Georgia Vegetable
Extension-Research Report
2001
Edited by William Terry Kelley
and David B. Langston, Jr.
The University of Georgia
College of Agricultural & Environmental Sciences
Cooperative Extension Service
Agricultural Experiment Station
U.S. Department of Agriculture
Notice to Users
Use of products mentioned in this publication must be consistent with the
manufacturer’s current label as registered with the appropriate agencies. Mention of a product
does not constitute an endorsement or guarantee by the University of Georgia or any other
agencies and personnel nor discrimination of similar products not mentioned. Trade names and
brand names are used only for informational purposes.
Authors are responsible for statements made and for the accuracy of the data presented.
The editors, affiliated associations, typists, etc., assume no responsibility for typographical or
other errors found in text or tables. Copies of this publication or parts of it should not be made
without the consent of authors. Reprints of reports may be obtained from the authors.
The Georgia Agricultural Experiment Stations, The Cooperative Extension Service and the
University of Georgia College of Agricultural and Environmental Sciences offer educational
programs, assistance and materials to all people without regard to race, color or national origin.
An Equal Opportunity Employer
UGA/CPES Research - Extension Publication No. 5-2001
December 2002
Issued in furtherance of Georgia Agricultural Experiment Stations research work, Cooperative
Extension work, Acts of May 8 and June 30, 1914, The University of Georgia College of
Agricultural and Environmental Sciences and the U.S. Department of Agriculture cooperating.
Gale A. Buchanan
Dean and Director
i
ii
Table of Contents
Cultural Practices
- Bed Press Incorporation Study.............................................................................................3
Paul E Sumner
- Effect of BM86 on Fall Snap Bean Production..................................................................11
William Terry Kelley
- Effect of BM86 and MZ63 on Fall Peppers........................................................................13
William Terry Kelley
- Effect of K-tionic on Fall Bell Pepper Production.............................................................15
William Terry Kelley
Variety Evaluation
- Cantaloupe Variety Trial, 2001...........................................................................................19
George E. Boyhan, Darbie M. Granberry, William Terry Kelley, C. Randell Hill
- Watermelon Variety Trial, 2001..........................................................................................21
George E. Boyhan, Darbie M. Granberry, William Terry Kelley, C. Randell Hill
- Georgia Commercial Pumpkin Variety Trials - 2001........................................................24
William Terry Kelley
- Commercial Snap Bean Fall Cultivar Evaluation - 2001...................................................28
William Terry Kelley
- Summer Squash Variety Trial - 2001..................................................................................32
William Terry Kelley, David Curry, Gregory Hardison
- Sweet Corn Variety Trial - 2001...........................................................................................45
William Terry Kelley, David Curry, Gregory Hardison
Weed Control
- Weed Management in Watermelon and Cantaloupe Transplanted on
Polyethylene Covered Seedbeds............................................................................................51
W. Carroll Johnson, III and Theodore M. Webster
- Sandea Has a Variable Affect on Squash Growth and Yield...........................................65
T.M. Webster
Disease Control
- Application Methods of Soil Chemical Treatments on Nematodes,
Disease and Yield of Cucumber............................................................................................71
A.S. Csinos, K. W. Seebold, P. Timper, R.F.Davis, J.E. Laska
- Soil Chemical Treatment Alternatives to Methyl Bromide in Cucumber......................82
iii
A.S. Csinos, K.W. Seebold, P. Timper, R.F. Davis, J.E. Laska
- Effects of Vydate and Telone Treatments for Management of
Nematodes, Diseases and Yield of Cucumber......................................................................93
A.S. Csinos, K.W. Seebold, P.Timper, J.E. Laska
- Evaluation of Chisel Placement of Telone Products and Drip
Irrigation for Efficacy and Yield in Bell Pepper................................................................103
A.S. Csinos, K.W.Seebold, P.Timper, J.E. Laska
- Telone C-17, Metham Sodium Combinations for Efficacy and
Evaluation of Phytotxicity in Squash .................................................................................114
A.S. Csinos, K.W. Seebold, P.Timper, J.E. Laska
- Effects of Tomato Spotted Wilt Virus on Plant Growth, Yield and Fruit
Quality of Drip-Irrigated Tomato Plants...........................................................................125
Juan C.Diaz-Perez, Dean Batal, Denne Bertrand, David Giddings
-Evaluation of Fungicides and Biological Control Materials for Control
of Cercospora Lea Spot of Turnip......................................................................................129
D.B. Langston, Jr, K.W. Seebold
-Evaluation of Fungicides and Spray Programs for Control of
Gummy Stem Blight of Watermelon..................................................................................132
D.B. Langston, Jr., R.T. Boland, Jr., J.G. Price
-Evaluation of Actigard, Messenger, and Vacciplant for Suppression of
Bacterial Spot of Tomato.....................................................................................................136
D.B. Langston, Jr., J.T. Flanders
-Evaluation of Fungicides and Biological Control Materials for Control of
Powdery Mildew in Transgenic Yellow Crookneck Squash............................................138
D.B. Langston, Jr., W.T. Kelley
-Evaluation of Fungicides and Biological Materials for Control of Downy
Mildew and Plectosporium Blight of Pumpkin.................................................................141
D.B. Langston, Jr., K.W.Seebold
-Evaluation of Fungicides and Protection Intervals for Control of Alternaria
Leaf Spot of Carrot Using Two Nitrogen Fertility Regimes.............................................144
D.B. Langston, Jr., J.E. Hudgins
- Screening Fungicides for Control of Phytophthora capsici in Summer Squash..........146
Kenneth W. Seebold, David B. Langston, Jr., T. Bryan Horton
- Evaluation of Experimental Fungicide for Control of Phytophthora
Crown Rot of Summer Squash...........................................................................................148
Kenneth W. Seebold, David B. Langston, Jr., T. Bryan Horton
Insect Control
iv
- Insect Pest Control Trials in Vegetables in 2000-2001..................................................153
David G. Riley
Economics & Marketing
- Commercial Vegetable Price Outlook ...........................................................................169
Greg E. Fonsah
iv
Cultural Practices
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-2-
Bed Press Incorporation Study
Paul E. Sumner
Extension Engineer
Biological and Agricultural Engineering Department
University of Georgia
Introduction
The phasing out of methyl bromide as a method of sterilizing the soil within the vegetable
bed has made the industry rethink methods for weed, disease and nematode control. Weed
control has become a major concern. Some chemicals are labeled but have had varying results
and damage to vegetable crops. To ensure maximum weed control, uniform mixing in the
recommended depth of the soil is essential. Growers and University scientist using herbicides for
weed control under plastic have had mixed results for weed control.
The objective of herbicide incorporation is to uniformly place the pesticide as close to the
target pest as possible. Most labels specify the proper depth of incorporation. Herbicides that
are not uniformly placed may result in hot spots of high concentration or untreated spots.
The objective of this study was to simulate the use of herbicides with flourescent dyes in
vegetable plastic culture and determine where the herbicide goes once the final bed has been
formed.
Methods and Materials
To study the chemical placement and distribution by different soil incorporation equipment
two different types of bed presses(Figure 1 and 2) were evaluated. A superbedder and
conventional bed press was used to make the final beds. Prior to bedding, the land was prepared
by turning the soil, next fluorescent dye sprayed and then incorporated with one of the following
pieces of equipment: disk-harrow, field cultivator, vertical tiller (rototiller) and combination
rototiller and bed shaper. The orange fluorescent dye was sprayed on a 6 foot by 9 foot area.
(Shown in Figure 3) The dye was then incorporated by an implement using either a single pass
or two passes.
After the tillage operations were performed on each plot, a cross-section was made by first
digging a trench perpendicular to the tillage direction. After the trench was dug, enough soil was
removed to place a four foot black light in front of the cross-section (Shown in Figure 4). The
fluorescent dye glowed wherever it was deposited, giving an example of where the herbicide
would have been placed with the tillage implement.
Results
The following figures show where the fluorescent dye was incorporated. The lighter spots in
the cross-section indicate the location of the dye. Figures 5-8 are illustrations of using a bed
press as the method of making the final bed before applying plastic. In all cases the operation of
this type of bed press added a layer of untreated soil to the top of the bed making it undesirable
for herbicide application.
-3-
Figure 5 shows the using a rototiller to incorporate the dye. Using a rototiller is the best
method of completely mixing the soil with in the set depth.
Figure 6 shows the cross-section resulting from a single pass incorporation using a diskharrow. The cross-section shows that a one pass incorporation leaves streaks of soil not moved
or mixed. It further indicates that the dye was placed at a depth of 6 inches in some locations,
which maybe too deep to be effective depending on the chemical used.
The incorporation obtained by a single pass-field cultivator is shown in Figure 7. The
horizontal distribution of dye is not uniform after one pass. The distribution of dye improved
with the second pass.
Figure 8 illustrates the effect of bedding two times. Some growers do this practice in order
to make a good firm bed. Shown are field cultivator and rototiller. When the second pass was
made more untreated soil was placed on top of the profile.
The use of two pass disk-harrow followed by a superbedder is shown in Figure 9. Mixing of
the dye was fairly uniform from top to bottom of the bed. Normally depth of incorporation for a
disk-harrow is half the depth of operation.
Figure 10 shows the incorporating with a rototiller to the depth of 4 inches. Dye distribution
was uniform from top to bottom of the incorporated area.
Figures 11 and 12 show the combination rototiller and bed shaper followed by the
superbedder. Incorporation shows streaks of concentrated dye, that may have been caused by
rototiller knives not being close enough together.
Conclusions
The study with the bed press showed that there was significant difference between the
different types of soil incorporation tillage equipment. The only problem being untreated soil
was place on top of bed. This may have been due to the fact of having to operate the bed press to
a depth that would have pulled untreated soil up.
The supperbedder was better than the bed press in the conditions tested. The combination of
tillage methods and the superbedder resulted in acceptable distribution of the dye throughout the
bed.
If growers incorporate herbicides prior to making the final bed and laying plastic covering
should be cautious of herbicide damage.
-4-
Figure 1. Superbedder bed press.
Figure 2. Bed Press.
-5-
Figure 3. Fluorescent dye sprayed on plot.
Figure 4. Daylight View of Black Lights & Soil Profile.
Figure 5. Rototiller incorporation followed by bed press.
Figure 6. Disk-harrow incorporation followed by bed press.
-6-
Figure 7. Field cultivator incorporation followed by bed press.
Figure 8. Double bed pressing of field cultivator(left) and rototiller(right).
-7-
Figure 9. Disk-harrow followed by super bedder.
Figure 10. Rototiller followed by super bedder.
-8-
Figure 11. Combination rototiller and bed shaper.
Figure 12. Combination rototiller and bed shaper followed by super bedder.
-9-
Figure 13. Dye applied prior to turning and again before disk-harrow followed by
super bedder.
-10-
Effect of BM 86 on Fall Snap Bean Production
William Terry Kelley
Extension Horticulturist, Rural Development Center
P.O. Box 1209, Tifton, Georgia 31793
wtkelley@uga.edu
Introduction
BM 86 is a foliar nutritional product manufactured by Goemar. It contains approximately 5%
nitrogen, 2.4% magnesium, 3.2% sulfur, 2.0% boron, 0.02% molybdenum and 0.6% sodium.
Since it is marketed to Georgia growers, BM 86 was tested on snap beans during fall production
to determine its effects on plant growth, pod characteristics and marketable yield.
Methods
“Bronco” variety (Seminis Seed Co.) snap beans were planted at the Coastal Plain
Experiment Station (elev. 382 feet) in Tifton, Georgia. Snap beans were direct-seeded on August
27, 2001 into a Tifton sandy loam (fine-loamy siliceous thermic Plinthic Kandiudults) soil. Plots
consisted of two side-by-side rows with three seed planted per foot of row. Plots were eight feet
in length with three feet between rows. The planting was arranged in a Randomized Complete
Block Design with four replications.
Normal cultural practices were used for bare ground snap bean culture in Georgia. Base
fertilizer consisted of 400 pounds/A of 10-10-10 incorporated prior to planting followed by two
sidedress applications of 15-0-14 (150 pounds/A each). Weed control was accomplished with a
pre-emergence application of s-metolachlor (0.94 lb a.i./A). Fungicide and insecticide
applications were made according to current University of Georgia recommendations. Irrigation
was applied as needed.
BM 86 was applied with a solo backpack sprayer at two quarts per acre at first bloom. An
additional two quarts was applied to the same plots at the pod stage. Treated plots were
compared to an untreated check.
Snap beans were harvested at maturity on October 17, 2001. Data were collected on
marketable yield, percent marketability, plant height, canopy width, and pod characteristics
including color, width, length, shape, straightness and smoothness. Results are summarized in
Tables 1 and 2.
Results
Marketable yield was greater in the untreated plots compared to the treated plots, although
not significantly. BM 86 plots produced more immature beans at harvest, but this also was not a
significant difference. Percent marketability, plant height, canopy width and all pod
characteristics were unaffected by treatments. There appears to be no significant effect of using
BM 86 for snap bean production.
-11-
Table 1.
Treatment
Yield, percent marketability and plant characteristics of snap beans treated
with BM 86 (two quarts /A at first bloom and two quarts/A at pod stage) and
untreated snap beans at Tifton, Georgia in 2001.
Marketable
Immature
Percent
Plant Height
Canopy
Yield (lb/A)
Yield (lb/A)
Marketable
(cm)
Width
(%)
(cm)
Untreated
9178
565
93.6
12.8
17.5
BM86
6735
653
90.9
12.6
17.5
Mean of Test
7957
609
92.2
12.7
17.5
L.S.D. (0.05)
3804
445
7.6
1.5
2.2
C.V. (%)
32.21
49.21
5.53
8.17
8.66
Table 2.
Treatment
Fruit characteristics of snap beans treated with BM 86 (two quarts /A at first
bloom and two quarts/A at pod stage) and untreated snap beans at Tifton,
Georgia in 2001.
Pod Color1 Pod Width
Pod
Pod Shape2
Pod
Pod
(mm)
Length
Straightnes Smoothnes
(cm)
s3
s4
Untreated
2.4
10.0
14.6
2.8
1.4
2.3
BM86
2.5
9.8
12.8
2.6
1.7
2.1
Mean of
Test
2.5
1.0
13.7
2.7
1.5
2.2
L.S.D.
(0.05)
0.5
1.4
3.1
0.4
0.3
0.7
C.V. (%)
12.39
9.63
15.30
9.16
13.73
20.73
Based on a scale of 1=dark green; 2=medium green; 3=light green; 4=yellow. 2Based on a
scale of 1=flat; 2=oval; 3=round. 3Based on a scale of 1=straight; 2=slightly curved; 3=curved.
4
Based on a scale of 1=smooth, 2=moderately smooth, 3=rough.
1
-12-
Effect of BM 86 and MZ 63 on Fall Pepper Production
William Terry Kelley
Extension Horticulturist, Rural Development Center
P.O. Box 1209, Tifton, Georgia 31793
wtkelley@uga.edu
Introduction
BM 86 and MZ 63 are foliar nutritional products manufactured by Goemar. BM 86 contains
approximately 5% nitrogen, 2.4% magnesium, 3.2% sulfur, 2.0% boron, 0.02% molybdenum
and 0.6% sodium. MX 63 contains 5% nitrogen, 1.89% magnesium, 5.72% combined sulfur,
1.57% water soluble manganese and 2.36% soluble zinc. Since these products are marketed to
Georgia growers, BM 86 and MZ 63 were tested on pepper during fall production to determine
its effects on plant growth, pod characteristics and marketable yield.
Methods
“Camelot” variety (Seminis Seed Co.) bell pepper transplants were commercially produced
in 200-cell polystyrene trays at a local greenhouse. Peppers were planted into the field at the
Coastal Plain Experiment Station (elev. 382 feet) in Tifton, Georgia on August 27, 2001 into a
Tifton sandy loam (fine-loamy siliceous thermic Plinthic Kandiudults) soil. Plots consisted of
two side-by-side rows on a plastic mulch-covered bed with eight plants in each row and 12
inches between plants. Beds were spaced six feet apart from center to center. Plots were eight
feet in length with three feet between plots. The planting was arranged in a Randomized
Complete Block Design with eight replications.
Normal cultural practices were used for bell pepper grown with plasticulture in Georgia.
Second crop plastic was used, therefore all fertilization was applied through the drip irrigation
system. Application rates ranged from 1.0 pounds nitrogen and potassium per acre per day for
the first two weeks up to 2.5 pounds/acre/day at the peak requirement times of fruit set and
enlargement. Total nutrients applied included approximately 165 pounds of N and K applied as a
7-0-7 analysis soluble fertilizer. Fungicide and insecticide applications were made according to
current University of Georgia recommendations. Irrigation was applied daily.
