion quality.
During previous years, with more heat and water stress potential, larger yield
differences were observed in favor of drip irrigation.
As a consequence of lower N fertilizer rates used for drip-irrigated onions than for
furrow-irrigated onion, more onions were produced for each pound of applied N using
drip (Table 1). The surveyed growers might have economized further on N fertilizer
costs through root tissue testing for nitrate. Thorough nutrient management for onion
has been described by Sullivan et al. (2001) and the methods they discuss are
underutilized.
Growers used less N fertilizer under drip irrigation and yields were on average similar to
furrow irrigation even though the soils in a few cases had less favorable physical and
chemical properties. Under furrow irrigation, much more water is applied at each
irrigation. The potential for deep leaching of nitrate and groundwater contamination is
substantial with furrow irrigation. With drip irrigation it is easier to maintain uniform soil
moisture, even on difficult sites. Since each water application with a drip system can be
carefully managed to just replace water used by the crop, nitrate leaching can be
greatly reduced with drip irrigation, and this results in better N fertilizer use at a
commercial scale.
Drip irrigation may provide an important option for growers who wish to rotate onion
onto soils not usually used for the crop. These fields may not be as highly infested with
pathogens from short rotations of cash crops.
References
Feibert, E.G.B., C.C. Shock, and L.D. Saunders. 1995. A comparison of sprinkler,
subsurface drip, and furrow irrigation of onions. Oregon State University Agricultural
Experiment Station, Special Report 947:59-67.
Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 2004. Plant population and nitrogen
fertilization for subsurface drip-irrigated onion. HortScience 39(7):1722-1 727.
95
Shock, CC., and J. Klauzer. 2003. Growers conserve nitrogen fertilizer on drip-irrigated
onion. Oregon State University Agricultural Experiment Station, Special Report
1048:61-63. http://www.cropinfo.net/AnnualReports/2002/OnionDripNitrogeno2.htm
Sullivan, D.M., B.D. Brown, C.C. Shock, D.A. Horneck, R.G. Stevens, G.Q. Pelter, and
E.B.G. Feibert. 2001. Nutrient management for sweet Spanish onions in the Pacific
Northwest. Oregon State University. Pacific Northwest Extension Publication PNW 546.
26 pages.
Table 1. Comparison of nitrogen (N) fertilizer rates, onion yield, and bulb yield per
pound of applied N in furrow-irrigated and drip-irrigated onion, Treasure Valley of
Oregon and Idaho, 2004.
Grower
2
1
Average
4
3
Furrow irrigation
N rate, lb/acre
Yield, cwt/acre
Ratio, cwt/lb N
250
810
3.24
320
800
2.5
275
855
250
750
3.11
3
Drip irrigation
N rate, lb/acre
Yield, cwt/acre
140
860
175
850
4.86
150
930
5
300
850
2.83
279
813*
2.94
230
172
173
550t
808*
850
Ratio,cwt/lbN 6.14
6.2
3.7
3.2
4.82
*Often drip-irrigated onion is grown on soil that is ess fav orab le than furrow-irrigated
onion.
I
tExtremely unfavorable soil.
96
PERFORMANCE OF HYBRID POPLAR CLONES ON AN ALKALINE SOIL
Clinton Shock and Erik Feibert
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
With timber supplies from Pacific Northwest public lands becoming less available,
sawmills and timber products companies are searching for alternatives. Hybrid poplar
wood has proven to have desirable characteristics for many nonstructural timber
products. Plantings of hybrid poplar for sawlogs have increased in the Treasure Valley.
Many hybrid poplar clones are susceptible to nutrient deficiencies in alkaline soils,
leading to chlorosis, poor growth, and eventual death of trees. Poor growth on alkaline
soil can be partly a result of iron deficiency caused by the low solubility of iron
compounds in alkaline soil. A symptom of iron deficiency is yellow leaves or
"chiorosis". Chlorosis can also be caused by other nutrient problems.
Previous clone trials planted in 1995 in Malheur County demonstrated that clone
OP-367 (hybrid of Populus deltoides x P. nigra) was the only clone performing well on
alkaline soils at that time. Growers in Malheur County have made experimental
plantings of hybrid poplars and found that other clones have higher productivity on soils
with nearly neutral pH. New poplar clones are continually being developed. The
current trial seeks to provide poplar growers with updated information on the relative
vigor and adaptability of a larger number of clones on alkaline soils.
Materials and Methods
2003 Procedures
The trial was conducted on Nyssa silt loam with 1.3 percent organic matter and a pH
ranging from 7.7 at the field top to 8.4 at the field bottom. The field had been planted to
wheat in the fall of 2002. On March 28, 2003, the wheat was sprayed with Roundup®
(Glyphosate) at 1.5 lb ai/acre. Based on a soil analysis, on April 9, 2003, 20 lb
magnesium (Mg), 40 lb potassium (K), 1 lb boron (B), and 1 lb copper (Cu) per acre
were broadcast. The field was again sprayed with Roundup at 1.5 lb ai/acre on April 9.
On April 10, 9-inch poplar sticks of 24 clones (Table 1) were planted in a randomized
complete block design with 5 replicates. Three of the clones were designated Malheur
1, 2, and 3 corresponding to three selections of eastern cottonwood (Populus deltoides)
found growing in Malheur County. Tree rows were spaced 5 ft apart and trees were
spaced 5 ft apart within the rows. Each plot consisted of four trees two rows wide and
two trees long. Goal® herbicide (Oxyfluorfen) at 2 lb ai/acre was applied on April 11.
The field was irrigated with 0.6 inch of water on April 11.
97
Drip tubing (Netafim Irrigation, Inc., Fresno, CA) was laid along the tree rows prior to
planting. The drip tubing had two emitters (Netafim On-line button dripper) spaced 12
inches apart for each tree. Each emitter had a flow rate of 0.5 gal/hour. The field was
irrigated when the soil water potential at 8-inch depth reached -25 kPa. Each irrigation
applied 0.6 inch of water based on an 8-ft2 area for each tree. This irrigation strategy
was able to maintain the soil water potential above -25 kPa until around mid-July.
Starting around mid-July the irrigation rate was increased to 1 inch per irrigation. This
increased irrigation rate did not maintain the soil water potential above -25 kPa due to
inadequate irrigation frequency, so starting in mid-August the field was irrigated 5-7
times per week until the last irrigation on September 30. Soil water potential was
measured with six Watermark soil moisture sensors (model 200SS, Irrometer Inc.,
Riverside, CA) installed at 8-inch depth. The soil moisture sensors are read every 8
hours by a Hansen Unit datalogger (Mike Hansen Co., Wenatchee, WA).
Analysis of leaf samples (first fully expanded leaf from clone OP-367) taken on July 11
showed unexpected needs for boron and sulfur fertilization (Table 1). On July 28, sulfur
at 10 lb/acre as ammonium sulfate and B at 0.2 lb/acre as boric acid were injected
through the drip system.
2004 Procedures
On March 25, 2004, Casoron 4G® at 4 lb ai/acre was broadcast for weed control.
Based on a soil analysis, nitrogen (N) at 80 lb/acre, Cu at 1 lb/acre, and B at 1 lb/acre
were injected through the drip tape on May 10. Analysis of leaf samples (first fully
expanded leaf from clone OP-367) on July 8 showed the need for B (Table 1). On July
19, B at 0.2 lb/acre was injected through the drip system. On August 20, a soil sample
consisting of 20 cores was taken from each replicate and analyzed for pH.
On August 10, leaf chlorophyll content was measured on two leaves per tree using a
Minolta SPAD 502 DL meter (Konica Minolta Photo Imaging U.S.A., Inc., Mahwah, NJ).
On August 20, trees in all plots were evaluated subjectively for visual symptoms of leaf
chlorosis. On September 10 the trees in all plots were evaluated subjectively for stem
defects. The heights and diameter at breast height (DBH, 4.5 ft from ground) of all
trees in each plot were measured in October 2003 and 2004. Stem volumes (cubic
feet, excluding bark and including stump and top) were calculated for each tree using
an equation (stem volume 1 0(2945047+1 .803973*LOG1 O(DBH)+1 .238853*LOG1 O(Hei9ht))) developed for
poplars that uses tree height and DBH (Browne 1962). Clonal differences in height,
DBH, and wood volume were compared using ANOVA and least significant differences
at the 5 percent probability level, LSD (0.05). The LSD (0.05) values at the bottom of
Table 2 should be considered when comparisons are made between clones for
significant differences in performance characteristics. Differences between clones
equal to or greater than the LSD (0.05) value for a characteristic should exist before any
clone is considered different from any other clone in that characteristic. To evaluate the
sensitivity of the clones to soil pH, a regression analysis of leaf chlorophyll content
against soil pH was run for each clone separately. If the regression analysis had a
probability level of 5 percent or less, the clone was considered to be sensitive to soil
pH.
98
Results and Discussion
Starting around mid-July 2003 and 2004, the soil water potential failed to remain above
the target of -25 kPa (Fig. 1). A total of 22 and 44 inches of water plus precipitation
were applied during the season to the whole field in 2003 and 2004, respectively (Fig.
2). Based on our previous work (Shock et al. 2002), greater tree growth and wood
volume would have been expected if the intended soil water potential could have been
maintained, which would have required a greater amount of water to be applied.
However, water infiltration in this field was restricted; we observed runoff out of the
bottom of the field.
Chiorotic leaves were observed on trees in replicates 2, 3, and 4 of the trial. The soil pH
was 7.7, 8.2, 8.4, and 8.4 for replicates 1 to 4, respectively. Relative leaf chlorophyll
content rankings ranged among clones from 25.8 to 49.3 percent (Table 2). The
regression analysis of soil pH and leaf chlorophyll content showed some clones to be
insensitive to soil pH in terms of leaf chlorophyll content (Table 2). The leaf chlorophyll
content of the sensitive clones decreased with increasing soil pH. The leaf chlorophyll
content of the clones insensitive to soil pH (12 clones) averaged 42.4 percent. The leaf
chlorophyll content of the clones sensitive to soil pH (12 clones) averaged 31.8 percent.
There was a linear relationship (R2 = 0.62, P = 0.001) between leaf chlorophyll content
and the visual rating of leaf chlorosis (Fig. 3). The trees insensitive to soil pH averaged
a subjective visual rating of leaf chlorosis of 0.52 (0 = no visual symptoms of chlorosis,
5 = very chlorotic). The trees sensitive to soil pH averaged a visual rating of leaf
chiorosis of 2.15. The three P. deltoides selections from Malheur County had among
the darkest green leaves, and leaf sizes were smaller. For the clones sensitive to soil
pH, tree growth decreased with increasing severity of leaf chlorosis and with decreasing
leaf chlorophyll content (Figs. 4 and 5). For the clones insensitive to soil pH, tree
growth was not related to leaf chlorosis or leaf chlorophyll content.
Subjective rating of stem defects (0 = no defects, 2 = more than half of the trees have
either split or crooked tops) ranged from 0 defects for clone 57-276 to 1.75 for clone
49-177 (Table 1).
Tree height in October 2004 ranged from 13 ft for 50-184 to 22.6 ft for 59-289 (Table 2).
Diameter at breast height ranged from 1.45 inches for 311-93 to 2.41 inches for
184-401. Stem volume ranged from 119.3 inch3 for 50-184 to 437 inch3 for 59-289.
Clones 59-289, Malheur 3, 184-401, and 50-197 were among those with the greatest
stem volume. Stem volume growth in 2004 ranged from 113.3 inch3 for 50-1 84 to 414.2
inch3 for 59-289. Clones 59-289, Malheur 3, 184-401, and 50-197 were among those
with the greatest stem volume growth in 2004.
Considering all measured characteristics, clones 59-289 and Malheur 3 had among the
best performance over the 2 years of the trial. These two clones had high growth, high
leaf chlorophyll content, insensitivity to soil pH, and low incidence of stem defects.
Clone 59-289 was taller than OP-367. Compared to OP-367, clones 59-289 and
Malheur 3 had greater stem volume, but were similar in leaf chlorophyll content,
99
insensitivity to soil pH, and incidence of stem defects. The choice of clones for
commercial production needs to be made on the basis of wood productivity through an
entire growth cycle and ultimately on wood quality, parameters that are currently
unavailable for 59-289 and Malheur 3.
References
Browne, J.E. 1962. Standard cubic-foot volume tables for the commercial tree species
of British Columbia. British Columbia Forest Service, Forest Surveys and Inventory
Division, Victoria, B.C.
Shock, C.C., E.B.G. Feibert, M. Seddigh, and L.D. Saunders. 2002. Water
requirements and growth of irrigated hybrid poplar in a semi-arid environment in eastern
Oregon. Western J. of Applied Forestry 17:46-53.
Table 1. Analysis of hybrid poplar leaf samples (first fully expanded leaf from clone
OP-367), Malheur Experiment Station, Orecion State University, Ontario, OR.
Sufficiency range*
Nutrient
July11, 2003 analysis July 8, 2004 analysis
N (%)
3 - 3.5
4.02
3.73
P (%)
0.3 - 0.4
0.45
0.41
K(%)
1.7-2.1
5.88
2.52
S (%)
0.3 - 0.4
0.22, deficient
0.64
Ca (%)
0.8- 1.2
0.9
1.55
Mg (%)
0.15 - 0.25
0.29
0.57
Zn (ppm)
15-25
36
29
Mn (ppm)
70-110
81
115
Cu(ppm)
3-5
12
16
Fe (ppm)
65 - 95
256
205
B (ppm)
35 - 45
17, deficient
25, deficient
analyses by Western Labs, Parma, ID.
100
0
-20
-40
0
-60
C',
-80
-100
104
275
218
161
Day of 2003
0
-20
a)
-40
0
-60
0
-80
crj
-100
1
60
118
177
235
294
Day of 2004
Figure 1. Average soil water potential at 8-inch depth during 2003 and 2004 for poplar
clones irrigated with a drip-irrigation system with two emitters per tree, Malheur
Experiment Station, Oregon State University, Ontario, OR.
101
a)
C.)
(U
C-)
20
0
CU
15
U)
CU
L..
10
a)
CU
a)
>
5
CU
E
0
0
100
134
169
203
238
272
240
274
Day of 2003
U)
C-)
CU
0
40
C-)
CU
-o
30
a)
CU
20
U)
CU
a)
>
10
CU
E
0
0
105
139
173
206
Day of 2004
Figure 2. Cumulative water applied to poplar clones in 2003 and 2004. Trees were
irrigated with a drip-irrigation system with two emitters per tree, Maiheur Experiment
Station, Oregon State University, Ontario, OR.
102
0)
5
Y = 6.14 - 0.13X
Co
R2 = 0.62, P = 0.001
a ..
U)
SS
Ci)
0
0
-c
0
(0
ci)
3
2
ci)
>
0
1
ci)
0
0
10
20
30
40
50
60
Relative leaf chlorophyll content, %
Figure 3. Relationship between relative leaf chlorophyll content measured with a
Minolta SPAD meter and subjective rating of leaf chlorosis (0 = no chiorosis symptoms,
5 = severe chiorosis symptoms), Malheur Experiment Station, Oregon State University,
Ontario, OR.
103
Table 2. Performance of hybrid poplar clones planted on April 10, 2003 at the Maiheur Experiment Station, Oregon State University,
Ontario, OR, 2004.
No. Clone
Cross
P. trichocarpaXP. deltoides
2 50-184
P. trichocarpaXP. deltoides
3 50-197
P. trichocarpaXP. deltoides
4 52-225
P. trichocarpaXP. deitoides
5 55-260
P. trichocarpaXP. deltoides
6 56-273
P. trichocarpaXP. deltoides
7 57-276
P. trichocarpaXP. deltoides
8 58-280
P. trichocarpaXP. deltoides
9 59-289
P. trichocarpaXP. deltoides
10 184-401
P. trichocarpa XP. deltoides
11 184-411
P.trichocarpaXP.deltoides
12 195-529 P. trichocarpaXP. deltoides
13 309-74
P. trichocarpaXP. nigra
14 311-93
P. trichocarpaXP. nigra
15 NM-6
P. trichocarpaXP. maximowiczll
16 DTAC-7 P. trichocarpaXP. deltoides
17 OP-367
P. deltoidesXP. nigra
18 PCi
P. deltoidesXP. nigra
19 PC2
P. trichocarpaXP. deltoides
2049-177
P. trichocarpaXP. deltoides
21 Malheur 1 P. deltoides, Malheur County, OR
22 Malheur2 P. deltoides, Malheur County, OR
23 Malheur3 P. deltoides, Malheur County, OR
24 DN-34
P. deltoidesXP. nigra
1
15-29
LSD (0.05)
Novembe r2004 measurem.
Height
DBH
Wood
volume
feet
inch
inch3/tree
18.89
283.6
1.95
13.02
119.3
1.63
20.20
2.19
348.5
18.77
252.1
1.93
16.62
203.6
1.80
19.81
2.11
318.6
16.85
214.3
1.90
17.76
252.4
2.00
22.56
437.0
2.30
20.39
2.41
407.1
19.61
2.05
312.5
17.68
1.96
246.3
19.89
2.02
302.6
16.40
141.9
1.45
18.60
214.0
1.78
15.18
1.66
171.0
284.9
18.10
2.10
20.17
2.09
310.3
18.68
1.82
221.0
18.75
237.8
1.82
19.79
1.53
186.4
18.18
177.8
1.59
19.92
407.9
2.37
20.25
1.87
259.3
2.17
102.9
0.32
Leaf
Regression analysis Trunk
2004 growth increment
Leaf
of soil pH vs. leaf defects
Height DBH
Wood chlorophyll chlorosis
content symptoms chlorophyll content
volume
0 - 5*
Probability 0 - 2t
feet
inch inch3/tree
R2
0 - 100
1.23
NS
7.98
252.9
35.70
1.50
0.20
1.00
1.19
0.001
5.66
113.3
31.10
2.50
0.67
1.00
1.45
0.05
10.07
333.2
3.00
0.38
0.25
30.30
1.35
3.00
0.81
0.001
9.90
240.5
26.60
0.50
7.24
1.25
2.75
0.001
191.7
25.80
0.58
0.75
1.48
NS
10.10
303.1
1.00
0.13
1.00
40.80
1.22
0.05
6.66
195.4
1.75
0.30
0.00
36.30
1.40
NS
9.01
240.2
44.40
0.75
0.01
0.75
NS
10.07
1.35
414.2
0.50
0.12
0.75
42.00
7.24
1.26
NS
1.00
385.5
34.00
0.50
0.26
0.01
10.02 1.38
1.50
0.43
0.50
300.4
32.40
1.29
7.25
227.3
1.50
0.31
0.05
0.75
32.20
0.001
8.78
1.28
2.75
0.74
282.4
26.30
0.75
7.66
1.00
3.25
0.001
133.9
30.20
0.73
1.25
1.14
NS
8.24
196.5
43.50
1.50
0.21
1.25
1.20
0.01
7.25
2.00
0.43
0.75
162.5
34.00
1.46
269.1
NS
8.14
0.00
0.26
0.25
40.60
NS
10.99 1.56
45.80
0.00
0.05
0.25
300.0
9.47
1.23
0.25
0.01
208.7
45.30
0.48
0.50
1.24
0.05
9.46
228.7
33.50
1.50
0.33
1.75
NS
10.16 1.01
0.00
176.7
49.30
0.02
0.50
NS
8.14
0.94
167.7
0.00
0.50
46.70
0.09
1.59
396.1
NS
9.64
42.20
0.00
0.19
0.25
NS
12.24 1.36
43.80
0.50
0.25
250.2
0.10
1.98
0.24
98.2
1.61
8.80
0.87
*Subjective evaluation of leaf chiorosis on a scale of 0-5: 0 = no symptoms, 5 = very chiorotic.
tSubjective evaluation of trunk defects on a scale of 0-2: 0 = all trees have straight stems and single tops, I = less than half of trees
have either split or crooked stems, 2 = more than half of the trees have either split or crooked stems.
500
C.)
G)
300
100
Y=286.52-25.91X
i
R2 = 0.22, P = 0.001
0
0
4
3
2
1
5
Subjective leaf chlorosis rating
Figure 4. Relationship between leaf chlorosis symptoms (0 = no symptoms, 5 = severe
chlorosis symptoms) and stem volume in September 2004 for hybrid poplar clones
sensitive to soil pH, Malheur Experiment Station, Oregon State University, Ontario, OR.
500
0)
Y
400
R2
118.8 + 3.53X
0.15, P = 0.01
.
100
S
.
•
C/)
0
0
10
20
30
40
50
60
Leaf chlorophyll content, %
Figure 5. Relationship between relative leaf chlorophyll content and stem volume in
September 2004 for hybrid poplar clones sensitive to soil pH, Malheur Experiment
Station, Oregon State University, Ontario, OR.
105
MICRO-IRRIGATION ALTERNATIVES FOR HYBRID POPLAR
PRODUCTION 2004 TRIAL
Clinton C. Shock, Erik B. G. Feibert, and Lamont D. Saunders
Maiheur Experiment Station
Oregon State University
Ontario, OR
Summary
Hybrid poplar (cultivar OP-367) was planted for sawlog production in April 1997 at the
Malheur Experiment Station. Five irrigation treatments were established in 2000 and
were continued through 2004. Irrigation treatments consisted of three water application
rates using microsprinklers and two water application rates using drip tape. Irrigation
scheduling was by soil water potential at 8-inch depth with a threshold for initiating
irrigations of -50 kPa in 2000 through 2002 and -25 kPa in 2003 and 2004. Increasing
the water application rate increased the annual growth in stem volume for the
microsprinkler-irrigated treatments. There was no significant difference between the
microsprinkler treatment irrigated at the highest rate and the drip-irrigated treatments in
terms of height, DBH, or stem volume growth in 2000 and 2001. In 2002 and 2003, drip
irrigation with two tapes per tree row resulted in higher tree growth than microsprinkler
irrigation. In 2004, the microsprinkler and the drip-irrigated treatments irrigated at the
highest rate had among the highest stem volume growth.
Introduction
With timber supplies from Pacific Northwest public lands becoming less available,
sawmills and timber products companies are searching for alternatives. Hybrid poplar
wood has proven to have desirable characteristics for many nonstructural timber
products. Growers in Malheur County, Oregon have made experimental plantings of
hybrid poplars for saw logs and peeler logs. Clone trials in Malheur County during 1996
demonstrated that the clone OP-367 (hybrid of Populus deltoides x P. nigra) grew well
on alkaline soils. Over the last 8 years OP-367 has continued to grow well on alkaline
soils. Some other clones have higher productivity on soils with nearly neutral pH.
Hybrid poplars are known to have high growth rates (Larcher 1969) and transpiration
rates (Zelawski 1973), suggesting that irrigation management is a critical cultural
practice. Research at the Malheur Experiment Station during 1997-1999 determined
optimum microsprinkler irrigation criteria and water application rates for the first 3 years
(Shock et al. 2002). These results showed that tree growth was maximized by irrigating
at -25 kPa, but 38 irrigations were required for 3-year-old trees, and more were
anticipated for larger trees. Based on simplicity of operations, we decided to use an
irrigation criterion of -50 kPa for the wettest treatments starting in 1998. In 2000 we
noticed that the rate of increase in annual tree growth started to decline in the wettest
106
treatment. One of the causes probably was the use of an irrigation criterion of -50 kPa.
Starting in 2003 the irrigation criterion was changed to -25 kPa for the wettest
treatment. The objectives of this study were to evaluate poplar water requirements and
to compare microsprinkler irrigation to drip irrigation.
Materials and Methods
Establishment. The trial was conducted on a Nyssa-Maiheur silt loam (bench soil)
with 6 percent slope at the Malheur Experiment Station. The soil had a pH of 8.1 and
0.8 percent organic matter. The field had been planted to wheat for the 2 years prior to
poplar and to alfalfa before wheat. In the spring of 1997 the field was marked using a
tractor, and a solid-set sprinkler system was installed prior to planting. Hybrid poplar
sticks, cultivar OP-367, were planted on April 25, 1997 on a 14-ft by 14-ft spacing. The
sprinkler system applied 1.4 inches on the first irrigation immediately after planting.
Thereafter the field was irrigated twice weekly at 0.6 inches per irrigation until May 26.
A total of 6.3 inches of water was applied in 9 irrigations from April 25 to May 26, 1997.
In late May 1997, a microsprinkler system (R-5, Nelson Irrigation, Walla Walla, WA)
was installed with the risers placed between trees along the tree row at 14-ft spacing.
The sprinklers delivered water at 0.14 inches/hour at 25 psi with a radius of 14 ft. The
poplar field was used for irrigation management research (Shock et al. 2002) and
groundcover research (Feibert et al. 2000) from 1997 through 1999.
Procedures common to all treatments. In March 2000 the field was divided into 20
plots, each of which was 6 tree rows wide and 7 trees long. The plots were allocated to
five treatments arranged in a randomized complete block design and replicated four
times (Table 1). The microsprinkler-irrigation treatments used the existing irrigation
system. For the drip-irrigation treatments, either one or two drip tapes (Nelson
Pathfinder, Nelson Irrigation Corp., Walla Walla, WA) were laid along the tree row in
early May 2000. The plots with 2 drip tapes per tree row had the drip tapes spread 2 ft
apart, centered on the tree row. The drip tape had emitters spaced 12 inches apart and
a flow rate of 0.22 gal/min/100 ft at 8 psi. Each plot had a pressure regulator (set to 25
psi for the microsprinkler plots and 8 psi for the drip plots) and a ball valve allowing
independent irrigation. Water application amounts were monitored daily by water
meters in each plot.
Soil water potential (SWP) was measured in each plot by 6 granular matrix sensors
(GMS; Watermark Soil Moisture Sensors model 200SS; Irrometer Co. Inc., Riverside,
CA); 2 at 8-inch depth, 2 at 20-inch depth, and 2 at 32-inch depth. The GMS were
installed along the middle row in each plot and between the riser and the third tree.
The GMS were previously calibrated (Shock et al. 1998) and were read at 8:00 a.m.
daily starting on May 2 with a 30 KTCD-NL meter (Irrometer Co. Inc., Riverside, CA).
The daily GMS readings were averaged separately at each depth within each plot and
over all plots in a treatment. Irrigation treatments were started on May 2.
107
The five irrigation treatments consisted of three water application rates for the
microsprinkler-irrigated plots and two water application rates for the drip-irrigated plots
(Table 2). From 2000 through 2002, all plots in the 3 microsprinkler-irrigated
treatments were irrigated whenever the SWP at 8-inch depth, averaged over all plots in
treatment 1, reached -50 kPa. The plots in each drip-irrigated treatment were irrigated
whenever the SWP at 8-inch depth, averaged over all plots in the respective treatment,
reached -50 kPa. Irrigation treatments were terminated on September 30 each year.
Soil water content was measured with a neutron probe. Two access tubes were
installed in each plot along the middle tree row on each side of the fourth tree between
the sprinklers and the tree. Soil water content readings were made twice weekly at the
same depths as the GMS. The neutron probe was calibrated by taking soil samples
and probe readings at 8-inch, 20-inch, and 32-inch depth during installation of the
access tubes. The soil water content was determined gravimetrically from the soil
samples and regressed against the neutron probe readings, separately for each soil
depth. The regression equations were then used to transform the neutron probe
readings during the season into volumetric soil water content. Coefficients of
determination (r2) for the regression equations were 0.89, 0.88, and 0.81 at P = 0.001
for the 8-inch, 20-inch, and 32-inch depths, respectively.
The heights and diameter at breast height (DBH, 4.5 ft from ground) of the central three
trees in the two middle rows in each plot were measured monthly from May through
September. Tree heights were measured with a clinometer (model PM-5, Suunto,
Espoo, Finland) and DBH was measured with a diameter tape. Stem volumes
(excluding bark and including stump and top) were calculated for each of the central six
trees in each plot using an equation developed for poplars that uses tree height and
DBH (Browne 1962). Growth increments for height, DBH, and stem volume were
calculated as the difference in the respective parameter between October of the current
year and October of the previous year. Curves of current annual increment (CAl) and
mean annual increment (MAI) over the 8 years for the treatment 1
microsprinkler-irrigated trees and for the 2 drip tape configurations were used to assess
the growth stage of the plantation. The CAl is the current increment in stem volume
and the MAI is the CAl divided by the tree age.
2000 Procedures. The side branches on the bottom 6 ft of the tree trunk had been
pruned from all trees in February, 1999. In March of 2000, another 3 ft of trunk were
pruned, resulting in 9 ft of pruned trunk. The pruned branches were flailed on the
ground and the ground between the tree rows was lightly disked on April 12. On April
24, Prowl® at 3.3 lb ai/acre was broadcast for weed control. The microsprinkler-irrigated
plots received 0.7 inch of water to incorporate the Prowl. To control the alfalfa and
weeds remaining from the previous years' groundcover trial in the top half of the field,
Stinger® at 0.19 lb ai/acre was broadcast between the tree rows on May 19, and
at 0.23 lb ai/acre was broadcast between the tree rows on June 1. On June 14,
Stinger at 0.19 lb ai/acre and Roundup® at 3 lb ai/acre were broadcast between the tree
rows on the whole field.
108
On May 19 the trees received 50 lb nitrogen (N)/acre as urea-ammonium nitrate
solution injected through the microsprinkler system. Due to deficient levels of leaf
nutrients in early July, the field had the following nutrients in pounds per acre injected in
the irrigation systems: 0.4 lb boron (B), 0.6 lb copper (Cu), 0.4 lb iron (Fe), 5 lb
magnesium (Mg), 0.25 lb zinc (Zn), and 3 lb phosphorus (P). The field was sprayed
aerially for leafhopper control with Diazinon AG500® at 1 lb ai/ac on May 27 and with
Warrior® at 0.03 lb al/acre on July 10.
2001 Procedures. In March of 2001, another 3 ft of trunk were pruned, resulting in 12
ft of pruned trunk. The pruned branches were flailed on the ground on April 2. On April
4, Roundup at 1 lb ai/acre was broadcast for weed control. On April 10, 200 lb N/acre,
140 lb P/acre, 490 lb Sulfer (S)/acre, and 14 lb Zn/acre (urea, monoammonium
phosphate, zinc sulfate, and elemental sulfur) were broadcast. The ground between
the tree rows was lightly disked on April 12. On April 13, Prowl at 3.3 lb al/acre was
broadcast for weed control. The microsprinkler-irrigated plots received 0.8 inch of water
to incorporate the Prowl.
A leafhopper, willow sharpshooter (Graphocephala con fluens, Uhier), was monitored by
three yellow sticky traps attached to the lower trunk of selected trees. Traps were
checked weekly. From mid-April to early June only adults were observed in the traps.
A willow sharpshooter hatch was observed on June 6 as large numbers of nymphs
were noted in the traps and on the lower trunk sprouts. The field was sprayed aerially
with Warrior at 0.03 lb al/acre on June 11 for leafhopper control.
2002 Procedures. In March of 2002, another 3 ft of trunk were pruned, resulting in 15
ft of pruned trunk. The pruned branches were flailed on the ground on April 12. On
April 23, 80 lb N/acre, 40 lb Potassium (K)/acre, 150 lb S/acre, 20 lb Mg/acre, 6 lb
Zn/acre, 1 lb Cu/acre, and 1 lb B/acre (urea, potassium/magnesium sulfate, elemental
sulfur, zinc sulfate, copper sulfate, and boric acid) were broadcast and the field was
disked. On April 24, Prowl at 3.3 lb al/acre was broadcast for weed control. The
microsprinkler-irrigated plots received 0.7 inch of water to incorporate the Prowl.
The willow sharpshooter was monitored by three yellow sticky traps attached to the
lower trunk of selected trees. Traps were checked weekly. The field was sprayed
aerially with Warrior at 0.03 lb ai/acre on June 10 for leafhopper control.
2003 Procedures. In March of 2003, another 3 ft of trunk were pruned, resulting in 18
ft of pruned trunk. The pruned branches were flailed on the ground on March 31. On
April 23, 80 lb N/acre as urea and 167 lb S/acre as elemental sulfur were broadcast and
the field was disked. On April 16, Prowl at 3.3 lb ai/acre was broadcast for weed
control. The microsprinkler-irrigated plots received 0.4 inch of water to incorporate the
Prowl.
Starting in 2003 the irrigation criterion was changed to -25 kPa and the water applied at
each irrigation was reduced accordingly (Table 2). All plots in the three
microsprinkler-irrigated treatments were irrigated whenever the SWP at 8-inch depth,
109
averaged over all plots in treatment 1 reached -25 kPa. The plots in each drip-irrigated
treatment were irrigated whenever the SWP at 8-inch depth, averaged over all plots in
the respective treatment, reached -25 kPa. Irrigation treatments were terminated on
September 30.
The drip tape needed to be replaced because iron sulfide plugged the emitters. The
drip tape was replaced with another brand (T-tape, T-systems International, San Diego,
CA) in mid-April because Nelson Irrigation discontinued production of drip tape. The
drip tape specifications were the same.
The willow sharpshooter was monitored by three yellow sticky traps attached to the
lower trunk of selected trees. Traps were checked weekly. The field was sprayed
aerially with Warrior at 0.03 lb ai/acre on June 5 for leafhopper control.
2004 Procedures. On March 31, 2004, N at 80 lb/acre, S at 250 lb/acre, P at 50
lb/acre,
K at 50 lb/acre, Cu at 1 lb/acre, Zn at 4 lb/acre, and B at I lb/acre were
broadcast.
The field was lightly disked on April 1. On April 13, Prowl at 3.3 lb
ai/acre
was broadcast for weed control. The microsprinkler-irrigated plots received 0.4 inch of
water to incorporate the Prowl. On June 12 the field was sprayed with Warrior at 0.03
lb ai/acre for leafhopper control. A leaf tissue sample taken on July 7 showed a P
deficiency. On July 9, P at 10 lb/acre as phosphoric acid was injected through the
sprinkler and drip systems.
Results and Discussion
In 2004, the microsprinkler-irrigated treatment with 1 inch of water applied at each
irrigation received 51.7 acre-inch/acre of water in 43 irrigations (Table 1). The drip
treatment with 1 inch of water applied with 2 tapes received 56 acre-inch/acre applied in
38 irrigations. The drip treatment with 0.5 inch of water applied with 1 tape received 34
acre-inch/acre in 44 irrigations. The large discrepancies between the number of
irrigations applied and the actual amount of water applied can be explained by
inefficiencies in the irrigation system, such as leaks caused by rodent damage. The
tree squirrel population in an adjacent walnut orchard was inadvertently allowed to
increase, resulting in extensive damage to the drip and microsprinkler irrigation systems
in the spring of 2004. Repairs to the irrigation system and squirrel control measures
brought the situation under control by mid-June.
In November 2004 (eighth year), trees in the wettest sprinkler-irrigated treatment and
the 2-drip-tape configuration had the highest stem volume (Table 2). In November
2004, trees in the wettest sprinkler-irrigated treatment averaged 67 ft in height, 9 inch in
DBH, and 2,459 ft3/acre in stem volume (Table 2). In November 2004, trees in the
drip-irrigated treatment with 2 drip tapes per tree row averaged 70 ft in height, 9.6 inch
in DBH, and 2,653 ft3/acre in stem volume. Trees in the wettest sprinkler-irrigated
treatment and the 2 drip-tape configuration had among the highest accumulated tree
growth from 2000 through 2004.
110
Comparing all treatments, drip irrigation with two tapes per tree row or the wettest
sprinkler-irrigated treatment (water application rate of 1 inch) resulted in among the
highest stem volume growth in 2004, although the differences in tree growth during
2004 were not statistically significant (Table 2).
Although tree growth increased with increasing applied water up to the highest amount
tested, tree growth was not maximized in this study (Fig. 1). There were similar linear
relationships, with similar slopes, between total water applied and stem volume growth
for the drip and microsprinkler systems in 2004 (Y = -245.37 + 16.56X, R2 = 0.91, P =
0.05 for the drip and Y = -393.37 + 20.14X, R2 0.91, P = 0.05 for the sprinkler).
For the period of 2000 through 2004, there were distinctively different linear
relationships, with similar slopes, between total water applied and the accumulated
stem volume growth for the drip and microsprinkler systems (Fig. 2). The greater stem
volume growth for the drip system reflected the higher water use efficiency of the drip
system.
The soil water potential at 8-inch depth was maintained above the criterion of -25 kPa,
except for brief periods during the season for microsprinkler irrigation with 1 inch of
water applied and for drip irrigation with 2 tapes (Fig. 3). The soil water potential at
8-inch depth was reduced, as expected, with the reductions in the water application rate
in the sprinkler treatments (Fig. 3, Table 3). During irrigations the soil water potential at
8-inch depth in the drip treatments was greater than in the sprinkler treatments, as
expected, since the wetted area was smaller with drip irrigation (Fig. 3). It was difficult
to maintain the irrigation criterion with the one drip tape configuration because of the
smaller amount of water applied at each irrigation. With 1 drip tape, it takes 33 hours to
apply 0.5 inch of water at each irrigation and usually about 30 hours later (the second
morning after) the soil water potential would be equal to or considerably drier than -25
kPa.
The rate of increase in annual stem volume growth increased (growth approximately
doubled every year) up to 2001, when the stem volume growth for the
microsprinkler-irrigated trees started to decline (Table 4, Fig. 4). In 2002 the stem
volume growth for the drip-irrigated trees started to decline. The decline in annual
growth was not expected until later, when the trees approach harvest size. The
reduction of the soil water potential from -25 to -50 kPa in 2000 might be associated
with the decline in annual stem volume growth. Tree growth was substantially greater
in 2003 and was approximately double the growth in 2002; this could have been due to
the change to a wetter irrigation threshold from -50 to -25 kPa. In 2004, tree growth
was less than in 2003 for the microsprinkler-irrigated and drip-irrigated trees for
unexplained reasons. There were fewer growing degree days (50-86°F) from April
through October in 2004 than in 2003 (Table 4).
Both the current annual increment (CAl) and the mean annual increment (MAI) continue
to increase over time for the trees in treatment 1 (microsprinkler) and treatment 4 (drip,
2 tapes)(Fig. 4). Typically, both the CAl and MAI initially increase, reach a culmination
111
point and then decline. The CAl will culminate before the MAI. The intersection of the
two curves is termed the economic rotation and indicates the harvest stage of the
plantation.
References
Browne, J.E. 1962. Standard cubic-foot volume tables for the commercial tree species
of British Columbia. British Columbia Forest Service, Forest Surveys and Inventory
Division, Victoria, B.C.
Feibert, E.B.G., C.C. Shock, and L.D. Saunders. 2000. Groundcovers for hybrid poplar
establishment, 1997-1999. Oregon State University Agricultural Experiment Station
Special Report 1015:94-103.
Larcher, W. 1969. The effect of environmental and physiological variables on the
carbon dioxide exchange of trees. Photosynthetica 3:167-1 98.
Shock, C.C., J.M. Barnum, and M. Seddigh. 1998. Calibration of Watermark Soil
Moisture Sensors for irrigation management. Pages 139-146 in Proceedings of the
International Irrigation Show, Irrigation Association, San Diego, CA.
Shock, C.C., E.B.G. Feibert, M. Seddigh, and L.D. Saunders. 2002. Water
requirements and growth of irrigated hybrid poplar in a semi-arid environment in eastern
Oregon. Western J. of Applied Forestry 17:46-53.
Wright, J.L. 1982. New evapotranspiration crop coefficients. J. Irrig. Drain. Div., ASCE
108:57-74.
Zelawski, W. 1973. Gas exchange and water relations. Pages 149-165 in S. Bialobok
(ed.) The poplars-Populus L. Vol. 12. U.S. Dept. of Comm., Nat. Tech. Info. Serv.,
Springfield, VA.
112
Table 1. Irrigation rates, a mounts, and water use efficiency for hybrid poplar submitted
to five irrigation regimes in 2004, Malheur Experiment Station, Oregon State University,
Ontario, OR.
Total
Treatment Irrigation threshold
kPat
-25
coincide with trt #1
coincide with trt #1
-25
-25
1
2
3
4
5
Water
application
Irrigation
system
number of Total water
irrigations
inch
1
0.77
0.39
1
0.5
Microsprinkler
Microsprinkler
Microsprinkler
Drip, 2 tapes
Drip, 1 tape
applied*
acre-inch!
acre
51.7
43.1
26.4
56.3
33.9
9.4
43
43
43
38
44
LSD (0.05)
1
Water use
efficiency
ft3 of
wood!acre-inch of
water
12.9
8.5
6.7
12.0
9.6
NS
*lncludes 2.39 inches of precipitation from May through September.
tSoil water potential at 8-inch depth.
Table 2. Height, diameter at breast height (DBH), and stem volume i n early November
2004, and 2004 growth in height, DBH, and stem volume for hybrid p oplar submitted to
five irrigation treatments, Maiheur Experiment Station, Oregon State University, Ontario,
OR.
Treatment
November 2004
measurements
Stem
Height
DBH
volume
2004 growth increment
Height
DBH
Stem
volume
2000-2004 growth
increment
Stem volume
ft
67.2
inch
ft3/acre
ft3!acre
ft3!acre
9.0
2,458.6
ft
4.4
inch
1
0.82
512.3
1,977.9
2
50.2
7.9
1,381.1
4.7
0.77
1,181.1
3
38.0
5.5
4.5
0.83
4
70.1
9.6
493.5
2,652.5
365.5
177.0
5.5
0.82
55.1
8.3
1,692.9
3.4
0.59
679.4
323.3
2,596.7
5
LSD (0.05)
NS
1.0
583.4
NS
NS
NS
730.1
113
416.7
1,510.1
Table 3. Ave rage soil water p otential and volumetric soil water content for hybrid poplar
submitted to five irrigation trea tments, Malheur Experiment Station, Oregon State
University, 0 ntario, OR.
Average soil water potential
Treatment
1St ft
2nd ft
3rd ft
kPa
21.6
22.2
32.9
1
2
3
33.1
99
4
20.2
5
30
58.9
22
16.7
13.0
35.0*
LSD (0.05)
*significant at P = 0.10.
19.1
30.4
72.4
22.8
20.6
6.5
Table 4. Annual stem volume growth, seasonal average soil water potential at 8-inch
depth, and growing degree days for the drip and microsprinkler treatments receiving the
most water, Malheur Experiment Station, Oregon State University, Ontario, OR.
Year
1997
1998
1999
2000
2001
2002
2003
2004
Annual stem volume
growth
Drip
Microsprinkler
ft3/acre ----
Seasonal average soil water
potential at 8-inch depth
Drip
Microsprinkler
---- kPa
1.3
387.9
479.9
440.1
737.9
679.4
78.5
177.7
401.5
354.7
256.8
450.7
512.3
-21.4
-20.0
-22.2
-37.9
-33.9
-35.8
-26.9
-22.2
-24.2
-26.4
-31.3
-21.8
-20.2
114
April - Oct. Growing degree
days (50 - 86°F)
3,049
2,968
2,846
3,067
3,118
3,023
3,354
3,106
U)
C)
Co
800
2004
4-'
a)
S
600
Y = -162.20 + 13.49X
R2= 0.65, P= 0.01
0I—
0)
S
400
S
U)
S
E
0
>
200
E
U)
4-'
(I)
0
10
0
20
40
30
50
60
Water applied, inch
Figure 1. Response of stem volume growth to water applied in 2004 for the drip and
microsprinkler systems combined, Malheur Experiment Station, Oregon State
University, Ontario, OR.
ci)
C-)
3000
-
CO
4-'
ci)
Drip
Y=-24.05+1089X
2000
R2= 0.94, P= 0.05
+
0
0)
S
+
#
#
a)
E
1000
+
0
Microsprinkler
Y = -792.29 + 12.63X
R2= 0.73, P= 0.05
a
>
-p.
E
U)
4-'
C')
0
0
100
200
300
Water applied, inch
Figure 2. Response of stem volume growth to water applied from March 2000 through
November 2004 for the drip and microsprinkler systems. Malheur Experiment Station,
Oregon State University, Ontario, OR.
115
20-inch
0
-
32-inch
microsprinkler, -25 kPa, 1 inch
-25
-50
0
microsprinkler, 0.77 inch
-25
-50
0
0
-25
microsprinkler, 0.39 inch
——..
-50
-75
———S.
-100
0
0
-25
-50
0
-25
-50
172
194
216
238
260
Day of 2004
Figure 3. Soil water potential at three depths using granular matrix sensors in a poplar
stand submitted to five irrigation regimes, Maiheur Experiment Station, Oregon State
University, Ontario, OR.
116
CAl
0)
800
0
Drip
('3
C
MAI
600
ci)
E
ci)
0
400
a)
E
0
>
200
E
ci)
(I)
0
1997
1998
1999
2000
2002
2001
2003
2004
Year
CAl
a)
MAI
800
- -
(-)
Sprinkler
('3
C
-
600
a)
E
a)
0
C
ci)
E
0
>
E
a)
4—
(I)
1997
1998
1999
2000
2001
2002
2003
2004
Year
Current annual increment (CAl, annual stem volume growth) and mean
annual increment (MAI, mean annual stem volume growth) starting at planting in 1997
through the eighth year for hybrid poplar irrigated with two drip tapes per tree row and
with microsprinklers. Data are from plots receiving the highest irrigation rates, Malheur
Experiment Station, Oregon State University, Ontario, OR.
Figure 4.
117
EFFECT OF PRUNING SEVERITY ON THE ANNUAL GROWTH
OF HYBRID POPLAR
Clinton Shock, Erik Feibert, and Jake Eaton
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Summary
Hybrid poplar (clone OP-367) planted at 14-ft by 14-ft spacing was submitted to 5
pruning treatments. Pruning treatments consist of the rate at which the side branches
are removed from the tree to achieve an 18-ft branch-free stem. Starting with a 6-ft
(from ground) pruned trunk, 3-year-old trees are pruned to 18 ft in either 3, 4, or 5
years. Starting in March 2000, the side branches on the trunk were pruned to a height
of 6, 9, or 12 ft. In subsequent years, the trees were pruned in 3-ft increments annually.
A check treatment where trees were pruned only to 6 ft was included. In 2004 the
percentage of the total tree height that was pruned ranged from 12 percent for the
check treatment to 35 percent. Stem volume growth in 2004 and over the previous 5
seasons was not affected by pruning up to 23 percent of the total tree height.
Introduction
With reductions in timber supplies from Pacific Northwest public lands, sawmills and
timber products companies are searching for alternatives. Hybrid poplar wood has
proven to have desirable characteristics for many timber products. Growers in Maiheur
County, Oregon have made experimental plantings of hybrid poplar and demonstrated
that the clone OP-367 (hybrid of Populus deltoides x P. nigra) performs well on alkaline
soils for at least 7 years of growth. Research at the Maiheur Experiment Station during
1997-1999 determined optimum irrigation criteria and water application rates for the first
3 years (Shock et al. 2002).
Pruning the side branches of trees allows the early formation of clear, knot-free wood in
the trunk and increases the trees' value as saw logs and peeler logs. The amount of
live crown removed might have an effect on tree growth. More severe pruning might
improve the efficiency of the pruning operation (fewer pruning operations to reach the
final pruning height), but could reduce growth excessively. The timing of pruning could
also affect the amount of epicormic sprouting (sprouts forming on pruned stem) during
the season, wound healing, and insect damage at wound sites. The objective of this
study was to evaluate the effect of pruning severity and timing on tree growth and
health.
118
Materials and Methods
The trial is being conducted on a Nyssa-Malheur silt loam (bench soil) with 6 percent
slope at the Maiheur Experiment Station. The soil had a pH of 8.1 and 0.8 percent
organic matter. The field had been planted to wheat for the 2 years prior to 1997 and
before that to alfalfa. Hybrid poplar sticks, cultivar OP-367, were planted on April 25,
1997 on a 14-ft by 14-ft spacing. The field was used for irrigation management
research (Shock et al. 2002) and groundcover research (Feibert et al. 2000) from 1997
through 1999. All side branches on the lower 6 ft of all trees had been pruned in
February 1999.
In March 2000, the field was divided into 20 plots that were 6 rows wide and 7 trees
long. The plots were allocated to five irrigation treatments that consisted of
microsprinkler irrigation with three irrigation intensities and drip irrigation. The
microsprinkler-irrigated plots used the existing irrigation system. For the drip-irrigated
plots, either one or two drip tapes (Nelson Pathfinder, Nelson Irrigation Corp., Walla
Walla, WA) were laid along the tree row in early May 2000. The management of the
irrigation trial is discussed in an accompanying article (see "Mircro-irrigation Alternatives
for Hybrid Poplar Production, 2004 Trial" in this report).
For the pruning study, only plots in the two wetter microsprinkler-irrigated treatments
and the drip-irrigated treatments were used. The trees in the two wetter
microsprinkler-irrigated treatments and the drip-irrigated treatments averaged 26 ft in
height and 4.2 inches diameter at breast height (DBH) in March 2000. The middle 2
rows in each irrigation plot were assigned to pruning treatment 3 (Table 1). The
remaining 2 pairs of border rows in each plot were randomly assigned to pruning
treatments 2, 4, and 5. The pruning treatments were replicated eight times. The trees
in treatments 2, 3, and 4 were pruned on March 27, 2000; March 14, 2001; March 12,
2002; March 12, 2003; and March 19, 2004. Trees in treatment 5 were pruned on May
16, 2000; May 21, 2001; May 15, 2002; and May 14, 2003. Trees were pruned by
cutting all the side branches up to the specified height on the trunk, measured from
ground level. The side branches were cut using loppers and pole saws. An additional
4 plots, in which the trees would remain pruned only to 6 ft, were selected for a check
treatment (treatment 1).
The five central trees in the middle two rows and the five central trees in each inside
row of each border pair in each plot were measured monthly for DBH and height. Trunk
volumes were calculated for each of the measured trees in each plot using an equation
developed for poplars that uses tree height and DBH (Browne 1962). Growth
increments for height, DBH, and stem volume for 2004 were calculated as the
difference in the respective parameter between October 2003 and October 2004.
Growth increments for the five seasons (2000-2004) were calculated as the difference
in the respective parameter between October 1999 and October 2004. Regression
analyses were run for the percent of total tree height that was pruned trunk against tree
growth. The maximum percent of total trunk height pruned that would not reduce tree
growth was calculated by the first derivative (maximum = -b/2c) of the regression
119
equation Y = a + b • X + c • X2, where Y is the trunk volume increment and X is the
percent of the total height pruned.
Results and Discussion
In 2004, the trees in the least intensive pruning treatment (treatment 2) were pruned to
18-ft height, completing the pruning treatments. In October 2004 the trees in the least
severe pruning treatment (treatment 2) averaged 65.2 ft in height and 9.3 inches DBH.
In 2003 the percentage of the total tree height that was pruned ranged from 12 percent
for the check treatment to 35 percent for treatment 5 (Table 1). The differences in the
percentage of the total tree height that was pruned trunk between treatments 2, 3, 4,
and 5 was not significant in 2004, as all trees in these treatments were branch-free to
18 ft.
Tree growth increased, reached a maximum, and then decreased with increasing
pruning severity, both in 2004 and over the 4 years (Figs. I and 2). The response of
tree growth to pruning suggests that pruning up to a certain severity is beneficial for tree
growth. Pruning removes branches from the lower canopy that might not contribute
much to the photosynthetic capacity of the tree due to shading. Pruning also changes
the trunk shape, with greater diameter growth occurring higher on the trunk than in
unpruned trees. The maximum trunk volume growth was achieved by limiting the
length of pruned stem to 22 percent of the total tree height in 2004 and to 23 percent of
the total tree height over the 4 years. Future tree measurements will determine if trees
subjected to the most severe pruning will eventually reach the same size as less
severely pruned trees. Tree growth reductions that occurred when trunks were pruned
above 25 percent of total tree height, as shown in this study, are inconsistent with the
Oregon State University Extension recommendation to limit pruning to 50 percent of
total height (Hibbs 1996).
Lower intensity pruning might increase pruning costs, because there will be more
pruning events before an 18-ft branch-free trunk is achieved than with higher intensity
pruning. Lower intensity pruning will also result in larger branches being pruned, which
increases labor costs and results in less clear wood.
References
Browne, J.E. 1962. Standard cubic-foot volume tables for the commercial tree species
of British Columbia. British Columbia Forest Service, Forest Surveys and Inventory
Division, Victoria, B.C.
Feibert, E.B.G., CC. Shock, and L.D. Saunders. 2000. Groundcovers for hybrid poplar
establishment, 1997-1999. Oregon State University Agricultural Experiment Station
Special Report 1015:94-103.
120
Hibbs, D.E. 1996. Managing hardwood stands for timber production. The Woodland
Workbook, Oregon State University Extension Service, Oregon State University,
Corvallis.
Shock, C.C., E.B.G. Feibert, M. Seddigh, and L.D. Saunders. 2002. Water
requirements and growth of irrigated hybrid poplar in a semi-arid environment in eastern
Oregon. Western J. of Applied Forestry 17:46-53.
Table I. Poplar pruning treatments and actual percentage of total height pruned
(percentage of total height that is branch-free stem after pruning) in successive years.
The amount of sprouting for trees pruned in winter is compared to spring. Trees were
planted in April 1 997, Malheur Experiment Station, Oregon State University, Ontario,
OR.
Actual percentage of total tree height
that was pruned trunk in March
Treatment 1999 2000 2001 2002 2003 2004 2000 2001 2002 2003 2004
1 Check
6
6
6
6
24.3
15.7
13.7
12.9
11.7
6
6
2
6
6
26.1
9
12
15
22.2
22.9
28.1
18
30.5
3
6
9
12
32.0
15
18
33.7
29.3
35.3
32.2
18
4
6
12
15
35.2
18
18
18
47.3
39.4
33.5
30.0
6
9
12
15
33.7
31.5
34.8
18
18
38.7
35.0
LSD (0.05)
2.7
2.1
3.5
3.0
3.4
Pruning height* (ft from ground)
*Trunk height to which all side branches were removed in March of the respective year.
in May. All others were pruned when trees were dormant.
121
15
Y=-318+0.819X-0.0175X2
12
r2 = 0.19, P = 0.001
09
0)
•
S
• •
—6
-c
•
S
S S.
555
•...•
—
..
*.
S
C)
I
•. •
•
SS
_.
S• •SS
SS Se C
IS
S
•
3
••
S
S
S
0
0
C-)
10
20
30
40
50
Y= 1.04-0.0104X
r2 = 0.04, P = 0.05
-I-i
.
•
s)
0
5.-
's
I
C)
cU
0o
0
10
20
30
40
50
0
10
20
30
40
50
(Y)
0
5.-
0)4
U)
E
0
>
Percent of total trunk height pruned
Figure 1. Poplar tree annual growth increment in 2004 in response to pruning severity,
Maiheur Experiment Station, Oregon State University, Ontario, OR.
122
50
-C
40
0
30
S.
j
20
C)
I
0)
10
S
S
.
S
S
Y = -2.45 + 3.61X - 0.0785
r2 = 0.54, P = 0.0001
--
0
S
20
10
0
0
S.
.1
S.
0)
S
40
30
8
S
C
6
S
0
I
4
S
C)
a
Y=3.35+0.2197X+0.0054X2
2
r2 = 0.37, P
0
20
10
0
0.00 1
16
0
0)
0)
E
0
>
=
F-
Y
14
12
-2.40 + 1.17X + 0.0256X2
= 0.42, P 0.001
30
40
50
40
50
S.
S. S
•SS
•5
10
8
S
6
4
S
2
0
0
10
20
30
Percent of total trunk height pruned
Figure 2. Poplar tree 5-year (2000-2004) growth in response to pruning severity,
Maiheur Experiment Station, Oregon State University, Ontario, OR.
123
SOYBEAN PERFORMANCE IN ONTARIO IN 2004
Erik B.G. Feibert, Clinton C. Shock, and Lamont D. Saunders
Malheur Experiment Station
Oregon State University
Ontario, OR
Introduction
Soybean is a potentially valuable new crop for Oregon. Soybean could provide a high
quality protein for animal nutrition and oil for human consumption, both of which are in
short supply in the Pacific Northwest. In addition, edible or vegetable soybean
production could provide a raw material for specialized food products. Soybean is
valuable as a rotation crop because of the soil-improving qualities of its residues and its
N2 -fixing capability. Because of the high-value irrigated crops typically grown in the
Snake River Valley, soybeans may be economically feasible only at high yields.
Soybean varieties developed for the midwestern and southern states are not
necessarily well adapted to Oregon's lower night temperatures, lower relative humidity,
and other climatic differences. Previous research at Ontario, Oregon has shown that,
compared to the commercial cultivars bred for the Midwest, plants for eastern Oregon
need to have high tolerance to seed shatter and lodging, reduced plant height,
increased seed set, and higher harvest index (ratio of seed to the whole plant).
M. Seddigh and G.D. Jolliff at Oregon State University, Corvallis identified a soybean
line that would fill pods when subjected to cool night temperatures. This line was
crossed at Corvallis with productive lines to produce OR 6 and OR 8, among others. At
this point, the development moved to Ontario, Oregon. The later two lines were
crossed at our request for several years with early-maturing high-yielding semi-dwarf
lines by R.L. Cooper (USDA, Agriculture Research Service, Wooster, OH) to produce
semi-dwarf lines with potential adaptation to the Pacific Northwest. Selection criteria at
the Malheur Experiment Station (MES) included high yield, zero lodging, zero shatter,
low plant height, and maturity in the available growing season. In 1992, 241 single
plants were selected from 5 F5 lines that were originally bred and selected for
adaptation to eastern Oregon. Seed from these selections was planted and evaluated
in 1993; 18 selections were found promising and selected for further testing in larger
plots from 1994 through 1999. Of the 18 lines, 8 were selected for further testing. In
1999, selections from one of the MES lines were made by P. Sexton at the Central
Oregon Agricultural Research and Extension Center (COAREC) in Madras, Oregon.
Sixteen of these Madras selections were chosen for further testing. In 2000, selections
were made from six of the 1992 MES lines and from OR-6. This report summarizes
work done in 2004 as part of the continuing breeding and selection program to adapt
soybeans to eastern Oregon.
124
Methods
The trial was conducted on a Greenleaf silt loam previously planted to wheat. Forty lbs
of nitrogen, 100 lb of sulfur, 2 lb of copper, and 1 lb of boron were broadcast in the fall
of 2003. The field was then disked twice, moldboard plowed, groundhogged twice, and
bedded to 22-inch rows.
Five commercial cultivars, 5 older lines selected at MES in 1992, 9 lines selected in
1999 at the COAREC from a MES line, and 24 lines selected in 2000 at MES were
planted in plots 4 rows by 25 ft. The plots were arranged in a randomized complete
block design with four replicates. The seed was planted on May 20 at 200,000
seeds/acre in rows 22 inches apart. Rhizobiumjaponicum soil implant inoculant was
applied in the seed furrow at planting. Emergence started on June 1. The field was
furrow irrigated as necessary. The field was sprayed on August 3 and August 11 with
dimethoate at 0.5 lb ai/acre for lygus bug and stinkbug control.
Plant height and reproductive stage were measured weekly for each cultivar. Prior to
harvest, each plot was evaluated for lodging and seed shatter. Lodging was rated as
the degree to which the plants were leaning over (0 = vertical, 10 = prostrate). The
middle two rows in each four-row plot were harvested on October 8 using a
Wintersteiger Nurserymaster small plot combine. Beans were cleaned, weighed, and a
subsample was oven dried to determine moisture content. Dry bean yields were
corrected to 13 percent moisture. Variety lodging, plant population, yield, and seed
count were compared by analysis of variance. Means separation was determined by
the protected least significant difference test.
Results and Discussion
Yields in 2004 ranged from 44.2 bu/acre for 'OR-8' to 70.5 bu/acre for 'M12' (Table 1).
Several of the lines had seed counts sufficient for the manufacturing of tofu (<2,270
seeds/Ib). Several lines combined high yields, little lodging, and early maturity.
Considerable yield advantages were obtained through continued selection.
125
Table 1. Performance of soybean cultivars ranked by yield in 2004, Malheur
Experiment Station, Oregon State University, Ontario, OR. Cultivars M92-085 through
M92-350 are from single plant selections made at the Malheur Experiment Station in
1992. Cultivars Ml through M16 are from single plants selected from M92-330.
Cultivar
M12
M3
M9
108
104
312
303
309
M92-085
M16
601
M13
M15
107
106
103
Ml
M2
311
101
313
308
M4
511
Korada
M92-220
M92-225
608
307
905
514
305
909
Gnome 85
Lambert
Evans
OR-6
Sibley
OR-8
LSD (0.05)
Origin
M92-330
M92-330
M92-330
M92-085
M92-085
M92-220
M92-220
M92-220
M92-330
M92-314
M92-330
M92-330
M92-085
M92-085
M92-085
M92-330
M92-330
M92-220
M92-085
M92-220
M92-220
M92-330
M92-237
M92-314
M92-220
OR-6
M92-237
M92-220
OR-6
Days to maturity
Days to harvest
maturity
days from emergence
Lodging
Height
seeds/lb
Yield
0-10
cm
90
103
105
seeds/lb
1,974
2,052
2,100
2,090
2,066
2,519
2,572
2,617
2,056
bu/acre
70.5
68.7
68.2
66.9
65.8
64.7
63.0
62.8
62.5
62.2
61.9
61.8
61.8
61.5
60.9
60.6
60.3
91
101
1.5
91
101
78
78
88
88
2.5
2.3
0.5
91
101
1.5
98
98
1.3
98
108
108
108
91
101
91
101
98
108
91
101
91
101
78
78
78
88
88
88
91
101
91
101
98
78
98
98
108
88
108
108
91
101
98
98
98
78
108
91
101
98
78
108
88
91
101
98
108
78
88
98
98
98
108
91
101
98
98
108
108
108
108
88
108
108
126
2.8
1.0
0.8
1.0
0.8
1.5
0.5
0.5
0.3
0.5
0.8
1.5
1.0
2.0
2.3
0.8
1.3
1.5
2.5
2.0
0.5
0.3
1.0
5.3
0.5
0.8
5.5
6.3
7.0
8.0
5.3
8.8
7.8
1.5
91
98
82
88
83
101
94
82
105
95
98
84
100
97
90
68
89
85
75
89
81
77
100
88
90
85
105
82
61
97
120
98
111
101
115
106
2079
2,459
2,119
2,198
2,142
2,012
2,104
2,123
1,952
2,530
2,003
2,459
2,681
2,081
2,666
2,422
2,569
2,307
2,237
2,752
2,453
2,423
2,630
2,251
2,072
2,220
2,072
2,309
1,946
1,894
244
60.1
59.9
59.7
59.5
59.4
58.1
58.0
57.7
57.0
56.5
56.4
55.1
55.1
54.9
54.8
53.0
52.9
52.7
50.9
50.1
49.0
44.2
8.4
Table 2. Performance of soybean varieties over years, Malheur Experiment Station,
Oregon State University, Ontario, OR.
Yield
Cultivar
2002
2003
M12
56.1
106
65.7
66.3
66.3
72.9
108
68.1
M92-085
M15
64.1
M9
104
305
Korada
73.8
66.9
65.7
70.4
69.6
68.5
63.7
65.7
65.0
64.7
64.2
68.8
67.2
M4
66.1
511
67.2
307
69.1
101
68.6
63.6
65.3
69.4
65.7
62.9
68.2
66.4
60.4
58.9
60.0
53.3
48.6
51.5
51.3
51.0
45.3
63.9
107
Ml
M13
103
601
M3
M16
M2
312
303
313
309
M92-220
308
Lambert
608
514
311
M92-225
Gnome 85
909
905
OR-6
Evans
Sibley
OR-8
Average
LSD (0.05)
10.1
2004
bu/acre
70.5
55.4
68.2
57.5
65.8
55.4
60.9
54.3
66.9
61.6
62.5
52.4
61.8
59.5
61.5
59.7
60.3
53.2
61.8
55.3
60.6
54.4
61.9
52.1
68.7
55.6
62.2
57.9
60.1
53.1
64.7
54.7
63.0
57.4
54.8
55.2
55.3
53.8
54.5
49.5
53.8
48.4
49.5
49.4
58.6
49.5
52.5
51.1
50.1
48.7
53.2
50.3
49.6
41.0
40.5
39.4
52.8
10.7
57.7
58.1
58.0
55.1
59.7
59.5
62.8
57.0
59.4
52.7
56.4
54.9
59.9
56.5
52.9
53.0
55.1
50.1
50.9
49.0
44.2
59.0
8.4
Averages 2002-2004
Lodging
Height
Average
Days to
maturity
64.1
94
0-10
3.5
63.3
63.2
90
4.1
92
63.1
90
63.1
90
97
3.8
2.9
2.7
3.0
94
3.3
87
3.0
92
3.0
92
3.3
90
94
92
3.0
1.4
3.6
2.3
97
3.6
62.7
62.7
62.6
61.9
61.8
61.8
61.6
61.5
61.2
61.0
99
60.8
60.6
60.3
60.0
59.8
59.7
59.6
59.3
59.0
58.8
58.6
58.2
101
1.1
101
2.7
58.1
103
58.0
57.9
92
57.1
101
101
1.5
101
4.1
94
2.7
99
1.9
99
1.7
92
3.5
3.5
103
101
101
103
2.2
3.2
0.7
7.8
55.2
87
2.8
0.9
0.4
3.0
53.9
53.2
51.3
50.4
47.7
46.8
43.0
58.5
101
7.5
90
6.8
7.0
7.4
127
89
90
94
103
8.7
8.8
8.4
96
3.7
103
108
cm
86.0
89.3
91.3
85.0
85.3
90.3
89.3
86.0
85.3
89.0
89.3
88.0
91.0
92.3
87.3
87.7
89.0
78.0
80.0
83.7
84.7
86.3
86.0
88.7
88.7
96.0
83.7
88.3
86.7
83.3
81.7
86.0
89.0
Seed
count
seeds/lb
2,071
2,191
2,173
2,056
2,113
2,121
2,199
2,159
2,224
2,250
2,081
2,393
2,221
2,155
2,093
2,436
2,465
2,458
2,410
2,198
2,505
2,528
2,027
2,445
2,519
2,556
2,539
2,355
2,117
2,264
2,403
2,277
2,193
89.0
88.3
2,271
88.3
91.7
91.3
86.0
87.4
2,323
2,214
2,156
2,123
2,273
2,361
POTATO VARIETY TRIALS 2004
Eric P. Eldredge, Clinton C. Shock, and Lamont D. Saunders
Malheur Experiment Station
Oregon State University
Ontario, OR
Introduction
New potato varieties were evaluated for their productivity and usefulness for
processing. Potatoes are grown under contract in Malheur County, Oregon for potato
processors to produce frozen products for the food service industry. There is very little
production for fresh pack or open market, and very few growers have potato storage
buildings on their farms. There is also no production of varieties for making potato
chips. Potato seed is not produced in Malheur County because high populations of
aphids result in virus infection in the tubers.
The varieties grown for processing are mainly 'Ranger Russet', 'Shepody', and 'Russet
Burbank'. Harvest begins in July, and potatoes go to processing plants directly from the
field. Yields are limited by "early die" syndrome, which causes early senescence of the
vines. Early die is caused by a complex of soil pathogens, including bacteria,
nematodes, and fungi, and is worse when crop rotations between potato crops are
short.
Small acreages of new varieties or advanced selections are sometimes contracted to
study the feasibility of expanding their use. To displace an existing processing variety, a
new potato variety needs to have several outstanding characteristics. The yield should
be at least as high as the yield of Russet Burbank. The tubers need to have low
reducing sugars for light, uniform fry color, and high specific gravity. A new variety
should be resistant to tuber defects or deformities caused by disease, water stress, or
heat. It should begin tuber bulking early if it is a variety for early harvest. Or, if it is a
late-harvest variety, it should be resistant to early die.
Potato variety development trials at Malheur Experiment Station (MES) in 2004
included the Western Regional Early Harvest Trial with 20 entries, the Western
Regional Late Harvest Trial with 20 entries, the Oregon Statewide Trial with 29 entries,
the Oregon Preliminary Yield Trial with 131 entries, a Malheur Preliminary Yield Trial of
6 strains selected in previous 8-Hill trials at MES, and an 8-Hill trial of 84 clones from
the USDA Agricultural Research Service (ARS) potato breeding program at Aberdeen,
Idaho. Through these trials and active cooperation with other scientists in Idaho,
Oregon, and Washington, promising new lines are bred, evaluated, and eventually
released as new varieties.
128
Materials and Methods
Six potato variety trials were grown under sprinkler irrigation on Owyhee silt loam,
where winter wheat was the previous crop in a potato, wheat, corn, wheat, potato
rotation. The wheat stubble was flailed and the field was irrigated and disked. A soil test
taken on September 16, 2003 showed 37 lb nitrogen (N)/acre in the top 2 ft of soil, and
102 lb available phosphate (P205), 851 lb soluble potash (1(20), 29 lb sulfate (SO4),
1966 ppm calcium (Ca), 463 ppm magnesium (Mg), 87 ppm sodium (Na), 1.6 ppm zinc
(Zn), 18 ppm iron (Fe), 4 ppm manganese (Mn), 0.7 ppm copper (Cu), 0.5 ppm boron
(B), organic matter 3.5 percent, and pH 7.4 in the top foot of soil. Fall fertilizer was
spread to apply 60 lb N/acre, 50 lb P205/acre, 80 lb K20/acre, 57 lb sulfur (S)/acre, 8 lb
Zn/acre, 5 lb Cu/acre, and 1 lb B/acre. The field was ripped, Telone Il® soil fumigant
was injected at 25 gal/acre, and the field was bedded on 36-inch row spacing.
Seed of all varieties was hand cut into 2-oz seed pieces and treated with Tops-MZ®+
Gaucho® dust one to two weeks before planting and placed in storage to suberize. On
March 22, 2004, the field was cultivated with a Lilliston rolling cultivator to reshape the
hills and to control winter annual weeds and volunteer wheat. On April 2 a soil sample
was taken that showed 43 lb N/acre in the top 2 ft of soil, 83 lb available P205, 688 lb
soluble K2O, 26 lb SO4, 1,835 ppm Ca, 353 ppm Mg, 69 ppm Na, 1.1 ppm Zn, 5 ppm
Fe, 1 ppm Mn, 0.4 ppm Cu, 1.2 ppm B, pH 7.4, and 3.0 percent organic matter in the
top foot of soil.
Potato seed pieces were planted in single-row plots using a 2-row cup planter with
9-inch seed spacing in 36-inch rows. Red potatoes were planted at the end of each plot
as markers to separate the potato plots at harvest. After planting, hills were formed over
the rows with the Lilliston rolling cultivator. Prowl® at I lb/acre plus Dual® at 2 lb/acre
herbicide was applied as a tank mix for weed control on May 7 and was incorporated
with the Lilliston. Matrix® herbicide was applied at 1.25 oz/acre on May 17 and was
incorporated with 0.41 inch of rain on the next day, followed by 0.89 inch of additional
rain through the end of May.
The Western Regional Early Harvest Trial was planted on April 13, 2004. The Western
Regional Late Harvest and the 8-Hill Trial were planted on April 19. The Statewide Trial
and the Preliminary Yield Trials were planted on April 26. The Malheur Preliminary Yield
Trial, planted on April 26, consisted of 2 entries with sufficient seed available to plant 4
replicates of 30 seed pieces, and 4 entries with enough seed available to plant 2
replicates of 20 seed pieces. The 8-Hill trial was unreplicated with plots 8 seed pieces
long, the Oregon Preliminary Yield Trial had 2 replicates with plots 20 seed pieces long,
and the Statewide, Western Regional Early Harvest, and Western Regional Late
Harvest Trials each had 4 replicates with plots 30 seed pieces long.
Irrigation was applied 21 times (Fig. 1), from June 4 to August 30, with scheduling
based on soil water potential. The average readings of 6 Watermark soil moisture
sensors (model 200 SS, lrrometer Co. Inc., Riverside, CA) were monitored every 8
hours by a Hansen model AM400 datalogger (M. K. Hansen Co., East Wenatchee,
129
WA). Sensors were installed in the potato row at the seedpiece depth, 10 inches from
the top of the hill. The AM400 unit was read frequently through the summer to predict
crop water needs; the objective was to apply an irrigation just before the average soil
moisture in the potato root zone at the seed piece depth reached -60 kPa (Fig. 2). Water
applied was estimated by recording the sprinkler set duration at 55 psi, and using the
nominal sprinkler head output. Crop evapotranspiration (ETa) was estimated by the U.S.
Bureau of Reclamation based on data from an AgriMet weather station at MES.
Fungicide applications to control early blight and prevent late blight infection started
with an aerial application of Ridomil Gold® and Bravo® at 1.5 pint/acre on June 12. On
June 25, Headline® fungicide was applied; on July 17, Topsin-M® fungicide plus liquid
sulfur with 1.5 lb P2O5/acre and 0.2 lb Zn/acre was applied by aerial applicator. On
August 8, Headline plus 6 lb S/acre was applied to prevent two-spotted spider mite
infestation and powdery mildew infection.
Petiole tests were taken every 2 weeks from June 14, and fertilizer was injected into the
sprinkler line during irrigation to supply the crop nutrient needs. A total of 103 lb N/acre,
44 lb P205/acre, 140 lb K2O/acre, 100 lb SO4/acre, 0.3 lb Mn/acre, 5 lb Mg/acre, 0.1 lb
Cu/acre, 0.1 lb Fe/acre, and 0.5 lb B/acre were applied.
Vines were flailed in the Western Regional Early Harvest Trial on August 16. Western
Regional Early Harvest Trial potatoes were lifted August 27 with a two-row digger that
laid the tubers back onto the soil in each row. Visual evaluations included observations
of desirable traits, such as a high yield of large, smooth, uniformly shaped and sized,
oblong to long, attractively russetted tubers, with shallow eyes evenly distributed over
the tuber length. Notes were also made of tuber defects such as growth cracks, knobs,
curved or irregularly shaped tubers, pointed ends, stem-end decay, stolons that
remained attached, folded bud ends, rough skin due to excessive russetting, pigmented
eyes, or any other defect, and a note to keep or discard the clone based on the overall
appearance of the tubers.
Tubers were placed into burlap sacks and hauled to a barn where they were kept under
tarps until grading. After grading, a 20-tuber sample from each plot in the Western
Regional Early Harvest Trial was evaluated for tuber quality traits for processing.
Specific gravity was measured using the weight-in-air, weight-in-water method. Ten
tubers per plot were cut lengthwise and the center slices were fried for 3.5 mm in 375°F
soybean oil. Percent light reflectance was measured on the stem and bud ends of each
slice using a Photovolt Reflectance Meter model 577 (Seradyn, Inc., Indianapolis, IN),
with a green tristimulus filter, calibrated to read 0 percent light reflectance on the black
standard cup and 73.6 percent light reflectance on the white porcelain standard plate.
The vines were flailed on the late harvest trials on September 21. The vines of most
entries had died by the date of the last irrigation on August 30. Potatoes in the Western
Regional Late Harvest Trial were dug on October 5. The 8-Hill Trial tubers and the
potatoes in the Statewide Trial were dug on October 6-7, and the Preliminary Yield Trial
tubers were dug on October 7-8. At each harvest, the potatoes in each plot were
130
visually evaluated as described above. Tubers were graded and a 20-tuber sample
from each plot was placed into storage. The storage was kept near 90 percent relative
humidity and the temperature was gradually reduced to 45°F. Tubers were removed
from storage November 19 through December 6 and evaluated for tuber quality traits,
specific gravity, and fry color as described above. Data were analyzed with the General
Linear Models analysis of variance procedure in NCSS (Number Cruncher Statistical
Systems, Kaysville, UT) using the Fisher's Protected LSD means separation t-test at
the 95 percent confidence level.
Results and Discussion
At the Malheur Experiment Station in 2004, spring weather was cool and wet, followed
by a summer without the usual extreme heat. Dry weather prevented late blight from
developing in 2004. No powdery mildew or mite problems were observed in the field.
Compared to the 2003 potato trials at this location, overall yields were lower by about
17 percent, and specific gravity of the tubers was lower.
Precipitation during May 1 through September 30 was 2.55 inches, the crop
evapotranspiration (EL) for the late-harvest trials totaled 26.19 inches, and the trials
(Fig. 1). The
received 22.15 inches of irrigation plus precipitation, or 84.6 percent of
step increases in the irrigation plus rainfall curve show the 21 sprinkler irrigations
applied during the growing season.
The trend of soil moisture during the growing season is shown in Figure 2. The data do
not show the individual irrigations because the sensors did not always respond to an
irrigation. The irrigation plus rainfall was less than
for the growing season, and the
sensor data show that average root zone soil water potential became drier than -60 kPa
at least four times during the growing season.
Soil water potential at the seed piece depth was allowed to become drier than -60 kPa
at the end of the growing season, after the vines died on the early maturing entries, by
applying frequent sprinkler irrigations of short duration, as shown in Figure 1. This was
necessary to avoid swollen lenticels and the associated possibility of rotting the tubers
of the early entries, while continuing to apply a portion of the
requirement for the
late maturing entries in shallow moisture increments.
Western Regional Early Harvest Trial
In the Western Regional Early Harvest Trial, among the highest in total yields were
'A92294-6', 'Shepody', 'AC93026-9Ru', 'A93157-6LS', and 'TC1675-lRu' with total
yield ranging from 473 to 546 cwtlacre (Table 1). Of those clones, only TC1675-lRu
had specific gravity above 1.080 g cm3, a desirable level for processing. In production
of marketable tubers for processing (the total of U.S. No.1 pIus U.S. No. 2 grades),
A92294-6, Shepody, AC93026-9Ru, A9305-10, TC1675-lRu, and A93157-6LS with
marketable yield from 423 to 499 cwt/acre were among the highest in marketable yield.
131
Western Regional Late Harvest Trial
The highest total yield In the Western Regional Late Harvest Trial was produced by
A92294-6, with 658 cwt/acre, and it also produced the highest marketable yield, 632
cwt/acre (Table 2). Among the highest producers of U.S. No. I tubers, on a percentage
basis, were 'AC92009-4Ru', 'ATX91137-lRu', and 'A096160-3', with ATX92230-lRu,
'Russet Norkotah', and 'A95109-1', ranging from 84 to 94 percent. Among the highest
total U.S. No. 1 tuber producers were ATX92230-lRu, A93157-6LS, A096160-3,
A92294-6, A9305-10, 'A95074-6', and TC1675-lRu, ranging from 377 to 437 cwt/acre.
Shepody, A92294-6, and Russet Burbank produced significantly more U.S. No. 2
tubers than other clones in this trial. In this late-harvest trial, specific gravity of
A93157-6LS, AC92009-4Ru, A096160-3, Ranger Russet, A92294-6, A95074-6, and
TC1675-lRu were among the highest, and acceptable for processing into frozen potato
products.
Oregon Statewide Trial
In the Oregon Statewide Trial, the six clones marked with an asterisk were retained by
the variety selection committee (Table 3). The clone AO96160-3 will stay in the
Statewide Trial and in the Western Regional Trial, 'AO96164-1' will advance to the
Western Regional Trial, 'A096141-3' and 'A098133-2' will advance to the Western
Regional Russet Early and Late Harvest Trials, and 'A096162-1' and 'A099099-3' will
be maintained in the Statewide Trial in 2005. At this location in 2004, A096160-3,
A096164-1, A096141-3, A098133-2, A096162-1, and AO99099-3 produced among
the highest total yields, with a high percentage of U.S. No. I tubers, good specific
gravity for processing, and light fry colors with no sugar ends. Russet Burbank
produced 102 cwt/acre U.S. No. 2 tubers, significantly more than any other entry, and
had 30 percent sugar ends.
Oregon Preliminary Yield Trial
In the Preliminary Yield Trial, 126 numbered clones were compared to Russet Burbank,
Ranger Russet, Shepody, Russet Norkotah, and 'Umatilla Russet' (Table 4). The
Oregon potato variety selection committee kept 11 clones, based on their performance
at Hermiston, Kiamath Falls, Powell Butte, and Ontario, to advance to the Statewide
Trial for 2005. The clones that were advanced were 'AO96305-3' 'A096365-2',
'A096370-2', 'AO98123-2', 'A098268-5', 'AO98282-5', 'A098307-6', 'A099065-2',
'A099081-1', 'AO99108-5', and 'A0991 11-9'. These clones yielded welt across the four
locations (Hermiston, Klamath Falls, and Powell Butte data are not shown in this
report), had a low incidence of undesirable characteristics, had high percentage of U.S.
No. 1 tubers, and if selected as promising clones for processing, had high specific
gravity, light fry color, and resistance to developing sugar ends in response to stress.
,
Malheur Preliminary Trial
This was the first year of a Malheur Preliminary Trial, a cooperative project by the
Malheur Agricultural Experiment Station and the USDA-ARS. Six clones from previous
8-Hill trials at Malheur were selected for their adaptation to the high early die pressure,
heavy soil texture, and hot, dry climate of the Treasure Valley. These clones were
compared to Russet Burbank, Ranger Russet, and Umatilla Russet (Table 5). The
132
clones 'A98345-1', 'A91814-2', 'A961 12-20', produced a high percentage of U.S. No. I
tubers, had specific gravity above 1.080 g cm3 (a level desirable for processing), and
produced no sugar ends. The clones 'A99133-6' and 'A99123-1' each produced 5
percent sugar ends, and 'A96783-1O9LB', produced 15 percent sugar ends.
8-Hill Trial
Eight hills were grown of each of 84 clones selected for long, russet tubers from the
Aberdeen ARS potato breeding program, including 17 clones with the LB suffix
signifying that they were bred for resistance to late blight. The 84 clones were evaluated
for tuber type, yield, grade, and processing quality (Table 6). Yield and grade data were
examined for clones having total yield greater than 530 cwtlacre and U.S. No. 1 tubers
at 93 percent or higher, without excessive U.S. No. 2, cull, or undersized (less than 4
oz) tubers. Twenty-six of the clones had high yields and produced a high percentage of
U.S. No. 1 tubers. Samples of these clones were analyzed for processing quality. The
clone 'C0A00329-1' yielded a total of 695 cwt/acre, with 85 percent U.S. No. 1 tubers,
specific gravity of 1.092 g cm3, and an average fry strip light reflectance of 47.8
percent, which was acceptable for processing, with 0 percent sugar ends. The clone
'A00345-3LB' yielded 644 cwt/acre total, with 91 percent U.S. No. I grade, specific
gravity 1.085 g cm3, and fry strip light reflectance of 44.5 percent.
133
30
25
-
Accumulated ETc
20
Accumulated irrigation+rain
15
10
5
0
0
N-
0
N-
CC)
Co
Co
Co
Co
Co
0)
Co
N-
£3
N-
£3
N-
0)
Co
0)
Co
CD
0)
Co
Figure 1. Crop evapotranspiration (EL) and sprinkler irrigation applied (plus rain) to
potato variety trials, Malheur Experiment Station, Oregon State University, Ontario, OR,
2004.
Co
£3
C)
0
-10
-20
Co
C
-30
ci)
0
0
0)
-50
-60
-70
Figure 2. Soil moisture data for sprinkler-irrigated potato variety trials, Malheur
Experiment Station, Oregon State University, Ontario, OR, 2004.
134
C)
0)
Table 1. Yield, grade, and processing quality of potato entries grown in the Western Regional Early Harvest Trial at Malheur
Experiment Station, Oregon State University, Ontario, OR, 2003.