MZ 63 was applied as a foliar spray with a solo backpack sprayer at three pints per acre two
weeks after transplanting. BM 86 was applied as a foliar spray with a solo backpack sprayer at
three pints per acre at first bloom and again in the same manner and at the same rate14 days
later. Treated plots were compared to an untreated check.
Pepper were harvested three times at maturity from November 7 through November 27,
2001. Data were collected on marketable yield, percent marketability, plant height, plant width,
and pod characteristics including width, length, wall thickness, size, number of locules and
smoothness. Results are summarized in Tables 1 and 2.
Results
Jumbo and U.S. No. 1 grade pepper yield was greater in the treated plots, although not
significantly. Total marketable yield was almost identical in both treatments. Jumbo size peppers
were only slightly larger in individual fruit weight in the untreated plots, while the reverse was
true for U.S. No. 1 grade individual fruit weight. Percent marketability was not different.
Fruit length and width also tended to be greater in untreated pepper, but not significantly so.
Other parameters were virtually equal, although plant height and width varied some between
treatments. BM 86 and MZ 63 did not show any significant improvement in yield and fruit
quality, however, additional testing on this product is needed.
-13-
Table 1.
Treatment
Untreated
BM86/MZ
Mean of
L.S.D.
C.V. (%)
Yield by grade, total marketable yield, average fruit size and percent
marketability of bell peppers treated with BM 86 and MZ 63 and untreated
peppers at Tifton, Georgia in 2001.
Yield (28# cartons)/Acre
Average Fruit Size (g)
Percent
Marketable
Total
(%)
Jumbo
U.S. No. 1
Jumbo
U.S. No. 1 Marketabl
Grade
e1
163
141
152
66
36.96
81
106
93
48
45.53
281
284
282
106
31.80
196
190
193
24
10.65
133
140
136
17
10.37
98.0
96.0
97.0
4.1
3.61
1
Total of Jumbo, U.S. No. 1 and U.S. No. 2 peppers. ZMZ-63 applied at 3 pints/A at 4-leaf stage; BM-86 applied at 3
pints/A at first flower and 7-14 days later.
Table 2.
Fruit and plant characteristics of bell peppers treated with BM 86 and MZ
63 and untreated peppers at Tifton, Georgia in 2001.
Fruit Characteristics
Plant Characteristics
Treatment
Fruit
Length
(cm)
Untreated
BM86/MZ
Mean of
L.S.D.
C.V. (%)
8.8
8.1
8.4
1.6
16.51
Fruit
Width
(cm)
8.2
8.0
8.1
2.0
21.20
Fruit
Smoothn
ess2
Fruit
Wall
Thicknes
s
2.2
2.1
2.1
0.3
13.83
1.1
0.8
0.9
0.9
86.28
2
No. of
Locules
3.2
3.1
3.1
0.5
14.76
Plant
Height
(cm)
13.8
13.1
13.5
2.8
17.37
Plant
Width
(cm)
14.4
15.1
14.8
3.3
18.74
Based on a scale of 1=smooth, 2=moderately smooth, 3=rough. ZMZ-63 applied at 3 pints/A at 4-leaf stage; BM-86
applied at 3 pints/A at first flower and 7-14 days later.
-14-
Effect of K-tionic on Fall Bell Pepper Production
William Terry Kelley
Extension Horticulturist, Rural Development Center
P.O. Box 1209, Tifton, Georgia 31793
wtkelley@uga.edu
Introduction
K-tionic is a nutrient uptake promoter manufactured by Grupo Bioquimico Mexicano (GBM)
that consists of 25% fulvic organic complex. It is recommended on all crops for use in
conjunction with a balanced fertilization program to promote and optimize nutrient uptake. It is
supposed to increase soil cation exchange capacity and buffering capability to enhance nutrient
availability. Since it is marketed to Georgia growers, K-tionic was tested on bell pepper during
fall production to determine its effects on plant growth, pod characteristics and marketable yield.
Methods
“Camelot” variety (Seminis Seed Co.) bell pepper transplants were commercially produced
in 200-cell polystyrene trays at a local greenhouse. Peppers were planted into the field at the
Coastal Plain Experiment Station (elev. 382 feet) in Tifton, Georgia on August 27, 2001 into a
Tifton sandy loam (fine-loamy siliceous thermic Plinthic Kandiudults) soil. Plots consisted of
two side-by-side rows on a plastic mulch-covered bed with eight plants in each row and 12
inches between plants. Beds were spaced six feet apart from center to center. Plots were eight
feet in length with three feet between plots. The planting was arranged in a Randomized
Complete Block Design with eight replications.
Normal cultural practices were used for bell pepper grown with plasticulture in Georgia.
Second crop plastic was used, therefore all fertilization was applied through the drip irrigation
system. Application rates ranged from 1.0 pounds nitrogen and potassium per acre per day for
the first two weeks up to 2.5 pounds/acre/day at the peak requirement times of fruit set and
enlargement. Total nutrients applied included approximately 165 pounds of N and K applied as a
7-0-7 analysis soluble fertilizer. Fungicide and insecticide applications were made according to
current University of Georgia recommendations. Irrigation was applied daily.
K-tionic was applied through the drip irrigation system at a rate of two quarts/acre at planting
with an additional two quarts/acre applied at the beginning of fruiting. Treated plots were
compared to an untreated check.
Pepper were harvested three times at maturity from November 7 through November 27,
2001. Data were collected on marketable yield, percent marketability, plant height, plant width,
and pod characteristics including width, length, wall thickness, size, number of locules and
smoothness. Results are summarized in Tables 1 and 2.
Results
Total marketable yield and jumbo yield was greater in the pepper treated with K-tionic,
although not significantly. Yield of U.S. No. 1 grade was almost identical in both treatments.
Jumbo size peppers were only slightly larger in individual fruit weight in the treated plots.
Percent marketability was not different.
Fruit length and width also tended to be greater in treated pepper, but not significantly so.
Other parameters were virtually equal. K-tionic showed a tendency to improve fruit size and
yield, however, since the data were not significant, there should be additional testing of this
product.
-15-
Table 1.
Treatment
Yield by grade, total marketable yield, average fruit size and percent marketability of bell peppers treated with
K-tionic and untreated peppers at Tifton, Georgia in 2001.
Yield (28# cartons)/Acre
Average Fruit Size (g)
Percent
Marketable
Total
(%)
Jumbo
U.S. No. 1
Marketable1
Jumbo Grade
U.S. No. 1
Untreated
163
87
281
196
133
98.0
K-tionicZ
223
81
351
206
146
95.8
Mean of Test
193
84
316
201
140
96.9
L.S.D. (0.1)
71
50
103
22
21
2.6
62.79
34.47
11.50
18.87
2.85
C.V. (%)
38.83
1
Z
Total of Jumbo, U.S. No. 1 and U.S. No. 2 peppers. K-tionic applied at two quarts/A at planting and two quarts/A at fruiting.
Table 2.
Fruit and plant characteristics of bell peppers untreated and treated with K-tionic at Tifton, Georgia in 2001.
Fruit Characteristics
Plant Characteristics
Treatment
Untreated
Fruit Width
(cm)
Fruit
Smoothness2
Fruit Wall
Thickness
No. of
Locules
Plant Height
(cm)
Plant Width
(cm)
8.1
8.2
2.2
1.0
3.2
13.9
14.4
10.1
8.8
1.9
0.9
3.9
14.0
14.2
Mean of Test
9.1
8.5
2.0
1.0
3.5
13.9
14.3
L.S.D. (0.1)
1.7
1.3
0.3
0.8
0.7
1.2
1.6
C.V. (%)
19.75
15.78
13.51
83.63
22.26
9.07
11.91
K-tionic
2
Fruit Length
(cm)
Z
Z
Based on a scale of 1=smooth, 2=moderately smooth, 3=rough. K-tionic applied at two quarts/A at planting and two quarts/A at fruiting.
-16-
Variety Evaluation
-17-
CANTALOUPE VARIETY TRIAL, 2001
-18-
*George E. Boyhan, Darbie M. Granberry, W. Terry, Kelley, C. Randell Hill
Extension Horticulturist, Horticulture - CES, P.O. Box 8112
Statesboro, GA 30460
A cantaloupe variety trial was held at the Vidalia Onion and Vegetable Research Center in
Lyons, Georgia with nine varieties. Seed were stared in the greenhouse at the Bamboo Farm and
Coastal Garden in Savannah, Georgia in March and April. The transplants were set on April 25,
2001. The experiment was arranged in a randomized complete block design with four
replications. Each experimental unit consisted of ten hills with an in-row spacing of three feet
and a between-row spacing of six feet.
The fertility program consisted of 750 pounds per acre of 10-10-10 applied preplant and
incorporated. This was followed by 750 pounds per acre of 15-0-14 applied on May 11, 2001.
This level of fertility is considered too high for cantaloupe in Georgia and was the result of a
miscommunication with the farm superintendent.
Weed control consisted of two quarts per acre of Cucurbit herbicide applied on April 27,
2001 over the top of the transplants. In addition, Poast Plus was applied at one quart per acre on
May 7, 2001 for control of post emergent grasses. Finally, Permit herbicide was spot sprayed on
May 7-8, 2001 to control nutsedge. Hand weeding was also used as needed. Neither the use of
Curbit over the top of transplants or the use of Permit on cucurbits is labeled. We did not apply
any fungicides or insecticides to see how the varieties perform under natural disease and insect
pressure.
Cantaloupe harvest began on June 29 and continued on July 5, 6, and 9, 2001. The
Bonferroni adjusted LSD divides the probability (0.05) by 5 before calculating to control the
experiment wise error rate. This allows up to five mean comparisons between varieties.
There were nine cantaloupe varieties in the trial with ‘Odyssey’ from Sunseeds having the
highest yields (Table 1). Both Eastern and Western types were in the trial with the Eastern types
yielding higher overall as well as having larger average fruit size. The Georgia market continues
to be dominated by Athena type cantaloupes. These are referred to as Eastern shipping types.
They are larger than their Western cousins with less netting overall. The can be harvested at
full-slip (full maturity) and still be shipped compared to Western types which are harvested at
half-slip and mature after harvest.
Table 2. Cantaloupe Variety Trial, Vidalia Onion and Vegetable Research Center, Lyons, GA,
2001
-19-
Variety
Source
Yield
(lbs/acr
e)
Fruit
Weight
(lbs)
Length
(in.)
Width
Flesh
(in.)
Thickness
(in.)
Soluble
Solids
(%)
Flesh
Color
Melon
Type
Comments
Odyssey
(7119)
Sunseeds
16,970
5.6
7.5
6.8
1.9
7.8
Orange
Eastern
Athena
Syngenta
13,891
4.0
6.9
6.2
1.8
9.8
Orange
Eastern
Vienna
Asgrow
10,557
5.5
6.8
6.8
2.0
8.1
Orange
Eastern
Eclipse
Petoseed
10,037
4.9
6.6
6.6
2.0
9.0
Orange
Eastern
EX 04204099
Asgrow
9,378
4.1
6.8
6.3
2.0
8.2
Orange
Eastern
AC-75-1A
Auburn
Univ
7,575
2.2
5.0
5.1
1.5
7.1
Orange
Western
Some Eastern type
Super 45
Willhite
6,044
2.9
6.2
5.2
1.5
7.5
Orange
Western
Some Eastern type
AC-89-55MI
Auburn
Univ
6,032
2.6
5.2
5.0
1.4
7.2
Orange
Western
Some Eastern type
AC-82-37RNL
Auburn
Univ
2,311
2.4
5.8
4.9
1.6
4.9
Orange
Western
R2
0,574
CV
60%
Adjusted LSD (p<0.05) 7,015
0.597
21%
WATERMELON VARIETY TRIAL, 2001
-20-
George E. Boyhan, Darbie M. Granberry, W. Terry Kelley, C. Randell Hill
Extension Horticulturist, Horticulture - CES, P.O. Box 8112
Statesboro, GA 30460
A watermelon variety trial was held at the Vidalia Onion and Vegetable Research Center in
Lyons, Georgia consisting of 29 varieties. Seed were stared in the greenhouse at the Bamboo
Farm and Coastal Garden in Savannah, Georgia in March and April. The transplants were set on
April 19, 2001. The experiment was arranged in a randomized complete block design with four
replications. Each experimental unit consisted of ten hills with an in-row spacing of five feet
and a between-row spacing of 12 feet. Although there was a 12 foot between-row spacing the
yield per acre was calculated based on a six-foot between-row spacing.
The fertility program consisted of 750 pounds per acre of 10-10-10 applied preplant and
incorporated. This was followed by 750 pounds per acre of 15-0-14 applied on May 11, 2001.
This level of fertility is considered a little too high for watermelon in Georgia and was the result
of a miscommunication with the farm superintendent.
Weed control consisted of two quarts per acre of Cucurbit herbicide applied on April 27,
2001 over the top of the transplants. In addition, Poast Plus was applied at one quart per acre on
May 7, 2001 for control of post emergent grasses. Finally, Permit herbicide was spot sprayed on
May 7-8, 2001 to control nutsedge. Hand weeding was also used as needed. Neither the use of
Curbit over the top of transplants or the use of Permit on cucurbits is labeled. We did not apply
any fungicides or insecticides to see how the varieties perform under natural disease and insect
pressure. The harvest began on July 2, 2001 and continued on July 5, 6 and 9, 2001.
The Bonferroni adjusted LSD divides the probability (0.05) by 5 before calculating to control
the experiment wise error rate. This allows up to five mean comparisons between varieties.
‘Royal Star’ watermelon from Petoseed was the highest yielding variety followed by ‘Big
Stripe’, “WX8', and ‘WX22' from Willhite (Table 1). ‘Montreal’ from Sunseeds rounds out the
top five performers. Surprisingly ‘Moon & Stars’ also had good yields. This is an old heirloom
variety with an unusual rind pattern (dark green with yellow spots of varying sizes from pencil
point to 2-3 inches across). The quality of this old variety was very poor, however, with white
streaking in the flesh.
Yields overall were poor in this trial due to the fact the vines were turned into the plots after
the fruit had set and was about 1-2 lbs in size. This resulted in damage to the vines were turned
into the plots after the fruit had set and was about 1-2 lbs in size. This resulted in damage to the
vines particularly where thy attach to the fruit.
Seedless watermelons continue to be tested and grow in popularity. Nine of the varieties or
almost a third were triploid varieties. We are beginning to see triploid varieties outside the
Crimson Sweet type. This year ‘WX55' from Willhite and ‘Revolution’ from Sunseeds were
Allsweet type and ‘Freedom’ was a Jubiliee type from Sunseeds.
Table 1. Watermelon Variety Trial, Vidalia Onion and Vegetable Research Center, Lyons, GA, 2001
-21-
Variety
Source
Yield
(lbs/acre)
Fruit
Weight
(lbs)
Length
(in.)
Width
Flesh
(in.)
Thickness
(in.)
Soluble
Solids
(%)
Flesh
Color
Melon
Type
Comments
Royal Star
Petoseed
27,240
16.0
12.5
8.9
0.75
10.2
Red
Crimson Sweet
Big Stripe
Willhite
25,406
14.9
12.7
8.6
0.83
10.4
Red
Jubilee Blocky
WX8 (large seed)
Willhite
23,766
12.6
13.6
8.1
0.78
10.8
Red
Allsweet
WX22 (small
seed)
Willhite
21,312
14.0
12.4
8.3
0.66
10.2
Red
Jubilee
Montreal (5023)
Sunseeds
21,225
13.3
12.7
8.2
0.53
10.0
Red
Allsweet
Moon & Stars
G.Hunter
20,045
16.7
11.6
9.6
0.78
8.6
Red
Moon & Stars
WX55 Triploid
Willhite
19,889
12.7
13.7
7.3
0.70
9.0
Red
Allsweet Seedless
Festival (large
seed)
Willhite
19,548
12.0
14.4
7.3
0.63
9.5
Pink/
Red
Allsweet
Revolution
(4034) Triploid
Sunseeds
19,471
10.9
12.8
7.9
0.81
11.7
Red
Allsweet Seedless
Variable some
jubilee fruit
Pinata
(large seed)
Willhite
19,185
13.9
12.4
8.4
0.83
9.4
Red
Allsweet
Some jubilee &
blocky types
XP 4525247
Asgrow
18,999
13.1
13.4
8.0
0.58
9.2
Red
Allsweet
Tribute
(PX59696)
Triploid
Petoseed
18,999
11.9
10.7
8.7
0.70
11.0
Red
Crimson Sweet
Seedless
Stars n Stripes
Asgrow
18,891
12.7
13.8
7.5
0.72
10.2
Red
Jubilee
Falcon
(PS 56395)
Petoseed
17,874
14.5
14.7
8.0
0.69
11.1
Red
Allsweet
Sweet Eat’n
Triploid
D.Palmer
17,598
10.3
9.6
7.7
0.67
11.4
Red
Crimson Sweet
Seedless
-22-
Some blocky &
jubilee fruit
Old variety, white
streaked flesh
Variable Fruit,
Some icebox size
Variety
Source
Yield
(lbs/acre)
Fruit
Weight
(lbs)
Length
(in.)