Average
U.S. No. i
Fry color,
Cull Length/ Specific
U.S. Marketable <4
Total
Percent Total
>12 6 - 12 4 - 6
Variety
yield
No. 1
cwt/acre
%
RangerRusset
431
Russet Burbank
Russet Norkotah
446
290
499
314
546
435
496
480
454
383
367
496
416
Shepody
A92030-5
A92294-6
A9304-3
A9305-10
A93157-6LS
A95074-6
A95109-1
AC92009-4Ru
AC93026-9Ru
A096160-3
ATX91137-lRu
ATX92230-lRu
CO93001-llRu
CO94035-l5Ru
PA95AII-14
1C1675-lRu
Mean
LSD (0.05)
74
49
88
54
90
74
84
No. 1
325
228
256
268
281
402
92
95
68
90
440
429
90
396
415
459
440
473
436
76
80
70
85
80
85
tNS= Not significant.
85
81
91
8
oz
oz
oz
No. 2
cwtlacre
366
400
406
369
354
348
337
375
81
oz
391
318
113
182
30
76
24
42
90
154
162
159
42
55
38
23
36
128
144
232
267
104
221
118
113
186
16
19
18
34
22
gravity
ratio
g cm3
0.0
12
2.2
21
2.0
16
1.9
5
1.8
1.076
55.5
53.4
47.6
52.2
1.9
1.068
51.8
0.0
0
2.0
1.078
1.072
1.080
55.1
0.0
53.8
55.6
0.0
49.6
58.2
0.0
0.0
49.9
52.8
54.0
54.7
0.0
35
2
2.2
30
1
1.9
166
128
203
219
27
45
413
406
21
0
0
1.8
1.8
1.065
19
203
186
189
229
179
53
96
16
14
30
42
65
27
49
32
348
413
377
432
395
83
59
27
0
1.7
0
1.9
61
3
2.0
1.064
1.064
1.072
33
28
10
6
1.9
1.081
8
1.9
1.072
0.005
82
67
43
20
0.0
13
14
385
40
0.0
56.4
447
423
397
457
109
123
69
0.0
55.1
411
5
1.8
10
405
345
2.5
52.5
47
1.7
121
41
5.0
47.7
2.2
19
37
62
144
45.1
5
1.9
249
177
160
0.0
40
19
10
2
352
140
140
64
24
%
49.9
499
189
15
2.3
3
155
214
174
Sugar
ends
98
45
8
2.1
31
101
35
55
light
reflectance
%
1.075
1.063
1.063
1.072
1.077
1.076
1.080
1.070
1.074
8
52
36
50
12
15
185
371
311
80
141
401
356
264
457
296
width
17
28
8
362
20
1
32
0.2
1.071
0.0
0.0
0.0
0.0
0.0
0.0
0.0
52.6
0
3.2
NSt
Table 2. Yield, grade, and processing quality of potato entries grown in the Western Regional Late Harvest Trial at Maiheur
Experiment Station, Oregon State University, Ontario, OR, 2003.
Total
yield
Variety
RangerRusset
Russet Burbank
Russet Norkotah
Shepody
A92030-5
A92294-6
A9304-3
A9305-10
A93157-6LS
A95074-6
A95109-1
AC92009-4Ru
AC93026-9Ru
A096160-3
ATX91137-lRu
ATX92230-lRu
C093001-llRu
CO94035-l5Ru
PA95AII-14
TC1675-lRu
Mean
LSD (0.05)
tNS = Not
cwt/acre
485
460
313
454
342
658
422
547
567
504
404
381
466
497
477
413
373
459
427
457
455
66
significant.
U.S. No. 1
Percent Total >12 6 -12 4 - 6
No. 1 No. 1
oz
oz
oz
%
319
225
178
55
113
130
84
45
83
64
74
76
76
75
84
94
265
202
285
425
312
415
435
382
339
356
282
434
437
358
292
344
299
377
339
68
97
90
119
82
85
221
114
108
143
183
88
92
87
78
73
71
83
75
10
Marketable
<4 oz
Cull
No. 2
cwt!acre
66
49
61
U.S.
171
157
174
282
241
129
172
195
152
137
213
120
40
141
130
97
206
176
171
161
151
151
61
140
182
143
44
123
147
51
28
40
49
147
30
28
47
23
25
217
39
207
85
100
87
64
50
51
70
27
32
33
91
48
67
91
42
98
71
49
20
181
21
12
145
29
18
29
36
80
76
36
83
43
Length!
width
Specific
gravity
g cm3
1.084
1.063
1.063
466
406
286
16
23
27
28
ratio
2.3
2.4
0
1.7
419
323
632
397
516
522
446
389
368
427
463
455
386
328
423
374
412
422
60
21
8
1.8
17
0
1.8
24
0
11
20
34
39
1
12
13
37
34
17
26
46
27
51
38
27
14
3
Average
Fry color,
light
reflectance
%
%
34.5
22.7
21.6
30
26.2
2.2
1.074
1.077
1.083
13
2.2
1.080
38.2
10
1.9
36.4
2.0
1.072
1.088
12
1.8
1.082
38.6
0
0
2
0
5
0
0
0
0
5
1.9
1.078
1.086
1.074
1.086
1.069
1.073
1.065
1.071
1.070
1.081
4
13
2.0
2.2
1.9
1.9
1.9
1.7
1.8
2.1
1.8
2.0
0.2
1.076
0.008
Sugar
ends
42.2
40.5
46.2
30.9
38.2
29.9
43.6
25.8
41.0
31.2
33.7
29.8
37.5
18
7
20
0
10
0
18
0
3
8
5
23
0
15
0
10
13
23
0
34.0
10
4.1
NSt
Table 3. Yield, grade, and processing quality of potato entries grown in the Oregon Statewide Trial at Malheur Experiment Station,
Oreqon State University, Ontario, OR, 2003.
Variety
Total
yield
Percent
389
474
282
437
437
399
423
497
60
79
84
76
88
83
69
83
398
356
96
79
381
91
424
308
467
444
469
415
332
88
84
84
77
72
79
90
371
91
456
417
429
474
422
79
82
88
429
470
78
80
84
88
84
No. 1
U.S. No. 1
Total >12
oz
6-12
oz
4-6
oz
U.S.
No. 2
139
164
142
177
66
50
54
112
113
65
102
61
61
48
55
Marketable <4 oz Cull
Length!
width
Specific
gravity
gcm3
R. Burbank
RangerR.
R. Norkotah
Umatilla R.
A096205-3
A098133-4
A094006-4
A094007-1
A096047-2
A096073-2
A098114-6
A098141-2
A099002-4
A099002-7
A099024-8
A099060-5
Umatilla4O7
Umatilla 418
Umatilla 432
Umatilla 311
Norkotah 101
Norkotah 206
Norkotah 210
Mean
LSD (0.05)
291
288
272
402
64
71
78
81
7
234
377
237
332
384
29
163
331
93
76
176
238
47
295
412
380
284
347
373
258
389
343
338
331
297
337
364
345
376
338
329
332
376
246
253
232
326
64
41
43
62
209
173
157
188
104
117
163
183
91
224
10
121
55
50
38
89
156
33
191
187
57
34
45
65
44
57
49
84
47
130
216
190
194
206
159
146
211
119
149
25
74
59
59
118
53
97
94
87
50
35
119
35
49
4
34
16
29
9
16
4
17
2
20
25
31
25
5
11
6
16
336
425
241
366
400
360
356
467
389
300
1
0
3
1
1.8
1.7
1.093
1
1.6
3
1.9
1.084
1.069
389
259
410
368
369
355
302
349
370
0
2.2
0
1.5
18
2
12
2.0
1
2.1
1
1.9
0
2.0
1
1.6
361
19
36
1.9
29
80
63
52
72
37
3
1.9
3
351
181
100
391
175
181
121
53
29
42
22
374
398
253
257
240
25
25
2
0
398
7
4
9
39
70
37
36
65
24
2.2
1.9
2.0
1.9
9
21
195
143
136
130
169
39
8
7
55
28
35
49
40
74
88
59
29
22
85
41
106
117
58
60
54
73
27
6
2.0
2.3
2.2
1.060
1.086
1.060
1.082
1.085
1.077
1.083
1.086
45
42
358
%
29.4
40.5
30.7
48.5
47.8
51.1
51.0
47.0
48.0
38.7
27.7
48.3
%
30
0
0
0
0
0
0
0
0
0
3
0
42.1
0
30.6
28
0
10
1.9
1.072
1.076
1.094
1.071
1.083
1.084
58.6
41.8
45.6
40.4
41.9
54.2
33.9
47.8
43.6
1
2.0
1.079
45.2
3
3
2.0
1.078
46.2
0
0
1.9
2.1
1.085
48.8
0
1.058
1.059
1.059
1.077
0.007
27.1
0
5
3
1
2.1
2.2
31
1
351
46
4.0
2.0
2.0
2.0
70
18
10
0.1
30
1.067
1.088
1.069
1.095
1.083
1.076
Average
fry color, light Sugar
reflectance
ends
0
25.7
26.6
41.7
3.8
3
0
5
0
0
0
0
3
8
Table 4. Yield, grade, and processing quality of 11 early selections from the 131 entries in the Oregon Preliminary Yield Trial,
compared to the 5 check entries, Malheur Experiment Station, Oregon State University, Ontario, OR, 2004.
U.S. No. 1
Average
Total
Percent Total >12 6 - 12 4 - 6
U.S. Marketable <4 Cull Length! Specific fry color, light
Variety
yield
No. I
oz
oz
oz
No. 2
oz
width
gravity
reflectance
cwtlacre
%
cwt/acre
ratio
g cm3
%
R. Burbank
511
68
281
85
141
56
130
411
49
36
2.5
1.065
28.9
RangerR.
Shepody
500
412
494
93
391
91
97
289
449
A096305-3
465
386
90
99
319
339
AO96365-2
A096370-2
A098123-2
472
542
604
94
395
444
547
A098268-5
AO98282-5
A098307-6
468
370
538
433
275
480
263
79
238
A099065-2
A099081-1
AO99108-5
A099111-9
501
253
240
349
350
Norkotah R.
Umatilla R.
Mean
LSD (0.05)
91
100
96
91
99
370
583
698
427
96
99
96
97
96
433
334
180
11
172
511
615
355
117
83
323
95
182
88
80
134
92
118
22
32
47
9
90
88
188
64
198
131
200
269
156
66
88
78
39
2
26
200
132
106
164
39
89
78
150
137
69
120
199
143
43
24
42
66
63
170
88
53
45
0
20
24
8
18
6
18
21
15
39
413
322
459
358
341
420
488
547
73
73
28
105
Sugar
ends
%
45
3
2.1
10
2
1.8
2.0
1.087
1.076
1.059
0
2.0
1.081
40.7
33.5
26.3
44.8
44
0
2.4
1.080
44.3
0
52
0
7
0
1.9
32.3
42.3
58.4
5
1.7
1.080
1.080
1.093
2.0
2.2
2.3
1.082
1.086
1.098
50.5
44.7
35
17
0
0
0
15
13
2.0
2.0
1.077
1.087
41
0
2.0
1.081
59
512
3
2.1
1.091
371
2
1.9
1.078
44.5
51.7
45.3
53.6
40.4
6.1
180
44
NS
0.3
0.015
12.1
22
453
299
487
451
340
530
636
40
57
15
71
44
1.8
52.1
0
20
5
0
0
0
0
0
0
0
0
0
0
Table 5. Yield, grade, and processing quality of early selections from the Malheur Preliminary Trial (in bold) compared to several
check entries grown at Malheur Experiment Station, Oregon State University, Ontario, OR, 2004.
Average
U.S. No. 1
Total Percent Total >12 6 - 12 4 - 6
U.S. Marketable <4 Cull Length! Specific fry color, light
Variety
yield
No. I
reflectance
gravity
oz
oz
oz
width
No. 2
oz
cwt/acre
%
%
ratio
g cm-3
cwt!acre
Trial with 4 replications
R. Burbank
389
60
29.4
234
2.2
1.060
29
139
66
102
336
45
6
RangerR.
474
40.5
79
377
163
7
1.9
1.086
164
50
49
425
42
R. Norkotah
282
84
30.7
237
1.060
41
142
54
4
241
39
2
2.0
UmatillaR.
437
76
48.5
1.9
1.082
332
43
177
112
34
70
0
366
Defender
407
42.1
79
325
1.089
91
172
62
361
46
0
1.7
36
Gemstar
437
52.6
94
413 258
1.7
1.076
128
26
11
424
11
0
A98345-1
A91814-2
506
622
444
60
68
85
78
335
527
347
64
154
55
104
500
494
68
93
97
281
391
85
117
323
465
90
319
A96112-20
A99123-1
A96783-1O9LB
Meant
411
440
360
529
430
99
99
100
98
96
369
370
284
432
357
LSDt (0.05)
180
10
172
Mean
LSD (0.05)
9
47
117
285
165
33
63
188
78
26
112
18
46
46
446
546
393
55
74
48
56
16
141
130
22
411
202
143
56
92
47
90
35
98
93
109
64
87
54
Sugar
ends
%
30
0
0
0
3
0
1.086
1.087
42.9
50.3
0
0
1.078
0.005
42.1
4
6
2.0
1.065
1.087
1.059
2.0
1.081
1
1.8
2
1.1
2
5
1.8
0.1
36
2.5
413
459
358
375
374
284
438
373
49
73
28
105
36
66
76
90
52
3
2
2.1
0
0
0
0
0
2
180
44
NSt
3.3
Trial with 2 replications
R.Burbank
RangerR.
Norkotah R.
Umatilla R.
A99133-6
511
tstatjstjcs based on 135 entries.
NS = Not significant.
449
95
255
95
31
121
151
170
182
80
134
80
178
160
9
39
6
4
0
7
15
39
45
1.9
1.084
2.1
1.091
1.8
1.077
28.9
40.7
26.3
44.8
43.9
52.4
47.8
1.5
1.091
43.1
0
5
0
0
0
5
0
1.9
0.3
1.078
40.6
6.1
0.015
12.2
22
Table 6. Yield, grade, and processing quality for 26 selections from 84 potato clones entered in an Un replicated 8-Hill Trial at
Malheur Experiment Station, Oreqon State University, 2004
U.S. No. 1
Average
Total
Percent Total >12 6 - 12 4 - 6 U.S. Marketable <4 Cull Length! Specific fry color, light
Variety
yield
No. 1
oz
oz
oz
No. 2
oz
width
gravity
reflectance
cwtlacre
%
cwtlacre
ratio
g cm3
%
A99031-12
442
95
420
347
61
A0012-2
A0031-4
552
370
487
140
76
129
A0068-5
A00138-1
A00138-4
A99074-9
A99074-15
A99134-1
A97257-3
A97320-1
A97322-1
506
403
592
545
585
329
380
487
430
533
99
96
95
97
88
C0A00329-1
C0A00369-4
695
85
659
TXA000I1-1
381
A00324-1
590
644
552
690
563
574
536
93
95
88
487
362
462
488
382
516
448
535
326
365
465
416
467
591
616
251
A0036-2
88
98
95
97
95
87
82
C0A00295-1
A00345-3LB
A00382-3LB
A00487-22LB
A00487-29LB
A00538-52LB
A00551-5OLB
A00718-3
A00645-1
671
581
91
91
80
81
78
74
93
81
89
451t
83t
tMeans based on 84 entries.
Means based on 26 entries.
Overall Mean
361
522
588
444
560
440
424
500
544
518
375t
251
307
348
230
373
180
357
268
194
287
344
348
13
96
36
26
8
428
7
15
0
50
37
60
0
27
61
5
8
0
30
76
5
8
11
45
142
125
0
50
3
494
362
470
488
382
516
475
540
326
370
465
428
467
641
619
0
0
361
42
119
21
131
14
8
220
124
326
106
113
130
144
68
88
54
12gt
72t
125
102
106
208
117
50
141
101
65
75
218
232
229
298
261
182
63
297
347
121
81
232
323
124
108
59
308
130
358
174t
201
0
9
0
0
Sugar
ends
%
14
57
0
1.6
1.071
48.0
0
0
1.7
1.071
50.2
0
5
0
1.8
1.092
49.0
0
16
0
1.8
1.077
45.8
0
18
0
1.8
1.079
43.1
0
21
0
1.4
1.074
40.3
0
40
70
45
28
1.2
1.073
31.1
0
0
1.6
1.073
34.7
0
0
1.7
1.077
34.3
0
3
0
2.1
1.079
43.1
0
10
0
1.6
1.070
38.3
0
22
0
1.7
1.074
35.9
0
2
0
2.0
1.070
36.0
0
40
0
1.6
1.088
39.5
10
54
0
1.8
1.092
47.8
0
0
1.9
1.064
34.0
0
0
2.0
1.074
21.2
0
0
1.9
1.070
26.5
0
0
1.6
1.085
44.5
0
0
1.9
1.067
19.8
10
122
123
138
36
94
23
0
0
0
0
0
0
1.7
1.076
1.082
1.079
37.8
24.6
39.6
40.9
10
10
33
40
542
590
457
568
440
436
500
577
558
40
20
48
49
94
19t
394t
54t
2t
2
0
12
0
1.4
1.7
1.5
1.071
1.071
1.9
1.065
1.8
46.1
28.4
0
10
0
10
TUBER BULKING RATE AND PROCESSING QUALITY OF EARLY
POTATO SELECTIONS
Clinton C. Shock, Eric P. Eldredge, and Monty D. Saunders
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Five potato cultivars 'Ranger Russet', 'Russet Burbank', 'Shepody', 'Umatilla Russet',
and 'Wallowa Russet', and two early selections, 'A92294-6', and 'A93157-6LS' were
compared at six harvest dates in this trial. Ranger Russet, Russet Burbank, and
Shepody are currently grown in the Treasure Valley for processing and served as the
check varieties. Umatilla Russet and Wallowa Russet are new releases from Oregon
State University (OSU) that have yield, grade, and processing quality generally superior
to Ranger Russet, Russet Burbank, and Shepody. The numbered clones have
performed well in several previous variety trials at this location, including the Western
Regional Early Harvest Trial. The first objective of this study was to quantify the tuber
bulking rate of potato cultivars that are currently grown, and some numbered clones
that may soon be released, and to compare their suitability for production of early
harvest potatoes for processing directly from the field. The second objective was to
determine which, if any, of these clones could continue to bulk tubers late in the
season.
Materials and Methods
The soil was Owyhee silt loam where the previous crop was winter wheat. The wheat
stubble was flailed and the field was irrigated and disked. A soil test taken on
September 16, 2003 showed 37 lb nitrogen (N)/acre in the top 2 ft of soil, and 102 lb
available phosphate (P205), 851 lb soluble potash (1<20), 29 lb sulfate (SO4), 1966 ppm
calcium (Ca), 463 ppm magnesium (Mg), 87 ppm sodium (Na), 1.6 ppm zinc (Zn), 18
ppm iron (Fe), 4 ppm manganese (Mn), 0.7 ppm copper (Cu), 0.5 ppm boron (B),
organic matter 3.5 percent, and pH 7.4 in the top foot of soil. Fall fertilizer was spread to
apply 60 lb N/acre, 50 lb P2O5/acre, 80 lb K2O/acre, 57 lb sulfur (S)/acre, 8 lb Zn/acre, 5
lb Cu/acre, and 1 lb B/acre. The field was ripped, Telone Il® soil fumigant was injected
at 25 gal/acre, and the field was bedded on 36-inch row spacing.
Potato seed was obtained from the OSU Potato Variety Development program at
Powell Butte, and the USDA/Agricultural Research Service (ARS) potato program at
Aberdeen, Idaho. Seed of Ranger Russet was commercial certified seed from eastern
Oregon, and seed of Umatilla Russet was commercial certified seed from central
Oregon. Seed was cut by hand into approximately 2-oz pieces, treated with Tops-MZ®
141
plus Gaucho®
2-row
seed treating dust, and counted into bags of 15 seed for each row of the
plots.
rows spaced 36 inches apart and
spacing between seed pieces in the row. The soil condition was excellent, with
good tilth and good soil moisture. The soil temperature at the seed piece depth,
10-inches, was 56°F. The experiment was laid out in a split-plot design, with the harvest
dates replicated four times as main plots within blocks and the varieties randomized in
each subplot. This was accomplished by planting the rows so that the six harvest date
passes through the four replicates would include all of the varieties.
The potato clones were planted on April 13, with
9-inch
A two-row per bed configuration was started at planting by leaving off the center
furrowing shovel of the two-row planter. On May 6, the two-row beds were formed with
a spike harrow pulling wide shovels to clean the furrows and form the shoulders of the
beds, and dragging a heavy chain to smooth and flatten the top of the bed. The tool bar
on back of the bed harrow also carried shanks and spools of drip tape to install a drip
tape at 2- to 3-inches depth directly above each potato row. The drip tape was 5/8-inch
diameter, with 5-mil wall thickness, 6-inch emitter spacing, 0.22 gal/mm/I 00-ft flow rate
(T-tape, T-Systems International, San Diego, CA).
Soil water potential was measured with six Watermark sensors Model 200SS (Irrometer
Co. Inc., Riverside, CA) installed in the potato row at the seed piece depth and
connected to an AM400 data logger (M.K. Hansen, East Wenatchee, WA) that
recorded soil water potential every 8 hours. Water potential readings were also
recorded manually from the data logger. Irrigations were scheduled to avoid soil water
potential at the root zone dropping below -30 kPa. Crop evapotranspiration (EL) was
estimated by an automated AgriMet (U.S. Bureau of Reclamation, Boise, ID) station
located about 0.5 mile away on the Malheur Experiment Station.
Prowl® at 1 lb/acre plus Dual® at 2 lb/acre was applied on May 7, before any potato
plants had emerged, and was incorporated with the bed harrow. Matrix® herbicide was
applied at 1.25 oz/acre on May 17, and was incorporated by 0.41 inch of rain on the
next day, followed by 0.89 inch additional rain through the end of May. Fungicide
applications to control early blight and prevent late blight infection started with an aerial
application of Ridomil Gold® and Bravo® at 1.5 pint/acre on June 12. On June 25,
Headline® fungicide was applied; on July 17, Topsin-M® fungicide plus liquid S with 1.5
lb P205/acre and 0.2 lb Zn/acre was applied by aerial applicator. On August 8, Headline
plus 6 lb S/acre was applied to prevent two-spotted spider mite infestation and powdery
mildew infection. No fertilizer was applied to the field in the spring. Petiole tests were
taken every 2 weeks from June 11, and fertilizer was injected into the drip system
during irrigation to supply the crop nutrient needs (Table 1).
Approximately 40 percent emergence was noted in the trial on May 12. On June 22, the
first tubers were dug from one plot in each replicate. Tubers were sorted by weight and
tubers in each weight category were counted and weighed. On July 13, tubers were
harvested from each replicate, and graded by the U.S. No. 1 and No. 2 for processing
142
standards, sorted by weight, and counted and weighed in each weight category.
Specific gravity and length-to-width ratio were measured using a sample of 10 tubers,
and fry color was measured on a sample of 20 tubers from each plot. The subsequent
harvests, on August 3, August 24, September 14, and October 5, followed the same
procedure as the second harvest.
Yield and quality results data were compared using analysis of variance (Number
Cruncher Statistical Systems, Kaysville, UT). The tuber bulking rate over time was
where y is the tuber yield in cwt/acre,
evaluated using the equation: y = A+B /
A, B, C, and D are the potato tuber bulking growth parameters, and t is the time in days
after planting (DAP). A suitable value for the exponential variable D was found by
preliminary regressions on all the varieties. An average tuber initiation date for all
clones was found by dividing the yield of the first harvest by the cwtlacre/day bulking
rate between the first and second harvests. The resulting tuber initiation (zero yield)
date was 59.9 DAP.
,
Results and Discussion
The 2004 growing season was cool and rainy in April and May and lacked the usual
prolonged heat in the summer months. The total amount of irrigation water applied
through the drip tape fell behind potato crop evapotranspiration (EL) through the
growing season, with a total of 15.22 inches of applied irrigation plus rain, and a total
accumulated
of 27.60 inches (Fig. 1). The soil moisture sensors showed an early
season moisture deficit (Fig. 2). This was due to the early season water being only
small rainfall events and irrigation beginning June 4. Through the period from 56 to 113
DAP, the sensors indicated wetter soil in the crop root zone than the optimum soil water
potential for drip-irrigated potato of -30 kPa, despite the irrigations being less than the
amount required to match ETC. The soil was intentionally allowed to become drier after
August 31, 140 DAP, to avoid rotting the tubers after vine senescence.
Because the crop root zone remained moist through the growing season, the plants
were not stressed and the fry color light reflectance was uniformly 40 percent or higher,
except for the stem-end light reflectance of Russet Burbank from the final harvest
(Table 2). Very few sugar ends were encountered in frying the samples. In the fourth
harvest, 132 DAP, one sugar end was found in A93157-6LS out of 80 tubers fried, or
1.25 percent. In the fifth harvest, 153 DAP, one sugar end was found in Russet
Burbank. In the sixth harvest, 174 DAP, one sugar end was found in Russet Burbank,
and one in Shepody.
Potato clones varied in yield and the size distribution of the tubers at the three latest
harvest dates (Tables 2 and 3). Among the potatoes tested, A92294-6 was the heaviest
bulking clone when harvested 132 DAP, with 466 cwtlacre total yield, and 90 percent
U.S. No. 1 tubers. At 153 DAP, A93157-6LS with 512 cwt/acre and A92294-6 with 494
cwt/acre were the highest in total yield.
143
Growers can only plant cultivars that have seed available and that have been accepted
by processing companies for contract production. Processors want specific gravity
above 1.080 to help assure quality products. Processors prefer tubers with a
length/width ratio of about 1.8 to 2.0, so that French fry production is efficient. At
present, seed is available for Wallowa Russet, Umatilla Russet, Shepody, and Ranger
Russet. When the bulking rate of Wallowa Russet, Umatilla Russet, Shepody, and
Ranger Russet are compared at the three latest harvest dates, Wallowa Russet has a
yield advantage, producing significantly more than the currently grown cultivars, except
for Ranger Russet at 153 DAP. Newer clones, which are not yet released and available
to growers, such as A92294-6 and A93157-6LS, had even higher productivity, with 568
and 512 cwt/acre total yield, respectively, at 174 DAP (Table 2).
The tuber bulking rate for total yield, U.S. No. 1, and Marketable categories was plotted
overtime and evaluated using the equation given above (Figs. 3-9). The U.S. No. 1
category includes all smooth tubers, even undersized tubers less than 4 oz. The
Marketable category consists of the U.S. No. I and U.S. No. 2 tubers over 4 oz (Figs.
3-9). Early in the growing season, from tuber initiation until tubers exceeded 4 oz, the
total yield was the same as the U.S. No. I yield, and the bulking rate was generally
linear. Where the Marketable yield line crosses the U.S. No. 1 yield line indicates the
DAP when U.S. No. 2 tubers outweighed the undersized tubers for each clone (Figs.
3-9).
In previous work (Shock et al. 2002) we showed that early dying of potato vines in
mid-August can be a major factor limiting potato productivity in Malheur County,
because it limits the ability of tubers to continue to bulk late in the growing season. In
the current work, the commercial varieties failed to have substantial marketable yield
increases after mid-September, 153 DAP (Figs. 5-7, 9). The lack of increase in
marketable yield after 153 DAP was noted for Ranger Russet, Russet Burbank,
Shepody, and UmatlIla Russet (Figs. 5-7, 9). In contrast, A92294-6, A93157-6LS, and
Wallowa Russet continued their upward trends in marketable yield to 174 DAP (Figs. 3,
4, 8) finishing with 568, 512, and 482 cwt/acre, respectively. These clones deserve
special attention in future trials and possible tests for resistance to the component
pathogens of the early die disease syndrome.
Shepody and Ranger Russet are not especially suitable as early harvest cultivars
based on yield. Other clones included in this trial bulked fairly early (Figs. 5-7, 9). From
the Western Regional Early Harvest potato variety trials in Ontario over the past few
years, several other new clones have also shown promise (data not shown).
References
Shock, C.C., E.P. Eldredge, and L.D. Saunders. 2002. Tuber bulking rate of processing
potato clones in relation to planting date. Oregon State University Agricultural
Experiment Station, Special Report 1048:152-1 58.
144
Table 1. Fertilizer applied through the drip irrigation system in response to petiole tests
on potato clones and cultivars grown under drip irrigation, Malheur Experiment Station,
Oregon State University, Ontario, OR, 2004.
N
Date
6/8
6/15
7/3
7/4
7/5
7/15
7/17
7/27
8/8
total
P205
K20
SO4
Zn
Mn
Cu
Fe
B
lb/acre
15
20
20
20
20
10
0.25
10
10
20
20
20
20
0.25
0.25
0.05
0.2
0.05
0.05
0.1
0.02
0.5
0.55
0.05
0.1
0.12
0.1
10
20
1.5
10
20
18
115
51.5
60
48
145
Table 2. Tuber yield, grade, length-to-width ratio, specific gravity, and fry color of five
potato clones and six potato varieties that grew until vine removal on August 24,
September 13, or October 4, and subsequent harvest on August 24, September 14, or
October 5 (Hrv 4, 5, 6), Malheur Experiment Station, Oregon State University, Ontario,
OR, 2004.
Cultivar, clone
A92294-6
A93157-6LS
RangerR.
R. Burbank
Shepody
WallowaR.
UmatillaR.
Mean
LSD (0.05)
Days
Total Percent Marketable
Light
after Total U.S.
U.S.
yield
Culls Length! Specific reflectance
planting yield No. 1 No. 1 Total 6-10 oz <4 oz width
gravity stem bud Av.
0/
o/
Hrv DAP -cwt!acrecwt!acre
ratio
gcm-3
4 132 466 420
90 444
196
23
2.05
1.087 53 55
54
5
153 494 465
94 461
234
33
2.02
1.086 55 54
55
6 174 568 526
92 529
209
40
2.04
1.088 54 53
54
4 132
422 403
95 395
154
27
1.78
1.088 43 44
43
5
153 512 497
97 472
211
40
1.78
1.090 45 44
44
6
174
512
479
93
468
146
44
1.90
1.092 46
46
46
4
377
400
324
363
86
159
160
1.94
91
362
376
15
5
132
153
24
1.89
1.086 45
1.087 46
49
47
47
47
6
174
438
394
90
406
134
31
2.02
1.090 50
50
50
4
362
356
298
292
83
82
339
5
132
153
331
152
172
23
25
2.07
2.02
1.073 45
1.074 40
42
44
44
42
6
174
419
324
77
385
157
34
2.07
1.071
37
44
41
4
5
132
153
348
344
285
288
81
334
15
13
1.63
1.076 47
1.079 52
51
331
115
136
1.55
84
48
49
50
6
174
413
338
82
385
113
28
1.66
1.078 46
45
46
4
5
132
153
428
409
411
412
394
169
210
16
15
1.91
393
96
96
1.90
1.084 47
1.087 49
50
47
48
48
6
174
482
461
96
460
162
22
1.90
1.086 52
48
50
4
303
327
261
86
143
1.97
1.081 49
1.079 50
52
48
51
91
40
44
1.92
298
263
282
121
5
132
153
6
174
371
325
87
306
141
65
2.02
1.082 50
49
50
4
132
343
371
152
181
1.89
1.082 47
49
48
91
364
378
23
153
387
406
88
5
28
1.89
1.083
48
47
48
6
174
458
407
88
420
152
38
1.94
1.084 48
48
48
47.7
NS
NS
NS
3.9 23.3
NS
NS
NS
5.7
6.3
NS
NS
NS NS NS
NS
Hrv
Cltr
HrvXCltr
23.8 27.1
NS
NS
146
21.1
NS
0.07
NS
0.002 2.1
NS 3.7
49
1.4
1.6
2.5
2.7
Table 3. Tuber grade and size distribution of five potato clones and six potato varieties
that grew until vine removal on August 24, September 13, or October 4, and
subsequent harvest on August 24, September 14, or October 5 (Hrv 4, 5, 6), Malheur
Experiment Station, Oregon State University, Ontario, OR, 2004.
4-6
Cultivar, clone
A92294-6
A931 57-6LS
Ranger R.
R. Burbank
Shepody
Wallowa R.
Umatilla R.
Mean
>16
4-6
U.S. Number 2, oz sizes
6-8 8-10 10-12 12-16
>16
Hrv DAP
80
58
21
26
7
3
13
4
7
4
6
4
83
54
6
5
4
72
88
65
64
75
62
40
61
91
24
55
2
4
1
1
1
75
67
70
118
46
3
72
74
72
77
51
50
52
52
22
40
6
3
65
62
62
70
63
5
88
94
53
58
37
26
2
76
22
15
4
174
56
73
64
50
39
132
153
30
39
48
67
51
5
39
28
6
174
37
4
5
132
153
59
98
105
106
6
174
72
4
5
132
153
35
46
42
48
80
54
63
56
65
76
6
174
64
4
5
7
7
6
7
8
9
9
4
8
3
0
0
3
6
3
1
5
7
14
13
4
4
6
4
10
7
7
16
9
4
4
6
6
19
3
5
8
15
3
5
6
12
22
14
21
10
10
5
9
11
10
18
40
53
56
52
33
4
4
5
6
11
10
9
8
13
13
18
13
43
67
46
77
58
6
6
8
11
22
20
84
62
35
26
2
2
2
3
4
0
8
5
0
2
85
80
112
44
2
4
2
3
7
3
41
21
14
2
11
33
28
4
5
4
4
2
5
9
3
4
58
10
2
70
58
43
28
4
5
7
7
3
10
8
58
72
68
23
5
8
5
4
10
10
94
77
52
27
3
5
5
5
7
8
70
71
49
40
60
53
55
54
75
40
4
5
5
7
11
16
2.4
3.9
NS
NS
7.0
9.2
NS
NS
NS
4
5
132
153
56
59
93
128
83
97
6
174
76
100
99
4
5
132
153
80
78
118
6
174
4
5
132
153
6
174
4
5
132
153
6
4
6
LSD (0.05)
U.S. Number 1, oz sizes
6-8 8-10 10-12 12-16
Hrv
CItr
HrvXCItr
66
59
42
47
42
72
1
NS
14.0
NS
12.5
16.0
9.2
1.3
NS
4.1
14.2
15.6
12.5
11.8
13.3
15.5
NS
3.5
NS
NS
NS
NS 24.0
NS
NS
6.1
4.3
NS
147
1
9
30
25
20
-c
0
C
15
10
5
0
U)
C'l
(D
U)
C/)
0
1-
C/)
CO
—
0)
N
U)
0
CO
0)
0)
0
(0
0)
.-
C'1
1-
U)
CO
Days after planting
Figure 1. Irrigation water applied through the growing season compared to crop
evapotranspiration (ETa) estimated by an AgriMet weather station, Oregon State
University, Malheur Experiment Station, Ontario, OR, 2004.
Days after planting
C>
N
N
cD
LU
p.>
CD
0,
p.-
CC
Cc
(0
C>
0,
N
0,
(0
N
C,
C
p.
-10
-20
ca
-30
S
-40
C
a>
a
-50
U)
-60
0
C/)
-70
-80
-90
-100
Figure 2. Soil water potential (kPa) measured by Watermark sensors during the
irrigation period of drip-irrigated potato clones, Oregon State University, Malheur
Experiment Station, Ontario, OR, 2004.
148
—
700
Total yield = -138 + 719 / (1+ 43.2.0.04t) R2 = 0.98
U.S. No. One = -104 + 6491(1+ 50.70.04t) R2 = 0.97
Marketable = -139 + 701 / (1 + 54.2 0.04t) R2 = 0.98
600
.
.
500
U)
C-)
CU
-o
U)
A
400
300
>-
200
Total
U.S. No. One
100
'•—'—'—'—'—'—
Marketable
0
48
69
90
111
132
153
Days after planting, t
Figure 3. Tuber bulking over time for potato clone A92294-6, Oregon State University, Maiheur Experiment Station,
Ontario, OR, 2004.
174
700
Total yield = -132 + 691 / (1+ 48.9 o.o4t) R2 = 0.96
U.S. No. One = -127 + 658/(1+ 48.3 0.04t) R2 = 0.96
Marketable = -125 + 655 / (1+ 59.7 o.04t) R2 = 0.95
600
500
.
4
.
a)
I—
.
400
$
S
A
I
300
>-
.
200
Total
U.S. NJo. One
100
Marketable
0
48
69
90
111
132
153
174
Days after planting, t
Figure 4. Tuber bulking over time for potato clone A93157-6LS, Oregon State University, Maiheur Experiment Station,
Ontario, OR, 2004.
700
Total yield = -170 + 617 / (1 + 28.0 o.04t) R2 = 0.98
U.S. No. One = -166 + 562 I (1+ 25.0 0.04t) R2 = 0.97
Marketable = -162+593/(1+ 35.30.04t) R2 0.97
600
500
..
ci)
C)
C',
ci)
.
.
400
I — — —— — —
A
300
A
>A
200
.
100
Total
—_—_______—_
U.S. No. One
II — I — I — I — I — I —
Marketable
0
48
69
90
111
132
153
174
Days after planting, t
Figure 5. Tuber bulking over time for Ranger Russet, Oregon State University, Maiheur Experiment Station, Ontario, OR,
2004.
700
Total yield -482 + 888 / (1+ g.4o.o4t) R2 = 0.96
U.S. No. One -553 + 875 / (1+ 6.40.04t) R2 = 0.93
Marketable = -259+ 650 / (1+ 19.6 0.04t) R2 = 0.94
600
500
a)
C)
Co
400
.
0
-o
0)
300
aa——
>-
—
.aaa—•——
A
A
A
200
p
100
Total
U.S. No. One
'——I—'—'——
Marketable
0
48
69
90
111
132
153
174
Days after planting, t
Figure 6. Tuber bulking over time for Russet Burbank, Oregon State University, Maiheur Experiment Station, Ontario, OR,
2004.
700
Total yield -283 + 685 / (1+ 16.0 0.04t) R2 = 0.94
U.S. No. One = -353 + 680 / (1+ 10.4 0.04t) R2 = 0.90
Marketable = -239.+ 650 1(1+ 20.9 0.04t) R2 = 0.93
600
.
.A
500
ci)
C)
Co
-o
U)
400
I
300
————
I—————•—
_S
>-
A
A
A
200
Total
100
_. . — _ _ — _ — _..
U.S. No. One
II — I — I — I — I — I —
Marketable
0
48
69
90
111
132
153
174
Days after planting, t
Figure 7. Tuber bulking over time for Shepody, Oregon State University, Maiheur Experiment Station, Ontario, OR, 2004.
700
Total yield = -138 + 627 / (1+ 36.0 0.04t) R2 = 0.96
U.S. No. One = -131 + 601 / (1+ 36.3 0.04t) R2 = 0.96
Marketable = -144 + 628/(1+ 45.1 0.04t) R2 0.96
600
500
.4
I—
C)
ci)
.
400
300
>-
I
200
Total
100
• — _ _ — _ _ — _ — _•
U.S. No. One
II — I — I — I — I — I —
Marketable
0
48
69
90
111
132
153
174
Days after planting, t
Figure 8. Tuber bulking over time for Wallowa Russet, Oregon State University, Maiheur Experiment Station, Ontario, OR,
2004.
700
Total yield = -492 + 845/(1+ 7.9o.o4t) R2 = 0.95
U.S. No. One = -589 + 900/(1+ 5.80.04t) R2 = 0.93
Marketable = -198 + 512 / (1+ 20.1 0.04t) R2 = 0.95
600
500
ci)
0
-o
U)
400
2
*
300
>-
.
A
200
—
100
Total
U.S. No. One
'—'—'—u—'—'—
Marketable
0
48
69
90
111
132
153
174
Days after planting, t
Figure 9. Tuber bulking over time for Umatilla Russet, Oregon State University, Maiheur Experiment Station, Ontario, OR,
2004.
PLANTING CONFIGURATION AND PLANT POPULATION EFFECTS ON
DRIP-IRRIGATED UMATILLA RUSSET POTATO YIELD AND GRADE
Clinton C. Shock, Eric P. Eldredge, Andre B. Pereira,
and Lamont D. Saunders
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Drip irrigation of potato for processing in the Treasure Valley of eastern Oregon and
Idaho is not a standard production practice. However, drip irrigation could provide
several advantages to growers, including no tailwater runoff from the field, the ability to
apply fertilizer to the crop root zone, precise irrigation application, minimal leaching of
chemicals or salts to the groundwater, and reduced canopy moisture with reduced risk
of fungal foliar diseases. Drip irrigation systems are costly to install and manage, and
growers are reluctant to install them on fields where capital has already been spent to
install furrow- or sprinkler-irrigation systems. To be profitable for potato production, drip
irrigation should provide yield and quality above that obtainable with other irrigation
methods. This study was conducted to test modified planting configurations on the
standard 72-inch tractor wheel spacing used in Treasure Valley potato production, to
test whether changes in the planting configuration could improve yield response to drip
irrigation.
By placing two rows on a single bed, plants would be spread apart over the soil surface.
They should not come immediately into competition with each other for sunlight during
June, increasing yield potential. Spreading the plants across the bed could allow a
higher plant population, which might enhance yield and reduce the number of oversize
potatoes. Furthermore, the distribution of plants across the soil surface would provide
better soil shading during June, a factor that might result in better tuber quality.
When potato seeds are planted directly in line with the drip tape, the roots and new
tubers are directly in the most saturated part of the soil. By placing the drip tape offset
from the seed, roots and tubers would develop in a less saturated part of the potato
bed, favoring tuber quality.
Methods
Both Years
The treatments consisted of two populations, 18,150 and 24,200 plants per acre, with
each population planted in three configurations. Drip tapes were shanked into the beds
on May 6. Configuration I was 2 rows 36 inches apart on a nominal 72-inch bed (72
inches furrow to furrow) with a drip tape directly above each row of potatoes (Table 1).
Configuration 2 was 2 rows 36 inches apart on a 72-inch bed with the drip tapes offset
156
7 inches to the inside of the bed from each potato row. Configuration 3 was 4 rows on a
72-inch bed with 16 inches between the pairs of rows, and the paired rows 14 inches
apart, with the drip tape centered between the pairs of rows. Plants were staggered in
the paired rows. Plots were 20 ft long by 2 beds (12 ft) wide, replicated 4 times.
Irrigations were controlled by a CR10 data logger (Campbell Scientific, Logan, UT)
connected to a multiplexer that provided connections for two Watermark (Irrometer Co.
Inc., Riverside, CA) soil moisture sensors in each plot. The sensors were installed in a
plant row at the seed piece depth. The data logger was connected through relays to a
24VAC solenoid valve for each treatment. The drip tape on each set of 4 plots of a
treatment was plumbed through 0.5-inch PVC pipe to 6 solenoid valves supplied with
water under constant pressure. The soil moisture sensors were read by the data logger
every 3 hours. At midnight and noon the data logger calculated the average sensor
readings for each treatment. If the average soil water potential for a treatment was
below -30 kPa, the valve opened for 3 hours to apply a 0.2-inch irrigation. Crop
evapotranspiration (EL) was estimated by an automated AgriMet (U.S. Bureau of
Reclamation, Boise, ID) station located about 0.5 mile away on the Malheur Experiment
Station.
The vines were flailed from the potato plants on October 2, 2003, and on September
21, 2004. The potatoes were dug on October 9, 2003 and on September 29, 2004. The
tubers from 15 ft of the center 2 rows of each 4-row plot were bagged and graded. Data
were statistically analyzed using the ANOVA procedure in NCSS (Number Cruncher
Statistical Systems, Kaysville, UT).
2003 Trial
The 2003 experiment was conducted on Owyhee silt loam, following winter wheat,
where potato had not been planted for 3 years. In September 2002, after the wheat
stubble had been chopped and irrigated, the field was disked. A soil test taken on
September 9, 2002 showed 18 ppm Nitrate (NO3), 18 ppm phosphorus (P), 306 ppm
potassium (K), organic matter 2.2 percent, and pH 7.6. Fall fertilizer was spread to
apply 21 lb Nitrogen (N)Iacre, 100 lb phosphate (P205)/acre, 60 lb potash (K20)/acre,
60 lb sulfur (S)/acre, 30 lb magnesium (Mg)/acre, 4 lb zinc (Zn)/acre, 2 lb copper
(Cu)/acre, 1 lb manganese (Mn)/acre, and 1 lb boron (B)/acre. The field was deep
ripped, disked, and Telone Il® was applied at 25 gal/acre, and the soil was bedded on
36-inch spacing. On April 4, 2003, Roundup® was applied at 1 qt/acre to control winter
annual weeds and volunteer wheat.
Certified seed of 'Umatilla Russet' was cut by hand into 2-oz seed pieces and treated
with Tops MZ + Gaucho® dust. On April 23 and 24, the cut seed was planted 8 inches
deep using a custom-built potato plot planter. The planter used cups on chains driven
by a ground wheel, with interchangeable drive sprockets providing the adjustment of
seed spacing in the row. Four individual planter units could be slid to different positions
on the frame so that two or four rows could be planted at various between-row
spacings. On April 28, the beds were shaped using a spike bed harrow pulling wide
157
shovels to maintain the wheel furrows and dragging a chain to pull soil into the center of
the bed and smooth the top flat.
Prowl® at 1 lb/acre plus Dual® at 2 lb/acre was applied on May 1. On May 6 the drip
tape was installed in each plot using a pair of drip tape injectors and spools mounted on
a tool bar and moved to the correct spacing for each treatment. The drip tape was
T-tape 0.22 gal/hour/I 00 ft, with 12-inch emitter spacing. Matrix® herbicide was applied
at 1.25 oz/acre on May 28. The first irrigation was applied on June 6. Bravo® plus
Ridomil Gold® was applied by aerial application on June 7 and again on June 25. Bravo
fungicide plus liquid sulfur was applied by aerial applicator on July 2, and again on
August 8. Sulfur dust was applied by aerial applicator on July 20 at 40 lb S/acre.
2004 Trial
The procedures were similar for the 2004 trial. The soil was Owyhee silt loam where the
previous crop was winter wheat. The wheat stubble was flailed and the field was
irrigated and disked. A soil test taken on September 16, 2003 showed 37 lb N/acre in
the top 2 ft of soil, and 102 lb available P2O5, 851 lb soluble K20, 29 lb sulfate (SO4),
1966 ppm Ca, 463 ppm Mg, 87 ppm Na, 1.6 ppm Zn, 18 ppm Fe, 4 ppm Mn, 0.7 ppm
Cu, 0.5 ppm B, organic matter 3.5 percent, and pH 7.4 in the top foot of soil. Fall
fertilizer was spread to apply 60 lb N/acre, 50 lb P205/acre, 80 lb 1K20/acre, 57 lb S/acre,
8 lb Zn/acre, 5 lb Cu/acre, and 1 lb B/acre. The field was ripped, Telone II soil fumigant
was injected at 25 gal/acre, and the field was bedded on 36-inch row spacing.
Potato seed of Umatilla Russet was commercial certified seed from central Oregon.
Seed was cut by hand into approximately 2-oz pieces, treated with Tops MZ plus
Gaucho seed-treating dust. The potatoes in plots with four rows per bed were planted
on April 29, and the two-row beds were planted on April 30. On May 1, the beds were
formed with a spike harrow pulling wide shovels to clean the furrows and form the
shoulders of the beds, and dragging a heavy chain to smooth and flatten the top of the
bed. The drip tape was installed on May 5 and 6, at 2- to 3-inches depth. The drip tape
was 5/8-inch diameter, with 5-mil wall thickness, 6-inch emitter spacing, 0.22
gal/mm/lOU ft flow rate (1-tape, 1-Systems International, San Diego, CA). Irrigations
began on June 16.
at 1 lb/acre plus Dual at 2 lb/acre was applied on May 7, 2004 before any potato
plants had emerged, and was incorporated with the bed harrow. Matrix herbicide was
applied at 1.25 oz/acre on May 17, and was incorporated by 0.41 inch of rain on the
next day, followed by 0.89 inch of additional rain through the end of May. Fungicide
applications to control early blight and prevent late blight infection started with an aerial
application of Ridomil Gold and Bravo at 1.5 pint/acre on June 12. On June 25,
Headline® fungicide was applied, on July 17, Topsin-M fungicide plus liquid sulfur with
1.5 lb P2O5/acre and 0.2 lb Zn/acre was applied by aerial applicator. On August 8,
Headline pIus 6 lb S/acre was applied to prevent two-spotted spider mite infestation and
powdery mildew infection. No fertilizer was applied to the field in the spring. Petiole
tests were taken every 2 weeks from June 11, and fertilizer was injected into the drip
system during irrigation to supply the crop nutrient needs.
Prowl
158
Fertilizer solution was injected into the drip system in response to bi-weekly petiole
tests. The total fertilizer applied from June 19 to August 14, both through the drip
system and by aerial application, was 108 lb N/acre, 28 lb P205/acre, 12 lb K20/acre, 14
lb S04/acre, 40 lb S/acre, 0.03 lb Ca/acre, 0.5 lb Mg/acre, 0.61 lb Zn/acre, 1.15 lb
Mn/acre, 0.69 lb Cu/acre, 0.06 lb Fe/acre, and 0.01 lb B/acre.
Results and Discussion
2003 Results
In 2003, the low-population (18,150 plants/acre), 36-inch hills with drip tape
configuration yielded 556 cwt/acre, significantly more than the 470 cwt/acre total yield in
the high-population (24,200 plants/acre), 36-inch hills with drip tape configuration
(Table 2).
For the marketable yield category, comprised of the U.S. No. 1 and No. 2 tubers over 4
oz, there was a significant difference between the high and low plant population on the
hills with drip tape configuration. The average marketable yield was higher with the low
plant population, and there was a significant interaction between population and
configuration because the marketable yield of the standard configuration at the high
plant population was 333 cwt/acre, which was significantly lower than all other
treatments.
There were no significant differences in percentage of U.S. No. 1 tubers among the
treatments. The overall average percentage of U.S. No. 1 tubers, 66 percent, was lower
than usual for Umatilla Russet at this location. Percentage U.S. No. 1 tubers ranged
from 70 percent for the staggered double row (configuration 3) at the low plant
population, to 63 percent for the 2 rows per bed with the drip tapes offset 7 inches
(configuration 2) at the high population.
The high plant population produced significantly more small, 4- to 6-oz, U.S. No. I
tubers, and undersized tubers. There were no significant differences in yield of 6- to
12-oz U.S. No. 1 tubers. The high plant population produced a lower 12- to 16-oz and
over 16-oz U.S. No. 1 yield. Total U.S. No. 1 yield was significantly higher at the low
plant population with configuration 1.
The yield of U.S. No. 2 tubers was significantly greater with the low plant population.
The high plant population standard configuration produced the lowest U.S. No. 2 yield,
but that treatment also produced the most undersize tubers of less than 4 oz.
2004 Results
In 2004, there was a significant interaction between population and configuration for
percentage of U.S. No. I tubers. There was a higher percentage of U.S. No. 1 in the
low population with 2 rows of potato plants on a 72-inch bed with 2 drip tapes offset 7
inches inside the row, compared to the 2 rows with the drip tape above the row at the
low population and 4 rows in a staggered planting with tapes between pairs of rows at
159
the high population (Table 3). This interaction in production of U.S. No. 1 tubers also
was seen in the total U.S. No. 1 production in 2004.
Both Years
The averaged data from 2003 and 2004 showed significantly higher total yield for
configuration 3 at the high population (Table 4). The high population produced
significantly more 4- to 6-oz tubers, and there was a significant year by population
interaction. The lowest yield of U.S. No. 2 tubers was produced by the high population
in two rows per bed with drip tape above the row (configuration 1).
The soil water remained adequate all season, since the soil water potential remained in
the ideal range for all treatments (Fig. 1).
The average water applied by the drip-irrigation systems is one of the interesting
aspects of this trial. The total amount of water applied by the drip systems plus rainfall
averaged only 15.76 inches, 66.3 percent of the estimated potato evapotranspiration
(23.78 inches) from May 25 to September 3 of 2004 (Fig. 2). This result suggests that
drip irrigation is a very efficient method for applying limited amounts of water for potato
production.
160
0
Treat I
-10
Treat 2
-20
Treat 3
a-
a)
4-
0
0.
Treat 4
-30
Treat 5
C)
4-
-40
Treat 6
0
Cl)
-50
40 50 60 70 80 90 100 110 120 130
Days after planting
Figure 1. Average soil water potential of six different drip-irrigation treatments for
potato, 2004, Malheur Experiment Station, Oregon State University, Ontario, OR.
U)
C)
.=
Treat I
25
C.)
C.)
I-
Treat 2
20
LU
Treat 3
15
-
a)
4CC
10
Treat 4
Treat 5
V
C)
4-.
CC
Treat 6
5
E
ETc
C)
C.)
0
30
50
70
90
110
130
Days after planting
Figure 2. Cumulative irrigation water plus rainfall for six different drip-irrigation
treatments for potato compared with the accumulated potato evapotranspiration from
May 25 through September 3, 2004, Malheur Experiment Station, Oregon State
University, Ontario, OR.
161
Table 1. Relationship of planting configuration treatments in the planting configuration
trial to a common potato production planting configuration, Malheur Experiment Station,
Oregon State University, Ontario, OR, 2003 and 2004.
Rows and row widths
Plant population
per 36-inch bed
1 row
Plants/acre
18,150
none
Configuration
Common grower
practice
Drip tape
placement relative
to plant row
Treatments in this
per 72-inch bed
trial
Treatment 1
2 rows
18,150
in row
Treatment 2
2 rows
18,150
offset 7 inches
from row
Treatment 3
2 double rows
18,150
between double
rows
Treatment 4
2 rows
24,200
in row
Treatment 5
2 rows
24,200
offset 7 inches
from row
Treatment 6
2 double rows
24,200
between double
rows
162
Table 2. Yield and grade of Umatilla Russet grown at two plant populations and three planting configurations with respect
to the drip tape, Malheur Experiment Station, Oregon State University, Ontario, OR, 2003
.
2003
Treatment
Population
Configuration
18,150
18,150
18,150
Mean
1
2
3
24,200
24,200
24,200
Mean
2
3
Average
Average
Average
Overall mean
2
3
1
1
LSD (0.05) Population
LSD (0.05) Configuration
LSD (0.05) P x C
LSD (0.05) Replicate
Total
yield
Marketable
yield
cwt/acre
U.S. No. 1 yield over 4 oz
4 to 6
over 12
6 to 12
Percent
oz
oz
%
556.4
516.7
516.0
529.7
469.9
447.4
459.3
458.9
67.9
65.4
70.4
67.9
77.6
70.3
68.9
72.3
191.8
178.4
201.9
190.7
469.7
530.9
533.0
511.2
333.3
424.8
447.2
401.8
63.4
62.7
67.0
64.4
113.3
91.8
98.4
155.1
101.1
169.3
200.7
175.0
513.0
523.8
524.5
520.4
401.6
65.6
436.1
64.1
453.3
430.3
68.7
66.1
95.4
81.0
83.7
86.7
22.5
31.8
39
NS
NS
NS
NS
13.5
16.6
NS
NS
NS
39
NS
55.1
45
Total
cwt/acre
377.1
107.7
339.2
90.6
91.1
361.9
359.4
96.5
oz
U.S.
No. 2
over 4
oz
Undersized
under 4 oz
92.8
108.2
97.4
99.5
86.4
69.2
56.7
70.8
35.7
89.2
89.6
71.5
136.4
54.1
297.6
335.6
357.6
330.3
173.4
173.8
201.3
182.8
68.5
82.5
74.8
75.3
337.3
337.4
359.8
344.8
64.3
98.7
93.5
85.5
111.4
87.7
71.3
NS
NS
NS
13.4
NS
NS
NS
13.3
NS
NS
NS
19.2
23.2
NS
NS
22.7
27.8
40.6
29.2
74.5
58.5
106.1
85.8
109.4
90.1
NS
32
Table 3. Yield and grade of Umatilla Russet grown at two pla nt populations and three planting configurations with respect
to the drip tape, Malheur Experiment Station, Oregon State University, Ontario, OR, 2004.
U.S.
2004
Treatment
Population
Configuration
18,150
18,150
18,150
Mean
2
3
24,200
24,200
24,200
Mean
2
3
Average
Average
Average
Overall mean
1
1
1
2
3
LSD (0.05) Population
LSD (0.05) Configuration
LSD (0.05) P x C
LSD (0.05) Replicate
Total
yield
Marketable
yield
cwt/acre
U.S. No. 1 yield over 4 oz
4 to 6
6 to 12
over 12
Percent
oz
oz
%
Total
cwt/acre
12.7
191.5
oz
344.4
384.7
373.5
367.5
254.9
325.8
281.5
287.4
55.0
75.2
63.5
64.5
54.5
59.7
84.5
66.2
124.2
178.6
130.5
144.5
52.9
20.2
28.6
291.2
235.2
239.3
402.1
357.4
380.5
380.0
331.2
277.1
71.1
151.5
77.1
288.1
143.1
267.0
291.7
62.7
51.9
61.9
59.5
59.7
61.6
60.3
117.9
137.5
22.9
20.2
40.0
225.6
199.6
237.8
373.3
371.0
377.0
373.8
293.1
63.1
301.4
274.2
289.6
68.9
57.7
63.2
57.0
59.7
73.0
63.2
137.9
160.8
124.2
141.0
44.9
37.9
20.2
34.3
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
16.6
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
No. 2
over 4
oz
63.4
34.6
46.3
Undersized
under 4 oz
48.1
86.8
58.9
90.4
78.7
43.2
51.5
67.4
54.0
70.8
75.4
113.2
86.4
239.8
258.4
217.4
238.5
53.3
78.8
43.1
56.8
51.1
101.8
82.6
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
88.7
NS
67.1
Table 4. Yield and grade of Umatilla Russet grown at two plant populations and three planting configurations with respect
to the drip tape, averaged over two years, Malheur Experiment Station, Oregon State University, Ontario, OR, 2004.
U.S. No.
2003 and 2004 Averaged
Treatment
Population Configuration
18,150
1
18,150
2
18,150
3
Mean
24,200
24,200
24,200
Mean
Average
Average
Average
Overall mean
1
2
3
1
2
3
LSD (0.05) Year
LSD (0.05) Population
LSD (0.05) Yearx
Population
LSD (0.05) Configuration
LSD (0.05) Yearx
Configuration
LSD (0.05) Population x
Config.
Marketable
yield
cwt/acre
450.4
362.4
450.7
386.6
444.7
370.4
448.6
373.1
Total
yield
435.9
Percent
percent
61.4
70.3
67.0
66.2
U.S. No. I yield over 4 oz
6 to 12
over 12
4 to 6 oz
oz
Total
oz
cwt/acre
Undersized
2
over 4
oz
under 4 oz
158.0
178.5
166.2
167.6
60.2
71.7
55.7
62.5
284.3
315.2
298.6
299.3
78.1
86.6
65.0
76.7
69.2
71.4
71.8
73.8
64.1
153.3
156.2
159.3
156.2
53.1
48.7
39.3
47.0
292.8
280.6
278.6
284.0
39.4
70.3
78.5
62.8
103.6
90.7
99.5
97.9
66.1
73.6
74.8
456.8
445.6
332.3
350.9
357.1
346.8
67.3
62.7
59.5
63.1
86.4
75.7
80.0
80.7
443.1
447.4
450.7
447.1
347.3
368.8
363.7
359.9
64.3
66.5
63.2
64.7
76.2
70.3
78.4
75.0
155.6
167.3
162.7
161.9
56.7
60.2
47.5
54.8
288.5
297.9
288.6
291.7
58.8
70.9
75.2
68.3
95.1
19.34
NSt
32.10
5.89
(6%)
12.46
NS
NS
NS
19.17
(9%)
24.88
36.72
8.81
NS
NS
NS
NS
NS
NS
6.74
(8%)
17.56
NS
NS
(8%)
NS
NS
NS
NS
NS
(6%)
15.26
NS
NS
NS
NS
NS
NS
(9%)
21.51
NS
30.01
NS
NS
(8%)
NS
NS
NS
NS
21.51
NS
444.1
tNot Significant at alpha = 0.05.
Becomes significant at this alpha level.
NS
77.4
86.5
86.3
A SINGLE EPISODE OF WATER STRESS REDUCES THE YIELD AND
GRADE OF RANGER RUSSET AND UMATILLA RUSSET POTATO
Andre B. Pereira, Clinton C. Shock, Eric P. Eldredge, and Lamont D. Saunders
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Deficit irrigation is a strategy where crops are allowed to sustain some degree of
water deficit in order to reduce costs and potentially increase revenues. English
and Raja (1996) described three deficit irrigation case studies where the
reductions in irrigation costs are greater than the reductions in revenue due to
reduced yields. In these case studies deficit irrigation can lead, in principle, to
increased profits when water supplies are limited.
Deficit irrigation has been used successfully with a number of crops. Shock et al.
(1998) reported that deficit irrigation of potatoes could be difficult to manage
because reductions in tuber yield and quality can result from even brief periods
of water stress. However, in some circumstances potatoes can tolerate limited
deficit irrigation before tuber set without significant reductions in tuber external
and internal quality.
It is generally recognized that some potato varieties are more drought tolerant
than others, that is, they give higher yields of tubers in dry years than other
varieties (Joyce et al. 1979). Nevertheless, there is not enough information on
the effects of slight or moderate water stress on yield of different varieties of
potato. The adoption of new potato cultivars by growers and processors makes it
desirable to reexamine deficit irrigation, particularly during tuber development.
The objectives of this study were to 1) determine 'Umatilla Russet' and 'Ranger
Russet' potato responses to a single episode of water stress during tuber
bulking, and 2) evaluate the potential for deficit irrigation to improve economic
efficiency of potato production in the Treasure Valley under a sprinkler-irrigation
system.
Materials and Methods
Two potato varieties (Umatilla Russet and Ranger Russet) were grown under
sprinkler irrigation on Owyhee silt loam, where winter wheat was the previous
crop in a potato, wheat, corn, wheat, and potato rotation. The wheat stubble was
flailed and the field was irrigated and disked. A soil test taken on September 16,
2003 showed 37 lb nitrogen (N)/acre in the top 2 ft of soil, and 102 lb available
166
phosphate (P205), 851 lb soluble potash (K20), 29 lb sulfate (SO4), 1966 ppm
calcium (Ca), 463 ppm magnesium (Mg), 87 ppm sodium (Na), 1.6 ppm zinc
(Zn), 18 ppm iron (Fe), 4 ppm manganese (Mn), 0.7 ppm copper (Cu), 0.5 ppm
boron (B), 3.5 percent organic matter, and pH 7.4 in the top foot of soil. Fertilizer
was spread in the fall to apply 60 lb N/acre, 50 lb P205/acre, 80 lb 1K20/acre, 57
lb sulfer (S)Iacre, 8 lb Zn/acre, 5 lb Cu/acre, and 1 lb B/acre. The field was
ripped, Telone Il® soil fumigant was injected at 25 gal/acre, and the field was
bedded on 36-inch row spacing.
Seed of the 2 varieties was hand cut into 2-oz seed pieces and treated with
Tops-MZ+ Gaucho® dust 1-2 weeks before planting and placed in storage to
suberize. On March 22 the field was cultivated with a Lilliston rolling cultivator to
reshape the hills and to control winter annual weeds and volunteer wheat. On
April 2 a soil sample was taken that showed 43 lb N/acre in the top two feet of
soil, 83 lb available P205, 688 lb soluble K20, 26 lb SO4, 1,835 ppm Ca, 353 ppm
Mg, 69 ppm Na, 1.1 ppm Zn, 5 ppm Fe, I ppm Mn, 0.4 ppm Cu, 1.2 ppm B, pH
7.4, and 3.0 percent organic matter in the top foot of soil.
Potato seed pieces were planted using a 2-row cup planter with 9-inch seed
spacing in 36-inch rows. Umatilla Russet was planted on April 19 and Ranger
Russet was planted on April 26. After planting, hills were formed over the rows
with a Lilliston rolling cultivator. Prowl® at 1 lb/acre plus Dual® at 2 lb/acre
herbicide was applied as a tank mix for weed control on May 7 and was
incorporated with the Lilliston. Matrix® herbicide was applied at 1.25 oz/acre on
May 17 and was incorporated by 0.41 inch of rain on the next day, followed by
0.89-inch additional rain through the end of May 2004.
Under non-water stress conditions irrigation was applied 16 times from June 4 to
August 30, with scheduling based on soil water potential (Fig. 1). The average
readings of 6 Watermark soil moisture sensors model 200 SS (Irrometer Co.
Inc., Riverside, CA) were monitored every 8 hours by a Hansen model AM400
datalogger (M. K. Hansen Co., East Wenatchee, WA). Sensors were installed in
the potato row at the seedpiece depth, 10 inches from the top of the hill. The
AM400 unit was read daily through the summer to establish when to irrigate, with
the objective to apply water before the average soil moisture in the potato root
zone at the seedpiece depth exceeded -60 kPa (Fig. 2). Water applied was
estimated by recording the sprinkler set duration at 55 psi, and using the nominal
sprinkler head output. Crop evapotranspiration (ETa) was estimated by the U.S.
Bureau of Reclamation based on data from an AgriMet weather station on the
Malheur Experiment Station.
For the water stressed treatment, a single irrigation was skipped on June 28
during tuber bulking (Fig. 1). Eight rain shelters 21 ft long and 10 ft wide were
made from clear polyethylene sheets stretched over PVC pipe. These rain
shelters were used to prevent sprinkler irrigation on four plots of Umatilla Russet
and four plots of Ranger Russet. The area of each plot was 3 potato plant-rows
167
spaced 3 ft apart, 21 ft long, with only the center 15 ft of the middle row
harvested. The statistical design was a randomized complete-block design with
four replicates. After the 5-hour, 1 .5-inch irrigation, the plastic sheets were
removed from the PVC frames.
Fungicide applications to control early blight and prevent late blight infection
started with an aerial application of Ridomil Gold® and Bravo® at 1.5 pint/acre on
June 12. On June 25, Headline® fungicide was applied; on July 17, Topsin-M®
fungicide plus liquid sulfur with 1.5 lb P205/acre and 0.2 lb Zn/acre was applied
by aerial applicator. On August 8, Headline plus 6 lb S/acre was applied to
prevent two-spotted spider mite infestation and powdery mildew infection.
Petiole tests were taken every 2 weeks from June 14, and fertilizer was injected
into the sprinkler line during irrigation to supply the crop nutrient needs. A total of
103 lb N/acre, 44 lb P2O5/acre, 140 lb K20/acre, 100 lb SO4/acre, 0.3 lb Mn/acre,
5 lb Mg/acre, 0.1 lb Cu/acre, 0.1 lb Fe/acre, and 0.5 lb B/acre were applied.
Vines were flailed on September 21 and Umatilla Russet and Ranger Russet
tubers were dug on October 5 and 6 with a two-row digger that laid the tubers
back onto the soil in each row. Visual evaluations included observations of
desirable traits, such as a high yield of large, smooth, uniformly shaped and
sized, oblong to long, attractively russetted tubers, with shallow eyes evenly
distributed over the tuber length.
Tubers from 15 ft of the middle row of the 3-row plot were picked up. Tubers
were placed into burlap sacks and hauled to a barn where they were kept under
tarps until grading. Tubers were graded and a 20-tuber sample from each plot
was placed into storage. The storage was kept near 90 percent relative humidity
and the temperature was gradually reduced to 45°F. Tubers were removed from
storage December 7 and evaluated for tuber quality traits, specific gravity, and
fry color. Specific gravity was measured using the weight-in-air, weight-in-water
method. Ten tubers per plot were cut lengthwise and the center slices were fried
for 3.5 mm in 375°F soybean oil. Percent light reflectance was measured on the
stem and bud ends of each slice using a Photovolt Reflectance Meter model 577
(Seradyn, Inc., Indianapolis, IN) with a green tristimulus filter, calibrated to read 0
percent light reflectance on the black standard cup and 73.6 percent light
reflectance on the white porcelain standard plate.
Data were analyzed with the General Linear Models analysis of variance
procedure in NCSS (Number Cruncher Statistical Systems, Kaysville, UT) using
the Fisher's Protected LSD means separation t-test at the 95 percent confidence
level.
168
Results and Discussion
Precipitation for May 1 through September 30 was 2.55 inches and the crop
evapotranspiration (ETa) totaled 26.19 inches. The potato plants received 22.15
inches of irrigation plus precipitation throughout the full growing season, or 84.6
percent of
(Fig. 1). The step increases in the irrigation plus rainfall curve
(control) show the 16 sprinkler irrigations applied during the growing season. For
the water stress treatment, 15 irrigation episodes were applied, with a single
deficit imposed on June 28 as pointed out by the arrow in Figure 1. The previous
irrigation was on June 22 and the first irrigation following stress was on July 4.
Rainfall during this time interval was 0.07 inch on June 24 and 0.03 inch on June
30.
The trend of soil moisture during the growing season is presented in Figure 2.
The data do not show the individual irrigations because the water did not always
penetrate the soil to the sensors. The irrigation plus rainfall was less than
for
the growing season, and the sensor data show that average root zone soil water
potential became drier than -60 kPa at least four times during the growing
season.
Soil water potential at the seedpiece depth was allowed to become drier than -60
kPa at the end of the growing season, due to the risk of tuber decay in this field.
Frequent sprinkler irrigations of short duration were applied, as shown in Figure
2. This was necessary to avoid swollen lenticels and the associated possibility of
rotting the tubers of the early maturity potato varieties planted in the same field,
while continuing to apply a portion of the
requirement for the late maturing
entries in shallow moisture increments.
Although mean total yield for both cultivars was not influenced by water
treatments tested in this preliminary trial, marketable yield and total yield of U.S.
No. 1 tubers were significantly affected by a single episode of water stress during
tuber bulking (Table 1). Deficit irrigation substantially reduced the percentage of
U.S. No. 1 and over-i 2-oz tubers, with Ranger Russet showing more
pronounced response to water stress than Umatilla Russet.
In this preliminary trial, Umatilla Russet responded positively to applied water for
total yield and was the most productive cultivar in total yield, besides the
non-significant differences among treatments; this agrees with the results
obtained by Shock et al. (2003). However, Ranger Russet showed the highest
total U.S. No. I and marketable yields under a non-limiting water supply.
Production of marketable tubers for processing (which comprises total U.S. No. 1
plus U.S. No. 2 grades) was significantly affected by a single missed irrigation for
both potato cultivars. A single episode of water stress during tuber bulking
brought about a reduction of 4.5 percent and 26.0 percent on marketable yield of
Umatilla Russet and Ranger Russet, respectively.
169
Shock et al. (2003) reported that well-watered potato subjected to irrigation
deficits during tuber bulking responded with reduced specific gravity. Although
nonsignificant differences were found between cultivars under both irrigation
treatments for specific gravity in this preliminary study, a slight tendency toward
reduced specific gravity was observed for Ranger Russet due to a single episode
of water stress during tuber bulking. The specific gravity ranged from 1.079 to
1.084 g
with Ranger Russet showing mean values above 1.080 g cm3
when water was applied at a rate as close as possible to EL, a desirable level
for processing into frozen potato products.
Length/width ratio was significantly affected by irrigation deficit, with a reduction
of about 9 percent for the Ranger Russet potato cultivar.
Acknowledgements
We would like to thank Conselho de Desenvolvimento Cientifico e Tecnologico
(CNPq) of Brazil for providing a Post-Doctoral scholarship and also for the
support from Oregon State University that enabled this work.
References
English, M., and SN. Raja. 1996. Perspectives on deficit irrigation. Agricultural
Water Management 32:1-1 4.
Joyce, R., A. Steckel, and D. Gray. 1979. Drought tolerance in potatoes. J.
Agric. Sci. (Cambridge) 92:375-381.
Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 1998. Potato yield and quality
response to deficit irrigation. HortScience 33:655-659.
Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 2003. 'Umatilla Russet' and
'Russet Legend' potato yield and quality response to irrigation. HortScience
38:1117-1 121.
170
1 Stress
Check
ETC
25
1..
a)
Cs
20
0
15
Ce
0
C
10
5
0
140
160
180
200
220
240
260
Day of the year
Figure 1. Crop evapotranspiration (ETa), sprinkler irrigation applied plus rainfall
(control), and a single episode of water stress (arrow) during tuber bulking of
Ranger Russet and Umatilla Russet potato, Malheur Experiment Station, Oregon
State University, Ontario, OR, 2004.
230
.
--
—
—.
——
——.—
—
•
•
•70
Figure 2. Soil moisture data over time for a sprinkler-irrigated potato trial,
Malheur Experiment Station, Oregon State University, Ontario, OR, 2004.
171
Table 1. Mean yield and grade of Ranger Russet and Umatilla Russet
sprinkler-stressed potato trial, Maiheur Experiment Station, Oregon State
University, Ontario, OR, 2004.
Variety + irrigation
treatment
Yield
<4oz
Yield
4-6oz
Umatilla check
Umatilla stress
Ranger check
Rangerstress
LSD (0.05) var.
LSD (0.05) stress
LSD (0.05) var. x stress
69.4
84.6
45.5
84.5
55.3
50.2
65.8
Variety + irrigation
treatment
Umatilla check
Umatilla stress
Ranger check
Rangerstress
LSD (0.05) var.
LSD (0.05) stress
LSD (0.05) var. x
stress
NS = Not significant.
80.1
14.5
NS
NS
NS
17.1
NS
Rotten
tubers
1.8
0.7
0.8
1.5
NS
NS
NS
Yield
Yield
6-l2oz
>l2oz
cwt/acre
120.4
35.3
107.7
15.9
96.8
90.1
109.2
7.5
NS
NS
NS
Marketable
yield
cwtlacre
211.0
280.7
173.8
268.2
252.7
319.5
196.8
236.7
23.2
NS
23.2
37.9
No. 1
yield
NS
NS
172
17.2
17.2
24.3
Total
yield
Yield
No. 2
Yield
cull
69.7
94.4
66.8
40.0
21.4
17.6
NS
NS
NS
NS
24.9
6.1
0.0
1.1
373.4
359.7
365.8
323.9
Specific
gravity
gcm3
1.079
1.079
1.084
1.080
Length
/width
ratio
2.19
2.15
2.16
1.96
NS
NS
NS
NS
NS
NS
NS
0.11
NS
IRRIGATION SYSTEM COMPARISON FOR THE PRODUCTION OF RANGER
RUSSET AND UMATILLA RUSSET POTATO
Clinton C. Shock, Eric P. Eldredge, Andre B. Pereira,
and Lamont D. Saunders
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Potato is most often produced using sprinkler irrigation. Over the past 5 years various
drip-irrigation layouts have been tested for potato production at the Malheur Experiment
Station. One option for drip irrigation that we have not tested in recent years would be
to plant potatoes in exactly the same way that potatoes are grown under sprinkler and
furrow irrigation in 36-inch beds. Since we were studying drip-irrigation designs, an
additional treatment was added to every replicate where potato was grown in
conventional beds. Plots of all treatments were lengthened in 2004 so that both
'Umatilla Russet' and 'Ranger Russet' could be grown in each planting configuration. In
addition, sprinkler-irrigated Umatilla Russet and Ranger Russet potatoes were grown
alongside the drip irrigation experiment. This allowed a comparison of sprinkler
irrigation, drip with conventional 36-inch hilled beds, and drip irrigation with various flat
bed configurations.
Methods
Umatilla Russet and Ranger Russet were grown using sprinkler irrigation and 4 drip
irrigation layouts at 18,150 plants/acre (Table 1). The drip-irrigation cultural practices
are described in Shock et al. "Planting configuration and plant population effects on
drip-irrigated Umatilla Russet potato yield and grade" found in this report. The
sprinkler-irrigation cultural practices are described in Pereira et at. "A single episode of
water stress reduces the yield and grade of Ranger Russet and Umatilla Russet potato"
also found in this report.
Drip tapes were shanked into the beds on May 6. Treatment 2 had a single drip tape
shanked in over conventionally hilled potato in single rows in 36-inch beds (Table 1).
Treatment 3 had 2 rows 36 inches apart on a nominal 72-inch bed (72 inches furrow to
furrow) with a drip tape directly above each row of potatoes (Table 1). Treatment 4 had
2 rows of plants 36 inches apart on a 72-inch bed with the drip tapes offset 7 inches to
the inside of the bed from each potato row. Treatment 5 had 4 rows of plants on a
72-inch bed with 16 inches between the pairs of rows, and the paired rows 14 inches
apart, with the drip tape centered between the pairs of rows. Plants were staggered in
the paired rows.
173
Planting dates and methods, irrigation management, cultural practices, harvest timing
and methods, and grading and quality evaluations are all described in the two
preceding reports cited above.
The drip plots were in a completely randomized design with the two varieties as split
plots. The replicated sprinkler-irrigated plots were alongside the drip irrigation
experiment. For simplicity, data were handled as if the sprinkler-irrigated treatments
were part of a completely randomized trial, which was not the design. Data were
analyzed with the General Linear Models analysis of variance procedure in NCSS
(Number Cruncher Statistical Systems, Kaysville, UT) using the Fisher's Protected LSD
means separation t-test at the 95 percent confidence level.
Results and Discussion
The reports cited above describe the soil moisture and water applied. Irrigation plus
rainfall varied from 22.15 inches for sprinkler irrigation to 12.59 inches for one of the
drip-irrigated treatments (Table 2). More water was applied to the sprinkler treatment
than any of the drip treatments and the sprinkler-applied water treatment resulted in the
lowest marketable yield per applied water, 13.4 cwt/acre-inch. The drip treatments with
the tape in line with the plant row (treatments 2 and 3) produced less marketable yield
per applied water than the treatments with the drip tape offset from the plant row
(treatments 4 and 5). Averaging over production systems, Ranger Russet produced
significantly more yield of applied water (19.98 cwtfacre-inch) than Umatilla Russet
(15.88 cwt/acre-inch). There was no significant interaction between irrigation system
and variety for yield/water applied in terms of cwt/acre-inch.
The yields for all irrigation systems were relatively low in this trial, a reflection of the
poor quality of this site (Table 3). There was a strong interaction between variety and
irrigation system. The greatest marketable yield occurred with Ranger Russet grown on
a flat bed with a single drip tape for each row of plants (treatment 3). Overall Ranger
Russet was more productive under drip irrigation than Umatilla Russet. Ranger Russet
was not more productive than Umatilla Russet under sprinkler irrigation (Table 3).
Where the drip tape was shanked directly in line with the potato plants, the production
system on flat beds (treatment 3), was 26.7 percent more productive of marketable
tubers than the production system with the drip tape in conventional beds (treatment 2).
174
Table 1. Irrigation systems compared for potato production, Maiheur Experiment
Station, Oregon State University, Ontario, OR, 2004.
Configuration
Plant rows p er
Plant rows per
Drip tape
Treatment
36-inch bed wit h the
72-inch bed with
placement relative
beds hilled
the beds flat
to plant row
No drip tape,
1. Sprinkler irrigated
1 row of plants
sprinkler irrigated
2. Drip in conventional
I row of plants
In plant row
potato hills
3. Drip with flat beds
2 rows of plants
In plant row
4. Drip with flat beds,
Offset 7 inches
2 rows of plants
drip tape offset
from plant row
5. Drip with flat beds,
2 double rows of
Between double
drip tape offset
plants
plant rows
Table 2. Marketable yield, water applied, and w ater use efficiency for irrigation systems
compared for potato production, Malheur Exper iment Station, Oregon State University,
Ontario, OR, 2004.
Applied water,
Marketable yield
Marketable yield
irrigation plus
Treatment
per applied water
precipitation
cwt/acre
acre-inch/acre
cwt/acre-inch
1. Sprinkler irrigated
300.1
22.15
13.4
2. Drip in conventional
255.4
14.41
17.7
potato hills
3. Drip with flat beds
290.1
18.16
17.6
4. Drip with flat beds,
309
15
19.8
drip tape offset
5. Drip with flat beds,
278
12.59
20.9
drip tape offset
LSD (0.05)
2.2
175
Table 3. Ranger Russet and Umatilla Russet performance under five irrigation systems, Maiheur Experiment Station,
Oregon State University, Ontario, OR, 2004
Treatment
Total
yield
Total
U.S.
No. 1
U.S. No.
u•s•
No. I
cwt/acre
Variety = Ranger Russet
1. Sprinkler check plots alongside
2. Hills with drip tape
3. Two row bed, tapes above rows
4. Two row bed, tapes offset 7"
5. Four row bed, tapes between pairs of
375.7
345.3
401.6
385.7
Marketable
yield
.
>12 OZ
6 to 12
4 to 6
oz
oz
U.S.
No. 2
yield
Under
sized
<4 oz
cwtlacre
%
367.1
230
249.3
306.5
288
252.8
62.3
72.2
76.2
74.7
68.7
rows
Mean
291.9
289.9
354.7
329.3
300.3
54.4
30.6
84.5
38.6
33.6
375.1
265.3
70.8
313.2
Variety = Umatilla Russet
1. Sprinklercheck plots alongside
2. Hills with drip tape
3. Two row bed, tapes above rows
4. Two row bed, tapes offset 7"
5. Four row bed, tapes between pairs of
363.5
290.1
384.9
357.6
338.5
233.7
141.5
222.5
204
165.9
63.6
48.9
rows
Mean
346.9
Average of both varieties
1. Sprinklercheck plots alongside
2. Hills with drip tape
3. Two row bed, tapes above rows
4. Two row bed, tapes offset 7'
5. Four row bed, tapes between pairs of
rows
Mean
LSD (0.05) treatment
LSD (0.05) variety
LSD (0.05) treatment x variety
1
116.7
159.6
58.8
167.1
187.9
160.8
48.4
56.8
48.9
308.3
218.8
290.3
263.2
226.7
70.9
5.9
22.9
20.4
193.5
55.3
369.6
317.7
393.3
371.7
352.8
231.8
195.4
264.5
246
209.3
62.9
60.5
67.2
65.8
58.8
361
229.4
42.8
19.9
NS
54.9
61.4
58.3
62
40.7
48.2
41.3
47.6
64.9
53.2
46.2
55.3
65.5
158.4
58.5
47.9
57
4.8
62.3
47.2
67.9
68
72.4
74.6
77.3
67.7
59.2
60.8
50
64.1
15
100.5
88.4
131.8
115.6
78.5
94.2
91.7
110.5
5.2
7.2
0.5
2.7
1.3
261.5
27
103
63.6
67.9
82.1
3.4
300.1
62.7
68.3
18.3
53.1
59
53.7
29.5
24.3
108.6
124
149.5
151.8
119.7
60.6
254.4
322.5
296.3
263.5
61.4
64.7
65.3
57.9
50.3
54.2
57.5
58.6
70.2
73.5
4.7
0.6
63.1
287.4
37.7
130.7
61
44
NS
NS (6%)
2.7
33.5
6.1
16.8
37.5
30.6
7.7
NS (6%)
15.1
17.2
26.9
NS
NS
NS
58.1
12
59
18.9
2.1
0.7
1.1
1.3
12
88
1.9
1.3
57.9
69.6
4.1
NS
8
20.9
9.8
NS
22
NS
NS
NS
DEVELOPMENT OF NEW HERBICIDE OPTIONS FOR WEED CONTROL IN
POTATO PRODUCTION
Corey V. Ransom, Charles A. Rice, and Joey K. Ishida
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Weed control in potatoes is essential for production of high yielding marketable tubers.