Width
Flesh
(in.)
Thickness
(in.)
Soluble
Solids
(%)
Flesh
Color
Melon
Type
Sentinel
(PS 36694)
Petoseed
17,544
11.8
12.0
7.9
0.72
11.3
Red
Allsweet
Sweetheart
(large seed)
Willhite
17,105
12.7
11.6
8.8
0.95
10.3
Red
Jubilee
Legacy (OP)
Willhite
16,212
10.6
12.3
7.6
0.72
8.3
Red
Allsweet
Blocky
Vista Fl
Hollar Seed
15,043
14.3
12.0
8.4
0.69
11.6
Red
Jubilee
AU Golden
Producer
Hollar Seed
14,810
13.2
9.9
8.8
0.67
10.0
Yellow
Crimson Sweet
Freedom (3022)
Triploid
Sunseeds
13,957
12.0
12.3
8.2
0.72
11.8
Red
Jubilee Seedless
AU Producer
ZYMV
Auburn U.
13,605
13.4
10.1
9.1
0.72
9.6
Red
Crimson Sweet
Afternoon Delight
Triploid
D.Palmer
13,511
8.9
9.2
8.4
0.77
11.5
Red
Crimson Sweet
Seedless
Stargazer
Asgrow
12,977
11.2
12.7
7.4
0.64
8.5
Red
Allsweet
WX24
(large seed)
Willhite
12,814
13.1
13.5
7.4
0.81
9.3
Red
Blocky Crimson
Sweet
Cooperstown
Asgrow
11,576
10.6
9.6
8.2
0.58
10.9
Red
Crimson Sweet
Seedless
Triton
Petoseed
11,558
10.0
8.9
8.4
0.75
11.3
Yellow
Crimson Sweet
Seedless
AU Allsweet
Auburn U.
11,489
13.8
12.0
7.4
0.61
9.1
Red
Allsweet
Sapphire Fl
Hollar Seed
2,222
10.2
8.8
7.5
0.66
10.9
Red
Crimson Sweet
Seedless
0.353
R2
CV
50%
Adjusted LSD (p<0.05) 14,199
0.563
14%
1.8
-23-
Comments
Some variability
with Crimson
Sweet Type
Some jubilee type
Georgia Commercial Pumpkin Variety Trials-2001
William Terry Kelley
Extension Horticulturist, Rural Development Center
P.O. Box 1209, Tifton, Georgia 31793
wtkelley@uga.edu
Introduction
Many new pumpkin varieties have been introduced to the commercial market in recent years.
Multi-year data has been collected from annual trials for the last several years. Many nearby
states use this information. This project is an annual evaluation to keep growers updated with
local information on new pumpkin variety releases.
Methods
Twenty-seven commercially-available pumpkin varieties and three experimental lines were
compared at the Georgia Mountain Branch Experiment Station (elev. 1900 feet) in Blairsville,
Georgia. Pumpkins were field-seeded on June 19-20, 2001 into a Transylvania clay loam soil.
Plots consisted of single rows which contained an appropriate number of hills for each variety’s
plant habit. Vining types were planted with four hills per plot, semi-bush (or semi-vining) types
with six hills and bush types with eight hills. Plots were 16 feet in length with eight feet between
rows. The planting was arranged in a Randomized Complete Block Design with three
replications.
Normal cultural practices were used for bare ground pumpkin culture in Georgia. Base
fertilizer consisted of 300 pounds/A of 10-10-10 incorporated prior to planting followed by two
sidedress applications of 10-10-10 (300 pounds/A each). Ethafluralin (0.75 lb a.i./A) was applied
pre-emergence for weed control. Fungicide and insecticide applications were made according to
current recommendations. Irrigation was applied as needed.
Pumpkins were harvested at maturity on October 2, 2001. Data were collected on yield, fruit
number and weight, rind color, rind texture and fruit shape. Results are summarized in Table 1.
Results
Overall yields and individual pumpkin weights were generally slightly lower than those
expected according to commercial variety descriptions. “Prizewinner” produced the greatest
yield and largest fruit size among all varieties; it was the only “giant” size variety in the test.
Among miniature varieties, “Jack Be Little” produced the most fruit. “Little October” and “Lil’
Ironsides” produced similar fruit numbers with weights in the 1½ to half-pound range. “Wee B
Little” only yielded a fraction of the fruit of these varieties.
Most large and medium varieties produced yields and fruit numbers within the range for
-24-
acceptability in north Georgia. Less than average performers included “Gold Strike”, “Harvest
Jack”, “HMX 0681", “HMX 6689" and “SVR 9022”. These did not produce yields and fruit
number per acre that were competitive with other similarly-sized pumpkins. “Appalachian”,
“Early Autumn”, “Gold Bouillon”, “Gold Gem”, “Gold Standard", “Howdy Doody” and
“Mother Lode” were all superior performers among the 10-20-pound pumpkins.
Among pumpkins in the five to 10-pound range, “Autumn Gold” and “Big Autumn” were the
best performers. In the two to five-pound size class, “Peek a Boo” and “Pick a Pie” produced the
most fruit and greatest yield.
Marketability was acceptable for most varieties, although “Gold Bouillon", “Gold Strike”
and “Jumpin’ Jack” were below 80% marketability. There was some variance among varieties
for rind color and rind texture. Rind color ranged from deep orange to light orange. “Lumina”
was the only pumpkins in the trial with a white rind. Fruit shape was generally in accordance
with the type of pumpkin, with smaller pumpkins having a flatter shape.
Table 1.
Yield, number, marketability and horticultural characteristics of 30 varieties
of pumpkins grown at Blairsville, GA in 2001.
-25-
No.
Fruit/A
Yield2
(lb/Acre)
Fruit
Wt
(lbs.)
Percent
Marketable
Wt
Large
Wt
Small
Rind3
Color
Fruit4
Shape
Rind5
Texture
Seigers
4311
65729
15.3
83.5
21.0
8.9
1.0
3.7
2.0
Autumn Gold
Seeds by Design
7487
47347
5.9
80.1
11.6
3.9
2.0
2.8
2.0
Big Autumn
Seeds by Design
4311
44613
9.4
81.5
18.9
5.8
2.7
2.7
2.0
Early Autumn
Seeds by Design
4084
47512
12.0
83.4
19.3
4.9
2.0
2.7
2.0
Frosty
Twilley
3630
38806
10.6
91.1
17.6
6.4
2.3
3.2
2.3
Ghost Rider
Rupp
2722
36004
15.0
81.0
19.9
6.6
2.3
3.0
2.0
Gold Bouillon
Rupp
2496
44574
17.1
71.1
23.0
7.7
2.0
3.3
2.0
Gold Gem
Rupp
3403
51640
14.8
87.0
25.1
7.9
1.3
3.0
1.7
Gold Standard
Rupp
4424
54034
12.3
93.9
16.4
5.6
1.7
2.7
1.7
Gold Strike
Rupp
1475
24053
14.7
69.5
22.1
8.9
1.7
4.0
2.0
Harvest Jack
Seeds by Design
1475
26748
17.5
100.0
25.2
14.3
1.3
3.5
2.0
HMX 0681
Harris Moran
2269
26419
11.8
92.7
16.0
8.3
2.3
3.7
2.3
HMX 6689
Harris Moran
1248
24734
19.8
88.1
27.3
14.6
1.3
3.0
2.0
Howdy Doody
Seeds by Design
6466
73726
12.5
100.0
22.7
7.1
2.0
3.0
2.3
Jack Be Little
Rupp
18149
8502
0.5
98.3
0.7
0.3
1.7
1.0
1.3
Jack Pot
Harris Moran
2042
38046
18.6
82.5
27.0
11.2
1.7
3.7
2.0
Jumpin Jack
Seeds by Design
567
6642
11.5
51.0
16.2
6.4
1.3
3.7
2.0
Lil Ironsides
Harris Moran
10776
20089
1.9
97.6
2.5
1.1
1.7
2.3
2.7
Little October
Willhite
11003
8366
0.8
95.9
1.1
0.5
1.7
2.2
2.7
Lumina
Stokes
1134
3834
5.0
85.7
6.1
1.0
4.7
2.0
3.0
Variety
Sponsor
Appalachain
-26-
No.
Fruit/A
Yield2
(lb/Acre)
Fruit
Wt
(lbs.)
Percent
Marketable
Wt
Large
Wt
Small
Rind3
Color
Harris Moran
2722
38386
14.3
88.8
21.0
6.9
1.3
2.7
1.7
Mother Lode
Rupp
2495
40144
15.5
88.4
24.5
10.6
2.0
3.8
2.3
Mystic Plus
Harris Moran
1475
6006
4.1
84.7
6.7
2.5
1.0
2.0
2.0
Peek a Boo
Seeds by Design
6693
23702
3.5
97.5
5.8
2.1
1.7
2.0
2.0
Pick a Pie
Rupp
5672
26095
4.6
98.1
5.7
2.9
1.7
2.0
2.0
Prize Winner
Seigers
2609
233673
89.4
100.0
131.3
54.3
3.0
2.2
2.7
Pro Gold #500
Rupp
1361
27303
23.6
85.3
25.3
13.3
1.7
3.0
2.0
SVR 9022
Seminis
1135
12676
10.0
81.5
18.1
4.5
2.5
3.5
2.0
Touch of Autumn
Rupp
9529
24501
2.5
95.2
3.2
1.2
1.7
2.0
2.3
Wee B Little
Seeds by Design
2723
1463
0.5
88.0
0.8
0.4
2.0
2.0
2.3
13.2
87.4
19.4
7.7
1.9
2.8
2.1
Variety
Sponsor
Magic Lantern
37512
Fruit4
Shape
Rind5
Texture
Mean of Test
4329
L.S.D. (0.05)
2933
27039
5.8
25.0
8.5
4.0
1.0
0.7
0.6
C.V. (%)
41.45
44.10
27.0
17.5
26.7
32.3
33.3
15.7
17.3
-27-
Commercial Snap Bean Fall Cultivar Evaluation-2001
William Terry Kelley
Extension Horticulturist, Rural Development Center
P.O. Box 1209, Tifton, Georgia 31793
wtkelley@uga.edu
Introduction
Although Bronco continues to be the most widely planted snap bean variety in Georgia,
several new varieties with similar characteristics have been introduced in the last several years.
Darker beans are the choice of the market in most cases. This project was done as an evaluation
of how some standard varieties and some newer cultivars perform during the fall growing
season.
Methods
Nine commercially-available and three experimental snap bean varieties were compared at
the Coastal Plain Experiment Station (elev. 382 feet) in Tifton, Georgia. Snap beans were directseeded on August 27, 2001 into a Tifton sandy loam (fine-loamy siliceous thermic Plinthic
Kandiudults) soil. Plots consisted of two side-by-side rows with three seed planted per foot of
row. Plots were eight feet in length with three feet between rows. The planting was arranged in a
Randomized Complete Block Design with four replications.
Normal cultural practices were used for bare ground snap bean culture in Georgia. Base
fertilizer consisted of 400 pounds/A of 10-10-10 incorporated prior to planting followed by two
sidedress applications of 15-0-14 (150 pounds/A each). Weed control was accomplished with a
pre-emergence application of s-metolachlor (0.94 lb a.i./A). Fungicide and insecticide
applications were made according to current University of Georgia recommendations. Irrigation
was applied as needed.
Snap beans were harvested at maturity on October 15-23, 2001. Data were collected on
marketable yield, percent marketability, plant height, canopy width, and pod characteristics
including color, width, length, shape, straightness and smoothness. Results are summarized in
Tables 2 and 3.
Results
Marketable yield varied greatly. “Festina” yielded the greatest marketable weight followed
by “Platina”, “EX 8184379" and “HMX 0104". The standard, “Bronco”, actually was one of the
lowest yielding varieties. “Tasman”, “Casino” and “Bronco” were the poorest yielding beans.
All varieties except “Bronco” were greater than 94% marketable.
Plant height for all varieties was between 10.7 (“Casino”) to 14.6 (“Festina”) inches. Canopy
-28-
width ranged from 17.6 (“Casino”) to 24.3 inches (“Festina”). Obviously, “Casino” was the
smallest framed plant and “Festina” the largest.
Pod characteristics were within normal ranges for most varieties. The darkest pods were
produced on “Casino”, “Festina” and “Nelson”. Lightest color was produced by “Grenoble”,
“Hialeah” and “WBL 420". Pod width was always in the range of 0.9 to 1.8 cm and length varied
from 9.7 to 16.2 cm. “EX 8184379" produced the shortest pods and “Nelson” the longest. Pod
shape was consistent in all varieties with the exception of “Nassau” and “Platina” which
produced strictly straight pods. All of the other varieties were slightly curved. There was little
variation in pod straightness and smoothness.
Since there were no great differences in pod characteristics, primary selection of variety
should be based on yield and market acceptability. Pod color would have the greatest influence
on acceptability. “Festina”, “HMX 0104" and “Nassau” appeared to have the best combinations
of yield and a dark pod color. All of these had other pod characteristics that were acceptable.
Table 1.
Varieties and sponsoring companies of snap beans in a variety trial at the Coastal
Plain Experment Station in Tifton, in Fall 2001.
Variety
Sponsor
Bronco
Seminis
Casino
Holland Select
EX 8184379
Seminis
Festina
Seminis
Grenoble
Seminis
Hialeah
Harris Moran
HMX 0104
Harris Moran
Nassau
Holland Select
Nelson
Holland Select
Platina
Holland Select
Tasman
Holland Select
WBL 420
Seminis
Table 2.
Marketable yield, percent marketability, plant height, plant width and pod color of
-29-
snap beans at the Coastal Plain Experment Station in Tifton, Georgia in 2001.
Variety
Marketable
Yield
(lbs/A)
Bronco
5863
88.0
12.8
19.3
2.8
Casino
5173
95.0
10.7
17.6
1.3
EX8184379
10326
97.0
12.5
23.5
2.8
Festina
12233
97.0
14.6
24.3
1.3
Grenoble
9531
94.0
11.5
19.1
3.0
Hialeah
8902
97.0
12.2
18.3
3.0
10028
97.0
12.2
22.3
2.1
Nassau
9611
96.0
11.5
19.3
2.2
Nelson
7267
94.0
13.7
24.2
1.7
Platina
11417
95.0
13.7
21.3
2.9
Tasman
4794
94.0
12.2
19.3
2.5
WBL 420
8744
95.0
11.3
19.0
3.1
HMX 0104
Percent
Marketability
(%)
Plant
Height
(inches)
Canopy
Width
(inches)
Pod
Color1
Mean
8741.0
1.0
12.0
21.0
2.0
CV (%)
35.72
3.12
13.59
15.34
16.78
L.S.D. (0.05)
4491.7
0.04
2.40
4.60
Based on a scale of 1=dark green; 2=medium green; 3=light green; 4=yellow.
0.60
1
Table 3.
Pod width, pod length, pod shape, pod straightness and pod smoothness of snap
-30-
beans at the Coastal Plain Experiment Station in Tifton, Georgia in 2001.
Variety
Pod Width
(cm)
Pod
Length
(cm)
Pod
Shape1
Pod
Straightness2
Pod
Smoothness3
Bronco
0.9
11.7
2.5
1.7
1.7
Casino
0.8
11.6
2.6
1.9
1.0
EX8184379
0.9
9.7
2.7
1.9
1.7
Festina
0.9
14.3
2.7
2.0
1.7
Grenoble
0.8
13.1
2.7
1.9
1.4
Hialeah
0.9
15.9
2.5
1.6
1.8
HMX 0104
0.9
14.1
2.6
1.4
2.1
Nassau
1.5
15.9
1.0
2.0
2.8
Nelson
0.9
16.2
2.5
2.1
1.6
Platina
1.8
15.1
1.0
1.3
2.3
Tasman
1.1
12.6
2.6
1.9
2.4
WBL 420
0.9
14.1
2.3
1.9
1.4
Mean
1.0
14.0
2.0
2.0
2.0
CV (%)
9.25
24.85
16.56
22.87
30.57
L.S.D. (0.05)
0.14
4.90
0.55
0.59
0.80
2
Based on a scale of 1=flat; 2=oval; 3=round. Based on a scale of 1=smooth; 2=somewhat
smooth; 3=rough; 3Based on a scale of 1=straight; 2=slightly curved; 3=curved;
1
-31-
Summer Squash Variety Trial - 2001
William Terry Kelley1, David Curry2 and Gregory Hardison3
1
Extension Horticulturist, Rural Development Center
P.O. Box 1209, Tifton, Georgia 31793
wtkelley@uga.edu
2
Toombs County Extension Director
Courthouse Square
Lyons, Georgia 30436
3
Montgomery County Extension Director
P.O. Box 276
Mount Vernon, Georgia 30445
Introduction
Summer squash production continues to be an important part of the Georgia vegetable
industry. Production occurs throughout the state, but mostly in the southern coastal plain. Both
yellow (crookneck and straightneck) and zucchini squash are produced. Introduction of virusresistant squash hybrids in the last few years has drastically changed variety selection in squash.
Some of the varieties currently produced have resistance to at least two and in some cases three
of the four major squash viruses. The first variety resistant to all four major squash viruses was
released this year. Some of the virus resistance has been obtained through genetic modification
while other varieties have been developed through traditional means. Varieties with the
precocious yellow gene are also used by Georgia growers. Continual evaluation of squash
varieties is necessary to determine which of these new varieties perform to an acceptable level of
production and quality under Georgia conditions.
Methods
Nine zucchini, five yellow crookneck and seven yellow straightneck squash varieties were
compared at the Vidalia Onion and Vegetable Research Center (elev. 250 feet) near Lyons,
Georgia. All varieties were commercially available except for three zucchini lines and three
yellow straightneck lines that were still in the experimental stage of development. Squash
varieties were field-seeded on 24 April, 2001 into an Irvington loamy sand soil (Fine-loamy,
siliceous, thermic Plinthic Fragiudults). Plots consisted of two side-by-side rows with zucchini
spaced 24 inches between plants and yellow spaced 18 inches between plants. Plots were 12 feet
in length. The planting was arranged in a Randomized Complete Block Design with four
replications.
Normal cultural practices were used for bare ground squash production in Georgia. Base
fertilizer consisted of 400 pounds/A of 10-10-10 incorporated prior to planting. Additional
fertilizer was through two side dressed applications of 300 pounds/A of 10-10-10 each.
Ethafluralin (0.75 lb a.i./A) was applied pre-emergence for weed control. Fungicide and
insecticide applications were made according to current University of Georgia recommendations.
Irrigation was applied through an overhead system as needed.
-32-
Squash were harvested on June 6, 11, 13, 16, 18 and 20, 2001. Data were collected on yield
by grade, early yield by grade, percent marketability, average fruit weight and fruit number.
Results are summarized in Tables 1-12.
Results
A higher percentage of squash fell into the medium grade than would be expected under
grower conditions since harvests were only conducted three times per week. Among zucchinis,
Cashflow, HMX 8714, Bobcat, Spineless Beauty and Tigress produced the highest yields of
fancy and medium squash (Table 1). Tigress, Spineless Beauty and Dividend produced the
greatest early yield. Tigress, Dividend and Bobcat had the highest percentage of marketability
while HMX 9728 had the lowest (Table 3). HMX 8714, Tigress, Dividend and Spineless Beauty
produced the greatest number of fancy fruit (Table 4).
Among yellow crookneck, Supersett and Dixie produced the highest yields of fancy and
medium fruit (Table 5). The same varieties produced the highest early yields (Table 6). All
varieties produced similar percentages of marketability. Supersett, Dixie and Sunglo produced
the greatest numbers of fancy fruit (Table 8).
Among yellow straightneck, Cougar, Enterprise, XPT 46020767 and XPT 1832 produced the
highest yield of fancy and medium squash (Table 9) with similar results for early yield (Table
10). All varieties produced marketability levels higher than 95%. XPT 1832, Cougar and
Multipik produced the greatest numbers of fancy fruit.
Table 1.
Season yield by grade and combined fancy and medium yield of zucchini squash
-33-
at the Vidalia Onion and Vegetable Research Farm in Lyons, Georgia in 2001.
Season Yield
(21-lb boxes/A)
Variety
Fancy
Bobcat
530
295
25
826
Cashflow
640
318
38
958
Dividend
495
218
0
713
HMX 8714
586
393
58
979
HMX 8715
359
346
66
705
HMX 9728
450
200
149
649
Independence II
232
138
61
370
Spineless Beauty
496
371
102
867
Tigress
577
358
0
935
Mean
485
293
55
778
34.64
46.20
143.40
30.88
245
197
116
351
CV (%)
L.S.D. (0.05)
Medium
Jumbo
Total Fan/Med
Harvests occurred on June 6, 11, 13, 16, 18 and 20, 2001. Planting date: April 24, 2001. Plot size: 12
plants per plot (two rows of six) on 36" X 24" spacing.
-34-
Table 2.
Early* yield by grade and combined fancy and medium yield of zucchini squash
at the Vidalia Onion and Vegetable Research Farm in Lyons, Georgia in 2001.
Early Yield
(21-lb boxes/A)
Variety
Fancy
Medium
Jumbo
Total Fan/Med
Bobcat
212
283
25
495
Cashflow
245
276
0
521
Dividend
330
207
0
537
HMX 8714
321
279
58
600
HMX 8715
206
303
66
509
HMX 9728
273
169
149
442
Independence II
149
138
61
287
Spineless Beauty
279
257
39
537
Tigress
365
334
0
698
Mean
264
249
44
514
40.57
51.72
152.45
31.46
157
188
98
236
CV (%)
L.S.D. (0.05)
Early* harvests occured on June 6, 11 and 13, 2001 . Planting date: April 24, 2001. Plot size: 12 plants
per plot (two rows of six) on 36" X 24" spacing.
-35-
Table 3.
Percent marketability by weight of early and season harvests and average weight
of fancy and medium grade zucchini squash at the Vidalia Onion and Vegetable
Research Farm in Lyons, Georgia in 2001.
Variety
Percent
Marketable
Season (%)
Percent
Marketable
Early (%)
Bobcat
97.0
96.0
169
744
Cashflow
95.8
100.0
175
605
Dividend
99.8
99.5
199
593
HMX 8714
95.5
94.5
177
701
HMX 8715
89.5
87.8
205
679
HMX 9728
81.3
71.0
214
725
Independence II
89.8
89.5
220
745
Spineless Beauty
90.5
94.0
202
709
Tigress
98.5
98.0
236
641
Mean
93.1
92.3
200
682
CV (%)
10.01
11.43
14.45
L.S.D. (0.05)
13.6
15.4
42
-36-
Average
Fancy Weight
(g)
Average
Medium Weight
(g)
17.54
175
Table 4.
Early and season fruit number by grade of zucchini squash at the Vidalia Onion
and Vegetable Research Farm in Lyons, Georgia in 2001.
*Early Harvest
Variety
Medium
Jumbo
9277
3722
202
29572
3923
202
Cashflow
10307
4289
0
34631
4894
259
Dividend
11732
3333
0
23826
3515
0
HMX 8714
14944
3287
303
31863
5203
303
HMX 8715
8635
3933
468
16748
4703
468
HMX 9728
9287
2234
1039
19753
2637
1039
Independence II
5661
1945
605
10458
1945
605
Spineless Beauty
10857
3574
347
23261
5175
693
Tigress
12312
4916
0
23383
5279
0
Bobcat
Fancy
Season Harvest
Fancy
Medium
Jumbo
Mean
10334
3470
329
23655
4141
396
CV (%)
34.62
52.52
169.14
31.41
46.41
156.05
L.S.D. (0.05)
5222
2660
812
10842
2805
903
Harvests occurred on June 6, 11, 13, 16, 18 and 20, 2001. Planting date: April 24, 2001. Plot size: 12
plants per plot (two rows of six) on 36" X 24" spacing. *Early harvest includes the first three harvests.
-37-
Table 5.
Season yield by grade and combined fancy and medium yield of yellow
crookneck squash at the Vidalia Onion and Vegetable Research Farm in Lyons,
Georgia in 2001.
Season Yield
(30-lb boxes/A)
Variety
Fancy
Medium
Jumbo
Total Fan/Med
Dixie
512
296
20
808
Gentry
317
241
11
530
Prelude II
281
293
11
574
Sunglo
332
278
25
610
Supersett
496
471
0
967
Mean
388
141
13.0
698
37.97
45.41
214.96
35.43
227
217
44
381
CV (%)
L.S.D. (0.05)
Harvests occurred on June 6, 11, 13, 16, 18 and 20, 2001. Planting date: April 24, 2001. Plot size: 12
plants per plot (two rows of eight) on 36" X 18" spacing.
-38-
Table 6.
Early* yield by grade and combined fancy and medium yield of yellow crookneck
squash at the Vidalia Onion and Vegetable Research Farm in Lyons, Georgia in
2001.
Early Yield
(30-lb boxes/A)
Variety
Fancy
Medium
Jumbo
Total Fan/Med
Dixie
307
195
20
502
Gentry
167
131
11
298
Prelude II
141
193
11
334
Sunglo
182
159
25
340
Supersett
254
392
0
645
Mean
210
214
13.0
424
57.45
54.14
214.96
44.09
186
178
44
288
CV (%)
L.S.D. (0.05)
Early* harvests occurred on June 6, 11 and 13, 2001. Planting date: April 24, 2001. Plot size: 12 plants
per plot (two rows of eight) on 36" X 18" spacing.
-39-
Table 7.
Percent marketability by weight of early and season harvests and average weight
of fancy and medium grade yellow crookneck squash at the Vidalia Onion and
Vegetable Research Farm in Lyons, Georgia in 2001.
Percent
Marketable
Season (%)
Percent
Marketable
Early (%)
Dixie
98.3
97.0
145
273
Gentry
96.3
93.5
106
271
Prelude II
97.8
96.3
108
299
Sunglo
94.5
90.0
110
288
100.0
100.0
112
289
97.4
95.4
116
284
Variety
Supersett
Mean
Average
Fancy Weight
(g)
Average
Medium
Weight (g)
CV (%)
3.76
6.62
35.6
10.21
L.S.D. (0.05)
5.6
9.7
64
45
Table 8.
Early and season fruit number by grade of yellow crookneck squash at the Vidalia
Onion and Vegetable Research Farm in Lyons, Georgia in 2001.
*Early Harvest
Variety
Fancy
Season Harvest
Medium
Jumbo
Fancy
Medium
Jumbo
Dixie
21131
9795
545
50465
14867
545
Gentry
19899
6386
272
40293
10321
272
Prelude II
16304
8605
227
35514
13194
227
Sunglo
20691
7351
545
40565
13068
545
Supersett
28357
17697
0
60028
21095
0
Mean
21277
9967
318
45373
14509
318
CV (%)
21.71
48.56
222.05
21.92
39.27
222.05
L.S.D. (0.05)
7115
7456
1087
15320
8777
1087
Harvests occurred on June 6, 11, 13, 16, 18 and 20, 2001. Planting date: April 24, 2001. Plot size: 12
plants per plot (two rows of eight) on 36" X 18" spacing. *Early harvest includes the first three harvests.
-40-
Table 9.
Season yield by grade and combined fancy and medium yield of yellow straight
neck squash at the Vidalia Onion and Vegetable Research Farm in Lyons,
Georgia in 2001.
Season Yield
(30-lb boxes/A)
Variety
Fancy
Medium
Jumbo
Total Fan/Med
Cougar
346
296
0
642
Enterprise
296
250
8
546
Liberator II
233
101
0
334
Multipik
311
93
25
403
XP 4970297
319
150
11
469
XPT 1832
464
38
0
502
XPT 46020767
311
296
0
513
Mean
326
161
6
487
30.33
89.15
350.83
45.27
147
214
33
327
CV (%)
L.S.D. (0.05)
Harvests occurred on June 6, 11, 13, 16, 18 and 20, 2001. Planting date: April 24, 2001. Plot size: 12
plants per plot (two rows of eight) on 36" X 18" spacing.
-41-
Table 10.
Early* yield by grade and combined fancy and medium yield of yellow straight
neck squash at the Vidalia Onion and Vegetable Research Farm in Lyons,
Georgia in 2001.
Early Yield
(30-lb boxes/A)
Variety
Fancy
Medium
Jumbo
Total Fan/Med
Cougar
224
197
0
421
Enterprise
133
171
8
304
Liberator II
155
70
0
225
Multipik
177
72
25
249
XP 4970297
161
91
11
251
XPT 1832
302
20
0
322
XPT 46020767
170
146
0
316
Mean
189
110
6
298
34.56
97.16
350.83
51.98
97
158
33
230
CV (%)
L.S.D. (0.05)
Early* harvests occurred on June 6, 11 and 13, 2001. Planting date: April 24, 2001. Plot size: 12 plants
per plot (two rows of eight) on 36" X 18" spacing.
-42-
Table 11.
Percent marketability by weight of early and season harvests and average weight
of fancy and medium grade yellow straight neck squash at the Vidalia Onion and
Vegetable Research Farm in Lyons, Georgia in 2001.
Variety
Percent
Marketable
Season (%)
Percent
Marketable
Early (%)
Average Fancy
Weight (g)
Average Medium
Weight (g)
Cougar
99.5
99.3
112
342
Enterprise
97.8
95.8
122
358
Liberator II
100.0
100.0
127
376
Multipik
95.8
93.8
91
318
XP 4970297
97.8
96.3
125
388
XPT 1832
99.8
99.5
99
385
XPT 46020767
99.8
99.8
136
394
Mean
98.6
97.8
116
366
CV (%)
3.83
6.02
18.74
15.52
L.S.D. (0.05)
5.6
8.7
32
84
-43-
Table 12.
Early and season fruit number by grade of yellow straight neck squash at the
Vidalia Onion and Vegetable Research Farm in Lyons, Georgia in 2001.
*Early Harvest
Season Harvest
Variety
Fancy
Medium
Jumbo
Fancy
Medium
Jumbo
Cougar
25297
7563
0
41102
10928
0
Enterprise
11081
6167
195
33367
9078
195
Liberator II
16195
2675
0
24640
3669
0
Multipik
21625
3157
545
45145
3860
545
XP 4970297
14954
2994
227
35694
5066
227
XPT 1832
35285
663
0
63944
1326
0
XPT 46020767
14561
5549
0
31821
6925
0
Mean
19857
4110
138
39388
5836
138
CV (%)
30.53
85.91
344.98
24.63
75.60
344.98
L.S.D. (0.05)
9005
5245
707
14410
6554
707
Harvests occurred on June 6, 11, 13, 16, 18 and 20, 2001. Planting date: April 24, 2001. Plot size: 12
plants per plot (two rows of eight) on 36" X 18" spacing. *Early harvest includes the first three harvests.
-44-
Sweet Corn Variety Trial - 2001
William Terry Kelley1, David Curry2 and Gregory Hardison3
1
Extension Horticulturist, Rural Development Center
P.O. Box 1209, Tifton, Georgia 31793
wtkelley@uga.edu
2
Toombs County Extension Director
Courthouse Square
Lyons, Georgia 30436
3
Montgomery County Extension Director
P.O. Box 276
Mount Vernon, Georgia 30445
Introduction
Sweet corn is by acreage one of the top three vegetable commodities in the state of Georgia.
In recent years sweet corn production has begun to branch out from the traditional center of
production in southwestern Georgia. A considerable amount of sweet corn is now produced in
eastern Georgia as well. New sweet corn varieties are numerous each year. Comparing these new
varieties to the current standards on the market is essential to growers who want to remain
competitive in the sweet corn market. This trial was conducted to compare new and existing
varieties of sweet corn in yellow, white and bi-color types.
Methods
Twelve yellow, five white and ten bi-color sweet corn varieties were compared at the Vidalia
Onion and Vegetable Research Center (elev. 250 feet) near Lyons, Georgia. All varieties were
commercially available except for two yellow and two bi-color varieties that were still in the
experimental stage of development. Corn varieties were field-seeded on 19 April, 2001 into an
Irvington loamy sand soil (Fine-loamy, siliceous, thermic Plinthic Fragiudults). Plots consisted
of a single row with nine inches between plants and 36 inches between rows. Plots were 20 feet
in length. The planting was arranged in a Randomized Complete Block Design with four
replications.
Normal cultural practices were used for sweet corn production in Georgia. Base fertilizer
consisted of 1000 pounds/A of 10-10-10 incorporated prior to planting. Additional fertilizer was
through two side dressed applications of 400 pounds/A of 10-10-10 each. Atrazine (2.0 lb a.i./A)
was applied pre-emergence for weed control. Insecticide applications were made according to
current University of Georgia recommendations. Irrigation was applied through an overhead
system as needed.
Corn was harvested at maturity from June 22 to July 5, 2001. Data were collected on yield,
percent marketability and average ear weight and subjected to analysis of variance and means
separated. Results are summarized in Table 1.