Herbicide options in potato production are limited. Outlook®, Spartan®, and Chateau®
(previously Valor®) demonstrate great promise for use in potato. Spartan and Chateau
represent a mode of action that is not currently used in potatoes and offer excellent
hairy nightshade control. Outlook (dimethenamid-p) has the same mode of action as
Dual® but controls a wider spectrum of weeds. Trials were conducted to evaluate new
herbicides for weed control in potatoes. The results of our research have been
provided to herbicide companies, the 1R4 program, and state regulators in support of
additional herbicide registrations in potatoes. Spartan was registered for use in potato
in 2004 and Outlook is registered for use in potato in 2005. Chateau is also registered
for use in potato and will be available in limited quantities for commercial evaluation for
2005. The registration of these herbicides gives producers additional tools for
controlling weeds and may increase economic returns through improved weed control.
Materials and Methods
Three trials were conducted at the Malheur Experiment Station to evaluate new
herbicides for weed control efficacy and crop tolerance in potatoes: Spartan alone and
in 2- and 3-way tank mixtures; comparisons of standard 2-way tank mixtures with
Chateau or Matrix® added in 3-way tank mixtures; and Outlook in 2- and 3-way tank
mixtures. In fall 2003, 50 lb nitrogen (N) and 100 lb phosphorus
was applied
prior to bedding in all trial areas. On October 17, 2003, Telone II" (20 gal/acre) and
Vapam® (20 gal/acre) were applied and the ground was bedded. Potatoes were
planted April 27, 2004 in an Owyhee silt loam soil with pH 7.6, 2.7 percent organic
matter content, and a cation exchange capacity of 19. 'Russet Burbank' seed pieces
were planted
9 inches in 36-inch-wide rows. Seed pieces were treated with TopsMZ® plus GauchoR. Experimental plots were 4 rows wide and 30 ft long. Plots were
sidedressed with 102 lb N, 4 lb P, 9 lb potassium (K), 8 lb sulfate, 32 lb elemental sulfur
(S), 5 lb zinc (Zn), and 1 lb boron (B)/acre on May 3 and rehilled on May 11.
Preemergence herbicides were applied with a CO2-pressurized backpack sprayer
delivering 20 gal/acre at 30 psi and incorporated with approximately 0.5 inch of sprinkler
irrigation on May 13. Petiole samples were taken and sent for nitrate analysis on July
13. On July 16, 25 lb N/acre was applied through the sprinkler. Aerial fungicide
applications included Bravo® and Ridomil GOldR on June 12, Headline® (12 oz/acre) on
177
June 26, Topsin-M® (20 oz/acre) plus liquid sulfur (6 lb/acre) on July 17, and Headline
(12 oz/acre) plus liquid sulfur (6 lb/acre) on August 8. In addition, 1.5 lb P and 0.2 lb
Zn/acre were added to the July 17 fungicide application.
Visual potato injury and weed control were evaluated throughout the growing season
and tubers were harvested from the center two rows of each plot on September 13-15.
Potatoes were graded for yield and size on September 20-27.
Herbicide screening for activity on dodder
Herbicides were screened in a petri dish assay to determine effects on dodder
germination and elongation. Dodder seeds were scarified using sandpaper and 10
seeds were placed in each petri dish. Each dish was treated with 6 ml of water
containing herbicides at rates equivalent to what would be applied in the field. Dodder
germination was counted 4 and 5 days after treatment (DAT), and dodder shoot length
was measured 5 DAT.
Results and Discussion
Spartan alone and in 2- and 3-way tank mixtures
Control of all weeds present in this trial was 93 percent or greater by treatments with
Spartan alone or combined with other herbicides (Table 1). Spartan caused potato
injury on June 9, consisting of interveinal chlorosis and necrosis on one set of leaves,
and injury tended to be greater with higher rates of Spartan (Table 1). No differences in
potato yield were observed between herbicide treatments, suggesting that the injury
was transient (Table 2).
Comparisons of standard 2-way tank mixtures with Chateau or Matrix added in 3way tank mixtures
The 2-way tank mixtures provided the same level of control as 3-way tank mixtures
including either Chateau or Matrix (Table 3). The exception was the combination of
Prowl® plus Eptam®, where pigweed control
was increased with the addition of Matrix.
The 3-way combination of Prowl, Eptam, and Chateau had lower pigweed and
barnyardgrass control than most other treatments. Plots treated with Chateau exhibited
severe injury on May 26 (Table 3). Injury symptoms included stunting and crinkling of
newly emerged shoots and leaves. Rainfall events at the time of potato emergence
may have increased the contact of Chateau with the emerging foliage. Some
treatments were still causing significant injury on June 9. In one instance, the
combination of Prowl, Eptam, and Chateau yielded lower than Prowl plus Eptam (Table
4). This could have been a result of the early injury when Chateau was in the tank
mixture.
Outlook in 2- or 3-way tank mixtures
Outlook combined with Prowl or Sencor® in 2-way tank mixtures or with both in a 3-way
tank mixture provided 96 percent or greater control of all weeds (Table 5). Potato yields
were not different among herbicide treatments (Table 6).
178
Herbicide screening for activity on dodder
Only Nortron® suppressed dodder germination compared to the untreated check (Table
7). However, all herbicides except Chateau shortened shoot length compared to the
untreated check. Nortron caused the greatest reduction followed by Kerb®, Prowl,
Nortron and Kerb are not registered for use in potato. The fact
Spartan, and
that Prowl and Spartan reduced dodder shoot growth suggests they may be useful in
managing dodder in potatoes. In this trial, both Prowl and Spartan rates were higher
than those registered for use in potato. Additional research needs to be done with
Prowl and Spartan rates that are used in potato production.
179
Table 1. Effect of Spartan® alone and in combinations on crop injury and weed control
in potato, Maiheur Experiment Station, Oregon State University, Ontario, OR, 2004.
Weed controlT
Potato injury
Treatment*
Rate
5-26
6-9
Pigweed*
Common
lambsquarters
Kochia
grass
0/
thai/acre
Untreated check
Barnyard
Hairy
nightshade
--
-
-
-
-
-
-
-
Spartan
0.094
0
14
100
100
100
100
98
Spartan
0.14
5
20
100
100
100
100
94
Spartan
0.187
3
20
100
100
100
100
98
Spartan+Prowl
0.094+1.0
3
14
100
100
100
100
93
Spartan+ Prowl
0.14+1.0
6
18
100
100
100
100
100
Spartan+DualMagnum
0.094+1.33
0
11
100
100
100
100
100
Spartan+DualMagnum
0.14+ 1.33
6
21
100
100
100
100
100
Spartan+Outlook
0.094+0.84
3
11
100
100
100
100
100
Spartan+Outlook
0.14+0.84
11
15
100
99
100
100
100
Spartan+Eptam
0.094+3.94
3
13
100
100
100
100
97
Spartan+Eptam
0.14+3.94
4
21
100
100
100
100
99
Spartan+ Prowl
+ Eptam
0.094+ 1.0
3
7
100
100
100
100
99
Spartan+Prowl
0.094+ 1.0
0
11
100
100
100
100
100
+ Dual Magnum
+ 1.33
Spartan+Prowl
0.094+ 1.0
9
5
100
100
100
100
100
NS
9
NS
NS
NS
NS
NS
+ Outlook
LSD (P = 0.05)
*Herbicide treatments
tWeed
+
3.94
+ 0.84
--
were applied preemergence on May 13, 2004.
control evaluations were taken September 2.
tPigweed species were a combination of Powell
amaranth and redroot pigweed.
180
Table 2. Effect of Spartan® alone and in combinations on potato yield and quality,
Maiheur Experiment Station, Oregon State University, Ontario, OR, 2004.
Potat oyieldt
U.S. No. 1
Treatment*
Rate
4-6 oz
6-12 oz
>12 oz
cwt/acre
Total
Percent
Total
No. 2
Total
marketable
Total
yield
--
106
113
15
234
65
5
cwt/acre
239
359
Spartan
0.094
90
316
62
467
75
70
537
616
Spartan
0.14
102
293
79
474
78
58
532
606
Spartan
0.187
87
316
86
488
77
70
558
623
Spartan+Prowl
0.094+1.0
91
289
46
427
73
71
497
583
Spartan +Prowl
0.14+ 1.0
91
298
69
457
74
87
544
609
Spartan + Dual Magnum 0.094 + 1.33
91
287
51
429
72
88
516
584
Spartan + Dual Magnum
0.14 + 1.33
77
306
65
447
75
71
518
592
Spartan + Outlook
0.094 + 0.84
81
290
65
435
74
76
511
586
Spartan + Outlook
0.14 + 0.84
85
295
64
444
73
82
525
601
Spartan + Eptam
0.094 + 3.94
93
296
54
443
74
80
522
598
Spartan + Eptam
0.14 + 3.94
81
319
85
484
78
68
552
617
Spartani-Prowl
0.094+1.0
102
311
64
476
76
71
547
624
lb al/acre
Untreated check
+ Eptam
%
+ 3.94
Spartan + Prowl
+ Dual Magnum
0.094 + 1.0
+ 1.33
97
275
39
411
72
83
493
572
Spartan+Prowl
0.094+1.0
90
290
66
446
75
67
513
590
NS
53
37
74
6.8
26
72
63
+ Outlook
LSD (P = 0.05)
+ 0.84
--
*Herbicide treatments were applied preemergence on May 13, 2004.
were harvested September 13 to 15. Total marketable yield = total number ones + total number twos.
181
Table 3. Comparison of standard 2-way tank mixtures with Chateau® or Matrix® added
in 3-way tank mixtures for potato crop injury and weed control, Maiheur Experiment
Station, Oregon State University, Ontario, OR, 2004.
Weed controlT
Potato injury
5-26
6-9
Pigweedt
Common
lambsquarters
--
-
-
-
1.33 + 0.5
3
3
1.0+0.5
0
Dual Magnum + Prowl
1.33 + 1.0
Prowl + Eptam
DualMagnum+Sencor
Treatment*
Hairy
nightshade
Kochia
Barnyard
grass
-
-
-
-
99
100
96
100
100
0
100
100
100
100
100
0
0
97
99
99
100
100
1.0 + 3.94
0
3
93
100
97
100
97
1.33+0.5
35
15
100
100
100
100
100
32
8
99
100
100
100
98
34
11
99
99
100
100
100
33
6
93
100
100
100
92
1
0
100
100
94
100
100
0
0
100
100
98
100
100
3
3
100
100
100
100
100
Rate
0/
lbai/acre
Untreated check
Dual Magnum + Sencor
Prowl+Sencor
+ Chateau
+ 0.048
Sencor+Prowl
0.5+1.0
+ Chateau
+ 0.048
Dual Magnum+ Prowl
+ Chateau
1.33+ 1.0
Prowl + Eptam
+ Chateau
1.0 + 3.94
+ 0.048
Dual Magnum + Sencor
+ Matrix
1.33 + 0.5
+ 0.0234
Sencor+ Prowl
0.5+ 1.0
+ Matrix
+ 0.0234
+ 0.048
Dual Magnum+ Prowl
1.33+ 1.0
+ Matrix
+ 0.0234
Prowl + Eptam
+ Matrix
1.0 + 3.94
+ 0.0234
0
0
100
100
100
100
100
LSD (P = 0.05)
--
4
5
5
NS
NS
NS
4
*Herbicide treatments were applied preemergence on May 13, 2004.
tWeed control evaluations were taken September 2.
tpigweed species were a combination of Powell amaranth and redroot pigweed.
182
Table 4. Effect of standard 2-way tank mixtures with Chateau® or Matrix® added in 3way tank mixtures on potato yield and quality, Maiheur Experiment Station, Oregon
State University, Ontario, OR, 2004.
Potat o yieldt
U.S. No. 1
Treatment*
Rate
4-6 oz
lbai/acre
>12 oz
6-12 oz
cwtlacre
Total
Percent
Total
No. 2
Total
marketable
cwt/acre
Total
yield
--
90
154
4
247
%
65
20
268
380
Dual Magnum + Sencor
1.33 + 0.5
93
290
69
450
75
76
526
602
Prowl + Sencor
1.0 + 0.5
88
303
68
459
76
67
526
606
Dual Magnum + Prowl
1.33 + 1.0
84
285
87
457
77
70
527
596
Prowl + Eptam
1.0 + 3.94
88
319
87
493
79
64
557
625
Dual Magnum + Sencor
+ Chateau
1.33 + 0.5
+ 0.048
94
290
63
447
74
53
501
602
Sencor+ Prowl
+ Chateau
0.5+ 1.0
103
275
68
445
75
64
509
597
Dual Magnum + Prowl
+ Chateau
1.33 + 1.0
+ 0.048
90
268
66
424
73
60
484
583
Prowl+Eptam
1.0+3.94
99
272
49
419
74
47
467
568
Untreated check
+ Chateau
+ 0.048
+ 0.048
Dual Magnum + Sencor
+ Matrix
1.33 + 0.5
+ 0.0234
87
294
81
462
74
81
543
624
Sencor + Prowl
+ Matrix
0.5 + 1.0
+ 0.0234
92
306
76
473
76
64
537
625
Dual Magnum+Prowl
1.33+ 1.0
78
315
116
508
78
65
574
649
+ Matrix
+ 0.0234
Prowl + Eptam
+ Matrix
1.0 + 3.94
+ 0.0234
101
284
50
437
72
76
514
603
LSD (P = 0.05)
--
NS
36
28
47
5
30
50
44
*Herbicide treatments were applied preemergence on May 13, 2004.
tpotatoes were harvested September 13 to 15. Total marketable yield = total number ones + total number twos.
183
Table 5. Potato injury and weed control with Outlook®, Prowl H20®, and Sencor®
combinations, Malheur Experiment Station, Oregon State University, Ontario, OR,
2004.
Treatment*
Rate
Potato injury
5-26
6-9
Pigweedt
Common
lambsquarters
Kochia
Barnyard
grass
0/
lbai/acre
Untreated check
Weed control7
Hairy
nightshade
--
-
-
-
-
-
-
-
Prowl H20 + Outlook
1.0 + 0.656
6
0
98
100
98
100
100
ProwlH2O+Outlook
1.0+0.84
6
0
100
100
100
100
100
Outlook + Sencor
0.656 + 0.5
0
0
100
100
97
100
100
Outlook + Sencor
0.84 + 0.5
1
0
100
100
96
100
100
Prowl H2O + Outlook
+ Sencor
1.0 + 0.656
+ 0.5
1
0
100
100
100
1
Prowl H2O + Outlook
1.0 + 0.84
1
0
100
100
97
100
100
NS
NS
NS
NS
NS
NS
+Sencor
LSD (P = 0.05)
+0.5
--
5
00
*Herbicide treatments were applied preemergence on May 13, 2004.
TWeed control evaluations were taken September 2.
species were a combination of Powell amaranth and redroot pigweed.
Table 6. Influence of Outlook®, Prowl H20®, and Sencor® combinations on potato yield
and quality, Malheur Experiment Station, Oregon State University, Ontario, OR, 2004.
Potato yieldt
U.S. No. 1
Treatment*
Rate
4-6 oz
6-12 oz
--
98
146
Prowl H2O + Outlook
1.0 + 0.656
91
Prowl H2O + Outlook
1.0 + 0.84
Outlook + Sencor
>12 oz
Total
No. 2
Total
marketable
Total
yield
Total
Percent
9
252
66
16
268
380
302
74
467
77
67
534
606
98
304
67
470
75
73
543
628
0.656 + 0.5
74
316
84
474
77
71
545
619
Outlook + Sencor
0.84 + 0.5
98
280
57
45
75
56
490
575
Prowl H2O + Outlook
+ Sencor
1.0 + 0.656
+ 0.5
90
279
56
425
72
72
497
589
Prowl H2O + Outlook
+ Sencor
1.0 + 0.84
+ 0.5
90
288
59
437
75
64
501
584
--
NS
55
30
64
6
26
61
54
lbai/acre
Untreated check
LSD (P = 0.05)
cwt/acre
%
cwtlacre
*Herbicide treatments were applied preemergence on May 13, 2004.
tpotatoes were harvested September 13 to 15. Total marketable yield = total number ones + total number twos.
184
Table 7. Dodd er germination and shoot length in response to herbicides in a petri-dish
screening trial, Malheur Experiment Station, Oregon State University, Ontario, OR,
2004.
Treatment*
Equivalent rate
lb al/acre
Untreated
--
Prowl
1.5
Kerb
Rate
mg al/liter
Dodder
Germination
5 DAT
4 DAT
%
Shoot
lengtht
----mm----
85
88
58
170
73
73
16
2.0
227
90
93
12
Dacthal
5.0
567
83
85
32
Chateau
0.096
11
80
83
61
0.0234
2.7
68
75
46
Spartan
0.25
28
87
87
24
Nortron
3.0
340
0
10
1.3
Matrix
LSD(P=0.05)
--15
16
3.8
*Herbicide treatments were applied in 5 ml of water on August 12, 2004.
tDodder shoot length was measured only on shoots that had emerged by 4 DAT.
185
SUGAR BEET VARIETY 2004 TESTING RESULTS
Eric Eldredge, Clinton Shock, and Monty Saunders
Malheur Experiment Station
Oregon State University
Ontario, OR
Introduction
The sugar beet industry, in cooperation with Oregon State University, tests commercial
and experimental sugar beet varieties at multiple locations each year to identify
varieties with high sugar yield and root quality. A seed advisory committee evaluates
the data each year to select the best varieties for sugar beet production. This report
provides the agronomic practices, experimental procedures, and sugar beet root yield
and quality for the Maiheur Experiment Station location of the 2004 trials.
Methods
Sugar beet varieties were entered by ACH Seeds, Betaseed, Hilleshog/Syngenta, Holly
Hybrids, and Seedex in 2004. Twenty-nine varieties were tested in the Commercial
Trial, and 31 varieties (including the 4 commercial check varieties) were tested in the
Experimental Trial. Seed for the Commercial Trial was organized by Amalgamated
Sugar Company. Seed of Experimental varieties was sent by the seed companies.
The sugar beet trials were grown on an Owyhee silt loam that had grown winter wheat
the year before. The grain stubble was chopped and the field was irrigated and disked,
then 60 lb nitrogen (N)/acre, 50 lb phosphate (P205)/acre, 80 lb potash (K2O)/acre, 57
lb sulfur (S)/acre, 8 lb zinc (Zn)/acre, 5 lb copper (Cu)/acre, and 3 lb boron (B)/acre
were applied according to fall soil sampling results. The field was then disked, ripped,
plowed, and groundhogged. On November 7, the soil was fumigated with Tetone C17®
at 15 gal/acre, and fall bedded on 22-inch rows.
On March 30, the beds were dragged off using a spike-tooth bed harrow with 3.75-inch
angle iron furrow slickers. Preplant herbicide Nortron® at 6 pint/acre was applied and
incorporated using the bed harrow. Both the Experimental Trial and the Commercial
Trial were planted on April 1. Seeds were planted in four-row plots with John Deere
model 71 flexi-planter units with double disc furrow openers and cone seeders fed from
a spinner divider that uniformly distributed the seed. Plots of each variety were 4 rows
wide (22-inch row spacing) by 23 ft long, with a 4-ft alley separating each tier of plots.
The seeding rate was 12 viable seed/ft of row. Each entry was replicated eight times in
a randomized complete block design.
A soil test taken on April 4, 2004, showed pH 7.8, 2.9 percent organic matter, 32 lb
nitrate (N03)/acre available in the top 2ft of soil, 20 ppm extractable phosphorus (P),
186
256 ppm exchangeable potassium (K), 10 ppm sulfate (SO4), 433 ppm magnesium
(Mg), 82 ppm sodium (Na), 4.1 ppm Zn, 5 ppm iron (Fe), 1 ppm manganese (Mn), 0.6
ppm Cu, and 0.8 ppm B.
On April 5 Counter 2OCR® was applied in a band over the row at 7.4 lb/acre (5 oz/1 ,000
ft of row). The first irrigation was applied on April 9, for 24 hours. A 44.5-hour irrigation
on April 12 that was applied to wet the seed rows for more uniform germination was
followed by 0.9 inch of rain April 19-21. On April 27, Poast® herbicide was applied at2
pint/acre to control grasses and volunteer wheat. On May 4, a tank mix of BetamixR at
32 oz/acre, UpbeetR at 0.5 oz/acre, and Stinger® at 3 oz/acre was applied for weed
control. Seedlings were thinned by hand to 1 plant every 6.4 inches on May 10 and 11.
On May lithe plots of two entries in the Experimental Trial that failed to emerge were
replanted with the border variety, PM21.
The field was sidedressed with Temik 15G® at 10 lb/acre on May 13 to control sugar
beet root maggot, and the field was irrigated for 24 hours to move the insecticide with
the wetting front into the sugar beet seedlings' root zone. On May 25, urea was
sidedressed to supply 182 lb N/acre. On May27 the field was cultivated and
with 9-inch sweeps ahead of 6-inch angle iron furrow slickers. On June 1,
TreflanR
herbicide was applied at 1.5 pint/acre and incorporated with the same
cultivator.
The field was furrow irrigated with surge irrigation from gated pipe. Irrigation was
monitored with Watermark soil moisture sensors Model 200SS (Irrometer Co. Inc.,
Riverside, CA) connected to an AM400 Hansen datalogger (M.K. Hansen Co.,
Wenatchee, WA) to maintain the soil water potential wetter than -70 centibar (kPa) at
10-inch depth in the beet row.
A petiole test was taken on June 14, and Thio-SuI® was applied in the irrigation water
on June 21 to supply 25 lb N plus 33 lb SO4/acre. Headline® fungicide was applied at
12 oz/acre by aerial applicator on June 25 for control of powdery mildew. On June 28, a
second petiole test was taken and the field was recorrugated the final time. On July 6,
20 lb N/acre, 10 lb P2O5/acre, 10 lb SO4/acre, 0.25 lb Zn/acre, and 0.2 lb B/acre were
applied in the irrigation water. A third petiole test was taken on July 12, and on July 15,
5 lb Mg/acre, 7 lb SO4/acre, and 0.5 lb B/acre were applied in the irrigation water. On
July 17, Topsin-M® fungicide at 20 oz/acre was applied by airplane in a spray mixture
that included S at 6 lb/acre, P205 at 1.5 lb/acre, and Zn at 0.2 lb/acre. An aerial
application of Headline fungicide at 12 oz/acre plus sulfur at 6 lb/acre was applied on
August 8.
The final irrigation was applied on September 2. Visual estimates of curly top virus and
powdery mildew foliar symptoms were recorded for each plot in the Experimental Trial
on September 10, and for each plot in the Commercial Trial on September 16. Bolted
beets were counted when the disease ratings were made.
187
Sugar beets were harvested from the Experimental Trial on October 13 and 14, and
from the Commercial Trial on October 14 and 15. The foliage was flailed and the
crowns were removed with rotating knives. All sugar beets in the center two rows of
each plot were dug with a two-row wheel-lifter harvester and weighed, and two eightbeet samples were taken from each plot. Samples were delivered each day to the
Snake River Sugar factory in Nyssa for laboratory analysis of percent sucrose, nitrate
concentration, and conductivity.
The root weight data were examined for outliers as is customary for calculations of
sugar beet variety data by Amalgamated in these trials. Observations more than two
standard deviations from the mean for each variety were deleted. Sugar sample data
were checked for errors in sugar percentages and conductivity. Any erroneous sample
readings were deleted from the data set. The companion samples of all missing or
deleted sugar data were good, so no plots were lost due to sugar sample errors.
The weight of sugar beets from each plot was multiplied by 0.90 to estimate tare. Sugar
concentrations were "factored" by multiplying measured sucrose by 0.98 to estimate the
sugar that would have been lost to respiration if the beets had been stored in a pile.
The data for each plot with two samples were averaged for analysis. The percent
extraction was calculated using the formula:
Ext = 250 + [(1,255.2 * Cond) -(15,000 * Sug) -6,185]! Sug * (98.66- 7.845 * Cond)
where Ext is percent extraction, Cond is the electrical conductivity in mm ho, and Sug is
the sugar concentration in percent.
Variety differences in yield, sucrose content, conductivity, percent extraction, and
estimated recoverable sugar were calculated using least-squares means analysis.
Sugar beet performance in both trials was compared to the check varieties ACH Seeds
'Crystal 217R', Betaseed 'Beta 4490 R', Hilleshog/Syngenta 'HM2986 Rz', and Seedex
'Raptor Rz'. Reports of previous years' Oregon State University variety trials are
available online at www.cropinfo.net.
Results
Early stand establishment was slow and erratic. The sixth irrigation, on June 29 (the
first irrigation in the wheel furrows), was effective in wetting the soil and the soil
moisture sensors responded to the irrigation (Fig. 1). Surge irrigation approximately
once a week maintained soil water potential wetter than -60 kPa through most of the
growing season.
Powdery mildew infection developed on sugar beet foliage in these trials and in
neighboring growers' fields. Curly top virus foliar symptoms were more severe in the
beets this year than is usually seen (Table 1). In the Experimental Trial, Beta
'3YK0019', Beta '4YK0023', Crystal '318R', and Beta '4YK0024' were among the
varieties showing the most severe curly top virus foliar symptoms. SX Raptor RZ, SX
188
'1522', Crystal 217R, and 'O4HX431RZ' were among the varieties showing the most
severe powdery mildew symptoms in the Experimental Trial. In the Commercial Trial,
Beta '4035R', Crystal '9906R', Beta '4490R', and Beta '4614R' were among the
varieties showing the most severe curly top virus foliar symptoms. Beta '4614R', Crystal
217R, Crystal '333R', and 'Beta '4773R' were among the varieties showing the most
severe powdery mildew symptoms in the Commercial Trial.
Variety results were grouped by seed company for the Commercial Trial (Table 2) and
the Experimental Trial (Table 3). Within each seed company's varieties, the varieties
are ranked in descending order of estimated recoverable sugar in pounds per acre. The
root weights were tared 10 percent in 2004; in previous years, a root tare of 5 percent
had been applied. The truck loads of border row beets delivered to the Nyssa factory in
2004 from the same field, dug with the same harvester, ranged from 5 to 7.9 percent
tare, and averaged 6.5 percent tare.
Root yield in the Commercial Trial averaged 42.98 tared ton/acre, average sugar
content was 17.95 percent, and average estimated recoverable sugar was 13,345
lb/acre. The varieties yielding among the highest estimated recoverable sugar in the
Commercial Trial were 'Beta 8600', with 14,867 lb/acre, Holly Hybrids 'Acclaim R' with
14,217 lb/A, and Seedex 'Cascade' with 14,192 lb/acre.
Data for the Experimental Trial are reported in Table 3. Root yield in the Experimental
Trial averaged 43.37 tared ton/acre, average sugar content was 17.64 percent, and
average estimated recoverable sugar was 13,144 lb/acre. The varieties yielding among
the highest estimated recoverable sugar in the Experimental Trial were 'HMPM9O' with
14,228 lb/acre, 'HM2993Rz' with 13,933 lb/acre, '04HX422 R' with 13,920 lb/acre, 'Beta
4YK0024' with 13,760 lb/acre, '04HX438 R' with 13,733 lb/acre, 'HM 2995Rz' with
13,680 lb/acre, 'Beta 2YK0016' with 13,607 lb/acre, and 'HM 2992Rz' with 13,572
lb/acre.
189
Date, 2004
0
(C
-0
(0
aD
(N
(0
N-
N-
IC)
N-
CO
(0
IC)
(\)
C)
(0
CO
(C
(0
a)
-10
-20
0
C,)
-60
-70
-80
Figure 1. Sugar beet trials average soil water potential of six Watermark soil moisture
sensors read by an AM400 Hanson datalogger, Oregon State University, Malheur
Experiment Station, Ontario, OR, 2004.
190
Table 1. Visual evaluations of foliar disease symptoms and bolting in sugar beet
varieties, Oregon State University, Malheur Experiment Station, Ontario, OR, 2004.
Experimental Trial
CTt
10 September
1.6
HM2986RZ
1.8
HM2991 RZ
4.0
1.8
HM2992 RZ
3.9
1.5
HM2993 RZ
0.9
1.4
HM2994 RZ
0.9
1.9
HM2995 RZ
2.9
1.9
HM PM9O
PM21 replant
PM21 replant
03HX353RZ
04HX422RZ
O4HX431RZ
04HX434RZ
04HX436RZ
04HX437RZ
04HX438RZ
SX Raptor RZ
SX1 521
SX1 522
Crystal 217R
Crystal 316R
Crystal 318R
Crystal4llR
Crystal4l2R
Beta449OR
Beta2YKOOl6
Beta3YKOOl9
Beta 3YK0020
Beta 4YK0023
Beta4YKOO24
Beta 4YK0025
Mean
LSD (0.05)
0.8
1.9
1.5
1.2
1.9
1.3
1.8
2.3
1.6
2.2
3.6
2.7
2.6
1.8
1.1
4.5
1.4
1.3
3.6
1.4
5.8
1.5
1.5
1.2
1.1
1.8
1.8
2.3
1.8
2.0
1.3
1.9
3.0
2.1
2.7
2.3
2.0
1.4
1.8
1.4
1.6
1.6
1.9
1 .4
5.3
4.5
3.6
2.4
1.8
1.3
0.9
1.1
1.5
1.7
Commercial Trial
CTt
16 September
2.3 2.3
HM1642
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.4
7.4
0.4
0.0
HM298ORZ
HM2984RZ
HM2986RZ
HM2988RZ
HM2989RZ
HMAlliance
4.1
1.8
1.9
2.4
2.2
1.9
3.8
2.4
1.4
1.6
2.3
2.4
1.5
2.4
1.4
1.4
2.0
HM Oasis
HM Owyhee
HM PM21
Acclaim RZ
Eagle RZ
HH142 RZ
Meridian RZ
0.9
1.9
1.9
1.3
PhoenixRZ
Cascade
Puma
Raptor RZ
ACH Mustang
Crystal 217R
Crystal333R
Crystal99O6R
Beta4O35R
3.3
0.9
2.1
0.0
0.0
0.0
0.0
0.8
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.3
0.8
1.2
0.8
1.8
2.5
4.3
1.2
Beta 4490R
4.8
2.0
2.3
3.5
5.8
6.4
5.0
5.8
Beta46l4R
5.1
Beta4l99R
Beta4773R
1.8
Beta 8220B
Beta 8600
Mean
LSD (0.05)
2.9
2.3
2.9
tAverage curly top virus symptom severity rating from 0 (none) to 10.
powdery mildew fungus symptom severity rating from 0 (none) to 10.
§Average number of bolted beets per 4-row plot, 23 feet long.
191
1.3
1.1
0.9
2.5
2.5
2.5
3.3
3.0
2.9
2.8
2.5
2.3
3.8
3.0
2.4
1.1
2.2
0.8
BolP
0.0
0.0
0.0
0.0
0.0
0.0
0.4
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.1
Table 2. Commercial sugar beet variety root yield, sugar content, root quality,
recoverable sugar, and nitrate content from varieties entered in the trial at Malheur
Experiment Station, Oregon State University, Ontario, OR, 2004.
Variety
ACH Seeds
ACH Mustang
Crystal 9906R
Crystal 217R
Crystal 333R
Betaseed
Beta 8600
Root
Sugar
yield
content
ton/acre
%
Gross Conduc- Extracsugar
tivity
tion
lb/acre mmho
%
Estimated
recoverable sugar
lb/ton
lb/acre
Nitrate
content
ppm
44.83
40.09
39.05
36.93
17.79
17.99
18.44
18.34
15,931
14,415
14,417
13,546
0.701
0.571
0.661
0.691
85.79
305.1
8751
86.00
314.8
318.8
315.4
13,666
12,614
12,457
11,647
119
102
136
95
Beta4l99R
47.71
42.97
43.14
44.19
41.52
17,158
15,650
15,687
15,459
15,436
0.638
0.678
Beta 8220B
Beta 4035R
Beta 4490R
17.99
18.21
18.19
17.50
18.60
86.65
86.16
85.59
86.62
86.43
311.8
313.8
311.6
303.2
321.5
14,867
13,482
13,430
13,392
13,340
106
110
112
126
85
Beta 4773R
Beta 4614R
39.51
18.53
14,654
0.649
86.59
321.0
12,691
112
41.92
17.15
14,374
0.611
86.83
297.8
12,481
110
42.24
43.73
43.32
42.88
42.13
42.07
42.68
42.59
42.73
40.56
18.81
15,887
15,910
15,962
15,680
15,550
15,365
15,316
15,310
15,192
14,798
0.578
0.613
87.55
87.00
86.42
87.45
87.25
87.76
329.3
316.6
318.6
319.9
322.2
320.5
312.8
111
18.19
18.43
18.29
18.46
18.26
17.93
18.00
17.77
18.24
17.13
16,662
17.11
17.28
17.18
17.28
16,174
16,063
15,763
14,681
45.69
17.71
41.40
18.04
SX Raptor Rz
42.04
Mean
LSD (0.05)
LSD (0.10)
42.98
Hilleshog/Syngenta
HM1642
HM Owyhee
HM 2989Rz
HM PM21
HM 2986Rz
HMAlliance
HM Oasis
HM 2980Rz
HM2984Rz
HM2988Rz
Holly Hybrids
Acclaim R
PhoenixR
Meridian R
EagleR
HH 142 R
Seedex
SX Cascade
SX Puma
CV (%)
0.721
0.633
0.662
86.41
86.12
86.70
87.66
310.1
308.2
319.7
13,908
13,842
13,794
13,711
13,569
13,486
13,359
13,183
13,173
12,971
0.727
85.32
292.4
14,217
146
0.678
0.676
0.704
0.708
85.96
86.02
85.62
85.59
294.1
138
162
123
295.8
13,900
13,817
13,497
12,567
16,178
0.550
87.72
310.8
14,192
101
14,932
0.588
87.29
315.0
13,032
123
17.77
14,927
0.665
86.25
306.5
12,873
150
2.51
2.11
17.95
0.50
0.42
15,412
914
766
0.640
0.040
0.034
86.60
0.55
0.46
311.0
9.6
5.9
2.8
6.0
6.3
0.6
48.63
47.30
46.49
45.93
42.53
192
0.661
0.579
0.597
0.554
0.593
0.678
0.630
0.562
87.21
297.3
294.1
113
149
110
104
108
123
131
141
144
151
8.1
13,345
792
664
122
43
36
3.1
6.0
35.6
Table 3. Experimental sugar beet variety root yield, sugar content, root quality,
recoverable sugar, and nitrate content from varieties entered in the trial at Malheur
Experiment Station, Oregon State University, Ontario, OR, 2004.
Variety
ACH Seeds
Crystal 316R
Crystal 318R
Crystal4llR
Crystal 412R
Crystal 217R
Betaseed
Beta 4YK0024
Beta 2YK0016
Beta 4YK0023
Beta 3YK0019
Beta 4490R
Beta 4YK0025
Beta 3YK0020
Root
Sugar
yield
content
ton/acre
%
45.29
43.00
44.28
Estimated
Gross Conduc- Extracrecoverable sugar
tion
tivity
sugar
lb/acre
lb/ton
%
lb/acre mmho
85.59
88.17
84.85
84.96
85.46
297.7
310.5
296.0
297.4
298.8
13,450
13,354
13,101
12,705
12,344
168
144
166
170
233
85.89
85.09
86.46
305.6
298.8
317.7
304.8
309.4
308.9
293.1
13,760
13,607
13,367
13,312
13,170
13,021
12,793
126
319.9
294.5
305.2
303.5
309.8
320.2
306.2
14,228
13,933
13,680
13,572
13,274
13,116
12,157
85.46
85.74
84.90
86.92
85.26
87.10
86.39
281.4
13,920
13,733
13,266
13,251
13,061
12,528
11,561
209
85.77
86.76
86.34
299.1
318.8
313.5
12,853
206
12,601
12,441
172
187
86.03
0.67
0.56
0.8
303.6
9.3
7.8
15,720
15,144
15,443
14,951
14,440
0.710
0.513
0.768
0.759
16,021
15,993
15,467
15,532
15,377
0.693
42.59
42.19
43.67
17.79
17.55
18.37
17.78
18.06
17.94
17.13
15,129
14,958
0.681
0.711
44.48
47.33
44.86
44.71
42.87
40.99
39.69
18.38
17.25
17.68
17.64
17.90
18.22
17.88
16,354
16,328
15,846
15,773
15,342
14,931
14,199
0.616
0.728
0.657
0.680
0.646
0.547
0.715
87.00
85.33
86.34
86.03
86.52
87.85
49.51
16.46
16.68
17.70
17.26
17.93
17.43
16,286
16,017
15,627
15,245
15,316
14,384
13,385
0.706
0.688
0.759
0.613
0.733
0.602
0.649
17.43
18.37
18.15
14,992
14,526
14,408
17.64
0.45
0.38
2.6
15,280
886
742
5.8
0.697
0.634
0.663
0.680
0.048
0.040
7.0
42.71
41.28
45.03
45.61
42.19
43.72
17.39
17.61
17.44
17.50
17.48
0.721
0.751
0.656
0.706
0.714
Nitrate
content
ppm
85.71
85.65
86.08
85.53
223
137
177
163
158
170
HilleshoglSyngenta
HM PM9O
HM 2993Rz
HM 2995Rz
HM 2992Rz
HM2986Rz
HM2991Rz
HM2994Rz
Holly Hybrids
04HX422 R
04HX438 R
04HX437 R
04HX434 R
04HX436 R
03HX353 R
04HX431 R
Seedex
SX Raptor Rz
SX1522
SX1521
Mean
LSD (0.05)
LSD (0.10)
CV (%)
48.02
45.70
43.06
44.39
40.12
38.44
43.03
39.54
39.71
43.37
2.50
2.10
5.8
17.11
193
85.61
286.1
290.5
307.7
294.4
312.3
301.1
3.1
13,144
763
639
5.8
190
219
176
176
149
138
189
191
250
201
217
141
205
181
51
43
28.4
KOCHIA CONTROL WITH PREEMERGENCE NORTRON® IN STANDARD AND
MICRO-RATE HERBICIDE PROGRAMS IN SUGAR BEET
Corey V. Ransom, Charles A. Rice, and Joey K. Ishida
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
The distribution of kochia resistant to UpBeet® (triflusulfuron) herbicide and other
acetolactate synthase (ALS) inhibitors (i.e., sulfonylureas, imidazolinones, and
triazolopyrimidines) has increased in recent years and poses a serious problem in
sugar beet production, as none of the currently registered postemergence herbicides
effectively control ALS-resistant kochia. In this trial, Nortron® (ethofumesate) was
evaluated for preemergence control of kochia in sugar beet. Nortron is a soil-active
herbicide used preemergence or early postemergence to control annual grasses and
broadleaf weeds.
Methods
This trial was established at the Malheur Experiment Station under furrow irrigation on
April 8, 2004. Sugar beets (Hilleshog 'PM-21') were planted in 22-inch rows at a 2-inch
seed spacing. On April 9, the trial was corrugated and Counter 20 CR® was applied in
a 7-inch band over the row at 6 oz/1 000 ft of row. Sugar beets were thinned to 8-inch
spacing on May 10 to 13. Plots were sidedressed on June 2 with 175 lb nitrogen
(urea), 30 lb potash (K2O), 35 lb sulfates (SO4), 38 lb elemental sulfur (S), 3 lb
manganese (Mn), 2 lb zinc (Zn), and 1 lb/acre boron (B). All plots were treated with
Roundup®
lb ai/acre) on April 13 prior to sugar beet emergence. On May 26,
Temik 15GR (14 lb prod/acre) was applied for sugar beet root maggot control. For
powdery mildew control, Headline® (12 fI oz/acre) was applied on June 25, Topsin M®
(20 oz prod/acre) plus S at 6 lb/acre, phosphate (P205) at 1.5 lb/acre, and Zn at 0.2
lb/acre were applied August 4, and Headline (12 fI oz/acre) plus S at 6 lb/acre were
applied August 8. All fungicide treatments were applied by air. Herbicide treatments
were broadcast-applied with a CO2-pressurized backpack sprayer calibrated to deliver
20 gal/acre at 30 psi. Plots were 4 rows wide and 27 ft long and treatments were
arranged in a randomized complete block design with 4 replicates.
The treatments in this trial consisted of both standard and micro-rate postemergence
weed control programs applied with or without a preemergence application of Nortron at
either 16, 24, or 32 oz ai/acre with and without postemergence UpBeet. For the microrate treatment without UpBeet, Nortron was also applied preemergence at 48 oz
ai/acre. UpBeet was omitted from selected treatments to simulate ALS resistance and
to better evaluate preemergence Nortron efficacy on kochia. Nortron was applied
194
preemergence on April 13. The standard rate program included three applications, with
the first applied to full cotyledon sugar beets on April 26, the second to two- to four-leaf
sugar beets on May 3, and the third application to six- to eight-leaf sugar beets on May
14. Progress (ethofumesate + phenmedipham + desmedipham) was applied at 4.0,
5.4, and 6.7 oz ai/acre in the first, second, and third applications, respectively. UpBeet
was applied at 0.25 oz ai/acre in all three applications (excluding treatments where
UpBeet was omitted). Stinger® (clopyralid) was applied in the second and third
applications at 1.5 oz ai/acre. The micro-rate program consisted of four applications
with the first applied to cotyledon sugar beets on April 23, the second to cotyledon to 2leaf sugar beets on April 30, the third application was inadvertently delayed and was
applied to 8-to 10-leaf sugar beets on May 15, and the fourth to 8-to 12-leaf sugar
beets on May 20. In the micro-rate program, Progress® was applied at 1.3 oz ai/acre in
the first two applications and at 2.0 oz ai/acre in the last two applications. All four
micro-rate applications included UpBeet at 0.08 oz ai/acre (excluding treatments where
UpBeet was omitted), Stinger at 0.5 oz ai/acre, and a methylated seed oil (MSO) at 1.5
percent v/v.
Sugar beet injury was evaluated May 10 and June 9 and weed control was evaluated
September 3. Sugar beet yields were determined by harvesting the center two rows of
each plot on October 8 and 9. Root yields were adjusted to account for a 5 percent
tare. One sample of 16 beets was taken from each plot for quality analysis. The
samples were coded and sent to Syngenta Seeds Research Station in Nyssa, Oregon,
to determine beet pulp sucrose content and purity. Sucrose content and recoverable
sucrose were estimated using empirical equations. Data were analyzed using analysis
of variance procedures and means were separated using protected LSD at the 95
percent confidence interval (P = 0.05). The untreated control was not included in the
analysis of variance for weed control or crop response.