Results
-45-
Yields were calculated by two methods. One method was on the basis of a 42-pound crate,
which is the standard accepted weight of a crate of corn. The other method was to use 50-ear
crates since most corn is packed to a count of 50 ears. Based on the 50-ear method, Brut, CNS
710A, Cronus, GSS 0966, Morningstar, Prime Plus and Variety #6800 all yielded more than 300
boxes per acre among yellow types. Percent marketability varied widely with Cronus having the
highest percentage and Brut the lowest. Sunvolt and CNS 710A had the largest ears by weight.
Among bi-color types, BSS 0977, HMX 8344, Twin Star and Variety # 8102 all yielded over
300 boxes per acre. HMX 8344 had the greatest marketability and BSS 0977 the lowest,
although all varieties were in a fairly narrow range. HMX 8344 had the largest ear based on
weight.
In the white corn types, Vail was the only variety that produced over 300 boxes per acre. Ice
Queen was the only variety above 80% marketable and WSS 1921 had the lowest marketability.
Vail also had the greatest ear weight.
-46-
Table 1.
Variety
Yield in 50-ear count boxes and 42-pound boxes, percent marketability and average ear
weight of sweet corn in 2001 at Lyons, Georgia.
Sponsor
Type
1
Yield/A
Yield/A
%
Avg Ear Wt.
(42-lb boxes)
(50-ear box)
Marketable
(grams)
Yellow
ACX 844
Abbott & Cobb
Ysh2
219
285
75.9
281.9
ACX 945
Abbott & Cobb
Ysh2
228
285
77.6
291.2
Brut
Seminis
Ysh2
270
355
54.8
294.5
CNS 710A
Crookham
Ysh2
262
306
81.9
329.0
Cronus
Syngenta
Ysh2
211
317
88.5
252.5
GSS 0966
Syngenta
Ysh2
225
322
76.7
268.7
GSS 5771
Syngenta
Ysh2
142
226
54.3
230.8
Morningstar
Harris Moran
Ysh2
222
305
79.3
279.2
Prime Plus
Syngenta
Ysh2
219
339
73.5
251.7
Sunvolt
Harris Moran
Ysh2
223
284
80.0
333.5
Variety #6800
Abbott & Cobb
Ysh2
240
338
82.2
264.9
Variety #7630
Abbott & Cobb
Ysh2
150
211
75.1
269.0
Mean of Test
216.0
294.6
74.3
279.5
L.S.D. (0.05)
133.6
172.4
17.0
79.8
43.1
40.8
15.9
19.9
C.V. (%)
Bi-Color
ACX 946 BC
Abbott & Cobb
BCsh2
224
269
80.0
315.0
Bigtime
BSS 0977
Syngenta
BCsh2
211
267
72.9
297.1
Syngenta
BCsh2
287
422
72.6
261.8
BSS 9686
Syngenta
BCsh2
257
289
78.1
341.4
HMX 8344
Harris Moran
BCsh2
314
325
87.1
374.5
Hollywood
Seminis
BCsh2
183
243
80.5
283.4
Tango
Crookham
BCsh2
222
284
81.5
301.4
Tethys
Syngenta
BCsh2
195
255
84.5
292.9
Twin Star
Harris Moran
BCsh2
297
366
74.2
319.1
Variety #8102
Abbott & Cobb
BCsh2
269
336
86.0
305.0
Mean of Test
245.8
305.5
79.7
309.2
L.S.D. (0.05)
110.8
148.0
14.1
57.2
31.1
33.4
12.2
12.8
C.V. (%)
White
Ice Queen
Harris Moran
Wsh2
116
175
80.1
249.1
Vail
Syngenta
Wsh2
262
332
75.0
304.9
Variety #6801
Abbott & Cobb
Wsh2
146
216
74.8
252.6
Variety #8101
Abbott & Cobb
Wsh2
222
278
71.2
300.3
WSS 1921
Syngenta
Wsh2
200
259
66.6
286.5
Mean of Test
186.4
249.8
75.3
276.7
L.S.D.(0.05)
119.8
134.9
22.6
89.3
C.V. (%)
40.2
33.8
BCsh2 = Bicolor shrunken, Ysh2 = yellow shrunken, Wsh2 = white shrunken.
18.8
20.2
1
-47-
-48-
Weed Control
-49-
-50-
WEED MANAGEMENT IN WATERMELON AND CANTALOUPE
TRANSPLANTED ON POLYETHYLENE COVERED SEEDBEDS
W. Carroll Johnson, III and Theodore M. Webster
Research Agronomists - Weed Science
USDA-ARS
Coastal Plain Experiment Station
Tifton, GA 31793
Introduction
Cucurbit crops are grown on approximately 11,000 A in Georgia, with watermelon and
cantaloupe accounting for 62% of the cucurbit acreage. In previous years, much of the
watermelon and cantaloupe acreage was direct seeded on freshly prepared seedbeds. Systems
using hybrid cultivars seeded in greenhouses and transplanted on polyethylene covered seedbeds
have recently become common. Currently, 57 and 35% of the cantaloupe and watermelon
acreage, respectively, are being grown as transplants on polyethylene covered seedbeds. Hybrid
seed are costly and transplanting reduces the risk of stand loss associated with direct seedings
caused by an assortment of early-season production problems. Polyethylene covered seedbeds
warm the soil, allowing for earlier planting and harvest during periods of historically premium
commodity prices. Polyethylene covered seedbeds are generally fumigated with a broadspectrum fumigant, particularly methyl bromide.
Methyl bromide fumigation controls most pests of cantaloupe and watermelon, including
annual and perennial weeds, pathogenic fungi, bacteria, plant parasitic nematodes, and soilinhabiting arthropods. Several weeks before seeding or transplanting, methyl bromide is injected
approximately 8-in deep and immediately covered with a polyethylene tarp forming a finished
seedbed approximately 12 to 60-in wide. Wider seedbeds are used for multiple crops during a
growing season with drip irrigation, compared to narrower seedbeds used for one crop during a
growing season with overhead irrigation. Approximately 51 and 74% of the transplanted
cantaloupe and watermelon acreage, respectively, is on narrow polyethylene covered seedbeds
and irrigated with overhead irrigation. Seedlings are transplanted through the polyethylene tarp
two to four weeks after fumigation to allow fumigant dissipation.
Methyl bromide is thought to contribute to the depletion of stratospheric ozone. In
anticipation of these findings, the U. S. Environmental Protection Agency initiated a mandatory
phase-out of all methyl bromide containing fumigants by 2005. Acceptable alternatives to
methyl bromide have been developed in vegetable crop transplant production and related
cropping systems. Metham has been shown to be effective as methyl bromide in controlling
many cool- and warm-season weeds. Sequentially applying metham with 1,3-D and/or
chloropicrin improved the control of pathogenic fungi, bacteria, plant parasitic nematodes, and
soil-inhabiting arthropods.
These studies inferred that growers could customize the fumigant combination according to
-51-
the pests present in the soil. For example, metham alone is an excellent herbicide capable of
killing dormant weed seed and fungicide. Furthermore, 1,3-D and/or chloropicrin are poor
herbicides but effective nematicides. Coupled with the innate differential selectivity of the
fumigants are the different types of application for optimum efficacy. Metham is chisel applied
8-in deep for control of root diseases of peanut, but provides little weed control when applied in
this manner. In contrast, metham applied as spray and incorporated to a depth of 3-in gives
excellent weed control, but is less effective on root diseases than chiseled applications.
There are few herbicides registered for use on watermelon and cantaloupe. In general
terms, annual grasses can be effectively controlled with ethalfluralin, bensulide, sethoxydim, or
clethodim. Troublesome dicot weeds such as annual morningglories (Ipomoea spp.),
smallflower morningglory [Jacquemontia tamnifolia (L.) Griseb.], common cocklebur
(Xanthium strumarium L.), sicklepod [Senna obtusifolia (L.) Irwin & Barneby], and Florida
beggarweed [Desmodium tortuosum (Sw.) DC] cannot be controlled by any of the herbicides
currently registered for use on watermelon or cantaloupe. Similarly, neither yellow nutsedge
(Cyperus esculentus L.) nor purple nutsedge (C. rotundus L.) can be adequately controlled in
these crops.
In 1998, trials were initiated with cantaloupe and watermelon to develop a weed
management system for these crops transplanted on polyethylene covered seedbeds.
Furthermore, these trials were also designed to study the role of metham fumigation, a proven
alternative to methyl bromide, for weed management in these crops.
Materials and Methods
Irrigated field trials were conducted at the Coastal Plain Experiment Station Ponder Farm
from 1998 to 2001. Cantaloupe trials were conducted in 1998, 1999, and 2001. Watermelon
trials were conducted 1998 and 2001. All trials in 2000 were terminated due to uncontrollable
foliar diseases of cantaloupe and watermelon that confounded all data. Soils were a Tifton
loamy sand (fine-loamy, kaolinitic, thermic Plinthic Kandiudults), composed of the following
fractions 1998 and 1999 - 86% sand, 8% silt, and 6% clay with 0.2% organic matter; 2001 - 88%
sand, 6% silt, and 6% clay with 0.6% organic matter
The experimental design was a split-plot with four replications. Main plots were preplant
soil fumigation; metham and a nonfumigated control. The entire experimental area was irrigated
to field capacity one day prior to fumigation. Metham was sprayed and incorporated in the
designated treatments with a modified power tiller using the implement described by Johnson
and Webster (2001). Nondiluted metham was sprayed and incorporated at 80 gal./A (broadcast
basis) in a 24-in band at a ground speed of 2 mi/h. Black polyethylene tarp (1 mil thick and 24in wide) was spread in a separate operation using a mulch layer1.
1
Pro-Junior Series mulch layer; Buckeye Tractor Company; P. O. Box 123; Columbus
Grove,OH 45830.
Sub-plots were herbicide systems in watermelon and cantaloupe; ethalfluralin (1.0 pt/A)
PRE, ethalfluralin PRE followed by glyphosate (1.0 qt/A) POST-SHIELDED, and a nontreated
control. Additional treatments were added in 1999 and 2001 to achieve better control of yellow
nutsedge. These additional treatments were ethalfluralin plus halosulfuron (b oz/A) PRE and
ethalfluralin plus halosulfuron PRE followed by glyphosate POST-SHIELDED. The PRE
treatments were applied immediately after transplanting. All PRE herbicides were applied with a
tractor-mounted plot sprayer pressurized with CO2, calibrated to deliver 25 gal/A with off-center
nozzle tips2 directing spray onto the edges of the polyethylene covered seedbed and into the row
middles. The width of the treated swath was approximately 18-in. The POST-SHIELDED
treatments were applied with a tractor mounted PTO-powered sprayer, with hoods3 mounted on a
rigid frame that used gauge wheels to stabilize the sprayer. The hoods were 28-in wide and had
three overlapping nozzles inside each hood, with a total output of 25 gal/A at 22 lb/in2. The
hoods were attached to the rigid frame using articulating mounts that allowed the hood height to
adjust according to topography of the field. Nylon brushes4 were added to the bottom edges of
the hoods to prevent spray from drifting under the hoods and keep the hoods from tearing the
polyethylene tarp covering the seedbeds.
Main plots in both crops were 6-ft. wide and 20-ft long, with crops established in one row
centered in the middle of the plot. Watermelon plots had a 12-ft. fallow border on either side of
the drill for the crop’s aggressive vine growth. The fallow border areas were kept weed free with
tillage until vine encroachment. Cantaloupe, a crop with less aggressive vine growth than
watermelon, did not require a fallow border between adjacent plots.
‘Cordele®’5 (1998 and 1999) and ‘Vienna®’7 (2001) cantaloupe and ‘Stargazer®’7
watermelon were seeded in Speedling®6 trays in a greenhouse in mid-March, which was
concurrent with the time of fumigation and laying the polyethylene tarp in the field. Cantaloupe
and watermelon seedlings were transplanted three weeks after fumigation. Seedlings were
established in the field using a Kennco®7 transplanter that cut holes in the polyethylene tarp and
transplanted in one operation. Cantaloupe seedlings were spaced 22-in apart, while watermelon
seedlings were spaced 36-in apart. Plots were irrigated as needed with a solid set sprinkler
system. Cultural practices and pest management decisions were based on recommendations
2
TeeJet® OC-03 spray tips; Spraying Systems Co.; P.O. Box 7900; Wheaton, Illinois
60189-7900.
3
RedBall Hooded Sprayer; Custom Ag Products, inc.; Benson, MN 56215.
4
Sealeze Corporation; 8000 Whitepine Rd.; Richmond, VA 23237.
5
Seminis Inc.; 2700 Camino del Sol; Oxnard, CA 93030-7967.
6
Hummert International, Earth City, MO 63045.
7
Kennco Manufacturing Inc., Ruskin, FL 33570.
from the Georgia Cooperative Extension Ser.
Visual estimates of weed control and crop injury were taken mid-season each year. Yields
were measured by harvesting mature fruits from the entire plot at multiple intervals, depending
on the continued presence of marketable fruits. The number and weight of cantaloupe and
watermelon fruits were recorded by harvest date.
Due to differences in growing conditions and weed species among years, data were not
pooled. Within each year, data were subjected to analysis of variance to determine sources of
variation and significant interactions. Difference in treatment means were determined using the
Fisher's Protected Least Significant Difference Test at P<0.05.
Results and Discussion
Weed control. Florida pusley (Richardia scabra L.) was present in cantaloupe nontreated plots
in 1998 and 1999 at approximately 10 and 2 plants/ft2, respectively. Most of the Florida pusley
were present in the row middles and some occasionally in the transplant hole. No Florida pusley
emerged through the polyethylene tarp. All of the PRE weed control systems effectively
controlled Florida pusley, including ethalfluralin alone (Table 1). The addition of halosulfuron
PRE or glyphosate POST-SHIELDED was not necessary for adequate Florida pusley control.
Regardless of the herbicides used, metham fumigation did not improve Florida pusley control
compared to nonfumigated plots.
Smallflower morningglory was present in cantaloupe in 1998 and 1999 at approximately 1
plant/ft2 both years. As was the case with Florida pusley, smallflower morningglory was present
in row middles or occasionally in the transplant hole. Ethalfluralin alone did not adequately
control smallflower morningglory. The sequential application of ethalfluralin PRE followed by
glyphosate POST-SHIELDED improved smallflower morningglory control. In 1999, the
addition of halosulfuron PRE provided a slight increase in smallflower morningglory control, but
not as much as glyphosate POST-SHIELDED. Generally, metham fumigation did not improve
smallflower morningglory control compared to nonfumigated plots. Smallflower morningglory
was unable to penetrate the polyethylene tarp, without respect to fumigation.
Smooth pigweed (Amaranthus hybridus L.) was present in watermelon in 1998 and 2001.
All of the PRE weed control systems effectively controlled smooth pigweed, including
ethalfluralin alone (Table 2). The addition of halosulfuron PRE or glyphosate POSTSHIELDED was not necessary for adequate smooth pigweed control. Metham fumigation did
not improve smooth pigweed control, compared to nonfumigated plots.
Crowfootgrass [Dactyloctenium aegyptium (L.) Willd.], southern crabgrass [(Digitaria
ciliaris (Retz.) Koel.], and Texas panicum (Panicum texanum Buckl.) were present in some of
the trials (Tables 1 and 2). Any of the PRE treatments which included ethalfluralin effectively
controlled these annual grasses in cantaloupe and watermelon. Metham fumigation did not
improve control of any of the annual grasses compared to nonfumigated plots. As seen with the
-54-
dicot weeds, the annual grasses did not emerge through the polyethylene tarp and were present
primarily in the row middles in the nontreated controls.
Yellow nutsedge was present in both crops 1999 and 2001 at approximately 10 and 2
plants/ft2, respectively. The most consistent and effective yellow nutsedge control in cantaloupe
and watermelon was a system of metham fumigation, followed by either halosulfuron PRE or
glyphosate POST-SHIELDED (Tables 1 and 2). Yellow nutsedge has been successfully
controlled in several cucurbit crops with halosulfuron, applied PRE and POST, although preplant
fumigation was not evaluated in those trials. In our trials, yellow nutsedge control with either
halosulfuron PRE or glyphosate POST-SHIELDED was inconsistent without metham
fumigation. In the absence of herbicides, metham fumigation provided only partial control of
yellow nutsedge. Clearly, effective control on yellow nutsedge in cantaloupe and watermelon
will require an integrated system of metham fumigation and either halosulfuron PRE or
glyphosate POST-SHIELDED. Relying strictly on one tactic for yellow nutsedge control will
result in escapes.
The ratings reflect a visual composite of weed control on the polyethylene covered seedbeds
and row middles. Most of the yellow nutsedge present in plots fumigated with metham were in
the row middles, which were not fumigated. Very little yellow nutsedge emerged through the
polyethylene tarp in plots fumigated with metham, indicating good to excellent control of yellow
nutsedge with metham applied using the modified power tiller developed by USDA-ARS at the
Coastal Plain Experiment Station in Tifton, GA (Figure 1).
Visual injury. Cantaloupe was not significantly injured by metham fumigation or any of the
herbicide treatments in 1998, 1999, and 2001 (Table 1). Injury was observed, but was sporadic
and nonsignificant. Watermelon was not injured by metham fumigation or any of the herbicide
treatments in 1998 (Table 2). However, some of the herbicide treatments stunted watermelon in
2001. The most injurious treatment to watermelon in 2001 was ethalfluralin plus halosulfuron,
despite precise application onto the shoulders of the polyethylene covered seedbed and with no
contact onto the cucurbit seedlings. Ethalfluralin applied after transplanting is an acceptable
time of application, without significant injury. Wells (1999) significantly injured watermelon
with halosulfuron PRE, although those applications were to direct seeded watermelon. Our
results demonstrate an overall acceptable level of crop safety by applying PRE herbicides to the
shoulders of the polyethylene covered seedbeds and avoiding direct contact with cantaloupe and
watermelon seedlings.
Cantaloupe yield. Cantaloupe yields (number of fruits/A) were not affected by the interactive
effects of metham fumigation and herbicide systems for weed control throughout the duration of
the trial (Table 3). Similarly, cantaloupe yields expressed as weight of fruits/A were not affected
(data not shown). Marketable cantaloupe fruits were harvested multiple times to determine if
treatments affected maturity. Data from each of the harvest dates showed no effect of metham
fumigation and herbicide systems on cantaloupe maturity (data not shown). Size of cantaloupe
fruits (lb/fruit) were not consistently affected by metham fumigation and herbicide treatments
-55-
throughout the duration of the trial (Table 3). Fruit size was significantly smaller only in 1999 in
the nonfumigated, nontreated control compared to any of the herbicide treatments in the
nonfumigated plots.
Watermelon yield. Watermelon yields (number of fruits/A) were not affected by the interactive
effects of metham fumigation and herbicide treatments (Table 4). Similarly, yields expressed as
weight of fruits/A were not affected (data not shown). Marketable watermelon fruits were
harvested multiple times to determine if treatments affected maturity. Data from each of the
harvest dates showed no effect of metham fumigation and herbicide treatments on watermelon
maturity (data not shown). Size of watermelon fruits were not affected by metham fumigation
and herbicide treatments throughout the duration of the trial (Table 4).
The lack of cantaloupe and watermelon yield response to weed control was not expected,
considering the extraordinary weed densities encountered each year. These results suggest that
transplanted cantaloupe and watermelon grown on polyethylene-covered seedbeds are quite
competitive with weeds and the polyethylene tarp itself may be an effective weed control
practice. The only weed to penetrate and emerge through the polyethylene tarp was yellow
nutsedge. All the dicot weeds and annual grasses in these trials were unable to penetrate the
polyethylene tarp. In addition, transplant holes were punched through the polyethylene tarp
concurrent with transplanting cantaloupe and watermelon seedlings. This appears to have helped
minimize incidence of weeds emerging through the transplant hole, compared to transplant holes
present for several days or weeks prior to planting. A rapidly growing cucurbit seedling has a
decided competitive advantage with newly emerged weeds in this system. Rapidly growing
cucurbit crops have been recognized as being highly competitive with weeds. The rapid crop
growth seen in systems of cucurbit transplants on polyethylene covered seedbeds gives growers
opportunities to manage many troublesome weed species, including yellow nutsedge, with
minimal dependence on herbicides.
It was beyond the scope of this trial to compare weed control strategies for direct seeded
versus transplanted cucurbits and bare ground versus polyethylene-covered seedbeds. However,
inferences can be made that weed control in cucurbits transplanted on polyethylene-covered
seedbeds will be assisted by the mechanical barrier provided by the polyethylene tarp. With the
weed densities and species diversity encountered in these trials, weed control efforts outside
those provided by the polyethylene tarp were generally not needed.
It is possible that under different conditions, additional weed control would be needed.
Metham fumigation effectively controlled all species under the polyethylene tarp, including
yellow nutsedge. Ethalfluralin PRE, halosulfuron PRE, and glyphosate POST-SHIELDED
effectively controlled the species encountered in these trials, without excessive crop
phytotoxicity and delays in maturity. Halosulfuron PRE and glyphosate POST-SHIELDED have
the potential to significantly broaden the weed control spectrum available to cucurbit growers if
granted registration. The occasional stunting of cantaloupe and watermelon from halosulfuron
PRE was not expressed in yield reduction or delayed maturity. It appears that the weed control
-56-
benefits of halosulfuron PRE in transplanted cantaloupe and watermelon compensate for the
risks of phytotoxicity in these cropping systems.
Regardless of weed control options employed by cucurbit growers, the most successful
approach is an integration of cultural practices (such as using transplants on polyethylene
covered seedbeds) and judicious use of fumigants and herbicides tailored for the pests present.
Optimum growing conditions and production practices are necessary for maximizing the
substantial crop competition benefits. Properly applying PRE and POST-SHIELDED herbicides
on the edges of the polyethylene covered seedbeds will optimize weed control efficacy and
minimize crop phytotoxicity.
Acknowledgments
We acknowledge the technical contributions of Daniel R. Evarts in these trials. Mr. Evarts was
solely responsible for the design and construction of the modified equipment used for preplant
fumigation and herbicide application in these trials, along with overall field operations. Seminis
Inc. graciously provided the cantaloupe and watermelon seeds used in these trials.
-57-
Literature Cited
Anonymous. 1998. Scientific assessment of ozone depletion: 1998 - executive summary.
World Meteorological Organization Global Ozone Research and Monitoring Project.
Report No. 44.
Cline, W. O. and M. K. Beute. 1986. Effect of metam sodium, peanut genotype and inoculum
density on incidence of Cylindrocladium black rot. Peanut Sci. 13:41-45.
Csinos, A. S., W. C. Johnson, III, A. W. Johnson, D. R. Sumner, R. M. McPherson, and R. D.
Gitaitis. 1997. Alternative fumigants for methyl bromide in tobacco and pepper transplant
production. Crop Protection 16:585-594.
Csinos, A. S., D. R. Sumner, W. C. Johnson, III, A. W. Johnson, R. M. McPherson, and C. C.
Dowler. 1999. Methyl bromide alternatives in tobacco, tomato and pepper transplant
production. Crop Protection (In press).
Doherty, B. A. and W. O. Mizelle, Jr. 2001. 2000 Vegetable Survey. Georgia Fruit and
Vegetable Growers News. Summer 2001.
Grey. T. L., D. C. Bridges, and D. S. NeSmith. 2000. Tolerance of cucurbits to the herbicides
clomazone, ethalfluralin, and pendimethalin. II. watermelon. HortScience. 35:637-641.
Johnson, W. C., III and T. M. Webster. 2001. A modified power-tiller for metham application
on cucurbit crops transplanted to polyethylene covered seedbeds. Weed Technol. 15:387395.
Mitchem, W. E., D. W. Monks, and R. J. Mills. 1997. Response of transplanted watermelon
(Citrullus lanatus) to ethalfluralin applied PPI, PRE, and POST. Weed Technol. 11:88-91.
Monks, D. W. and J. R. Schultheis. 1998. Critical weed-free period for large crabgrass
(Digitaria sanguinalis) in transplanted watermelon (Citrullus lanatus). Weed Sci. 46:530532.
Nerson, H. 1989. Weed Competition in muskmelon and its effects on yield and fruit quality.
Crop Protection. 8:439-443.
Noling, J. W. and J. O. Becker. 1994. The challenge of research and extension to define and
implement alternatives to methyl bromide. Suppl. J. Nem. 26:573-586.
Teasdale, J. R. and R. B. Taylorson. 1986. Weed seed response to methyl isothiocyanate and
metham. Weed Sci. 34:520-524
USDA. 1999. Administration extends deadline on methyl bromide ban to 2005. Methyl
Bromide Alternatives 5:1.
-58-
Webster, T. M., A. S. Csinos, A. W. Johnson, C. C. Dowler, D. R. Sumner, and R. L. Fery.
2001. Methyl bromide alternatives in a bell pepper-squash rotation. Crop Protection.
20:605-614.
Wells, J. J. 1999. Yellow nutsedge control in summer vegetables and development of
glyphosate-tolerant spinach. PhD Dissertation. University of Arkansas. 127 p.
-59-
Table 1. Visual estimates of weed control and crop injury in transplanted cantaloupe on polyethylene covered seedbeds at Tifton, GA.
1998
RCHSC1
IAQTA1
1999
Injury
------------ % ------------
RCHSC
IAQTA
CYPES1
2001
PANTE1
Injury
------------------------- % -------------------------
CYPES
DIGSP1
Injury
------------ % ------------
Metham fumigation
Ethalfluralin
90
69
0
95
92
78
95
0
76
90
0
Ethalfluralin/glyphosate
94
85
0
95
93
95
94
0
79
90
0
Ethalfluralin + halosulfuron
-
-
-
95
95
95
95
2
88
90
1
Ethalfluralin + halosulfuron/glyphosate
-
-
-
95
94
95
95
7
89
90
0
43
64
0
73
70
75
68
0
73
48
3
Ethalfluralin
93
85
0
90
88
77
94
0
54
90
5
Ethalfluralin/glyphosate
95
93
0
95
95
78
92
2
55
90
3
Ethalfluralin + halosulfuron
-
-
-
93
90
82
88
2
56
90
4
Ethalfluralin + halosulfuron/glyphosate
-
-
-
95
95
92
95
0
60
90
10
Nontreated
0
0
0
0
0
0
0
0
0
0
0
5
14
-
7
7
14
11
ns
16
2
6
Nontreated
Nonfumigated
LSD (0.05)
1
Abbreviations: CYPES, yellow nutsedge, Cyperus esculentus L.; DIGSP, southern crabgrass, Digitaria ciliaris (Retz.) Koel.; IAQTA, smallflower
morningglory, Jacquemontia tamnifolia (L.) Griseb.; PANTE, Texas panicum, Panicum texanum Buckl.; RCHSC, Florida pusley, Richardia scabra L.
-60-
Table 2. Visual estimates of weed control and crop injury in transplanted watermelon on polyethylene covered seedbeds at Tifton, GA.
1998
AMACH1
DTTAE
2001
Injury
CYPES
------------ % ------------
AMACH
DIGSP
Injury
------------------------- % -------------------------
Metham fumigation
Ethalfluralin
95
95
0
76
89
90
5
Ethalfluralin/glyphosate
95
95
0
89
90
90
6
Ethalfluralin + halosulfuron
-
-
-
89
90
90
13
Ethalfluralin + halosulfuron/glyphosate
-
-
-
89
90
90
0
50
50
0
90
70
40
0
Ethalfluralin
91
94
0
80
90
90
11
Ethalfluralin/glyphosate
95
95
0
71
90
90
3
Ethalfluralin + halosulfuron
-
-
-
85
89
90
18
Ethalfluralin + halosulfuron/glyphosate
-
-
-
88
90
90
13
Nontreated
0
0
0
0
0
0
0
8
7
-
12
10
1
12
Nontreated
Nonfumigated
LSD (0.05)
1
AMACH, smooth pigweed, Amaranthus hybridus L.; CYPES, yellow nutsedge, Cyperus esculentus L.; DIGSP, southern crabgrass, Digitaria ciliaris (Retz.)
Koel.; DTTAE, crowfootgrass, Dactyloctenium aegyptium (L.) Willd.
-61-
Table 3. Effect of weed control with metham fumigation and herbicides on transplanted cantaloupe yield at Tifton, GA.
Total Yield1
1998
1999
Fruit Size
2001
1998
1999
2001
------------------- no/A -------------------
------------------ lb/fruit ----------------
Ethalfluralin
5900
2420
5900
1.0
1.1
1.9
Ethalfluralin/glyphosate
4810
4960
5450
1.1
1.2
1.9
Ethalfluralin + halosulfuron
-
2780
6810
-
1.2
1.8
Ethalfluralin + halosulfuron/glyphosate
-
3510
5990
-
1.2
1.7
3900
2300
5450
0.8
1.1
1.8
Ethalfluralin
5170
3510
5630
1.1
1.4
1.7
Ethalfluralin/glyphosate
5720
4360
6170
1.1
1.3
1.7
Ethalfluralin + halosulfuron
-
3750
5900
-
1.3
1.4
Ethalfluralin + halosulfuron/glyphosate
-
3270
5530
-
1.3
1.8
3810
2780
5530
0.8
1.0
1.7
ns
ns
ns
ns
0.2
ns
Metham fumigation
Nontreated
Nonfumigated
Nontreated
LSD (0.05)
1
Total yield from multiple harvest dates; 1998, four harvests; 1999, two harvests; 2001, three harvests.
-62-
Table 4. Effect of weed control with metham fumigation and herbicides on transplanted
watermelon yield at Tifton, GA.
Total Yield1
1998
2001
------- no/A -------
Fruit Size
1998
2001
----- lb/fruit -----
Metham fumigation
Ethalfluralin
2810
3000
5.2
5.8
Ethalfluralin/glyphosate
4170
3810
5.4
5.9
-
2720
-
6.0
-
3090
-
6.0
2450
1810
4.9
5.0
Ethalfluralin
3090
3000
5.3
6.0
Ethalfluralin/glyphosate
3180
3270
5.4
6.5
-
2180
-
5.8
-
2630
-
5.9
2720
910
5.2
4.2
ns
ns
ns
1.5
Ethalfluralin + halosulfuron
Ethalfluralin +
halosulfuron/glyphosate
Nontreated
Nonfumigated
Ethalfluralin + halosulfuron
Ethalfluralin +
halosulfuron/glyphosate
Nontreated
LSD (0.05)
1
Total yield from three harvest dates.
-63-
LIST OF FIGURES
Figure 1. Overall view of Ferguson Tillervator® modified for banded applications of metham in
transplanted cantaloupe and watermelon on polyethylene covered seedbeds. Notable features
include: gang of C-shaped tines set to till a band width of 24-in, gauge wheels to stabilize depth
of tillage, a single flood-jet spray tip spraying a band 24-in wide, metal shield protecting the
spray pattern from disruption by tilled soil, fluted coulter, a single in-row subsoil shank with
mounting bracket allowing clearance beneath PTO shaft, hiller disks to shape seedbeds after
tillage, and steel plate to seal the tilled seedbed with a light crust. A complete description of this
tiller is published in Weed Technol. 15:387-395 (2001). This tiller was designed and constructed
by Mr. Dan Evarts, USDA-ARS.
-64-
SANDEA® HAS A VARIABLE AFFECT ON SQUASH
GROWTH AND YIELD
T. M. Webster
Crop Protection and Management Research Unit
USDA-Agricultural Research Service, Tifton, GA 31793
Introduction
Yellow and purple nutsedge are among the most troublesome weeds in Georgia vegetables
(Webster and MacDonald 2001). The impending elimination of methyl bromide in 2005 will
soon leave vegetable growers without a valuable tool for pest management, with limited options
for suppression of nutsedge growth. One potential herbicide that is being evaluated in several
vegetable crops by the IR-4 (Inter-Regional Project #4) program is Sandea® (common name:
halosulfuron). This herbicide controls yellow and purple nutsedge, stops tuber production, and
reduces tuber viability. The objective of this study was to evaluate the effect of nutsedge
management treatments (including Sandea®) on squash growth and yield and nutsedge control.
Materials and Methods
Spring crop field studies were conducted in 2000 at the Blackshank Farm and in 2001 at the
Jones Farm in Tifton, GA. Black polyethylene mulch was laid in 40-foot plots, leaving a bed top
30 inches wide. Zucchini squash (‘Spineless Beauty’) was transplanted into the first half of each
plot and direct-seeded into the other half. Prior to planting, the experimental area was treated
with Inline® (combination of 1,3-dichloropropene and chloropicrin) injected through the drip
tape irrigation system1. The test was managed uniformly for fertility and pests following
University of Georgia Extension recommendations. Nutsedge management treatments included
1) Vapam® (common name: metham) applied through the drip tape irrigation at 75 gal/A of
product (320 lbs ai/A)1, 2) Sandea® applied PRE to the soil surface prior to plastic laying at 0.75
oz/A of product (0.035 lbs ai/A), 3) Sandea® applied PRE through the drip tape following the
laying of plastic at 0.75 oz/A of product, 4) nontreated control with black plastic mulch, and 5)
nontreated control without black plastic mulch (bare-ground). Treatments were arranged as a
randomized complete block design with four replications. Crop growth (measured in terms of
plant diameter) and nutsedge control were evaluated throughout the season. Squash yields were
measured two to three times a week, for a total of 5 and 11 harvests in 2000 and 2001,
respectively.