Results and Discussion
Postemergence herbicides were very effective this year. Kochia control was greater
than 98 percent with either the standard rate or micro-rate treatments containing
UpBeet regardless of whether preemergence Nortron was applied (Table 1). Removing
UpBeet from the standard rate and the micro-rate resulted in a respective 18 and 58
percent decrease in kochia control on July 17. For the standard rate treatments without
UpBeet, the addition of Nortron at any rate provided kochia control similar to the
standard rate with UpBeet. For micro-rate treatments without UpBeet, the addition of
preemergence Nortron, regardless of the rate, did not control kochia as well as the
micro-rate with UpBeet. Increasing Nortron rates increased kochia control. Pigweed
control also was reduced when UpBeet was omitted from the micro-rate. The addition
of Nortron at 16 or 24 oz ai/acre improved kochia control, but the 32- or 48- oz ai/acre
rates were required to control kochia equal to the micro-rate with UpBeet. There were
no differences among treatments for common lambsquarters, hairy nightshade, or
barnyardgrass control. Common lambsquarters and hairy nightshade control was 98
percent or higher while barnyardgrass control ranged from 87 to 99 percent.
195
Injury on May 10 was significantly higher for standard rate treatments with UpBeet
compared to standard rate treatments without UpBeet or compared to any of the microrate treatments (Table 2). Within the micro-rate treatments, the 48- oz al/acre rate of
Nortron caused greater injury (23 vs 5-14 percent) than any of the other micro-rate
treatments with or without Nortron preemergence. On June 9, injury was similar among
all treatments. Sugar beet yields were not significantly different among any of the
standard rate treatments. Sugar beet yields were lowest with the micro-rate applied
without UpBeet. The addition of preemergence Nortron at 32 oz al/acre to the microrate without UpBeet was the only treatment that produced yields similar to the microrate with UpBeet. The lower Nortron rates had lower yields and the 48- oz al/acre
Nortron treatment also yielded less than the micro-rate with UpBeet. The lower yield
with the high rate of Nortron may have been related to the increased sugar beet injury.
In areas where kochia has become resistant to UpBeet, a preemergence application of
Nortron followed by postemergence herbicides at standard rates should provide
effective control. Removing UpBeet from the spray mixture may not be advisable since
UpBeet would still be effective in controlling non-UpBeet-resistant kochia and also helps
control other weeds. The micro-rate should not be used in areas with UpBeet resistant
kochia because even with high rates of preemergence Nortron, acceptable kochia
control cannot be achieved.
196
Table 1. Kochia control with preemergence Nortron® in standard and micro-rate
herbicide programs, Maiheur Experiment Station, Oregon State University, Ontario, OR,
2004.
Weed control
K ochia
Treatment*
Rate
Timingt
7-27
9-3
Pigweed
spp.
7-27
0/
ozai/acre&%v/v
Untreated control
Standard Rate Program
Progress + UpBeet
Progress + UpBeet + Stinger
Progress + UpBeet + Stinger
Micro-Rate Program
Progress + UpBeet + Stinger +
MSO
Progress + UpBeet + Stinger +
MSO
Nortronfb
Standard with Upbeet
Nortronfb
Standard with UpBeet
BarnyardHairy
Lambsgrass
quarters nightshade
7-27
7-27
7-27
--
--
--
--
--
--
--
--
4.0 + 0.25
5.4 + 0.25 + 1.5
6.7 + 0.25 + 1.5
3
100
100
100
100
99
95
1.3 + 0.083 + 0.5 +
1.5% v/v
2.0 + 0.083 + 0.5 ÷
1.5% v/v
24
98
98
97
100
100
97
100
100
99
100
100
97
100
100
100
100
100
98
100
100
100
100
100
99
100
100
100
100
100
93
94
96
98
100
100
93
98
98
100
100
100
97
100
100
100
99
100
91
99
99
100
100
100
97
5
6
7,8
16.0
1
---
3,5,6
24.0
---
3,5,6
1
Nortronfb
Standard with UpBeet
32.0
1
---
3,5,6
Nortronfb
Standard w/out UpBeet
16.0
---
3,5,6
Nortronfb
Standard w/out UpBeet
24.0
---
3,5,6
Nortronfb
Standard w/out UpBeet
32.0
---
3,5,6
Nortronfb
Micro with UpBeet
16.0
---
2,4,7,8
Nortronfb
Micro with UpBeet
24.0
---
2,4,7,8
Nortronth
Micro with UpBeet
32.0
1
100
100
100
100
100
95
Nortronfb
Micro w/out UpBeet
16.0
---
1
62
58
91
100
100
93
2,4,7,8
Nortronfb
Micro w/out UpBeet
24.0
1
66
65
91
100
100
92
---
2,4,7,8
Nortronfb
Micro w/out UpBeet
32.0
1
75
73
98
100
100
92
---
2,4,7,8
Standard w/out UpBeet
---
3,5,6
82
88
95
100
100
95
Micro w/out UpBeet
---
2,4,7,8
40
48
80
100
100
87
Nortron fb
Micro w/out UpBeet
48.0
1
84
86
98
98
100
97
---
2,4,7,8
1
1
1
1
1
NS
NS
NS
8
8
6
LSD ( 0.05)
*fb = Followed by.
tApplication timings were (1) April 13 preemergence, (2) April 23 to cotyledon beets, (3) April 26 to full cotyledon beets, (4) April 30
to 2-leaf beets, (5) May 3 to 2- to 4-leaf beets, (6) May 14 to 6- to 8-leaf beets, (7) May 15 to 8- to 10-leaf beets, and (8) May 20 to
8- to 12-leaf beets.
tpigweed species included Powell amaranth and redroot pigweed.
197
Table 2. Sugar beet injury and yield with preemergence Nortron® in standard and
micro-rate herbicide programs, Maiheur Experiment Station, Oregon State University,
Ontario, OR, 2004
Sugar beet
Injury
Treatment*
Rate
Timingt
5-10
Untreated control
Standard Rate Program
Progress + UpBeet
Progress + UpBeet + Stinger
Progress + Upbeet + Stinger
Micro-Rate Program
Progress + UpBeet + Stinger +
MSO
Progress + UpBeet + Stinger +
MSO
6-9
0/
oz al/acre and % v/v
--
--
--
4.0 + 0.25
5.4 + 0.25 + 1.5
6.7 + 0.25 + 1.5
3
5
6
1.3 + 0.083 + 0.5 +
2,4
Root yield
Sucrose
Extraction
0/
ton/acre
ER&
lbs/acre
--
6.1
16.6
93.5
1,958
33
21
41.1
16.7
93.6
12,802
9
9
44.3
16.5
93.0
13,614
30
18
42.7
17.1
93.4
13,616
30
15
39.8
17.1
93.2
12,653
32
20
40.9
16.9
93.3
12,940
13
11
40.6
16.9
93.1
12,770
15
21
39.6
16.4
93.0
12,067
18
14
42.1
16.1
93.9
12,613
11
18
42.2
16.5
93.7
13,025
10
11
42.2
16.3
93.1
12,792
1.5%v/v
2.0 + 0.083 + 0.5 +
1.5% v/v
7,8
Nortron fb
Standard with UpBeet
16.0
---
3,5,6
Nortron fb
Standard with UpBeet
24.0
---
3,5,6
Nortron fb
Standard with UpBeet
32.0
---
3,5,6
Nortron fb
Standard w/out UpBeet
16.0
---
3,5,6
Nortron fb
Standard w/out UpBeet
24.0
---
3,5,6
Nortron fb
Standard w/out UpBeet
32.0
---
3,5,6
Nortron fb
Micro with UpBeet
16.0
---
2,4,7,8
Nortron fb
Micro with UpBeet
24.0
---
2,4,7,8
Nortron fb
Micro with UpBeet
32.0
1
13
14
40.5
17.1
93.5
12,918
Nortron fb
Micro w/out UpBeet
16.0
---
1
11
18
29.4
17.4
93.3
9,509
2,4,7,8
Nortron fb
Micro w/out UpBeet
24.0
---
14
15
34.5
17.6
93.6
11,386
2,4,7,8
Nortron fb
Micro w/out UpBeet
32.0
---
5
13
38.0
17.3
93.5
12,300
2,4,7,8
Standard w/out UpBeet
---
3,5,6
19
13
38.8
17.0
93.4
12,345
Micro w/out UpBeet
---
2,4,7,8
6
6
29.3
17.7
93.9
9,786
Nortron fb
Micro w/out UpBeet
48.0
---
1
23
26
35.2
17.5
93.4
11,490
2,4,7,8
8
13
6.1
0.8
NS
1,937
LSD (0.05)
1
1
1
1
1
1
1
1
1
1
--
*fb = Followed by
tApplication timings were (1) April 13 preemergence, (2) April 23 to cotyledon beets, (3) April 26 to full cotyledon beets, (4) April 30
to 2-leaf beets, (5) May 3 to 2 to 4-leaf beets, (6) May 14 to 6 to 8-leaf beets, (7) May 15 to 8 to 10-leaf beets, and (8) May 20 to 8
to 12-leaf beets.
tSugar beets were harvested October 8 and 9.
= estimated recoverable sucrose.
198
TIMING OF DUAL MAGNUM® AND OUTLOOK® APPLICATIONS FOR WEED
CONTROL IN SUGAR BEET
Corey V. Ransom, Charles A. Rice, and Joey K. Ishida
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Outlook® (dimethenamid-P) and Dual Magnum® (s-metolachlor) are soil-active
herbicides that are labeled for postemergence application in sugar beet. They can be
applied to two-leaf or larger beets. Outlook or Dual Magnum was applied at different
timings as part of a standard rate herbicide program. The objectives of this trial were to
1) determine if weed control can be improved with Outlook or Dual Magnum in the
standard rate program, and 2) determine if the application timing of these herbicides
influences weed control or crop response.
Methods
This trial was established at the Malheur Experiment Station under furrow irrigation on
April 8, 2004. Sugar beets (Hilleshog 'PM-21') were planted in 22-inch rows at a 2-inch
seed spacing. On April 9, the trial was corrugated and Counter 20 CR® was applied in
a 7-inch band over the row at 6 oz/l ,000 ft of row. Sugar beets were thinned to 8-inch
spacing on May 10 to 13. Plots were sidedressed on June 2 with 175 lb nitrogen (N)
(urea), 30 lb potash (1<20), 35 lb sulfates (SO4), 38 lb elemental sulfur (5), 3 lb
manganese (Mn), 2 lb zinc (Zn), and 1 lb/acre boron (B). All plots were treated with
Roundup®
lb ai/acre) on April 13 prior to sugar beet emergence. On May 26,
Temik 15GR (14 lb prod/acre) was applied for sugar beet root maggot control. For
powdery mildew control, Headline® (12 ft oz/acre) was applied on June 25, Topsin M®
(20 oz prod/acre) plus S at 6 lb/acre, phosphate (P205) at 1.5 lb/acre, and Zn at 0.2
lb/acre were applied on August 4, and Headline (12 fI oz/acre) plus S at 6 lb/acre were
applied on August 8. All fungicide treatments were applied by air. Herbicide treatments
were broadcast applied with a CO2-pressurized backpack sprayer calibrated to deliver
20 gal/acre at 30 psi. Plots were 4 rows wide and 27 ft long and treatments were
arranged in a randomized complete block design with 4 replicates.
Outlook, Dual Magnum, and Treflan® were applied at various timings as part of a
standard rate herbicide program to evaluate the effect of application timing on weed
control and crop response. The standard rate program consisted of Progress® applied
at 4.0, 5.4, and 6.7 oz ai/acre in the first, second, and third applications,
UpBeet® was applied at 0.25 oz ai/acre in all three applications and StingerR at 1.5 oz
al/acre in the last two applications. Dual Magnum was applied preemergence only, or
in the second or third postemergence application, or preemergence and in the second
199
application, or in the second and third applications. Outlook was applied in the second
or third applications. Both Dual Magnum and Outlook were applied in combination with
Treflan in the second postemergence application. The preemergence treatments were
applied April 13. The first, second, and third postemergence applications were made
on April 26, May 3, and May 14, to cotyledon, 2-to 4-leaf, and 6-to 10-leaf beets,
respectively.
Sugar beet injury was evaluated on May 10 and June 9 and weed control was
evaluated on September 3. Sugar beet yields were determined by harvesting the
center two rows of each plot on October 8 and 9. Root yields were adjusted to account
for a 5 percent tare. One sample of 16 beets was taken from each plot for quality
analysis. The samples were coded and sent to Syngenta Seeds Research Station in
Nyssa, Oregon, to determine beet pulp sucrose content and purity. Sucrose content
and recoverable sucrose were estimated using empirical equations. Data were
analyzed using analysis of variance procedures and means were separated using
protected LSD at the 95 percent confidence interval (P = 0.05). The untreated control
was not included in the analysis of variance for weed control or crop response.
Results and Discussion
The addition of Outlook or Dual Magnum or combinations of Outlook or Dual Magnum
with Treflan improved barnyardgrass control compared to the standard postemergence
treatment alone (Table 1). For all other weeds, control was similar among treatments.
There also were no differences in sugar beet injury (Table 2) or sugar beet stand (data
not shown) among treatments. All herbicide treatments had greater yields compared to
the untreated control, but yields did not differ among herbicide treatments.
This research suggests that both Dual Magnum and Outlook can be applied in
combination with standard rate herbicides in sugar beets without significant sugar beet
injury. No injury was observed with preemergence applications of Dual Magnum in this
trial. However, in other sugar beet production regions, under extremely wet conditions,
Dual Magnum has caused sugar beet injury when applied preemergence. In 2004,
weather conditions were favorable and maximized the weed control provided by
postemergence herbicide treatments. Under different environmental conditions, Dual
Magnum or Outlook may have provided increased levels of broadleaf weed control.
Besides helping control annual weeds, both Dual Magnum and Outlook are effective in
suppressing yellow nutsedge in sugar beet.
200
Table 1 Weed control in sugar beet with standard rate herbicide treatments including
postem ergence applications of Outlook® and Dual Magnum®, Malheur Experiment
Station, Oregon State University, Ontario, OR, 2004.
.
Weed controlt
Treatment
Rate
Timing*
Kochia
Pigweed
Spp.
Lambsquarters
BarnyardHairy
grass
nghtshade
0/
oz ai/acre
Untreated control
Progress + UpBeet +
Dual Magnum
Progress + UpBeet + Stinger +
Dual Magnum
Progress + UpBeet + Stinger
4.0 + 0.25 +
1
5.4 + 0.25 + 1.5 +
6.7 + 0.25 + 1.5
15.3
2
3
Progress + UpBeet
Progress + UpBeet + Stinger +
Dual Magnum
Progress + UpBeet + Stinger +
Dual Magnum
4.0 + 0.25
5.4 + 0.25 + 1.5 +
2
Dual Magnum
Progress + UpBeet
Progress + UpBeet + Stinger +
Dual Magnum
Progress + UpBeet + Stinger
20.3
4.0 + 0.25
5.4 + 0.25 + 1.5 +
100
1
100
100
100
100
97
1
100
100
100
100
100
100
100
100
100
100
99
100
100
100
84
100
100
100
100
100
100
100
100
100
98
100
100
100
100
100
100
100
100
100
100
100
100
100
100
98
100
100
100
100
98
NS
NS
NS
NS
6
15.3
6.7 + 0.25 + 1.5 +
3
15.3
PRE
1
2
15.3
6.7 + 0.25 + 1.5
Progress + UpBeet
Progress + UpBeet + Stinger
Progress + UpBeet + Stinger
4.0 + 0.25
5.4 + 0.25 + 1.5
6.7 + 0.25 + 1.5
Dual Magnum
Progress + UpBeet
Progress + UpBeet + Stinger
Progress + UpBeet + Stinger
4.0 + 0.25
5.4 + 0.25 + 1.5
6.7 + 0.25 + 1.5
20.3
3
1
2
3
PRE
1
2
3
4.0 + 0.25
5.4+0.25+1.5
6.7 + 0.25 + 1.5 +
2
3
15.3
4.0 + 0.25
1
5.4+0.25+1.5+
2
13.4
6.7+0.25+1.5
3
4.0 + 0.25
1
5.4+0.25+1.5+
2
13.4 + 8.0
6.7+0.25+1.5
3
Progress + UpBeet
Progress + UpBeet + Stinger
Progress + UpBeet + Stinger +
Outlook
4.0 + 0.25
1
5.4+0.25+1.5
6.7+0.25+1.5+
2
3
Progress + UpBeet
Progrees + UpBeet + Stinger +
Dual Magnum + Treflan
Progress + UpBeet + Stinger
4.0 + 0.25
5.4 + 0.25 + 1.5 +
15.3 + 8.0
6.7 + 0.25 + 1.5
LSD (0.05)
100
3
6.7 + 0.25 + 1.5
Progress + UpBeet
Progress + UpBeet + Stinger +
Outlook + Treflan
Progress + UpBeet + Stinger
100
2
4.0 + 0.25
5.4 + 0.25 + 1.5 +
Progress + UpBeet
Progress + UpBeet + Stinger +
Outlook
Progress + UpBeet + Stinger
100
15.3
Progress + UpBeet
Progress + UpBeet + Stinger +
Dual Magnum
Progress + UpBeet + Stinger
Progress + UpBeet
Progress + UpBeet + Stinger
Progress + UpBeet + Stinger +
Dual Magnum
100
15.3
13.4
1
2
3
--
*Application timings were (PRE) April 13, (1) April 26 to cotyledon beets, (2) May 3 to 2- to 4-leaf beets, and (3) May 14 to 6- to 10leaf beets.
tWeed control was evaluated October 8 and 9. Pigweed species included Powell amaranth and redroot pigweed.
201
Table 2. Sugar beet injury and yield with standard rate herbicide treatments including
postemergence applications of Outlook® and Dual Magnum®, Malheur Experiment
Station, Oregon State University, Ontario, OR, 2004.
Sugar beet
Yieldt
Injury
Treatment
Rate
Timing* 5-10
0/
oz ai/acre
Untreated control
Progress + UpBeet +
Dual Magnum
Progress + UpBeet + Stinger +
Dual Magnum
Progress + UpBeet + Stinger
Extraction
0/
ton/acre
ERS
lbs/acre
--
--
--
11.9
17.4
93.4
3,901
4.0 + 0.25 +
1
24
9
46.0
17.5
93.6
15,019
27
13
43.0
16.8
93.4
13,594
21
20
44.1
17.0
93.4
14,053
35
20
41.8
17.3
93.7
13,506
25
11
44.3
17.8
93.7
14,717
31
16
42.1
17.2
93.4
13,552
27
13
44.4
17.1
93.4
14,191
30
24
43.0
17.3
94.5
13,902
29
10
43.8
17.3
93.6
14,187
30
15
40.9
17.1
93.5
13,063
24
10
45.2
17.6
93.7
14,917
NS
NS
6.6
NS
NS
2,283
15.3
5.4 + 0.25 + 1.5 +
2
15.3
6.7 + 0.25 + 1.5
4.0 + 0.25
5.4 + 0.25 + 1.5 +
Progress + UpBeet
Progress + UpBeet + Stinger +
Dual Magnum
Progress + UpBeet + Stinger +
Dual Magnum
Dual Magnum
Progress + UpBeet
Progress + UpBeet + Stinger +
Dual Magnum
Progress + UpBeet + Stinger
Progress + UpBeet
Progress + UpBeet + Stinger
Progress + UpBeet + Stinger
4.0 + 0.25
5.4 + 0.25 + 1.5 +
3
1
2
15.3
6.7 + 0.25 + 1.5
3
1
2
15.3
6.7 + 0.25 + 1.5 +
3
15.3
20.3
4.0 + 0.25
5.4 + 0.25 + 1.5 +
PRE
1
2
15.3
6.7 + 0.25 + 1.5
3
4.0 + 0.25
5.4 + 0.25 + 1.5
6.7 + 0.25 + 1.5
2
20.3
PRE
1
3
4.0 + 0.25
5.4 + 0.25 + 1.5
6.7 + 0.25 ÷ 1.5
2
Progress + UpBeet
Progress + UpBeet + Stinger
Progress + UpBeet + Stinger +
Dual Magnum
4.0 + 0.25
5.4 + 0.25 + 1.5
6.7 + 0.25 + 1.5 +
2
Progress + UpBeet
Progress + UpBeet + Stinger +
Outlook
Progress + UpBeet + Stinger
4.0 + 0.25
5.4 + 0.25 + 1.5 +
Progress + UpBeet
Progress + UpBeet + Stinger +
Outlook + Treflan
Progress + UpBeet + Stinger
4.0 + 0.25
5.4 + 0.25 + 1.5 +
13.4 + 8.0
6.7 + 0.25 + 1.5
Progress + UpBeet
Progress + UpBeet + Stinger
Progress + UpBeet + Stinger +
Outlook
4.0 + 0.25
5.4 + 0.25 + 1.5
6.7 + 0.25 + 1.5 +
Progress + UpBeet
Progrees + UpBeet + Stinger +
Dual Magnum + Treflan
Progress + UpBeet + Stinger
4.0 + 0.25
5.4 + 0.25 + 1.5 +
15.3 + 8.0
6.7 + 0.25 -I- 1.5
LSD (0.05)
Sucrose
--
Progress + UpBeet
Progress + UpBeet + Stinger +
Dual Magnum
Progress + UpBeet + Stinger
Dual Magnum
Progress + UpBeet
Progress + UpBeet + Stinger
Progress + UpBeet + Stinger
6-9
Root
yield
1
3
1
3
15.3
1
2
13.4
6.7 + 0.25 + 1.5
3
1
2
3
1
2
3
13.4
1
2
3
--
0Application timings were (PRE) April 13, (1) April 26 to cotyledon beets, (2) May 3 to 2-to 4-leaf beets, and (3) May 14 to 6-to 10leaf beets.
tSugar beets were harvested on October 8 and 9. ERS = estimated recoverable sucrose.
202
COMPARISON OF CALENDAR DAYS AND GROWING DEGREE-DAYS FOR
SCHEDULING HERBICIDE APPLICATIONS IN SUGAR BEET
Corey V. Ransom, Charles A. Rice, and Joey K. Ishida
Maiheur Experiment Station
Oregon State. University
Ontario, OR, 2004
Introduction
Timely herbicide application is critical to achieve effective weed control in sugar beet.
Often, the amount of time between sequential herbicide applications is based on a
given number of calendar days since the prior herbicide application. Under most
circumstances this approach works well. When spring weather is cooler than normal,
applying herbicides on a calendar day schedule may result in applications too close
together. This can result in greater injury to the beets or herbicides being applied
before they are needed. Since weed and beet growth depend on temperature, it is
logical that using accumulated growing degree-days (GDD) to schedule herbicide
applications may be superior to calendar days. GDD accounts for variations in the
weather and gives a more accurate idea of how fast plants are growing. If the weather
is ideal for weed and beet growth, herbicide applications are made closer together; if
the weather is cool, then applications are spaced further apart. Evaluation of a GDD
model for timing herbicide applications may provide producers with a tool to improve the
efficacy of the herbicides they are using.
Methods
A trial was established at the Malheur Experiment Station under furrow irrigation on
April 8, 2004. Sugar beets (Hilleshog 'PM-21') were planted in 22-inch rows at 2-inch
seed spacing. On April 9, the trial was corrugated and Counter 20 CR® was applied in
a 7-inch band over the row at 6-ozIl 000 ft of row. Sugar beets were thinned to an 8inch spacing on May 10 to 13. Plots were sidedressed on June 2 with 175 lb nitrogen
(N) (urea), 30 lb potash (1(20), 35 lb sulfates (SO4), 38 lb elemental sulfur (S), 3 lb
manganese (Mn), 2 lb zinc (Zn), and I lb/acre boron (B). All plots were treated with
Roundup®
lb ai/acre) on April 13 prior to sugar beet emergence. On May 26,
Temik 15GR (14 lb prod/acre) was applied for sugar beet root maggot control. Poast®
at 16 oz/acre plus crop oil concentrate at I qt/acre were applied to the trial area on
June 16. For powdery mildew control, Headline® (12 fI oz/acre) was applied on June
25, Topsin M® (20 oz prod/acre) plus S at 6 lb/acre, phosphate (P205) at 1.5 lb/acre,
and Zn at 0.2 lb/acre were applied on August 4, and Headline® (12 fI oz/acre) plus S at
6 lb/acre were applied on August 8. All fungicide treatments were applied by air.
Herbicide treatments were broadcast applied with a C02-pressurized backpack sprayer
calibrated to deliver 20 gal/acre at 30 psi. Plots were 4 rows wide and 27 ft long and
treatments were arranged in a randomized complete block design with 4 replicates.
203
Standard rate, increased standard rate, and micro-rate treatments were compared
when applied on fixed calendar day schedules or when applied on different GDD
accumulation schedules. The standard and high-standard-rate treatments were applied
every 7 or 10 days and these timings were compared to applications at 150, 175, or 225
accumulated GDD since the previous application. The micro-rate treatments were
applied on a 5- or 7-day schedule or at 150, 175, or 225 GDD since the previous
application. Growing degree-days were calculated on a base of 34°F using the
equation GDD = [(daily high temperature — daily low temperature)/2] — 34. GDD were
calculated beginning the day after each herbicide application. Herbicide application
dates and GDD measured between applications are shown in Table 1.
Table 1. Application dates for herbicide treatments applied to sugar beet on calendar
day or growing degree-day (GDD) schedules, Malheur Experiment Station, Ontario, OR,
2004.
Application
Treatment*
Timingt
PRE
Standard/High Rate
7 Day
4/13
4/26
5/3
5/10
--
Standard/High Rate
10 Day
4/13
4/26
5/6
5/16
--
Standard/High Rate
150 GDD
4/13
4/26
5/3 (151)
5/10 (199)
--
Standard/ High Rate
175 GDD
4/13
4/26
5/4 (187)
5/12 (173)
--
Standard/High Rate
225 GDD
4/13
4/26
5/6 (252)
5/17 (228)
--
1st
2nd
3rd
4th
Calendar date (GDD since previous application)
Micro-rate
Micro-rate
5 Day
4/13
4/23
4/29
5/4
5/9
7 Day
4/13
4/23
5/1
5/8
5/15
Micro-rate
150 GDD
4/13
4/23
5/1 (152)
5/7 (164)
5/15 (153)
Micro-rate
175 GDD
4/13
4/23
5/2 (180)
5/9 (206)
5/22 (201)
Micro-rate
225 GDD
4/13
4/23
5/4 (249)
5/12 (220)
5/26 (228)
*Standard and high-standard-rate treatments were applied on the same dates.
tApplication timing based on GDD were determined by calculating the number of GDD beginning the day
after the previous application, using the equation GDD = [(daily high temperature — daily low
temperature)/2} — 34.
Sugar beet injury was evaluated on May 29 and June 9, and weed control was
evaluated on September 3. Sugar beet yields were determined by harvesting the
center two rows of each plot on October 8 and 9. Root yields were adjusted to account
for a 5 percent tare. One sample of 16 beets was taken from each plot for quality
analysis. The samples were coded and sent to Syngenta Seeds Research Station in
Nyssa, Oregon, to determine beet pulp sucrose content and purity. Sucrose content
and recoverable sucrose were estimated using empirical equations. Data were
analyzed using analysis of variance procedures and means were separated using
protected LSD at the 95 percent confidence interval (P = 0.05). The untreated control
was not included in the analysis of variance for weed control or crop response.
204
Results and Discussion
For the standard and high-rate herbicide treatments, the number of days between
herbicide applications was the same for the 7-day schedule and the 1 50-GDD
schedule. Applications on the 10-day schedule were within a day of the applications
based on 225 GDD. The 175-GDD-spray schedule was between the other schedules.
The final application of the standard and high rate herbicide treatments varied by as
much as 7 days between application schedules. For micro-rate treatments, the 5-day
application schedule was shorter than all other application schedules with the final
application made by May 9. The 7-day application timing was almost the same as the
timing based on 150-GDD. Applications based on 175 GDD were generally ito 7 days
later than the I 50-GDD schedule and applications with the 225-GDD schedule were
likewise delayed 2 to 4 days compared to 175 GDD. The final application date among
the different application schedules varied by as much as 17 days. In different years,
the GDD application schedules could be significantly different from the fixed day
application timings, depending on the weather patterns.
Postemergence treatments were very effective this year and timing had little effect on
weed control. Pigweed and common lambsquarters control were reduced when the
micro-rate was applied on a 225-GDD interval compared to all other treatments (Table
2). All other treatments and timings provided 94 percent or higher control of pigweed,
common lambsquarters, hairy nightshade, kochia, and barnyardgrass. It is surprising
that such a wide range of application timings could produce such complete control of all
species. Since the standard rate was so effective, no differences were observed
between the standard rate and the high-standard-rate treatments.
On May 24, injury from the standard or high-standard-rate treatments was among the
greatest with the I 75-GDD-application timing (Table 3). This does not appear to be
related to the interval between herbicide applications, but seems to be related to rainfall
events preceding those herbicide applications. There was no difference in sugar beet
injury among the micro-rate treatments. By June 9, there were no differences in sugar
beet injury between any of the herbicide treatments or application timings.
All herbicide treatments increased sugar beet root yield and estimated recoverable
sugar compared to the untreated check (Table 3). There were no differences in percent
extraction or sugar content for any treatment. Root yields were not different among the
herbicide treatments and application timings. The high rate applied on a 10-day interval
produced more estimated recoverable sucrose than the standard rate applied on the
same 10-day schedule or the micro-rate applied on the 225-GDD-application schedule.
This year application timing was not critical because the postemergence treatments
worked very well. In addition, the initial postemergence applications were made at the
correct time while weeds were small. If the initial timing is delayed, the time between
subsequent applications may be much more critical.
205
Table 2. Weed control in sugar beet with standard rate, high-standard-rate, and microrate herbicide treatments applied on a calendar day schedule or at different growing
degree-day (GDD) intervals, Maiheur Experiment Station, Ontario, OR, 2004.
Weed controlt
Treatment*
Pigweed
spp.
Common
lambsguarters
Hairy
Barnyard
-grass
Rate
Timingt
ozai/acreor%v/v
--
4.0 + 0.25
5.4 + 0.25 + 1.5
5.4 + 0.25 + 1.5
7 Day
99
100
100
100
Same as above
Same as above
10 Day
97
100
100
100
98
Standard Rate
150 ODD
100
100
100
100
100
Standard Rate
Same as above
175 GDD
100
100
100
100
100
Standard Rate
Same as above
225 ODD
99
100
100
100
97
Micro-Rate
Progress + UpBeet + Stinger
1.3 + 0.08 + 0.5
5 Day
96
99
100
99
98
Standard Rate
Progress + UpBeet
Progress + UpBeet + Stinger
Progress + UpBeet + Stinger
Standard Rate
nightshade Kochia
0/
96
+MSQ
Progress + UpBeet + Stinger
+MSO
Progress + UpBeet + Stinger
+MSO
Progress + UpBeet + Stinger
+MSO
2.0 + 0.08 + 0.5
Micro-Rate
Same as above
7Day
96
100
100
100
100
Micro-Rate
Same as above
150 ODD
94
98
100
98
100
Micro-Rate
Same as above
175 ODD
98
99
100
100
100
Micro-Rate
Same as above
225 ODD
86
93
100
98
99
High Rate
Progress + UpSeet
Progress + UpBeet ÷ Stinger
Progress + UpBeet÷ Stinger
4.0 + 0.25
6.7 + 0.37 + 1.5
8.1 + 0.5 + 1.5
7 Day
100
100
100
100
98
High Rate
Same as above
10 Day
98
100
100
100
98
HighRate
Same as above
150 ODD
100
100
100
100
100
HighRate
Same as above
175 GDD
99
100
100
100
100
HighRate
Same as above
225 ODD
100
100
100
100
100
--
--
4
2
NS
NS
NS
LSD (P = 0.05)
+1.5%v/v
1.3 + 0.08 + 0.5
+15%v/v
+15%v/v
2.0 + 0.08 + 0.5
+15%v/v
*Standard and high-standard-rate treatments were applied on the same dates.
tApplication timing based on GDD were determined by calculating the number of ODD beginning the day after the
previous
application using the equation ODD = [(daily high temperature — daily low temperature)/21 —34.
tWeed control was evaluated September 3. Pigweed species are a mixture of redroot pigweed and Powell
amaranth.
206
Table 3. Sugar beet injury and yield with standard rate, high-standard-rate, and microrate herbicide treatments applied on a calendar day schedule or at different growing
degree-day (GDD) intervals, Maiheur Experiment Station, Ontario, OR, 2004.
Sugar beets
Yield
Injury
Treatment*
Rate
Timingt
oz ai/acre or % v/v
--
5-24
6-9
0/
Extraction
ERS
Sucrose
0/
ton/acre
Untreated control
Standard Rate
Progress + UpBeet
Progress + UpBeet + Stinger
Progress + UpBeet + Stinger
Root yield
lbs/acre
6.6
93.7
17.0
2,119
4.0 + 0.25
+ 0.25 + 1.5
5.4 + 0.25 + 1.5
7Day
14
11
45.2
93.1
16.6
14,001
Standard Rate
Same as above
10 Day
21
14
42.6
93.4
16.9
13,422
Standard Rate
Same as above
15OGDD
11
8
47.7
93.4
16.6
14,822
Standard Rate
Same as above
175GDD
26
11
46.0
93.4
16.4
14,141
Standard Rate
Same as above
225 GDD
14
10
46.0
93.3
16.8
14,409
Micro-Rate
Progress + UpBeet + Stinger
+ MSO
Progress + UpBeet + Stinger
+ MSO
Progress + UpBeet + Stinger
+ MSO
Progress + UpBeet + Stinger
+ MSO
1.3 + 0.08 + 0.5
+ 1.5% v/v
1.3 + 0.08 + 0.5
+ 1.5% v/v
2.0 + 0.08 + 0.5
+ 1.5% v/v
2.0 + 0.08 + 0.5
+ 1.5% v/v
5 Day
8
11
46.9
93.2
16.7
14,568
Micro-Rate
Same as above
7 Day
15
13
46.6
93.1
16.8
14,532
Micro-Rate
Same as above
150 GDD
17
11
45.6
93.1
16.7
14,195
Micro-Rate
Same as above
175 GDD
11
9
44.3
93.3
16.7
13,823
Micro-Rate
Same as above
225 GDD
9
10
42.5
93.4
16.9
13,398
High Rate
Progress + UpBeet
Progress + UpBeet + Stinger
Progress + UpBeet + Stinger
4.0 + 0.25
6.7 + 0.37 + 1.5
8.1 + 0.5 + 1.5
7Day
19
6
47.3
93.4
16.3
14,396
High Rate
Same as above
10 Day
21
10
47.1
93.9
17.2
15,231
High Rate
Same as above
150 GDD
20
13
46.5
93.3
17.1
14,852
High Rate
Same as above
175 GDD
34
19
44.3
93.6
16.9
14,019
High Rate
Same as above
225 GDD
11
3
46.4
93.3
16.6
14,334
9
NS
4.4
NS
NS
1,459
LSD
(P =
0.05)
5.4
*Standard and high standard rate treatments were applied on the same dates.
tApplication timing based on GDD were determined by calculating the number of GDD beginning the day after the previous
application using the equation GDD = [(daily high temperature — daily low temperature)/2] — 34.
tSugar beets were harvested October 8 and 9. ERS = estimated recoverable sucrose.
207
2004 WINTER ELITE WHEAT TRIAL
Eric P. Eldredge, Clinton C. Shock, and Lamont D. Saunders
Malheur Experiment Station
Oregon State University
Ontario, OR
Introduction
Maiheur Experiment Station provides one location for the Oregon State University
Statewide Winter Elite Wheat variety-testing program. This location compares cereal
grain variety performance in a furrow-irrigated, high potential yield environment. Plant
breeders can use information on variety performance to compare advanced lines with
released cultivars. Growers can use this information to make decisions about which soft
white winter wheat varieties may perform best in their fields.
Methods
The previous crop was sweet corn. After harvest, the corn stalks were flailed, the field
was disked, and the soil was sampled and analyzed. The analysis showed 138 lb
nitrogen (N), 80 lb available phosphate (P205), 1,478 lb soluble potash (1(20), and 70 lb
sulfate (S04)/acre in the top 2 ft of soil, with 2,361 ppm calcium (Ca), 443 ppm
magnesium (Mg), 107 ppm sodium (Na), 1.7 ppm zinc (Zn), 26 ppm iron (Fe), 7 ppm
manganese (Mn), 0.6 ppm copper (Cu), 0.8 ppm boron (B), pH 7.6, and 3.2 percent
organic matter in the top foot of soil. Pre-plant fertilizer was a broadcast application on
October 7, 2003 of 97 lb N/acre, 5 lb Cu/acre, and 1 lb B/acre. The soil was deep
ripped, plowed, and groundhogged to prepare the seedbed. The field was corrugated
into 30-inch rows.
The Winter Elite Wheat Trial was comprised of 40 soft white winter wheat cultivars or
lines, 3 of which were club head types. Seed of all entries was treated with fungicide
and insecticide seed treatment prior to planting. Grain was planted at 30 live seed/ft2,
corresponding to a seeding rate of approximately 110 lb/acre. The experimental design
was a randomized complete block with three replications. Grain was planted on October
17, 2003, with a small plot grain drill, into plots 5 by 20 ft, and then the field was
recorrugated. The field was partially furrow irrigated on November 11 to promote
emergence. The irrigation had to be stopped because the runoff water was interfering
with irrigation district repairs.
A soil sample was taken from the field on April 2, 2004. The soil analysis showed
ammonia and nitrate forms of N in the top 2 ft of soil totaled 86 lb N, with 38 lb
extractable P2O5, 861 lb available 1(20, 83 lb S04/acre in the top 2 ft of soil, with 12
ppm Ca, 370 ppm Mg, 108 ppm Na, 1.2 ppm Zn, 2 ppm Fe, 1 ppm Mn, 0.5 ppm Cu, I
ppm B, pH 7.7, and 3.2 percent organic matter. Urea prills fertilizer (95.6 lb N/acre) was
208
broadcast over the trial on March 30, 2004. This application was an error. Broadleaf
weeds were controlled with Bronate® at lqt/acre applied on May 3. On May 20, fertilizer
was broadcast to supply 13 lb N/acre, 60 lb P205/acre, 3 lb Zn/acre, and 1 lb Cu/acre.
The field was furrow irrigated for 24 hours on April 9, May 5, and June 3. Observations
of heading date were started on June 4, after 100 percent heading had already
occurred in many varieties. Heading date observations should have started in May.
Alleys 5 ft wide were cut with a Hege small plot combine on July 21. The length of each
plot was measured and recorded after the alleys were cut, and the plots were harvested
on July 21 with a Hege small plot combine.
Results
The grain plants in the Winter Elite Wheat Trial grew very lush, with lodging already
observed on May 20, before heading. A thunderstorm brought 0.41 inch of rain and
strong winds on May 18, followed by 0.89 more inches of rain in storms with wind over
the following 10 days, contributing to the lodging that was observed. Plant height at
maturity could not be measured in the trial this year because of extensive lodging. The
residual nitrate plus ammonium in the fall of 2003 was substantial, and the trial received
too much N fertilizer during its growth and development.
Among the soft white winter wheat varieties, the highest yielding was 'ORHOIO918' at
115 bushel/acre, which was not significantly (at LSD 0.05) higher than other entries in
this trial (Table 1). Due to the heavy lodging observed, the trial is useful to compare
variety resistance to lodging. 0RH010918 was the only entry to show no lodging at
harvest, suggesting that it may have exceptional straw strength, similar to 'ORCF-lOt,
'ORHOl 1483', '0RH010920', 'CODA', '0R12020015', '0R9901887', 'MEL1, 'SIMON',
'CLEARFIRST', and '0R9900513', which were among the least severely lodged entries
in this trial.
209
Table 1. Winter Elite Wheat Trial entries, market class, lodging, and yield,
Maiheur Experiment Station, Oregon State University, Ontario, OR, 2005.
Entry Variety
37 ORHOIO918
1
31
25
23
40
39
10
STEPHENS
OR9901887
OR9801757
0R3970965
0RH011483
0RH011481
DUNE
GENE
3
38 ORHO1O92O
9 SIMON
36 OR2010353
19 ORCF-101
8
26
14
33
35
7
21
BRUNDAGE96
OR9900553
CODA
OR2010239
OR2010242
ROD
0RI2020015
20 OR12010007
18 IDO587CL
11
17 CLEARFIRST
34 OR2010241
28 OR9900598
4 WEATHERFORD
16 MEL
6 FINCH
30 OR9900513
24 OR9801695
13 WESTBRD528
2 MADSEN
32 OR9901619
5 TUBBS
29 0R9900547
15 CHUKAR
12 MOHLER
27 OR9900548
22 OR941611
Mean
LSD (0.05)
*Adjusted to 10% moisture,
= Not Significant.
Market
class
SWW
SWW
SWW
SWW
SWW
SWW
SWW
SWW
SWW
SWW
SWW
SWW
SWW-Clearfield
SWW
SWW
Club
SWW
SWW
SWW
SWW-Clearfielcj
SWW-Clearfjeld
SWW-Clear-field
SWW
SWW-Clearfield
SWW
SWW
SWW
Club-Clearfield
SWW
SWW
SWW
SWW
SWW
SWW
SWW
SWW
Club
SWW
SWW
SWW
Origin or
develoDer
OSU
OSU
OSU
OSU
OSU
OSU
OSU
Uofl
OSU
OSU
Uofl
OSU
OSU
U of I
OSU
ARS-WSU
OSU
OSU
WSU
OSU
OSU
U of I
U of I
Gen. Mills
OSU
OSU
OSU
Gen. Mills
ARS-WSU
OSU
OSU
Westbred
ARS-WSU
OSU
OSU
OSU
ARS-WSU
Westbred
OSU
OSU
%
0
57
43
97
90
17
60
60
60
30
47
100
3
67
67
37
67
90
97
40
67
70
57
50
83
90
93
43
63
50
80
90
80
90
97
93
57
100
100
70
66.3
52.1
lb/bushel.
210
115.3
114.3
113.2
107.4
106.6
106.3
105.9
105.3
105.2
103.8
102.4
99.5
98.8
98.6
97.1
96.6
95.7
95.0
94.6
93.4
93.2
91.8
89.5
89.3
88.5
88.0
87.7
87.2
85.4
85.4
84.3
83.2
80.8
80.1
78.2
75.1
74.5
64.4
63.8
63.2
92.2
AUTOMATIC COLLECTION, RADIO TRANSMISSION, AND USE OF
SOIL WATER DATA1
Clinton C. Shock, Erik B. G. Feibert, Andre B. Pereira,
and Cedric A. Shock
Oregon State University
Malheur Experiment Station
Ontario, OR, 2004
Abstract
Precise scheduling of drip irrigation has become very important to help assure optimum
drip-irrigated crop yield and quality. Soil moisture sensors have often been adopted to
assure irrigation management. Integrated systems for using soil moisture data could
enhance widespread applicability. An ideal system would include the equipment to
monitor field conditions, radios to transmit the information from the field because wires
impede cultivation and can complicate cultural practices, interpretation of soil water
status, and the equipment to automatically control irrigation systems.
Key words: automation, irrigation scheduling, onion, A/hum cepa
Introduction
Onions (All/urn cepa) require frequent irrigations to maintain high soil moisture. Drip
irrigation has become popular for onion production because a higher soil moisture can
be maintained without the negative effects associated with furrow irrigation. Drip
irrigation can also be automated. Automated drip irrigation of onions has been used for
irrigation management research at the Malheur Experiment Station since 1995 (Feibert
et al. 1996; Shock et al. 1996, 2002). However, the extensive wiring impedes
cultivation and can complicate cultural practices. Several companies manufacture
automated irrigation systems designed for commercial use that use radio telemetry,
reducing the need for wiring. This trial tested three commercial soil moisture monitoring
systems and compared their irrigation on onion performance to the research system
based on Campbell Scientific (Logan, UT) components currently used (Shock et al.
2002).
Materials and Methods
The onions were grown at the Malheur Experiment Station (MES), Ontario, Oregon, on
an Owyhee silt loam previously planted to wheat. Onion (cv. 'Vaquero', Nunhems,
Parma, ID) was planted in 2 double rows, spaced 22 inches apart (center of double row
to center of double row) on 44-inch beds on March 17, 2004. The 2 rows in the double
row were spaced 3 inches apart. Onion was planted at 150,000 seeds/acre. Drip tape
1 This report is provided as a courtesy to onion growers. This work was supported by
sources other than the Idaho-Eastern Oregon Onion Committee.
211
(T-tape, T-systems International, San Diego, CA) was laid at 4-inch depth between the
2 double onion rows at the same time as planting. The distance between the tape and
the center of the double row was 11 inches. The drip tape had emitters spaced 12
inches apart and a flow rate of 0.22 gal/mm/i 00 ft.
Onion emergence started on April 2. The trial was irrigated with a minisprmnkler system
(RiO Turbo Rotator, Nelson Irrigation Corp., Walla Walla, WA) for even stand
establishment. Risers were spaced 25 ft apart along the flexible polyethylene hose
laterals that were spaced 30 ft apart.
Weed and insect control practices were similar to typical crop production standards and
fertilizer applications were similar to common practices and followed the
recommendations of Sullivan et al. (2001).
The experimental design was a randomized complete block with three replicates. Each
irrigation system was tested in 3 zones that were 16 rows by 50 ft long. There were
four automated irrigation systems tested. Each integrated system contained several
distinctive parts, some automated and some requiring human input: soil moisture
monitoring, data transmission from the field, collection of the data, interpretation of the
data, decisions to irrigate, and control of the irrigation. Additionally, all data were
downloaded for evaluation of the system.
Campbell Scientific
The system currently used for research at MES uses a Campbell Scientific Inc. (Logan,
UT) datalogger (CR1OX). Each zone had four granular matrix sensors (GMS,
Watermark Soil Moisture Sensor Model 200SS, Irrometer Co. Inc., Riverside, CA) used
to measure soil water potential (SWP) (Shock 2003). The GMS from all three zones
were connected to an AM416 multiplexer (Campbell Scientific), which in turn was
connected to the datalogger at the field edge. The soil temperature was also monitored
and was used to correct the SWP calibrations (Shock et al., 1998a). The datalogger
was programmed to monitor the soil moisture and controlled the irrigations for each
zone individually. The Campbell Scientific datalogger was programmed to make
irrigation decisions every 12 hours: zones were irrigated for 8 hours if the SWP
threshold was exceeded. The Campbell Scientific datalogger used an average soil
water potential at 8-inch depth of-20 kPa or less as the irrigation threshold. The
datalogger controlled the irrigations using an SDM 16 controller (Campbell Scientific) to
which the solenoid valves at each zone were connected. Data were downloaded from
the datalogger with a laptop computer or with an SM192 Storage Module (Campbell
Scientific) and a CR1OKD keyboard display (Campbell Scientific). The datalogger was
powered by a solar panel and the controller was powered by 24 V AC. The Campbell
Scientific system was started on May 15, 2004.
Automata
Automata, Inc. (Nevada City, CA) manufactures dataloggers, controllers, and software
for data acquisition and process control. Each one of the three zones had four GMS
connected to a datalogger (Mini Field Station, Automata). The dataloggers at each
212
zone were connected to a controller (Mini-P Field Station, Automata) at the field edge
by an internal radio; The controllers were connected to a base station (Mini-P Base
Station, Automata) in the office by radio. The base station was connected to a desktop
computer. Each zone was irrigated individually using a solenoid valve. The solenoid
valves were connected to and controlled by the controller. The desktop computer ran
the software that monitored the soil moisture in each zone and made the irrigation
decisions every 12 hours: zones were irrigated for 8 hours if the SWP threshold was
exceeded. The irrigation threshold was the average SWP at 8-inch depth of -20 kPa or
less. The Mini Field Stations were powered by solar panels and the Mini-P Field
Station was powered by 120 V AC. The Automata system was started on June 24,
2004.
Watermark Monitor
Irrometer manufactures the Watermark Monitor datalogger that can record data from
seven GMS and one temperature probe. The soil temperature is used to correct the
SWP calibrations. Each of the three Watermark Monitor zones had seven GMS
connected to a Watermark Monitor. Data were downloaded from the Watermark
Monitor both by radio and with a laptop computer. The Watermark Monitors were
powered by solar panels. Irrigation decisions were made daily by reading the GMS
data from each Watermark Monitor. When the SWP reached -20 kPa the zone was
irrigated manually for 8 hours. The Watermark Monitors were started on May 15, 2004.
Acclima
Acclima (Meridian, ID) manufactures a Digital TDTTM that measures volumetric soil
moisture content. Each zone had one TDT sensor and four GMS. The TDT sensors
were connected to a model CS3500 controller (Acclima) at the field edge. The
controller monitored the soil moisture and controlled the irrigations for each zone
separately using solenoid valves. The controller was powered by 120 V AC. Data was
downloaded from the controller using a laptop computer. For comparison and
calibration, the GMS were connected to the Campbell Scientific datalogger which
monitored the soil water potential as described above. The Acclima system was started
on May 16. The CS3500 controller was programmed to irrigate the zone when the
volumetric soil water content was equal to or lower than 27 percent. The soil water
potential data was compared to the volumetric soil water content data to adjust the
CS3500 controller to irrigate each zone in a manner equivalent to the irrigation
scheduling using the GMS (Fig. 1). Due to excessive soil moisture, on June lithe
lower threshold at which irrigations were started was changed from 27 percent to 19
percent, and 21 percent for Acclima zones one and two, respectively, to correspond to
-20 kPa soil water potential. When installed, due to a software constraints, the
controller could only water a maximum of 4 hours at each irrigation. On July 21 the
software was upgraded allowing irrigation durations to be increased to 8 hours. Given
the flow rate of the drip tape, 8 hour irrigations applied 0.48 inches of water. Previous
research indicates that the ideal amount of water to apply at each irrigation is 0.5
inches (Shock et al., 2004).
213
All soil moisture sensors in every zone of the four systems were installed at 8-inch
depth in the center of the double onion row. The GMS were calibrated to SWP (Shock
et al. 1998). The Campbell Scientific, Acclima, and Automata controllers were
programmed to make irrigation decisions every 12 hours: zones were irrigated for8
hours if the soil moisture threshold was exceeded. The Campbell Scientific and
Automata dataloggers used an average soil water potential at 8-inch depth of -20 kPa
or less as the irrigation threshold. The Irrometer zones also had a threshold of -20 kPa.
The amount of water applied to each plot was recorded daily at 8:00 a.m. from a water
meter installed downstream of the solenoid valve. The total amount of water applied
included sprinkler irrigations applied after emergence and water applied with the drip
irrigation system from emergence through the final irrigation.
Onion evapotranspiration (ETa) was calculated with a modified Penman equation
(Wright 1982) using data collected at the Malheur Experiment Station by an AgriMet
weather station (U.S. Bureau of Reclamation, Boise, Idaho). Onion
was estimated
and recorded from crop emergence until the final irrigation on September 2.
On September 24 the onions were lifted to field cure. On September 27, onions in the
central 40 ft of the middle four double rows in each zone were topped and bagged. On
September 28 the onions were graded. Bulbs were separated according to quality:
bulbs without blemishes (No. is), double bulbs (No. 2s), neck rot (bulbs infected with
the fungus Botrytis al/il in the neck or side), plate rot (bulbs infected with the fungus
Fusarium oxysporum), and black mold (bulbs infected with the fungus Aspergi//us
niger). The No. 1 bulbs were graded according to diameter: small (<21,4 inch), medium
(2% to 3 inch), jumbo (3 to 4 inch), colossal (4 to 4% inch), and supercolossal (>414
inch). Bulb counts per 50 lb of supercolossal onions were determined for each zone of
every variety by weighing and counting all supercolossal bulbs during grading.
Differences in onion performance and water application among irrigation systems were
determined by protected least significant differences at the 95 percent confidence level
using analysis of variance (Hintze, 2000).
Results and Discussion
Marketable onion yield was excellent, averaging 1,041 cwt/acre (116.6 Mg/ha) over the
4 drip irrigation systems (Table 1). The average onion bulb yield in the Treasure Valley
was 625 cwt/acre (70.0 Mg/ha) in 2000, 630 cwt/acre (70.6 Mg/ha) in 2001, and 645
cwt/acre (72.2 Mg/ha) in 2002 (USDA 2003). The excellent onion performance with all
the systems used was consistent with the maintenance of SWP within the narrow range
required by onion (Shock et al. i998b, 2000).
A comparison of the systems in terms of onion yield and grade is not completely
justified because the systems were started at different times. In addition, the Acclima
and Automata systems required adjustments and modifications after the start of
operation.
214
The Acclima system resulted in among the lowest marketable yield and yield of colossal
bulbs. The Acclima system maintained the soil very wet at the beginning of the season
due to our lack of knowledge of the appropriate volumetric soil water content that
corresponded to ideal SWP (Figs. 2 and 3). After changes were made to the irrigation
threshold for each Acclima zone separately (Fig. 1), the soil volumetric water content
(Fig. 3) was very stable with some seasonal deviations from the target SWP of -20 kPa
(Fig. 2). Due to initial software limitations, the Acclima system had irrigation durations
of 4 hours until July 21. After July 21 the software was upgraded and the irrigation
durations were increased to 8 hours. Irrigation durations of less than 8 hours have
been shown to reduce onion yield (Shock et al. 2004). Also, early heavy irrigation could
have leached nitrate needed for optimal onion growth.
The Campbell Scientific and Automata maintained the SWP relatively constant and
close to the target of -20 kPa (Fig. 4). The lrrometer Watermark Monitors maintained
the SWP on target, but with larger oscillations than the other systems, due to human
collection of the SWP data and human control of irrigation onset and duration (Fig. 4).
Water applications over time followed
during the season (Fig. 5). The total water
applied plus precipitation from emergence to the end of irrigation on September 2 was
31.5, 40.0, 43.9, and 36.2 inches (800, 1,016, 1,115, and 919 mm) for the Campbell
Scientific, Irrometer, Automata, and Acclima systems, respectively. Precipitation from
onion emergence until irrigation ended on September 2 was 3.88 inches (99 mm).
Onion evapotranspiration for the season totaled 30.9 inches (785 mm) from emergence
to the last irrigation. The Automata system used a new version of software that had
initial bugs to work out. The Acclima system over-applied water when first installed,
until the irrigation thresholds were adjusted downwards.
Conclusions
All the systems tested performed well in this preliminary evaluation. Onion yield, grade,
and quality were excellent. Any small shortcomings in precise irrigation may have been
due to our unfamiliarity and inexperience using these systems.
References
Feibert, E.B.G., C.C. Shock, and L.D. Saunders. 1996. Plant population for
drip-irrigated onions. Oregon State University Agricultural Experiment Station Special
Report 964:45-48.
Hintze, J.L. 2000. NCSS 97 Statistical System for Windows, Number Cruncher
Statistical Systems, Kaysville, Utah.
Shock, C.C., 2003. Soil water potential measurement by granular matrix sensors.
Pages 899-903 in B.A. Stewart and l.A. Howell (eds.). The Encyclopedia of Water
Science. Marcel Dekker.
215
Shock, C.C., J. Barnum, and M. Seddigh. 1998a. Calibration of Watermark soil
moisture sensors for irrigation management. Pages 139-146 in Proceedings of the
International Irrigation Show. Irrigation Association. San Diego, CA.
Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 1996. Nitrogen fertilization for
drip-irrigated onions. Oregon State University Agricultural Experiment Station Special
Report 964:38-44.
Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 1998b. Onion yield and quality
affected by soil water potential as irrigation threshold. HortScience 33:1188-1191.
Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 2000. Irrigation criteria for
drip-irrigated onions. HortScience 35:63-66.
Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 2004. Irrigation frequency, drip tape
flow rate, and onion performance. Oregon State University Agricultural Experiment
Station Special Report 1055:58-66.
Shock, C.C., E.B.G. Feibert, L.D. Saunders, and E.P. Eldredge. 2002. Automation of
subsurface drip irrigation for crop research. Pages 809-816 in American Society of
Agricultural Engineers, World Congress on Computers in Agriculture and Natural
Resources. Iguacu Falls, Brazil.
Sullivan, D.M., B.D. Brown, C.C. Shock, D.A. Horneck, R.G. Stevens, G.Q. Pelter, and
E.B.G. Feibert. 2001. Nutrient management for onions in the Pacific Northwest. PubI.
PNW 546. Pacific Northwest Ext., Oregon State University, Corvallis, OR.
USDA. 2003. Vegetables 2002 Summary. Agricultural Statistics Board, NatI. Agric. Stat.
Serv. Vg 1-2 (03): 32-34.
Wright, J.L.1982. New evapotranspiration crop coefficients. J. Irrig. Drain. Div. ASCE
108:57-74.
216
Table 1. Onion yield and grade for a drip-irrigated onion field irrigated automatically by
four systems, Oregon
- State University Malheur Experiment Station, Ontario, OR 2004.
Marketable yield by grade
System
Total
yield
Total
>4% in 4-4% in
3-4 in
Nonm arketable yield
Supercolossal
Small
2%-3 in counts Total rot No. 2s
#/50 lb
cwtlacre
Campbell Sci.
Irrometer
Automata
Acclima
Average
LSD (0.05)
1035.9
1081.4
1072.4
1008.4
1049.5
51.2
1026.1
1076.1
21.4
36.2
1064.0
997.9
1041.0
52.0
18.2
15.7
22.9
NS
258.5
337.2
306.0
215.2
279.2
86.5
727.4
685.6
724.6
746.4
721.0
NS
18.8
17.1
15.2
20.6
17.9
NS
Mg/ha
Campbell Sci.
Irrometer
Automata
Acclima
Average
LSD (0.05)
116.0
121.1
120.1
112.9
117.5
5.7
114.9
120.5
119.2
111.8
116.6
5.8
2.0
29.0
37.8
34.3
1.8
24.1
2.6
NS
31.3
9.7
2.4
4.1
81.5
76.8
81.2
83.6
80.8
NS
217
2.1
1.9
1.7
2.3
2.0
NS
42.6
39.5
41.8
47.9
43.0
NS
%oftotal
0.5
0.2
0.4
0.3
0.3
NS
#/50 lb %oftotal
yield
42.6
0.5
39.5
0.2
41.8
0.4
47.9
0.3
43.0
0.3
NS
NS
-- cwt/acre -1,3
3.1
0.0
3.4
2.2
4.2
3.2
NS
1.5
3.7
1.6
NS
--Mg/ha-0.2
0.0
0.2
0.4
0.2
NS
0.4
0.4
0.3
0.5
0.4
NS
0
a.
Y = -74.80 + 4.55X - 0.0782X2
R2 = 0.35, P = 0.001
0
10
5
20
15
25
30
Volumetric soil water content, %
ii:
=
/
21%
Y=-58.71 +1.77X
R2 = 0.45, P = 0.001
-40
0
10
5
15
20
25
30
35
Volumetric soil water content, %
27%
-30
y = + 13.62- 2.79X + 0.0564X2
o
R2=0.42,P=0.001
(I)
-40
0
10
20
30
40
50
Volumetric soil water content. %
Figure 1. Regressions of volumetric soil water content from Acclima TDT sensors
against soil water potential from Watermark soil moisture sensors for each Acclima plot.
Malheur Experiment Station, Oregon State University, Ontario OR.
218
0
-10
-20
-30
-40
Irrigation
threshold 19%
-50
0
-10
0
-20
-30
-40
0
Irrigation
threshold 21%
-50
0
-10
-20
-30
-40
-50
135
Irrigation
threshold 27%
161
187
213
239
265
Day of year
Figure 2. Soil water potential at 8-inch depth for a drip-irrigated onion field using the
Acclima automated irrigation system with 3 irrigation thresholds, Oregon State
University Malheur Experiment Station, Ontario, OR 2004.
219
--—-----
40
----—
---
-
C
a)
C
30
0
0
a)
20
0
U)
()
Irrigation threshold: 19%
134
156
200
178
222
244
Day of year
40
C
a)
C
30
0
C)
a)
Ca
20
0
U)
C)
a)
E
10
Irrigation threshold: 21%
0
>
0
--
134
156
200
178
222
244
Day of year
40
C
a)
0
0
30-
a)
20
-
10
-
0
U)
0
a)
E
Irrigation treshold: 27%
:3
0
>
134
156
178
200
222
244
Day of year
Figure 3. Volumetric soil water content at 8-inch depth for a drip-irrigated onion field
using the Acclima irrigation system with 3 soil water content irrigation thresholds,
Oregon State University, Maiheur Experiment Station, Ontario, OR 2004.
220
0
Campbell Scientific
-10
-20
-30
161
213
187
239
265
Automata
-10
ci)
o
-20
-30
—
0
175
193
229
211
247
265
Irrometer
-10
-20
-30
-40
180
201
222
243
264
Day of year
Figure 4. Soil water potential at 8-inch depth for a drip-irrigated onion field using 3
automated irrigation systems, Oregon State University Malheur Experiment Station,
Ontario, OR 2004.
221
40
30
Campbell Scientific
20
U)
U)
0
c
10
0
40
I rrometer
30
Automata
Acclima
20
10
90
121
152
183
214
245
Day of year
Figure 5. Water applied plus precipitation over time for drip-irrigated onions with 4
automated irrigation systems. Thin line is water applied and thick line is EL, Oregon
State University Malheur Experiment Station, Ontario, OR 2004.
222
USE OF IRRIGAS® FOR IRRIGATION
SCHEDULING FOR ONION UNDER FURROW IRRIGATION
Andre B. Pereira, Clinton C. Shock, Cedric A. Shock,
and Erik B.G. Feibert
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Irrigation scheduling consists of applying the right amount of water at the right time.
Incentives to onion (A/hum cepa L.) growers for precise irrigation scheduling are based
on the fact that underirrigation leads to a loss in market grade, bulb quality, and
contract price, whereas overirrigation leads to a loss in water, electricity for pumping,
leaching of nitrogen, and it may favor weeds and wastes labor. Overirrigation results in
soil erosion, increases the potential for contamination of surface and groundwater, and
requires additional chemicals and fertilizers. One of the several tools growers can use
to schedule irrigation is based on the monitoring of soil water potential (SWP) and a
criterion has been established at —27 kPa for furrow-irrigated onion grown on silt loam
(Shock et al. 1 998b). The SWP is of direct importance to plants because it reflects the
force necessary to remove water from the soil.
This trial had the following objectives: 1) to evaluate the performance of six different
kinds of soil moisture sensors in a furrow-irrigated onion field; 2) to compare the
irrigation criterion of the Irrigas® to that defined by previous research carried out at the
Malheur Experiment Station for onions under furrow irrigation; and 3) to verify if the
nominal functioning pressure of the Irrigas performs reliably through wetting and drying
cycles on silt loam in eastern Oregon, and observe onion yield and quality.
Materials and Methods
Six types of soil moisture sensors were compared by their response to wetting and
drying in furrow-irrigated onion grown on Owyhee silt loam at the Malheur Experiment
Station. Seeds were planted on 17 March 2004 in double rows on 22-inch beds. The
double onion rows were spaced 3 inches apart. The sensors were tensiometers with
pressure transducers (Irrometers, Irrometer Co. Inc., Riverside, CA, Model RA), ECH2O
dielectric aquameter (Decagon Devices, Inc., Pullman, WA), granular matrix sensors
(GMS, Watermark soil moisture sensors Model 200SS, Irrometer Co., Inc.), Irrigas
(National Center for Horticultural Research of EMBRAPA, Brasilia, DF, Brazil), and two
experimental granular matrix sensors not described further here. Sensors were
installed at 8-inch depth below the double row of onions on 15 July 2004 and replicates
were spread 60 ft apart down an irrigation furrow in a 3-acre field. The statistical design
was a randomized complete block with four replicates.
223
Tensiometers, GMS, and ECH2O dielectric aquameters were attached to three AM416
multiplexers (Campbell Scientific, Logan, UT) that in turn were wired to a CR lOX
datalogger (Campbell Scientific), which was programmed to make readings once an
hour. Two temperature sensors were installed at 8-inch depth to allow for temperature
corrections of GMS readings. Data were collected from the datalogger using a laptop
computer. Each replicate contained two tensiometers, two GMS, one ECH2O dielectric
aquameter, and two Irrigas. The ECH2O dielectric aquameters were calibrated against
volumetric soil water content by taking two soil samples near each probe centered at
8-inch depth, once when the soil was relatively wet, and once when the soil was
relatively dry, and by preparing oven-dry soil and placing the probes in the oven-dry soil
at the end of the trial. Gravimetric data were converted to volumetric water contents
using soil bulk density. Irrigas operates on the principle of air permeability of porous
ceramics explained below. Data were collected from all sensors from July 15 to
September 30, 2004.
Air permeability of porous ceramics has been used to estimate SWP (Kemper and
Amemiya 1958). Air permeability of a specific porous ceramic is a function of its water
content. As water dries from the ceramic, the pores allow the passage of air. The
"initial bubbling pressure" (IBP) of a water-saturated porous ceramic is the lowest
applied pressure at which air permeability is observed.
The IBP of a specific porous ceramic can be used to estimate whether a soil has
reached a specific SWP used as an irrigation criterion. The National Center for
Horticultural Research of EMBRAPA, Brazil used IBP to develop a SWP indicator,
Irrigas (Calbo 2004; Calbo and Silva 2001). Irrigas consists of a porous ceramic cup, a
flexible tube, a transparent barrel, a rigid thin plastic support, and a moveable container
of water. The porous ceramic cup is installed in the effective rooting zone of the crop
and connected to a small transparent barrel by means of the flexible tube. The porous
ceramic cup is designed to retard free air movement out of the cup until the soil and cup
reach a predetermined water potential. To make a reading, the barrel is immersed in
the container of water. The free air passage through the porous ceramic cup gets
blocked whenever the soil water saturates the pores in the ceramic. As the soil dries,
its moisture drops below a critical tension value, and the porous cup becomes
permeable to air passage. In dry soils when the barrel is immersed into the water, the
meniscus (air-water boundary) rapidly moves upwards in the barrel to equalize it to the
water level in the container. Whenever water enters the barrel, the soil is at least as dry
as the calibration of the porous ceramic cup. The soil moisture is evaluated once a day
to determine the moment to irrigate. In sandy soils the evaluation is made twice a day.
The Irrigas had a nominal calibration of -25 kPa and when we subjected Irrigas to
progressive amounts of suction, the porous ceramic freely bubbled air at -25 kPa.
Irrigas readings were taken every day at 9:00 AM.
The onion crop was irrigated at -25 kPa throughout the season based on average GMS
readings (Shock et al. 1 998b). With the establishment of this experiment in an onion
field, the onions in the entire sensor calibration trial were irrigated when the average
224
GMS reading reached -25 kPa on July 17 and 22. Since the Irrigas had not provided
positive readings, the next five irrigations were delayed until at least half of the eight
Irrigas sensors indicated the need for irrigation.
The onions were lifted on September 8 to field cure. Onions from the middle two rows
in each replicate were topped by hand and bagged on September 15. Onions were
graded on September 16. During grading, bulbs were separated according to quality:
bulbs without blemishes (No. Is), split bulbs (No. 2s), neck rot (bulbs infected with the
fungus Botrytis al/il in the neck or side), plate rot (bulbs infected with the fungus
Fusarium oxysporum), and black mold (bulbs infected with the fungus Aspergillus
niger). The No. 1 bulbs were graded according to diameter: small (<2.25 inches),
medium (2.25-3 inches), jumbo (3-4 inches), colossal (4-4.25 inches), and
supercolossal (>4.25 inches). Bulb counts per 50 lb of supercolossal onions were
determined for each plot of every variety by weighing and counting all supercolossal
bulbs during grading.
Results and Discussion
All the sensors used in this study had advantages of low unit cost and simple
installation procedures. Both tensiometers and GMS demonstrated similar
responsiveness to wetting and drying of the soil (Fig. 1). In this trial, there were two
episodes of irrigation based on GMS readings at —25 kPa and five irrigation events
based on the Irrigas criterion (Fig. 1). It took the same amount of time (4 hours) for all
the tensiometers and all GMS to indicate that the soil at 8-inch had reached saturation
after the onset of each irrigation episode. The relative similarity in responsiveness
between tensiometers with pressure transducers and granular matrix sensors (GMS)
was statistically confirmed by regression with a coefficient of determination of 0.92 (Fig.
2). The Irrigas indicated free air permeability close to -35 kPa for Owyhee silt loam in
this trial (Fig. 1).
Large changes in tensiometer readings from -10 to -40 kPa translated into small
changes in water content readings for the ECH2O dielectric aquameter (Fig. 3). The
exact responsiveness of the ECH2O dielectric aquameter to the soil water content was
beyond the scope of this work. A comparison of the ECH2O dielectric aquameter
readings with soil volumetric water content from this field indicated that the readings
were relatively flat and nonlinear in response to changes in volumetric soil water
content (Fig. 4). The relatively small changes in volumetric soil water content as read
by the ECH2O dielectric aquameter occurred across the critical range of SWP for onion
irrigation decisions.
The ECH2O dielectric aquameter was relatively easy to automate. The ECH2O
dielectric aquameter was used in only one experiment and the readings were relatively
unresponsive to changes in soil water potential in the range of -10 to -40 kPa (Fig. 3)
and relatively unresponsive to changes in volumetric soil water content in the range of
23 to 38 percent (Fig. 4). The need for site specific calibrations noted here for the
ECH2O dielectric aquameter is consistent with the work of Evett et at. (2002), who
225
tested a variety of capacitance probes in widely divergent soils and recommended site
specific calibrations.
The tensiometers with pressure transducers were easily automated. The tensiometers
required servicing twice during the 76 days of the trial. More frequent servicing to
replace lost water should be expected when soils are not maintained as wet as in the
present experiment. The GMS have limitations in reading SWP in soils wetter than —10
kPa (Fig. 2), as has been described previously (Shock et al. 1998a), and in responding
in coarse texture soils (Shock 2003).
The model of Irrigas was only tested in one comparison experiment, where it appeared
to be promising for irrigation scheduling at —35 kPa in silt loam, not the nominal
specifications of —25 kPa. Kemper and Amemiya (1958) pointed out that soil particles
which surround and are in contact with a porous ceramic could cut down on air
permeability to some extent. From the limited experience of this trial, the interference
of the soil with air permeability of porous ceramics is a possibility for further study. We
would expect greater interference in fine textured soils at relatively high (wetter) SWP
and less interference with coarse textured soils and at relatively low (drier) SWP.
Scheduling furrow irrigations at a criterion near -27 kPa has been shown to optimize
long-day onion yield and grade (Shock et al. 1998b). However, perhaps the Irrigas
irrigation threshold of -35 kPa for August through the end of growing season may not
have been detrimental and may bring about a convenient reduction in irrigation
frequencies. An Irrigas type instrument could probably be manufactured with porosity
designed specifically for measurements at -25 kPa in silt loam.
The irrigation scheduling used in this field trial appeared to be adequate, since there
was an average onion marketable yield of 993 cwtlacre. Average marketable onion
yield for 2000 through 2002 from commercial production in the Treasure Valley was 633
cwt/acre.
Acknowledgments
We would like to thank Adonai Gimenez Calbo from CNPH-EMBRAPA, Brasilia, OF,
Brazil, and Enison Pozzani from E-Design, Jundiai, SP, Brazil, for providing 8 -25 kPa
Irrigas for testing. We would also like to thank Conselho de Desenvolvimento Cientifico
e Tecnologico (CNPq) of Brazil for providing the Post-Doctoral scholarship and support
from Oregon State University that enabled this work.
References
Calbo, A.G. 2004. Gas irrigation control system based on soil moisture determination
through porous capsules. United States Patent, 6705542 B2.
226
Calbo, A.G., and W.L.C. Silva. 2001. Irrigas — novo sistema para controle da irrigacao.
Pages 177-1 82 in Anais do Xl Congresso Brasileiro de Irrigacao e Drenagem.
Fortaleza, CE.
Evett, S.R., J.P. Laurent, P. Cepuder, and C. Hignett. 2002. Neutron scattering,
capacitance, and TDR soil water content measurements compared on four continents.
Pages 1021-1-1021-10 in Transactions 17th World Congress of Soil Science, August
14-21, 2002, Bangkok, Thailand (CD-ROM).
Kemper, W.D., and M. Amemiya. 1958. Utilization of air permeability of porous
ceramics as a measure of hydraulic stress in soils. Soil Science 85:117-124.
Shock, C.C. 2003. Soil water potential measurement by granular matrix sensors. Pages
899-903 In B.A. Stewart and T.A. Howell (eds.). The Encyclopedia of Water Science.
Marcel Dekker.
Shock, C.C., J.M. Barnum, and M. Seddigh. 1998a. Calibration of Watermark soil
moisture sensors for irrigation management. Pages 139-146 in Proceedings of the
International Irrigation Show, Irrigation Association, San Diego, CA.
Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 1998b. Onion yield and quality
affected by soil water potential as irrigation threshold. HortScience 33:1188-1191.
227
- GMS
— Tensiometer
0
-10
-20
0
-30
-40
0
-50
200
210
220
230
240
250
260
270
Day of the year
Figure 1. Soil water potential over time for tensiometers with pressure transducers and
granular matrix sensors in a furrow-irrigated onion trial. Arrows denote furrow irrigations
with 75 mm of water applied. The last five irrigations started based on Irrigas. Malheur
Experiment Station, Oregon State University, Ontario, OR 2004.
0
a-
Y=2.090+ 1.622X+O.01605X2
R20.924 P0.0001 n=1852
-30
0
0
Tensiometer soil water potential, kPa
Figure 2. Soil water potential measured in a furrow-irrigated onion trial by a tensiometer
with transducers (X axis) regressed against soil moisture suction measured by a
granular matrix sensor (Y axis). Data points are the average of eight instruments.
Malheur Experiment Station, Oregon State University, Ontario, OR 2004.
228
-
______________________________________________
050
40
20
30
10
0
Tensiometer soil water potential, kPa
Figure 3. Soil water potential measured in a furrow-irrigated onion trial by a tensiometer
with transducers (X axis) regressed against volumetric soil water content measured by
an ECH2O dielectric aquameter (Y axis). Data points for soil water potential are the
average of eight tensiometers. Data points for the ECH2O dielectric aquameter are the
average of four sensors. Maiheur Experiment Station, Oregon State University, Ontario,
OR 2004.
C)
40
0
20
-
15
10
V
-$
0
5
33.16(1 - EXP(-0.1005(X -. 06930)))
0.970 P = 0.01 n = 24
10
15
20
25
30
35
40
Dielectric volumetric water content, %
Figure 4. Regression of the volumetric soil water content measured by an ECH2O
dielectric aquameter (X axis) against the classical gravimetric method (Y axis). Data
points from each of four ECH2O dielectric aquameters were compared with two soil
samples in each of three soil moisture ranges. Malheur Experiment Station, Oregon
State University, Ontario, OR 2004.
229
FACTORS INFLUENCING VAPAM® EFFICACY ON YELLOW NUTSEDGE TUBERS
Corey V. Ransom, Charles A. Rice, and Joey K. Ishida
Maiheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Yellow nutsedge is a perennial weed common in irrigated row crop production in the
Treasure Valley of Eastern Oregon and Southwestern Idaho. It is particularly
problematic in onion production. Onion plants are relatively short in stature with vertical
leaves producing an incomplete canopy with limited potential to effectively suppress
weeds. The conditions of high light intensity as well as frequent irrigation and high
nitrogen fertilization required to maximize onion yield also serve to stimulate yellow
nutsedge growth (Keeling et at. 1990). We have demonstrated that without any
competition a single yellow nutsedge plant can produce over 18,000 tubers in a single
year (Rice et al. 2004). We have also found that heavily infested commercial fields can
have as high as 1,800 tubers/ft2 in the top 10 inches of soil (unpublished data).
Producers often apply Vapam® (metham sodium) in the fall prior to planting onions in an
attempt to control yellow nutsedge. Control with Vapam is often variable and seems to
depend on a number of environmental factors. The objective of this research was to
determine the effect of metham rate, duration of exposure, temperature of exposure,
and yellow nutsedge tuber condition on metham sodium efficacy.
Materials and Methods
Trials were conducted at the Malheur Experiment Station in the laboratory to determine
the influence of metham sodium rate, duration of exposure, temperature during
exposure, and tuber conditioning on yellow nutsedge control. Yellow nutsedge tubers
were extracted from the soil in November and either stored at a constant 50°F in a small
volume of soil or washed and subjected to 38°F for 4 weeks prior to the initiation of the
experiment. The conditioning treatment was meant to reduce tuber dormancy.
Washing and chilling have been reported as effectively overcoming dormancy
(Tumbleson and Kommedahl 1961). All tubers were produced from a single plant the
previous summer. Soil (1.76 Ib) and 15 tubers were placed in 1-quart jars. The soil was
an Owyhee silt loam. The soil was wetted to 14 percent moisture on a weight for weight
basis by adding one third of the water to the bottom of the jar, adding half the volume of
soil and then the yellow nutsedge tubers, adding another third of water, adding the
remaining soil and then the final third of the water. The jars were placed in growth
chambers at 41, 55, or 77°F for 24 hr to equilibrate. Vapam was injected into the soil
0.5 inch below the tubers at equivalent field rates of 0, 20, 40, 60, and 80 gal of product
per acre based on soil volume. Jars were sealed and placed back in their respective
temperatures for 1, 3, or 5 days. After each duration of exposure, the soil was removed
230
from the jars and the tubers were washed from the soil. Extracted tubers were placed in
petri-dishes between 2 pieces of filter paper and 5 ml of water was added to each dish.
The petri-dishes were sealed and placed in the dark at 77°F. Germinated tubers were
recorded at the time of removal and weekly for 6 weeks. Treatments were replicated
four times and the trial was repeated once after the initial run. Total percent tuber
germination was analyzed by ANOVA. For each combination of exposure temperature,
exposure duration, and tuber conditioning, tuber sprouting response to Vapam dose
was fitted to the logistic model:
1
+
D —C
(x / 150
)b
Where y = the percent sprouting yellow nutsedge tubers, x = metham sodium rate, C =
percent tubers sprouting at high rates, D = percent of tubers sprouting in the non-treated
= the dose providing 50 percent
treatment, b = the slope at the /50 dose, and
reduction in sprouting tubers (Seefelt et al. 1995).
Results and Discussion
In general, tuber sprouting was affected by metham sodium rate, temperature of
exposure, duration of exposure, and yellow nutsedge tuber conditioning. This is in
agreement with research by Boydston and Williams (2003), which evaluated fumigant
affects on volunteer potatoes. All main effects and interactions were significant (Table
1). The /5Q dose for metham sodium under various conditions ranged from 21.64 to
>80.0 gal/acre and was lower for conditioned tubers compared to nonconditioned tubers
across all conditions except for tubers exposed at 77°F for 3 or 5 days (Table 2). Nonconditioned tubers had lower germination in preliminary trials (data not shown), but
washing and other conditions during the trial overcame any dormancy as D values
(maximum germination) were similar among all treatments. Nonconditioned tubers did
require more time to germinate than conditioned tubers (data not shown).
Nonconditioned tubers were unaffected by metham sodium rate at I day exposure at
41°F (Fig. 1). For nonconditioned tubers, increasing exposure temperature, and
increasing duration of exposure decreased sprouting. As duration of exposure or
temperature of exposure increased, differences among conditioned and nonconditioned
tUbers decreased. Metham Sodium must be converted to methyl isothiocyanate (MITC)
to have activity against yellow nutsedge. At lower temperatures conversion of metham
sodium to MITC takes place at a slower rate. In addition to slow conversion of metham
to MITC, the reduced response of yellow nutsedge tubers at cooler temperatures could
also be attributed to yellow nutsedge tubers being less metabolically active. The similar
response of conditioned tubers regardless of duration of exposure at 59 or 77°F and the
increased response of nonconditioned tubers to increasing duration of exposure,
suggests that at 59 and 77°F metham sodium conversion to MITC is not the limiting
factor, but rather uptake by the nonconditioned nutsedge tubers may have been the
limiting factor. In contrast, at 41°F, both conditioned and nonconditioned tubers
responded to increasing duration of exposure, suggesting that both rate of metham
231
sodium conversion to MITC and uptake by the tubers were having an affect on metham
sodium efficacy. /50 values were actually lower for conditioned tubers exposed for 5
days at 41°F compared to 59 or 77°F. This result is difficult to explain. It may be that
while conversion of metham sodium to MITC is faster at high temperatures, breakdown
of MITC is also increased. This research illustrates that fumigant efficacy depends on
the dose reaching the target organism. While the rate applied directly influences the
dose, environmental or physiological factors may affect what dose the yellow nutsedge
receives. Applying metham sodium at a time when yellow nutsedge tubers are more
susceptible may increase metham sodium efficacy against yellow nutsedge.
References
Boydston, R. A., and M. M. Williams II. 2003. Effect of soil fumigation on volunteer
potato (Solanum tuberosum) tuber viability. Weed Technol. 17:352-357.
Keeling, J. W., 0. A. Bender, and J. R. Abernathy. 1990. Yellow nutsedge management
in transplanted onions. Weed Technol. 4:68-70.
Rice, C. A., C. V. Ransom, and J. K. Ishida. 2004. Yellow nutsedge (Cyperus
esculentus) response to irrigation and nitrogen fertilization. Proc. West. Soc. Weed Sd.
57:42-43, No.65.
Seefelt, S. S., J. E. Jensen, and E. P. Fuerst. 1995. Log-logistic analysis of herbicide
dose-response relationships. Weed Technol. 9:218-225.
Tumbleson, M. E., and 1. Kommedahl. 1961. Reproductive potential of Cyperus
esculentus by tubers. Weeds 9:646-653.
Acknowledgement
Thanks to the Idaho/Eastern Oregon Onion Growers Association for financial support.
232
Table 1. Significance of ANOVA main effects and interactions for total percent of yellow
nutsedge tubers sprouting.
Factor
P
Dose
0.00001
Temperature
0.00001
Time
0.00001
Conditioning
0.00001
Dose by temperature
0.00001
Dose by time
0.00001
Temperature by time
0.00001
Conditioning by dose
0.00001
Conditioning by temperature
0.00001
Conditioning by time
0.00001
Dose by temperature by time
0.00001
Dose by temperature by conditioning
0.00001
Temperature by time by conditioning
0.00001
Dose by time by conditioning
0.00001
Dose by temperature by time by
0.00001
conditioning
233
1 day exposure
3 day exposure
5 day exposure
• Non-conditioned
100
Conditioned
80
60
41 F
40
20
• Non-conditioned
0
o
CondItioned
100
180
59 F
.0
C)
40
C)
>100
80
60
77 F
40
20
0•
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
Equivatent Vapam rate (gal/acre)
Figure 1. Yellow nutsedge germination in response to
rate, temperature of
exposure, duration of exposure, and conditioning of the yellow nutsedge tubers.
Conditioned tubers were washed and chilled at 38°F for 4 weeks prior to trial initiation.
Nonconditioned tubers were stored in soil at a constant 50°F. Malheur Experiment
Station, Oregon State University, Ontario, OR, 2004.
234
Table 2. Estimated parameters for nonlinear regression analysis of yellow nutsedge sprouting in response to Vapam®
rate, exposure temperature, exposure duration, and yellow nutsedge tuber conditioning. Standard errors are in
Darentheses.*. Maiheur Experiment Station, Oregon State University, Ontario, OR, 2004.