Results and Discussion
Sandea® applied PRE under the plastic or injected through the drip tape reduced squash
growth 19 to 23% relative to the Vapam® treatment, for both the transplanted and direct-seeded
squash (Table 1). Most of the visual injury observed from Sandea® was a reduction in plant size
-65-
(i.e. smaller plant diameters). In the early season, squash plants were a shade of yellow lighter
than the dark green plants in the Vapam® and nontreated plots, but often grew out of this
condition by the conclusion of the season. Early-season nutsedge control was equivalent in all
plots that had black plastic mulch, including the nontreated control, and had fewer nutsedge
shoots than the bareground-nontreated control (Table 1). By the conclusion of the
season,crowfootgrass, pink purslane, smallflower morningglory, and Florida pusley had
outcompeted the purple nutsedge in the bareground nontreated control, virtually eliminating it
from the plot. Therefore, late-season weed ratings were expressed as a percent of the number of
purple nutsedge shoots in the plastic-mulch nontreated control. The Vapam® and Sandea®
systems reduced late-season purple nutsedge shoot populations 66 to 76% relative to the plastic
mulch-nontreated control.
Highest squash yields occurred in plots treated with Vapam® and were lowest in the
bareground-nontreated control plots in both years and with both transplanted and direct-seeded
crops (Table 2). Squash yields did not respond to Sandea® in a consistent manner. In 2000, all
halosulfuron treatments were similar to Vapam® treatments, with the exception of Sandea®
applied PRE to transplanted squash. In 2001, only halosulfuron applied through the drip tape to
transplant squash had total yields similar to the highest yielding Vapam® treatment. Sandea®
yields of direct-seeded squash were at least 23% lower than the direct-seeded Vapam® treatment
in 2001.
Squash yields in the plastic mulch-nontreated controls were lower than yields in the Vapam®
treatments. The cause of these differences is unknown. Squash yields from all Sandea®
treatments were not different than their respective plastic mulch-nontreated controls. While
nutsedge populations were present in each plot, shoot densities coming through the plastic
mulch-nontreated control were relatively low (1.13 shoots/ft2). Other researchers have found
that 1.4 yellow nutsedge shoots/ft2 reduced cucumber yields 5% (Johnson and Mullinix 1999),
7.4 purple nutsedge shoots/ft2 reduced tomato yields 14% (Kadir et al. 1999), and 18.6 purple
nutsedge shoots/ft2 reduced bell pepper yields 32% (Morales-Payan et al. 1997). Therefore, the
effect of Sandea® on squash yields was at most, equivalent to the effect of competition from low
populations of purple nutsedge.
Conclusions
1. Sandea® reduced squash growth relative to Vapam®, but squash growth was similar to the
plastic mulch-nontreated control.
2. Nutsedge control was similar among Sandea®-PRE, Sandea®-drip, and Vapam®-drip
treatments.
3. Squash yields were highest in Vapam® plots and lowest in bareground-nontreated control
plots. Squash yields in Sandea® treatments were equivalent to the plastic mulch-nontreated
controls.
-66-
4. Both direct-seeded and transplant squash responded similarly to Sandea®, in terms of growth
reduction and crop yield.
Future Studies
The future of pesticide (especially herbicide) applications through drip tape irrigation systems
is promising, though there has been little research on this subject. Crop safety is one of key
issues with application of Sandea®. The current study on zucchini squash will be repeated and
concluded in 2002. Additional studies will be initiated in 2002 to compare cucumber and
eggplant response to Sandea® when applied through the drip tape irrigation following crop
planting. Future studies will also need to compare the efficacy of POST over-the-top
applications of Sandea® to Sandea® applied through the drip-tape.
Acknowledgements
The author recognizes the technical support of James E. Davis. His expertise and technical skills
were vital in conducting this study.
Citations
Johnson, W. C. and B. G. Mullinix 1999. Cyperus esculentus interference in Cucumis sativus.
Weed Sci. 47: 327-331.
Kadir, J. B., R. Charudattan, W. M. Stall and T. A. Bewick 1999. Effect of Dactylaria higginsii
on interference of Cyperus rotundus with L. esculentum. Weed Sci. 47: 682-686.
Morales-Payan, J. P., B. M. Santos, W. M. Stall and T. A. Bewick 1997. Effects of purple
nutsedge (Cyperus rotundus) on tomato (Lycopersicon esculentum) and bell pepper
(Capsicum annuum) vegetative growth and fruit yield. Weed Technol. 11: 672-676.
Webster, T. M. and G. E. MacDonald 2001. A survey of weeds in various crops in Georgia.
Weed Technol. 15: 771-790.
-67-
Table 1. The effect of weed management treatments on squash growth and nutsedge control.a
Squash growth
Purple nutsedge controlc
Treatment
Reductionb
Early season
Late
season
_________
______
_________
%
% control _________
Sandea®: drip tape
19 bc
97 a
75 a
Sandea®: PRE
23 bc
94 a
66 a
Vapam®: drip tape
0a
99 a
76 a
Nontreated control:
plastic mulch
15 b
79 a
0b
Nontreated control:
bareground
28 c
0b
N/Ad
a
Treatment means separated using Fisher’s Protected LSD0.05. Means with the same
letter were not different from one another.
b
Squash growth reduction evaluated in terms of measured plant diameter, expressed as a
percent reduction relative to the Vapam® treatment.
c
Control ratings made using counts of nutsedge shoot populations in each treatment,
expressed as a percent reduction relative to the bare-ground nontreated control (early
season) and plastic-mulch nontreated control (late season).
d
While nutsedge populations dominated the bare ground nontreated control early in the
season, by the conclusion of the season other species outcompeted purple nutsedge for
resources, virtually eliminating it from the plot.
Table 2. The effect of weed management treatment on squash yield.a
_________
_________
Treatment
2000 _________
2001 _________
Transplan Direct Seed Transplan
Direct
t
t
Seed
_________
b _________
Squash Yield (% of highest yield)
Sandea®: drip tape
75 a-c
82 a-c
84 ab
65 cd
Sandea®: PRE
60 c
78 a-c
70 bc
57 c-e
Vapam®: drip tape
89 ab
100 a
100 a
88 ab
Nontreated control: plastic mulch
66 bc
66 bc
76 bc
62 cd
Nontreated control: bare ground
25 d
1d
51 de
42 e
a
Treatment means separated using Fisher’s Protected LSD0.05. Squash yields can
be compared within a crop year. Treatment means with the same letters were not
different from one another.
b
Squash yields are expressed as a percent of the highest yielding treatment in each of the
years (42 lbs/plot and 89 lbs/plot in 2000 and 2001, respectively).
-68-
Disease Control
-69-
-70-
APPLICATION METHODS OF SOIL CHEMICAL TREATMENTS ON NEMATODES,
DISEASE AND YIELD OF CUCUMBER
A. S. Csinos, Phytopathologist, Department of Plant Pathology,
University of Georgia, Tifton Campus
K. W. Seebold, Plant Pathologist, Department of Plant Pathology,
University of Georgia, Tifton Campus
P. Timper, Crop protection and Management Research Unit,
USDA-ARS Tifton, GA
R. F. Davis, Crop protection and Management Research Unit,
USDA-ARS Tifton, GA
J. E. Laska, Agricultural Research Coordinator, Plant Pathology
University of Georgia, Tifton Campus
Introduction
Methyl bromide is a broad-spectrum biocide and is an important management tool for
controlling nematodes, soilborne diseases and other pests in a wide range of crops including
vegetable crops. The developing vegetable industry in Georgia is valued at over $635 million.
By the year 2005 all uses of methyl bromide in the United states are scheduled to be terminated.
Methyl bromide production and importation will be reduced from 1991 levels as follows: 25% in
1999, 50% in 2001, 70% in 2003, and 100% in 2005. Therefore, alternative pest management
strategies must be developed before 2005. The objective of this study was to determine the
effects of soil chemical treatments on a susceptible cultivar of cucumber on yield, nematodes,
and residual effects on cucumber, using two different soil fumigant injection rigs.
Materials and Methods Cucumber Crop
Field plots were established 8 August 2001 at the Blackshank Research Farm in Tifton
Georgia, and maintained through November 2001 on a Tifton loamy sand (fine-loamy, siliceous
thermic Plinthic Kandiudults: 85% sand, 10% silt, 5% clay; 0.5% organic matter; pH 5.4). The
plots were naturally infested with Meloidogyne incognita, Patatrichodorus, Helicotylenchus,
Pythium spp.
The experiment was a randomized block design with drip tape irrigation and chemical
treatments injected with chemical injection rigs and replicated five times. Initially, the soil was
disc-harrowed, plowed 10 to 12 inches deep with a moldboard plow and shaped into beds 30
inch wide and 8 inches high. Five hundred pounds per acre of 5-10-15 fertilizer was applied
broadcast to all plots and incorporated approximately four inches deep with a tractor-powered
rototiller. Whole-plots were 30 inches wide and 25 feet long. All treatments, except number 6,
were injected on 8 August. The final treatment, number 6, was injected 23 August. Non-treated
plots served as controls. The irrigation drip tubing, “Aquatraxx” brand, with emitters spaced 12
inches apart, each emitter delivering 0.30 gallons per hour at 10 psi of pressure, was placed in
the center of all beds as they were covered with 3 mil white polyethylene.
Thirteen days after the last treatment, 5 September, holes (2 inches diam.) were cut 18
-71-
inches apart in single rows using a mechanical-hand transplanter and a single greenhouse-grown
cucumber seedling, cultivar “General Lee”, was planted in each hole per bed.
The total number of living plants per plot was recorded on 17 September. A vigor rating
was done on 27 September, with 1 to10 scale, 10 representing live and healthy plants and 1
representing dead plants.
All cucumbers were hand-harvested, each harvest was separated into marketable and cull,
counted, and weighed. There were a total of four harvests, they were as follows; 15, 24, and 31
October, and a final on 7 November.
All plots were sprayed with Manex + Zinc (1.8 qts./A) and Kocide LF (5 pts./A) on a 7to 10- day schedule for foliage disease control and Ambush (10 oz./A), alternating with Pounce
3.2 (6 oz./A) for insect control on a 7 to 10 day interval. As per the recommendation of the
University Of Georgia Extension service, all plots received liquid fertilizer (Miracle-Gro 15-3015) injected through the irrigation tubing, at a rate of 12 pounds of nitrogen per acre, per week
through the growing season.
Twenty cores of soil, 2.5-cm-diam. × 25-cm-deep, were collected from each row of each
subplot on 5 September and 15 November. Soil cores were mixed, and nematodes were
extracted from a 150-cm3 sub-sample with centrifugal flotation (Jenkins, 1964).
Following final harvest on 14 November, ten plants were dug from each row and rated
for root galling by M. incognita on a 1 to 5 scale: 1 = 0%, 2 = 1% to 25%, 3 = 26% to 50%, 4 =
51% to 75%, 5 = 76% to 100% roots galled (Barker et al., 1986). All data collected was analyzed
with an analysis of variance (P = 0.05) and means were separated using Duncan’s Multiple range
test.
Two different injection rigs were used in this study. The first injector, we refer to as the
chisel injector, was specially built for these applications. It has chisel shanks for injecting
chemicals 8-10 inches deep and is equipped with a combination rototiller for applying chemicals
such as metam sodium in combination with injectable products. The second injection rig,
referred to as the Yetter rig, it is an injection unit designed for deep chemical injection 10-14
inches deep. It also is equipped with large 36 in. round disks which slice through field debris and
trash such as old plastic and drip tape left behind after previous film mulch plantings.
Results and Discussion
Methyl bromide and all treatment including Telone II or Telone C-35 suppressed rootknot nematode populations (Table 1) and root galling (Table 2) better than the control (treatment
8) or treatments receiving only metam sodium (treatment 5). Vigor ratings (Table 2), cumulative
number of marketable cucumbers (Table 3), and cumulative weight of marketable cucumbers
(Table 4) were lower with treatments that had higher root-knot nematode populations and gall
ratings. The Yetter fumigant injection rig and the chisel fumigant injection rig were equally
effective in applying fumigant nematicides.
All Telone C-35 application alone or with metam sodium performed as well as the
methyl bromide standard. Telone C-35 applied at 35 gallons per acre, performed batter than the
methyl bromide standard to increase yield of cucumber.
Populations of Fusarium spp. three weeks after fumigation were significantly reduced in
comparison to the untreated control by all fumigation treatments except Vapam injected alone at
-72-
37.5 GPA. Three months after fumigation, populations of Fusarium spp. in plots treated with
Telone II in combination with chloropicrin, Telone C-35 (shallow and deep injection), and
Telone C-35 plus Vapam (applied 3 weeks prior to transplanting) were significantly lower than
the untreated check. Fusarium populations were higher where Telone C-35 was injected at a
depth of 8 inches as compared to 12 inches. All treatments significantly reduced populations of
Pythium spp. at three weeks after fumigation; however, Vapam injected alone was the least
effective material. Telone C-35, injected at 8 or 12 inches, and Telone C-35 plus Vapam
(applied 3 weeks prior to transplanting) significantly reduced total populations of Pythium spp.
three months after fumigation. No differences in Rhizoctonia populations were seen between
any fumigation treatment and the untreated check at either three weeks or three months after
fumigation.
Survival of Fusarium solani, was reduced only by fumigation with Telone C-35, injected
at either 8 or 12 inches. Telone C-35, injected at 8 or 12 inches, and Telone C-35 plus Vapam
(applied 3 weeks prior to transplanting) significantly reduced the survival of yellow nutsedge
nutlets as compared to the untreated check. Treatment effects on Phytophthora capsici and
Rhizoctonia solani could not be determined due to microbial contamination of the inoculum
recovered from test plots.
Acknowledgments
The authors wish to thank Unessee Hargett, Don Hickey, Lewis Mullis, Tonya Jo
Cravens, Brandi Hogan, Bryan Horten, Eduvina McDonald, Donnie Starling, Matt McKinnon,
Thomas H. Hilton, David L. Clements, Billy Wilson, and A. Kyle Monfort for technical support,
Cindy H. LaHue for typing. Also, Dow Agrosciences for financial support.
-73-
Table 1. Effects of soil chemical treatments on nematode population densities in cucumbers 2001a
Treatment
Rate
5th September
Method of Application
M.i.b
1. Telone II
18 gal/A
Yetter Rig (deep application at 12")
100-125lbs/A
Chisel Rig (shallow application at 8") (3 weeks)
2. Telone C-35
35 gal/A
3. Telone C-35
P.m.
Nematodes per 150-cm3 soil
15th November
C.o.
M.i.
P.m.
C.o.
276
0
8
16 c
60 a
0b
Chisel Rig (shallow application at 8") (3 weeks)
200
0
0
0c
0b
0b
35 gal/A
Yetter Rig (deep application at 12")
(3 weeks)
232
0
4
0c
0b
0b
4. Telone C-35
35 gal/A
Chisel Rig (shallow application at 8")
984
0
0
2c
20 b
0b
+ Metam Sodium
37.5 gal/A
Rototill (3 weeks)
5. Metam Sodium
37.5 gal/A
Chisel Rig Rototill (shallow application at 8") (3
weeks)
216
0
4
174 b
0b
0b
6. Telone C-35
10 gal/A
Chisel Rig (shallow application at 8")
48
0
0
2c
0b
0b
+ Metam Sodium
37.5 gal/A
Rototill (1 week)
7. Methyl Bromide
200 lbs ai/A
Chisel Rig (shallow application at 8")
(3 weeks)
168
0
0
6c
0b
0b
8. Control
N/A
*****************
120
0
0
646 a
0b
100 a
+ Chloropicrin
a
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
No letters indicate non-significant.
b
M.i. = Meloidogyne incognita, P.m. = Paratrichodorus, C.o. = Criconemoides.
-74-
Table 2. Effects of soil chemical treatments on root-gall indices, Vigor and stand counts of cucumbers - 2001a
Treatment
1. Telone II
Rate
Method of Application
Vigor Rating
September 27
Stand
count d
September 17
1.6 b
9.2 a
17
Root-gall index
14 November
b
c
18 gal/A
Yetter Rig (deep application at 12")
100125lbs/A
Chisel Rig (shallow application at 8") (3 weeks)
2. Telone C-35
35 gal/A
Chisel Rig (shallow application at 8") (3 weeks)
1.2 b
9.2 a
17
3. Telone C-35
35 gal/A
Yetter Rig (deep application at 12")
(3 weeks)
1.3 b
8.4 a
17
4. Telone C-35
35 gal/A
Chisel Rig (shallow application at 8")
1.3 b
8.8 a
16
+ Metam Sodium
37.5 gal/A
Rototill (3 weeks)
5. Metam Sodium
37.5 gal/A
Chisel Rig Rototill (shallow application at 8") (3
weeks)
4.8 a
6.0 b
17
6. Telone C-35
10 gal/A
Chisel Rig (shallow application at 8")
+ Metam Sodium
37.5 gal/A
Rototill (1 week)
1.5 b
8.6 a
17
7. Methyl Bromide
200 lbs ai/A
Chisel Rig (shallow application at 8") (3 weeks)
1.3 b
8.6 a
17
8. Control
N/A
*****************
5.0 a
5.2 b
17
+ Chloropicrin
a
Data are means of five replications. Means in the same column followed by the same letter are not different (P = 0.05) according to Duncan’s
multiple range test. No letters indicate non-significant difference.
b
Root Gall Index 1-5 scale: 1 = no galls, 2 = 1% to 25%, 3 = 26% to 50%, 4 = 51% to 75%, and 5 = 76% to 100% of roots galled.
c
Vigor was done a 1-10 scale with 10= live and healthy plants and 1=dead plants.
d
Maximum number of plants per plot = 17.