R2
b
D
C
Temperature' Time Tuber condition
150
—--gal/acre
°F
days
%
0.00
----41
Nonconditioned
1
0.65
1.82 (1.15)
49.57 (36.77)
0.00 (56.29)
Conditioned
93.16 (6.23)
0.84
6.59 (3.73)
63.18 (7.10)
96.21 (3.21)
6.34 (26.29)
3
Nonconditioned
0.92
3.80 (0.68)
0.00 (4.33)
29.57 (2.09)
Conditioned
89.99 (3.83)
0.97
10.00 (1.67)
0.00 (2.96)
46.07 (1.32)
96.02 (1.87)
Nonconditioned
5
0.96
10.00
(26.72)
21.64
(4.61)
1.69
(2.04)
90.84 (2.84)
Conditioned
0.80
5.57 (4.91)
0.00 (126.09) 75.24 (37.21)
98.20 (2.78)
59
1
Nonconditioned
0.98
5.96 (1.14)
0.00 (1.86)
23.69 (0.95)
97.50 (2.37)
Conditioned
0.95
4.28 (0.81)
34.82 (1.59)
87.78 (2.86)
0.00 (3.67)
Nonconditioned
3
0.97
6.38 (1.44)
0.00 (1.88)
23.62 (1.05)
98.33 (2.46)
Conditioned
0.98
10.00 (10.28)
98.01 (1.88)
37.36 (2.49)
0.00 (2.63)
Nonconditioned
5
1.00
10.00 (0.99)
99.01 (1.04)
0.00 (0.75) — 27.48 (0.93)
Conditioned
0.98
6.72
(1.76)
38.62
(0.63)
0.00
(2.65)
95.86
(1.64)
77
Nonconditioned
1
—
0.96
6.02 (1.06)
25.37 (1.31)_
0.00 (2.31)
94.99 (2.95)
Conditioned
0.97
6.21
(0.94)
26.24
(1.31)_
0.00 (2.22)
95.60 (2.86)
Nonconditioned
3
0.97
4.83 (0.70)
24.15 (0.94)
0.00 (2.06)
93.33 (2.41)
Conditioned
0.98
7.98 (0.99)
28.36 (1.26)
0.00 (1.45)
96.18 (2.11)
Nonconditioned
5
0.99
9.20 (1.35)
0.00 (1.29)
28.64 (1.48)
94.16 (1.78)
Conditioned
*Abbreviations: D, percent of tubers sprouting in nontreated treatment; C, percent of tubers germinating at high metham
dose; 15Q, dose causing a 50 percent reduction in sprouting tubers; b, slope at '50 dose. For one treatment the /50 was
higher than the rates evaluated.
I
YELLOW NUTSEDGE GROWTH IN RESPONSE TO ENVIRONMENT
Corey V. Ransom, Charles A. Rice, Joey K. Ishida, and Clinton C. Shock
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Yellow nutsedge is a perennial weed common in irrigated row crop production in the
Treasure Valley of eastern Oregon and southwestern Idaho. It is particularly
problematic in onion production. Onions are relatively short statured plants with vertical
leaves producing an incomplete canopy with limited potential to effectively suppress
weeds. Yellow nutsedge has a C4 photosynthetic pathway and therefore responds well
to conditions of high light intensity that exist in onion production. Management
practices including frequent irrigation and high nitrogen fertilization required to maximize
onion yield also serve to stimulate yellow nutsedge growth (Keeling et al. 1990).
Yellow nutsedge reproduces and is dispersed primarily by tubers' that are formed at the
apical ends of underground rhizomes. Tubers are produced in the upper 18 inches of
the soil profile with the greatest concentration located in the upper 6 inches (Stoller and
Sweet 1987, Tumbleson and Kommedahl 1961). After a period of dormancy, tubers
germinate and produce shoots in subsequent growing seasons. Tubers may remain
viable for 1-3 years, providing an effective means of survival. Asexual reproduction by
yellow nutsedge tubers can be quite prolific. Tumbleson and Kommedahl (1961)
reported that a single tuber produced 6,900 tubers the first fall after planting and 1,900
plants the following spring in an area of approximately 34ft2. Yellow nutsedge grows
best where soil moisture is high (Bendixin and Nandihalli 1987). Garg et al. (1967)
reported that nitrogen promotes vegetative growth over reproductive growth in yellow
nutsedge, leading to increased basal bulb formation (and subsequent shoot production)
as opposed to tuber formation.
Two trials were conducted in 2004 at the Malheur Experiment Station to evaluate yellow
nutsedge growth with various environmental factors.
Methods
Yellow nutsedge emergence and growth as influenced by depth of germination
The objectives of this experiment were to 1) determine the depth from which a yellow
nutsedge tuber can emerge in the field, 2) determine the date of emergence based on
depth of burial, and 3) determine the growth (i.e., shoot and tuber production) potential
based on burial depth.
236
Yellow nutsedge tubers were harvested from a plot from the previous year's irrigation
trial on April 16, 2004. The tubers were washed from the soil, rinsed with deionized
water, and placed in a refrigerator at 38.5°F for approximately 14 days. Both washing
and chilling have been shown to effectively break tuber dormancy (Tumbleson and
Kommedahl 1961, Bell et al. 1962). This was necessary to ensure that the tubers
would readily germinate when buried and that any differences in emergence would be
based on depth of burial and/or soil temperature and not differences in dormancy. Ten
tubers were buried in a single container at a selected depth of either 2, 4, 6, 8, 10, 12,
14, 16, 18, or 24 inches on May 1. Each depth was replicated four times. Containers
consisted of 10-inch-diameter pvc pipe. Temperature sensors were placed at 6, 12, 18,
and 24 inches deep in 1 tube in each replication. Each container was irrigated by a
single drip emitter with an output of 0.5 gal/hr. Watermark sensors (Irrometer Co. Inc.,
Riverside, CA) were buried 6 inches deep in every pot in the first and third replicate of
the trial. Soil water potential was measured every morning. Irrigations were initiated
each time the average of the Watermark sensors was greater than or equal to -20 kPa.
Shoots were counted throughout the season and shoots and tubers were harvested on
July 7.
Yellow nutsedge growth in response to irrigation and nitrogen fertilization
The objectives of this experiment were to 1) monitor patch expansion from a single
yellow nutsedge tuber in the absence of crop competition over the course of one
growing season, 2) evaluate the effects of selected irrigation regimes on yellow
nutsedge growth, and 3) evaluate the effect of nitrogen fertilization on yellow nutsedge
growth.
Tubers for this trial were harvested from a ditch bank, were washed from the soil, rinsed
with deionized water, and stored in a refrigerator at 38.5°F for approximately 40 days.
Tubers weighing from 0.18 to 0.2 g and measuring between 6 and 7 mm were selected
and planted in flats in the greenhouse. Tubers of similar size and weight were selected
because research has shown that tuber size can affect early plant vigor, with plants
from smaller tubers being less vigorous. On June 4, a single germinated tuber with a
shoot of at least 1 inch long was transplanted into the center of each circular plot of 6-ft
diameter. Transplanted yellow nutsedge plants were used to ensure a more uniform
date of establishment among the 18 individual plots. The circular plots consisted of 14inch-wide galvanized valley flashing cut to a length of 19 ft with the ends riveted
together to produce a circle with a diameter of 6 ft. The flashing was then buried
approximately 10 inches deep in the soil. Prior to transplanting, each plot was drip
irrigated to a soil moisture potential of -20 kPa to incorporate fertilizer applications and
to provide similar moisture conditions for early yellow nutsedge establishment.
The trial consisted of 18 circular plots, 6 each for the 3 irrigation regimes and 3 each for
the 2 fertilization levels split over the irrigation regimes. Irrigation water was applied to
the plots through 6 drip emitters evenly spaced in a circular pattern, where each emitter
was located 1.5 ft from the center of the plot. The 6 emitters had a combined output of
3.0 gal/hr. The values for irrigation criteria were -20, -50, and -80 kPa and were
selected to represent soil moisture conditions similar to those in wheat, sugar beet, and
237
dry bulb onion production systems, respectively. The 2 fertilization levels consisted of
plots receiving nitrogen (N) (46 percent urea) at rates of either 90 or 268 lbs N/acre. All
plots were fertilized before transplanting with 90 lbs phophorus/acre, 90 lbs sulfur/acre,
1 lb copper/acre, 1 lbs boron/acre, and 9 lbs magnesium/acre. Soil water potential was
measured in each plot with a single Watermark soil moisture sensor installed at a 6inch depth equidistant from the yellow nutsedge plant at the center of the plot and the
drip line, Irrigation water was applied independently for each regime when the average
6-inch soil water potential from the 6 sensors reached either -20, -50, or -80 kPa. The
sensors were read by a datalogger every 3 hours, and once every 12 hours irrigation
was initiated using a solenoid valve if the soil water potential had exceeded the
treatment criteria during the previous 12-hour period. Water meters were installed
between the solenoid valves and the water line for each individual irrigation regime to
record the amount of water applied daily.
Yellow nutsedge growth was measured initially by counting shoot numbers within each
plot and by taking overhead digital images of each plot. At a point where shoots
became too numerous to efficiently count, only overhead digital images were taken of
each plot. These images were used to quantify the plot area that was covered by
yellow nutsedge shoots using a software program produced at Oregon State University
(OSU). Shoots and tubers were harvested from subsamples within each plot on
September 29 and 30. Thirteen subsamples were collected across the 6-ft diameter of
the plots. The subsamples consisted of 4.25-inch-diameter circles from which shoots
were counted to estimate the total shoot number per plot. The shoots were then
clipped at ground level and placed in bags to be dried. The dry weights were used to
estimate the total above-ground biomass. Once the shoots were removed, a soil core
measuring 4.25 inches in diameter by 8 inches in depth was taken from the same area
where the shoots were removed. The individual core samples were bagged and
recorded as to their location within the plot. The core samples were then emptied into a
bucket with multiple 11/64-inch holes in the bottom and sides. Water was sprayed into
the bucket to remove the soil from the tubers. The tubers were then counted and
weighed and those numbers were used to estimate the total tuber population for each
of the plots.
Results and Discussion
Yellow nutsedge emergence and growth as influenced by depth of germination
Plots where tubers were planted from 2 to 12 inches deep had an average of 1-5
shoots emerged on May 24, while deeper depths had no shoots for another week or
more (data not shown). The time required for treatments to produce an average 5
shoots per plot ranged from 24 to 68 days after planting. The time required for 10
shoots per plot to emerge ranged from 34 to 55 days for burial depths up to 18 inches.
The tubers buried at the 24-inch depth produced a maximum of 6 shoots at the time the
plots were harvested. The average daily soil temperatures at 6, 12, 18, and 24 inches
from planting through harvest are illustrated in Figure 1 and show that temperature
extremes are greatest nearer the soil surface, If tubers were buried earlier in the year,
we might expect to see greater differences among emergence dates based on
238
differences in the time required for the soil at each depth to reach temperatures
favorable for yellow nutsedge germination. Figure 2 shows the emergence of shoots as
affected by planting depth from May 24 through June 7. At harvest, shoot numbers
were similar in plots where tubers were planted from 2 to 16 inches deep (Table 1).
Tubers planted 18 and 24 inches deep had fewer shoots than all other planting depths
and the 24-inch depth had the least number of shoots. The average weight per shoot
was less for 16-, 18-, or 24-inch depths compared to depths from 2 to 12 inches (data
not shown). Tuber numbers were lower for plots where the planting depth was 14
inches or greater, with significant decreases as depth increased from 12 to 24 inches.
This research demonstrates that yellow nutsedge shoot emergence is delayed at
depths below 12 inches. Those shoots that emerge are fewer in number and at depths
below 16 inches are also smaller in size. This delay in emergence affects how many
tubers can be produced, and it is reasonable to expect that the delay in emergence and
reduction in individual shoot fitness would correlate with reduced competitiveness from
yellow nutsedge emerging from depths greater than 14 inches in the soil.
Table 1. Yellow nutsedge shoot emergence and shoot and tuber production as
influenced by depth of germination, Malheur Expe riment Station, Oregon State
University, Ontario, OR, 2004.
Time to emergence
Average> 5
Average
Yellow nutsedge production*
10
Tubers
Shoots
Depth of burial
days after planting
no/plot
2-inch
35
41
91 b
250 b
4-inch
25
39
ll5ab
334a
6-inch
24
34
101 ab
333 a
8-inch
27
39
126a
313ab
10-inch
27
39
lO8ab
240b
12-inch
31
39
119a
272ab
14-inch
39
40
119a
167c
16-inch
39
45
lO8ab
97cd
18-inch
45
55
66c
3Ode
24-inch
68
>68
6d
lOe
*Yellow nutsedge tubers were buried at the various depths on May 1 2004, and yellow nutsedge shoots and tubers were harvested
on July 7, 2004. Data followed by the same letter are not signficicant according to LSD (0.05).
tDays after planting for which the average of the 4 replicates for the given depth of burial were greater than or equal to 5.
tDays after planting for which the average of the 4 replicates for the given depth of burial were greater than or equal to 10.
239
80
75
LL
G)
I-
70
0)
65
0)
4-I
60
aE
-J
6"
0
C/)
55
—
—
—.
18"
24"
50
4/26/2004
5/10/2004
5/24/2004
6/7/2004
6/21/2004
7/512004
Date
Figure 1. Average daily soil temperature at 6-, 12-, 1 8-, and 24- inch depths from
yellow nutsedge tuber planting up to shoot and tuber harvest, Malheur Experiment
Station, Oregon State University, Ontario, OR, 2004.
140
4-I
0
0
a-
0
C
———v--——
0)
C.)
C
100
0)
a)
L.
0)
E
•
120
——
— —0—. —
80
0)
0)
.D
60 -
C
40
0
2-in
6-in
8-in
10-in
12-in
14-in
16-in
18-in
24-in
/
'7'
0)
0
0)
20
0)
C,
0)
-0
0--
0
>
5/23/05
5/30105
6/6/05
6/13/05
6/20/05
6/27/05
7/4/0 5
Date
Figure 2. Yellow nutsedge shoot emergence over time as influenced by depth of
germination, Malheur Experiment Station, Oregon State University, Ontario, OR, 2004.
240
Yellow nutsedge growth in response to irrigation and nitrogen fertilization
There were no significant interactions between irrigation criteria and fertilization.
Nitrogen fertilization did cause a significant increase in shoot number, but not on shoot
biomass, tuber number, total tuber weight per plot, or individual shoot or tuber weight
(data not shown). Since there were no interactions, irrigation criteria data were
averaged over fertilization levels. Irrigation events and total water applied are shown in
Table 2. The number of irrigations and the total amount of water applied were much
less for the -20-kPa and —50-kPa irrigation treatments compared to 2003. This may
have been because temperatures were lower in 2004 compared to 2003. Soil moisture
potential over time by irrigation regime is illustrated in Figure 3. Irrigation had a
significant effect on yellow nutsedge shoot number and total weight (Table 3). The —20kPa irrigation treatment produced an average of 1,747 shoots per plot. This was
significantly greater than the —50-kPa and —80-kPa irrigation treatments, which
produced 444 and 411 shoots per plot, respectively. All shoot numbers were much
lower than in 2003. The —50-kPa and —80-kPa treatments produced similar numbers of
shoots, while in 2003 the —50-kPa treatment produced almost twice as many shoots as
the —80-kpa treatment. The —20-kPa irrigation treatment produced an average of 2.7 lb
of shoot biomass per plot and the shoots in this treatment had higher weight per shoot
than in the other irrigation treatments. Based on the digital images, the area infested by
the yellow nutsedge shoots grew quickest for the —20-kPa treatment and much slower
with either the —50- or —80-kPa treatments (Fig. 4). Similar to 2003, the amount of area
infested was fairly small from June 4 to July 19. Over a 27-day period from July21 to
August 17 the area infested by yellow nutsedge in the —20-kPa treatments increased
from 2.6 to 22.6 ft2. Yellow nutsedge tuber production was higher with the —20-kPa
irrigation criterion compared to the other irrigation criteria and total numbers for this
treatment were similar to 2003 (Table 4). An average of 19,508 tubers/plot were
produced from a single plant with the —20-kPa treatment. The —50- and —80-kPa
treatments produced 4,447 and 5,826 tuber, respectively. The —50-kPa treatment
produced 10,000 fewer tubers in 2004 than in 2003.
This year's results demonstrate that under high levels of irrigation yellow nutsedge can
produce large numbers of shoots and tubers. This continues to be much higher than
previously reported in the literature. However, the differences between 2003 and 2004
suggest that factors other than irrigation criteria may significantly affect the productive
potential of yellow nutsedge when irrigation levels are moderate.
241
Table 2. Number of irrigations, amount applied per irrigation, and total water applied,
Maiheur Experiment Station, Oregon State University, Ontario, OR, 2004.
Irrigation criteria
Total applied*
Irrigations
kPa
-20
number/plot
inches/event
inches/plot
45
0.32
15.9
-50
7
1.0
8.5
-80
4
1.38
7.0
*Total includes 1 .48 inch of rainfall.
0
-10
Ct
-20
-30
-40
0
-50
-60
Ct
-70
0
Cl)
-80
-90
-100
6/11
6/21
6/30
7/10
7/20
7/29
8/8
8/18
8/27
9/6
9/15
Date
Figure 3. Soil moisture potential over time by irrigation regime, Malheur Experiment
Station, Oregon State University, Ontario, OR, 2004.
242
Table 3. Yellow nutsedge shoot production as influenced by irrigation, Maiheur
Experiment Station, Orecion State University, Ontario, OR, 2004.
Yellow nutsedge shoots*
Irrigation
kPa
-20
no./plot
no/ft2
lb/plot
lb/ft2
g/shoot
1,747a
62a
2.7a
0.095a
0.71a
-50
444 b
16 b
0.5 b
0.019 b
0.51 b
-80
411 b
15b
0.5b
0.018b
0.56b
*Values followed by the same letter de signation are not s tatistically different (P
0.05).
5000
•
4000
-2OkPa
-5OkPa
N
3000
C)
4-I
(0
2000
C
(0
C)
1000
——---V
——----y--—--—v
0
6/1104
7/1/04
8/1/04
9/1/04
10/1/04
Date
Figure 4. Yellow nutsedge patch expansion over time based on percent ground
coverage between transplanting and harvest, Malheur Experiment Station, Oregon
State University, Ontario, OR, 2004.
243
Table 4. Yellow nutsedge tuber production as influenced by irrigation, Maiheur
Experiment Station, Oreaon State University, Ontario, OR, 2004.
Irrigation
kPa
-20
Yellow nutsedge tubers
no/plot
19,508 a
no/ft2
690 a
lb/plot
5.1 a
0.18 a
g/tuber
0.12 b
-50
4,447b
157b
1.5b
0.005b
0.15 a
-80
5,826b
207b
1.7b
0.006b
0.13b
lb/ft2
*Values followed by the same letter designation are not statistically different (P = 0.05).
References
Bell, R. S., W. H. Lachman, E. M. Rahn, and R. D. Sweet. 1962. Life history studies as
related to weed control in the northeast. 1. Nutgrass. Rhode Island Agric. Exp. Stn. Bull.
364. 33 pages.
Bendixen, L. E., and U. B. Nandihalli. 1987. Worldwide distribution of purple and yellow
nutsedge (Cyperus rotundus and C. esculentus). Weed Technol. 1:61-65.
Garg, D. K., L. E. Bendixen, and S. R. Anderson. 1967. Rhizome differentiation in
yellow nutsedge. Weed Sci. 15:124-128.
Keeling, J. W., D. A. Bender, and J. R. Abernathy. 1990. Yellow nutsedge (Cyperus
esculentus) management in transplanted onions (A ilium cepa). Weed Technol. 4:68-70.
Tumbleson, M. E., and T. Kommedahl. 1961. Reproductive potential of Cyperus
esculentus by tubers. Weeds 9:646-653.
Stoller, E. W., and R. D. Sweet. 1987. Biology and life cycle of purple and yellow
nutsedges (Cyperus rotundus and C. esculentus). Weed Technol. 1:66-73.
244
YELLOW NUTSEDGE CONTROL IN CORN AND DRY BEAN CROPS
Corey V. Ransom, Charles A. Rice, and Joey K. Ishida
Malheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Yellow nutsedge is an increasing weed problem in the Treasure Valley of eastern
Oregon and southwestern Idaho. Yellow nutsedge is particularly detrimental in onion
production due to the noncompetitive nature of the crop and the ability of yellow
nutsedge to proliferate under the growing conditions that exist in onion production.
Previous research conducted in the Treasure Valley evaluating yellow nutsedge control
in onion has met with limited success, in part due to the lack of effective herbicide
options and the weed's ability to germinate over long periods of time during the growing
season. An integrated approach is needed to manage yellow nutsedge, including the
use of effective herbicide treatments in each of the crops within a rotation. In 2003,
several herbicide treatments in corn and dry bean significantly reduced the number of
yellow nutsedge tubers in the soil. This research was conducted to further evaluate the
effects of crop species and herbicides on growth and development of yellow nutsedge
in field corn and dry bean production.
Methods
Studies were conducted in a field heavily infested with yellow nutsedge located north of
Ontario on the Oregon Slope. The soil was a Owyhee silt loam with pH 8.5 and 1.7
percent organic matter. The field was disked on May 19 and ground hogged on May
20. The field was bedded for corn and dry bean on May 21 and preirrigated. Plots
were 7.33 ft wide and 30 ft long and were replicated 4 times and arranged in a
randomized block design. Pretreatment nutsedge tubers were sampled May 31, which
consisted of taking 8 core samples measuring 4.25 inches in diameter and 7 inches
deep from the center furrow within each individual plot. The samples were combined
and the tubers were extracted from the soil by washing the soil through screens with
11/64-inch holes. To determine treatment effects on tuber numbers, core samples
were taken again at harvest. Season-end core samples were taken from the bed tops
of the center two rows in each plot. Four cores were sampled from each row. The
extraction process for season-end yellow nutsedge tubers was the same as for the
initial samples. In total, tuber sampling involved taking 1,280 core samples and
washing tubers from approximately 3.9 tons of soil. Herbicide applications were made
with a CO2-pressurized backpack sprayer calibrated to deliver 20 gal/acre at 30 psi.
Crop injury and visual evaluations of yellow nutsedge control were made throughout the
growing season. Yields were taken for each crop by harvesting the center two rows of
each plot.
245
Corn
Beds were sidedressed with 150 lbs of nitrogen (N) on May 31. The field was harrowed
on June 1 and preplant incorporated (PPI) Dual II Magnum® (s-metolachlor) treatments
were applied to plots and incorporated by making two passes with the bed harrow in
opposite directions. Pioneer 'P-36N69 Roundup Ready' field corn was planted on June
1 on a 7-inch seed spacing on 22-inch rows. Mid-postemergence treatments were
applied June 21 and late postemergence treatments were applied on June 29.
treatments included Basagran® (bentazon), Permit® (halosulfuron), and
RoundupR (glyphosate). Basagran and Roundup were applied once following PPI Dual
Magnum, twice alone, or twice following PPI Dual Magnum. Permit was applied once
alone and in combination with Basagran following PPI Dual Magnum. Basagran and
Permit were applied in combination with a crop oil concentrate (COC) while ammonium
sulfate (AMS) was added to Roundup applications. Yield was determined by harvesting
ears from the center two rows of each plot on October 12. The ears were shelled, and
grain moisture content and weights were recorded. Final yields were adjusted to 12
percent moisture content.
Dry Bean
On May 31, plots were sidedressed with 150 lb N/acre. On June 1, beds were
harrowed, and PPI herbicide treatments were applied and incorporated by harrowing
the beds twice more in opposite directions. PPI treatments included Dual MagnumR (smetolachlor), Eptam® (EPTC), and a combination of Dual Magnum plus Eptam. Small
white beans ('Aurora' variety) were planted and Prowl® (pendimethalin) was applied
preemergence to help control weeds other than yellow nutsedge. On June 11, due to
poor bean emergence, we decided to replant. The field was sprayed with 0.75 lb
ai/acre Roundup and 2.5 lb/acre of AMS to remove the beans that had emerged. A
different variety of pinto bean 'Othello' was planted on June 14. Postemergence
treatments were applied July 6 and included Sandea® (halosulfuron) plus nonionic
surfactant (NIS) and Basagran plus COC. The plots treated with Basagran received a
second application of Basagran on July 21. On September 16, plants were pulled from
the center two rows of each plot to determine dry bean yield. After the bean plants had
dried, the beans were threshed by with a Hege plot combine.
Results and Discussion
Corn
The corn rotation had some of the best yellow nutsedge control and all treatments had
less tuber production compared to the untreated check (Table 1). Corn was not injured
by any of the herbicide treatments evaluated. Yellow nutsedge control ranged from 68
to 97 percent on July 8 and 79 to 97 percent on July 28 (Table 1). Dual II Magnum
alone and Roundup applied twice provided the least control on July 8 and Dual II
Magnum provided less control than all other treatments on July 28. Treatments with
herbicides applied PPI and followed by multiple postemergence (POST) applications
tended to have greater yellow nutsedge control than treatments with only PPI or POST
treatments. Tuber numbers increased by 55 percent in the untreated plots. In
246
herbicide-treated plots the change in yellow nutsedge tuber numbers ranged from a 68
percent decrease to a 2 percent increase. Dual II Magnum followed by Permit plus
COC resulted in significantly fewer tubers than Dual II Magnum followed by one
application of Basagran plus COC. Corn yields did not differ significantly among
treatments and ranged from 224 to 246 bu/acre.
Dry Bean
Dry beans also appear to have effective options for yellow nutsedge control. On the
July 8 evaluation, yellow nutsedge control was significantly better with Eptam plus Dual
Magnum when both were applied PPI as compared to Eptam applied PPI and Dual
Magnum applied preemergence (PRE) (Table 2). On July 8, treatments with Dual
Magnum applied PPI were more effective than Eptam PPI followed by Dual Magnum
PRE. At this rating, POST treatments had been applied only 2 days earlier and yellow
nutsedge was not exhibiting symptoms. On July 28, herbicide treatments provided 5991 percent yellow nutsedge control. Treatments with only PPI or POST herbicides were
generally less effective than combinations with a PPI application followed by one or two
POST herbicide applications. Yellow nutsedge tuber numbers increased by 77 percent
in the untreated plot. In the herbicide-treated plots, the change in yellow nutsedge
tuber numbers ranged from a 43 percent decrease to a 7 percent increase with no
significant differences between herbicide treatments. All herbicide treatments
increased dry bean yield compared to the untreated check. Basagran applied twice
POST had lower bean yield than Eptam plus Dual Magnum applied PPI.
247
Table 1. Corn yield, yellow nutsedge control, and yellow nutsedge tuber response to
herbicide treatments, Malheur Experiment Station, Oregon State University, Ontario,
OR, 2004.
Nutsedge control
Treatment3
Rate
lb ai/acre
Timingb
7-28
7-8
Average nutsedge tubers
Initial
/
bu/acre
%v/v
Untreated control
Crop
yield
Final
no/ft
2
Change
,,
--
--
224
--
--
148
220
55
1.6
PPI
243
68
79
164
77
-32
Basagran + COC
Basagran + COC
1.0 + 1.0%
MP
LP
240
94
86
172
62
-57
1.0 + 1.0%
Roundup + AMS
Roundup + AMS
0.58 + 2.5
0.58 + 2.5
MP
LP
235
69
88
193
75
-54
Dual II Magnum
Basagran + COC
1.6
PPI
LP
236
84
89
123
78
2
1.0 + 1.0%
Dual II Magnum
Roundup + AMS
PPI
MP
246
79
87
154
72
-49
0.58 + 2.5
Dual II Magnum
Permit + COC
PPI
MP
231
83
95
238
64
-68
0.031 + 1.0%
PPI
MP
229
97
97
260
69
-67
PPI
MP
LP
245
83
92
248
89
-53
Dual II Magnum
1.6
1.6
Dual II Magnum
Basagran +
Permit + COC
0.031 + 1.0%
Dual II Magnum
Roundup + AMS
Roundup + AMS
0.58 + 2.5
0.58 + 2.5
Dual II Magnum
Basagran + COC
Basagran + COC
PPI
MP
LP
242
96
97
199
73
-58
1.0 + 1.0%
1.0 + 1.0%
--
--
NS
10
6
NS
33
59
LSD (0.05)
1.6
1.0 +
1.6
1.6
= crop oil concentrate, AMS = ammonium sulfate.
bApplication timing abbreviations and dates: Preplant incorporated (PPI) on June 1
late postemergence (LP) on June 29.
248
mid-postemergence (MP) on June 21, and
Table 2. Dry bean yield, yellow nutsedge control, and yellow nutsedge tuber response
to herbicide treatments, Maiheur Experiment Station, Oregon State University, Ontario,
OR, 2004.
Nutsedge control
Treatmenta
Rate
Timingb
lb al/acre
%v/v
Crop
yield
7/8
7/28
Average nutsedge tubers
Initial
Change
no/ft2
cwt/acre
Untreated control
Final
33
--
--
236
365
77
Dual Magnum
1.6
PPI
41
76
59
198
149
3
Eptam
Dual Magnum
3.9
1.6
PPI
PRE
42
40
68
352
231
-14
Eptam
Dual Magnum
3.9
1.3
PPI
PPI
45
78
76
218
141
-28
Dual Magnum
Sandea + NIS
1.6
PPI
.031+25%
POST
44
81
91
235
172
7
43
73
91
271
128
-43
40
4
70
255
177
-24
43
75
85
206
155
-12
42
75
90
279
158
-20
4
20
10
156
75
65
Dual Magnum
1.6
.031+
PPI
Sandea+
Basagran + NIS
1.0+25%
Basagran + COC
Basagran + COC
1.0+1.0%
1.0+1.0%
Dual Magnum
Basagran + COC
1.6
PPI
1.0+1.0%
POST
Dual Magnum
Basagran + COC
Basagran + COC
1.6
PPI
1.0+1.0%
1.0+1.0%
POST
LSD (0.05)
POST
POST
POST
LP
LP
aThe entire trial was treated with Prowl (1.0 lb al/acre) preemergence for control of weeds other than yellow nutsedge.
ionic surfactant, COC = crop oil concentrate.
bApplication timing abbreviations and dates: Preplant incorporated (PPI) on June 1 preemergence (PRE), postemergence (POST)
on July 6, and late postemergence (LP) on July 21.
249
CHEMICAL FALLOW FOR YELLOW NUTSEDGE SUPRESSION FOLLOWING
WHEAT HARVEST
Corey V. Ransom, Charles A. Rice, and Joey K. Ishida
Maiheur Experiment Station
Oregon State University
Ontario, OR, 2004
Introduction
Yellow nutsedge is extremely competitive with onions and other crops. Few herbicide
treatments are effective for managing yellow nutsedge within an onion crop. Herbicides
that can be used in corn and dry bean can effectively reduce yellow nutsedge tubers in
the soil. Generally, we think that yellow nutsedge does not grow well in a wheat crop
because wheat is so competitive. However, following wheat harvest, yellow nutsedge
shoots can be seen actively growing. Little is known about yellow nutsedge growth
following wheat harvest and its potential to produce additional tubers during this time.
Also, the time between wheat harvest and fall ground preparation may be a window to
further reduce the yellow nutsedge population. A special registration for Eptam® in
Arizona allows its use in the late summer as a fallow treatment in preparation for a
winter crop. We conducted a trial to determine the number of tubers produced by
yellow nutsedge following wheat harvest, and whether the use of Eptam as a chemical
fallow could reduce tuber production.
Methods
A wheat field with a prior history of severe yellow nutsedge infestation was selected for
this trial. Following wheat harvest, the field was corrugated and irrigated. As soon as
the field was dry enough it was disked to remove yellow nutsedge shoots that had
emerged and to level the field. Once the surface was dry, Eptam was applied at 7.0
pt/acre and immediately incorporated by disking to approximately 6-inch depth. The
treatments compared in the trial included disking only or disking plus Eptam. The trial
area was left undisturbed until bedding in the fall. Eptam was applied with a CO2pressurized backpack sprayer delivering 20 gal/acre at 30 psi. Plots measured 12 ft
wide by 30 ft long and were replicated 4 times in a randomized complete block design.
Shoot emergence was monitored by counting shoots within 1-yd2 quadrats. Changes in
tuber numbers were documented by taking 8 core samples 4.25 inches in diameter and
7 inches deep from each plot and washing the tubers from the soil. Core samples were
taken prior to treatment and again at the conclusion of the trial. Initial core samples
were taken August 3 and final core samples were taken October 21. In addition to
sampling in the trial area, samples were taken from an area adjacent to the trial to
provide observational data on the effect of disking once, disking twice, and disking twice
with Eptam incorporated with the second disking.
250
Data were analyzed using paired t-tests at the 5 percent level (0.05).
Results and Discussion
The Eptam fallow label says that the field should not be irrigated for as long as possible
to prevent the Eptam from volatilizing from the soil. The day after the Eptam treatments
at least 0.5 inches of rain fell across the valley. Eptam incorporated with disking
reduced yellow nutsedge shoot and tuber numbers compared to disking alone (Table
1). In plots that were disked only, tuber numbers increased by 97 percent while in plots
where Eptam was incorporated with the disking, tuber numbers only increased 7
percent. When 1-ft2 quadrats were harvested by hand in an attempt to recover tubers
attached to actively growing shoots, there were significantly fewer tubers in the Eptamtreated plots compared to the disked-only plots (Table 2). The ratio of tubers in the
Eptam-treated plots compared to the disked-only plots was much smaller than from the
core samples. This demonstrates that the Eptam was reducing the production of new
yellow nutsedge tubers, and likely inhibiting the germination of tubers that were present
when the Eptam was applied. Sampling from nonreplicated strips in the field suggests
that any additional management of yellow nutsedge growth decreased the total number
of tubers produced. Disking once had the highest number of tubers followed by disking
twice, and then by disking once and then applying Eptam and incorporating with a
second disking.
This research demonstrated that significant numbers of yellow nutsedge tubers can be
produced following wheat harvest. Management of yellow nutsedge growth following
wheat harvest is essential to prevent the production of additional tubers and the
potential buildup of tubers to levels that will make yellow nutsedge control difficult in
following crops. The use of Eptam as a chemical fallow treatment significantly reduced
yellow nutsedge shoot and tuber production.
4
251
Table 1. Yellow nutsedge shoot and tuber numbers in response to disking and Eptam®
plus disking, Malheur Experiment Station, Ontario, OR, 2004.
Yellow nutsedge tubers
Yellow nutsedge shoots
Final
Change
Initial
Treatment
Sept. 16
Oct. 4
no/yd2
Disking only
Eptam + Disking
%
17
23
45
79
+ 94
7
14
45
48
+7
Table 2. Yellow nutsedg e shoot and tuber numbers in response to disking and
taken from hand-harvest ed qua drats on October 21, Malheur Experiment Station,
Ontario, OR, 2004.
Yellow nutsedge
Treatment
Shoots
Tubers
Disking only
Eptam + Disking
no/yd2
37
33
11
7
Table 3. Average ye 110w nutsedge shoot and tuber numbers in response to disking and
Eptam®, taken from non replicated strips adjacent to the trial area on October 6,
Malheur Experiment Station, Ontario, OR, 2004.
Yellow nutsedge
Treatment
Shoots
Tubers
no/ft2
Disked once
60
47
Disked twice
32
20
Disked followed by Eptam + Disking
14
5
252
APPENDIX A. HERBICIDES AND ADJUVANTS
Trade Name
Common or Code Name
Manufacturer
Basagran
Betamix
Bronate
Buctril
Callisto
Casoron 4G
Chateau
Clarion
Command
Dacthal
Distinct
Dual, Dual Magnum,
Dual II Magnum
Dyne-Amic
Eptam
Goal, Goal 2XL
Gramoxone
Karmex
Kerb
Matrix
Option
Outlook
Nortron
Permit
Poast, Poast HC
Progress
bentazon
desmedipham + phenmedipham
bromoxynil + MCPA
bromoxynil
mesotrione
dichlobenil
flumioxazin
nicosulfuron + rimsulfuron
clomazone
DCPA
diflufenzopyr + dicamba
metolachlor
BASF Ag Products
Bayer CropScience
Bayer CropScience
Bayer CropScience
Syngenta
Crompton
Valent
DuPont
proprietary surfactant blend
Helena Chemical
Syngenta
Dow Agrosciences
Syngenta
Griffin LLC
Dow Agrosciences
Dupont
Bayer CropScience
BASF Ag Products
Bayer CropScience
Monsanto
BASF Ag Products
Bayer CropScience
Prowl, Prowl H2O
Quest
Roundup,
Roundup Ultra
Sandea
Sencor
Sinbar
Spartan
Stinger
Treflan
UpBeet
Valor
EPTC
oxyflurorfen
paraquat dichioride
diuron
pronamide
rimsulfuron
foramsulfuron
dimethenamid-p
ethofumesate
halosulfuron
sethoxydim
desmedipham + phenmedipham
+ ethofumesate
pendimethalin
proprietary spray additive
glyphosate
halosulfuron
metribuzin
terbacil
sulfentrazone
clopyralid
triflu ralin
triflusulfuron
flumioxazin
253
FMC
Syngenta
BASF Ag Products
Syngenta
BASF Ag Products
Helena Chemical
Monsanto
Gowan Company
Bayer CropScience
DuPont
FMC
Dow Ag rosciences
Dow Ag rosciences
Dupont
Valent
APPENDIX B. INSECTICIDES, FUNGICIDES, AND NEMATICIDES
Trade Name
Common or Code Name
Manufacturer
Asana
Aza-Direct
Bayleton
Bravo, Bravo Weather Stik
Captan
Capture
Counter 20 CR, Counter 15G
Diazinon AG500
Dibrom
Dimethoate
Dithane
Ecozin
Gaucho
Guthion
Headline
Kocide
Lannate
Lorsban, Lorsban 15G
Malathion
Messenger
Metasystox-R
esfenvalerate
azadirachtin
DuPont
Gowan Company
Bayer CropScience
Syngenta
Micro Flo
MSR
Mustang
Penncap-M
Ridomil Gold MZ
Success
Super-Six
Telone C-17
Telone II
Temik 15G
Thimet
Topsin M
Tops-MZ
Vapam
Vydate, Vydate L
Warrior
Warrior I
triad imefon
chlorothalanil
captan
bifenthrin
terbufos
diazinon
naled
dimethoate
mancozeb
azadirachtin
imidacloprid
azinphos-methyl
pyraclostrobin
copper hydroxide
methomyl
chlorpyrifos
malathion
harpin protein
oxydemeton-methyl
oxydemeton-methyl
zeta-cypermethrin
methyl parathion
metalaxyl
spin osad
liquid sulfur
dichloropropene + chloropicrin
dichloropropene
aldicarb
phorate
thiophanate-methyl
thiophanate-methyl
metham sodium
oxamyl
cyhalothrin
cyhalothrin
254
FMC
BASF Ag Products
Helena Chemical
UAP
Several
Dow Agroscience
Amvac
Gowan Company
Bayer CropScience
BASF Ag Products
Griffin
DuPont
Dow Agroscience
UAP
Eden BioScience
Gowan Company
Gowan Company
FMC
Cerexagri, Inc.
Syngenta
Dow Agrosci.
Plant Health Tech.
Dow Agrosci.
Dow Agrosci.
Bayer Cropscience
BASF Ag Products
Cerexagri, Inc.
UAP
Amvac
DuPont
Syngenta
Syngenta
APPENDIX C. COMMON AND SCIENTIFIC NAMES OF CROPS,
FORAGES AND FORBS
Scientific names
Common names
Medicago sativa
alfalfa
barley
Hordeum vulgare
bluebunch wheatgrass
Pseudoroegneria spicata
corn
Zea mays
dry edible beans
Great Basin wildrye
Phaseolusspp.
Leymus cinereus
hicksii yew
Taxus x media
onion
A/hum cepa
pacific yew
Taxus brevifolia
poplar trees, hybrid
Populus deltoides x P. nigra
potato
Solanum tube rosum
Russian witdrye
Psathyrostachysjuncea
Agroyron fragile
Glycine max
Siberian wheatgrass
soybeans
spearmint, peppermint
sugar beet
Mentha sp.
supersweet corn
Zea mays
sweet corn
Zea mays
triticale
Triticum x Secale
western yarrow
Achillea milhifohium
wheat
Triticum aestivum
Beta vulgaris
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APPENDIX D. COMMON AND SCIENTIFIC NAMES OF WEEDS
Scientific names
Common names
Sonchus oleraceus
annual sowthistle
Chenopodium album
common Iambsquarters
downy brome
Bromus tectorum
dodder
Cuscutasp.
green foxtail
Setaria viridis
redroot pigweed
Amaranthus retroflexus
barnyardg rass
Echinochloa crus-galli
kochia
Kochia scoparia
hairy nightshade
Powell amaranth
prickly lettuce
Solanum sarrachoides
Amaranthus powellll
Russian knapweed
Acroption repens
Cyperus esculentus
yellow nutsedge
Lactuca serriola
APPENDIX E. COMMON AND SCIENTIFIC NAMES OF DISEASES AND INSECTS
Common names
Scientific names
Diseases
onion black mold
Aspergillus niger
onion neck rot, (gray mold)
Botrytis all/i
onion plate rot
Fusarium oxysporum
onion translucent scale
potato late blight
Phytophthora infestans
Insects
cereal leaf beetle
lygus bug
onion maggot
onion thrips
pea aphid
seed corn maggot
stinkbug
spidermite
sugar beet root maggot
willow sharpshooter
Oulema melanopus
Lygus hesperus
Delia antiqua
Thrips tabaci
Acyrthosiphon p/sum
Della platura
Pentatomidae sp.
Tetranychus sp.
Tetanops myopae form/s
Graphocephala con fluens (U hler)
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