Table 3. Effect of soil chemical treatments on marketable yield of cucumbers -2001a
-75-
Number
Treatment
1. Telone II
Method of Application
15
18 gal/A
Yetter Rig (deep application at 12")
100125lbs/A
Chisel Rig (shallow application at 8") (3
weeks)
2. Telone C-35
35 gal/A
3. Telone C-35
of
marketable cucumbers per plot (35 lin. ft. row)
October
November
Total
24
31
7
Mean
31.6 a
78.8 a
59.8 ab
18.8 a
189.0 ab
Chisel Rig (shallow application at 8") (3
weeks)
31.6 a
75.6 a
68.4 a
20.0 a
195.6 a
35 gal/A
Yetter Rig (deep application at 12")
(3 weeks)
31.2 a
94.6 a
47.0 bc
23.8 a
196.6 a
4. Telone C-35
35 gal/A
Chisel Rig (shallow application at 8")
30.4 a
84.8 a
61.2 ab
17.6 ab
194.0 a
+ Metam Sodium
37.5 gal/A
Rototill (3 weeks)
5. Metam Sodium
37.5 gal/A
Chisel Rig Rototill (shallow application
at 8") (3 weeks)
8.2 b
48.6 a
21.6 e
11.0 bc
89.4 c
6. Telone C-35
10 gal/A
Chisel Rig (shallow application at 8")
30.6 a
79.8 a
43.2 bcd
22.4 a
176.0 ab
+ Metam Sodium
37.5 gal/A
Rototill (1 week)
7. Methyl Bromide
200 lbs ai/A
Chisel Rig (shallow application at 8")
(3 weeks)
27.0 a
84.4 a
35.4 cde
23.2 a
170.0 b
8. Control
N/A
*****************
4.0 b
38.6 b
25.6 de
7.6 c
75.8 c
+ Chloropicrin
a
Rate
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
Table 4. Effect of soil chemical treatments on marketable yield of cucumbers - 2001a
-76-
Treatment
1. Telone II
Weight (lbs.) of marketable cucumbers per plot (35 lin. ft. row)
October
November
Total
15
24
31
7
Mean
Method of Application
18 gal/A
Yetter Rig (deep application at 12")
100-125lbs/A
Chisel Rig (shallow application at 8")
(3 weeks)
2. Telone C-35
35 gal/A
3. Telone C-35
15.2 a
59.7 a
32.1 ab
9.8 a
116.9 ab
Chisel Rig (shallow application at 8")
(3 weeks)
14.1 a
54.8 a
36.7 a
10.6 a
116.3 ab
35 gal/A
Yetter Rig (deep application at 12")
(3 weeks)
12.5 a
65.1 a
24.8 bc
12.5 a
115.0 ab
4. Telone C-35
35 gal/A
Chisel Rig (shallow application at 8")
15.4 a
62.4 a
32.2 ab
9.0 a
119.2 a
+ Metam Sodium
37.5 gal/A
Rototill (3 weeks)
5. Metam Sodium
37.5 gal/A
Chisel Rig Rototill (shallow application
at 8") (3 weeks)
3.1 b
34.1 b
11.3 d
4.2 b
52.8 c
6. Telone C-35
10 gal/A
Chisel Rig (shallow application at 8")
12.9 a
53.8 a
25.8 bc
11.1 a
103.7 b
+ Metam Sodium
37.5 gal/A
Rototill (1 week)
7. Methyl Bromide
200 lbs ai/A
Chisel Rig (shallow application at 8")
(3 weeks)
12.9 a
62.7 a
20.5 cd
10.7 a
106.9 ab
8. Control
N/A
*****************
1.5 b
27.3 b
13.4 d
3.4 b
45.8 c
+ Chloropicrin
a
Rate
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
-77-
Table 5. Effect of soil chemical treatment on cull yield of cucumbers - 2001a
Number
Treatment
1. Telone II
Rate
Method of Application
15
18 gal/A
Yetter Rig (deep application at 12")
100-125lbs/A
Chisel Rig (shallow application at 8")
(3 weeks)
2. Telone C-35
35 gal/A
3. Telone C-35
of
cull cucumbers per plot (35 lin. ft. row)
October
November
Total
24
31
7
Mean
0.0
2.2 a
1.4 ab
3.2 ab
6.8 bc
Chisel Rig (shallow application at 8")
(3 weeks)
0.4
1.2 ab
2.6 ab
5.2 a
9.4 ab
35 gal/A
Yetter Rig (deep application at 12")
(3 weeks)
0.0
1.6 ab
3.6 a
5.8 a
11.0 a
4. Telone C-35
35 gal/A
Chisel Rig (shallow application at 8")
0.4
2.6 a
2.2 ab
1.8 b
7.0 bc
+ Metam Sodium
37.5 gal/A
Rototill (3 weeks)
5. Metam Sodium
37.5 gal/A
Chisel Rig Rototill (shallow application
at 8") (3 weeks)
0.0
0.4 b
1.0 ab
5.6 a
7.0 bc
6. Telone C-35
10 gal/A
Chisel Rig (shallow application at 8")
0.2
1.4 ab
2.6 ab
3.8 ab
8.0 abc
+ Metam Sodium
37.5 gal/A
Rototill (1 week)
7. Methyl Bromide
200 lbs ai/A
Chisel Rig (shallow application at 8")
(3 weeks)
0.8
2.6 a
2.0 ab
3.2 ab
8.6 ab
8. Control
N/A
*****************
0.2
0.6 b
0.4 b
3.4 ab
4.6 c
+ Chloropicrin
a
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
No letters indicate non- significant difference.
Table 6. Effect of soil chemical treatment on cull yield of cucumbers - 2001a
-78-
Treatment
1. Telone II
Rate
Method of Application
18 gal/A
Yetter Rig (deep application at 12")
100-125lbs/A
Chisel Rig (shallow application at 8")
(3 weeks)
2. Telone C-35
35 gal/A
3. Telone C-35
Weight (lbs.) of cull cucumbers per plot (35 lin. ft. row)
October
November
Total
15
24
31
7
Mean
0.0
1.6 a
0.4 ab
1.0 ab
3.1 abc
Chisel Rig (shallow application at 8")
(3 weeks)
0.1
0.1 ab
0.7 ab
1.5 ab
3.2 ab
35 gal/A
Yetter Rig (deep application at 12")
(3 weeks)
0.0
1.2 ab
0.9 a
2.0 a
4.1 a
4. Telone C-35
35 gal/A
Chisel Rig (shallow application at 8")
0.1
1.6 a
0.6 ab
0.6 b
2.9 abc
+ Metam Sodium
37.5 gal/A
Rototill (3 weeks)
5. Metam Sodium
37.5 gal/A
Chisel Rig Rototill (shallow
application at 8") (3 weeks)
0.0
0.3 b
0.3 ab
1.7 a
2.4 bc
6. Telone C-35
10 gal/A
Chisel Rig (shallow application at 8")
0.1
1.1 ab
0.6 ab
1.5 ab
3.3 ab
+ Metam Sodium
37.5 gal/A
Rototill (1 week)
7. Methyl Bromide
200 lbs ai/A
Chisel Rig (shallow application at 8")
(3 weeks)
0.4
1.7 a
0.5 ab
1.0 ab
3.6 ab
8. Control
N/A
*****************
0.1
0.4 ab
0.1 b
1.0 ab
1.6 c
+ Chloropicrin
a
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
No letters indicate non-significant difference.
Table 7. Population densities of Pythium spp., Rhizoctonia spp., and Fusarium spp., and viability of Phytophthora capsici, Fusarium solani,
-79-
Rhizoctonia solani, and yellow nutsedge in soil after treatment with alternatives to methyl bromide in August, 2001 (cucumber test).
Fungal populations a
Treatment
1. Telone II
Rate
Method of Application
Fusarium
YN
18 gal/A
Yetter Rig (deep application at 12")
100-125lbs/A
Chisel Rig (shallow application at 8") (3
weeks)
2. Telone C-35
35 gal/A
3. Telone C-35
Pathogen and weed viability b
Pythium Rhizoctonia PC
FS
RS
1344 c
0d
0.08
0.0
6.6 abc
0.0 b
5.4 abc
Chisel Rig (shallow application at 8") (3
weeks)
1168 c
0.8 cd
0.0
0.0
6.4 bc
0.0 b
3.8 cd
35 gal/A
Yetter Rig (deep application at 12")
(3 weeks)
688 c
4.8 cd
0.03
1.6
5.0 c
0.0 b
1.0 de
4. Telone C-35
35 gal/A
Chisel Rig (shallow application at 8")
1072 c
0d
0.0
1.8
7.2 abc
0.0 b
0.0 e
+ Metam Sodium
37.5 gal/A
Rototill (3 weeks)
5. Metam Sodium
37.5 gal/A
Chisel Rig Rototill (shallow application at
8") (3 weeks)
8752 a
25.6 b
0.0
0.0
10.0 a
0.0 b
7.8 ab
6. Telone C-35
10 gal/A
Chisel Rig (shallow application at 8")
2928 bc
8.8 c
0.0
0.6
7.6 abc
5.6 a
8.8 ab
+ Metam Sodium
37.5 gal/A
Rototill (1 week)
7. Methyl
Bromide
200 lbs ai/A
Chisel Rig (shallow application at 8") (3
weeks)
1312 c
0d
0.0
2.0
9.6 ab
0.0 b
4.8 bc
8. Control
N/A
*****************
+ Chloropicrin
5184 b
39.2 a
0.03
0.0
10.0 a
0.0 b
8.0 ab
Total populations of Fusarium spp., Pythium spp., and Rhizoctonia spp. expressed as the number of colony forming units per gram of soil.
b
Number of pathogen-infested grains or yellow nutsedge nutlets (out of 10 per mesh bag) that were viable after removal from treated soil prior to transplanting
of cucumbers on 9 September. PC=Phytophthora capsici, FS=Fusarium solani, RS=Rhizoctonia solani (AG-4), and YN=yellow nutsedge.
Means followed by the same letter do not differ significantly as determined by Fisher’s protected least significant difference test (P#0.05).
No letters indicate non-significant difference.
a
-80-
Table 8. Population densities of Pythium spp., Rhizoctonia spp., and Fusarium spp., and viability of Phytophthora capsici, Fusarium solani, Rhizoctonia solani,
and yellow nutsedge in soil on November 20th after treatment with alternatives to methyl bromide in August, 2001 (cucumber test).
Treatment
1. Telone II
Rate
Fungal populations a
Method of Application
18 gal/A
Yetter Rig (deep application at 12")
100125lbs/A
Chisel Rig (shallow application at 8") (3
weeks)
2. Telone C-35
35 gal/A
3. Telone C-35
Fusarium
Pythium
Rhizoctonia
4288 cd
14.4 b
0.0 b
Chisel Rig (shallow application at 8") (3
weeks)
9408 ab
3.2 c
0.0 b
35 gal/A
Yetter Rig (deep application at 12")
(3 weeks)
3328 cd
0.8 c
0.0 b
4. Telone C-35
35 gal/A
Chisel Rig (shallow application at 8")
3712 cd
0.0 c
0.0 b
+ Metam Sodium
37.5 gal/A
Rototill (3 weeks)
5. Metam Sodium
37.5 gal/A
Chisel Rig Rototill (shallow application
at 8") (3 weeks)
6944 bc
33.6 a
0.05 b
6. Telone C-35
10 gal/A
Chisel Rig (shallow application at 8")
1104 d
13.6 b
0.0 b
+ Metam Sodium
37.5 gal/A
Rototill (1 week)
7.Methyl Bromide
200 lbs
ai/A
Chisel Rig (shallow application at 8") (3
weeks)
12288 a
6.4 bc
0.0 b
8. Control
N/A
*****************
11024 ab
14.4 b
0.13 a
+ Chloropicrin
a
Total populations of Fusarium spp., Pythium spp., and Rhizoctonia spp. expressed as the number of
colony forming units per gram of soil.
Means followed by the same letter do not differ significantly as determined by Fisher’s protected
least significant difference test (P#0.05).
-81-
SOIL CHEMICAL TREATMENT ALTERNATIVES TO
METHYL BROMIDE IN CUCUMBER
A. S. Csinos, Phytopathologist, Department of Plant Pathology,
University of Georgia, Tifton Campus
K. W. Seebold, Plant Pathologist, Department of Plant Pathology,
University of Georgia, Tifton Campus
P. Timper, Crop protection and Management Research Unit,
USDA-ARS Tifton, GA
R. F. Davis, Crop protection and Management Research Unit,
USDA-ARS Tifton, GA
J. E. Laska, Agricultural Research Coordinator, Plant Pathology
University of Georgia, Tifton Campus
Introduction
Methyl bromide is a broad-spectrum biocide and is an important management tool for
controlling nematodes, soilborne diseases and other pests in a wide range of crops including
vegetable crops. The developing vegetable industry in Georgia is valued at over $635 million.
By the year 2005 all uses of methyl bromide in the United states are scheduled to be terminated.
Methyl bromide production and importation will be reduced from 1991 levels as follows: 25% in
1999, 50% in 2001, 70% in 2003, and 100% in 2005. Therefore, alternative pest management
strategies must be developed before year 2005. The objective of this second Methyl Bromide
Alternative study was to determine the effects of soil chemical treatments on a susceptible
cultivar of cucumber on yield, nematodes, and residual effects on cucumber.
Materials and Methods Cucumber Crop
Field plots were established 8 August 2001 at the Blackshank Research Farm in Tifton
Georgia, and maintained through November 2001 on a Tifton loamy sand (fine-loamy, siliceous
thermic Plinthic Kandiudults: 85% sand, 10% silt, 5% clay; 0.5% organic matter; pH 5.4). The
plots were naturally infested with Meloidogyne incognita, Patatrichodorus, Helicotylenchus, and
Pythium spp.
The experiment was a randomized block design with drip tape irrigation and chemical
treatments injected with chemical injection rigs and replicated five times. Initially, the soil was
disc-harrowed, plowed 10 to 12 inches deep with a moldboard plow and shaped into beds 30
inches wide and 8 inches high. Five hundred pounds per acre of 5-10-15 fertilizer was applied
by broadcast to all plots and incorporated approximately four inches deep with a tractor-powered
rototiller. Whole-plots were 30 inches wide and 25 feet long.
Two treatments, number 4 and 7, were chisel injected on 9 August. All other treatments
were injected through the drip tape over a 6 hour delivery period. Treatments 2, 3, and 5a were
injected on 14 August. Treatments 1 and 6 were injected on 15 August. The final treatment 5b
was injected on 17 August. Non-treated plots served as controls.
-82-
The irrigation drip tubing, Toro “Aquatraxx” brand, with emitters spaced 12 inches
apart, each emitter delivering 0.30 gallons per hour at 10 psi of pressure, was placed in the
center of all beds as they were covered with 3 mil white polyethylene.
Nineteen days after the last treatment, 5 September, holes (2 inches diam.) were cut 18
inches apart in single rows using a mechanical-hand transplanter and a single greenhouse-grown
cucumber seedling, cultivar “General Lee”, was planted in each hole per bed. The total number
of living plants per plot was recorded on 17 September. A vigor rating was done on 27
September, with 1 to10 scale, 10 representing live and healthy plants and 1 representing dead
plants.
All cucumbers were hand-harvested, each harvest was separated into marketable and cull,
counted, and weighed. There were a total of four harvests, they were as follows; 15, 24, and 31
October, and a final on 7 November.
All plots were sprayed with Manex + Zinc (1.8 qts./A) and Kocide LF (5 pts./A) on a 7to 10- day schedule for foliage disease control and Ambush (10 oz./A), alternating with Pounce
3.2 (6 oz./A) for insect control on a 7 to 10 day interval. As per the recommendation of the
University Of Georgia Extension service, all plots received liquid fertilizer (Miracle-Gro 15-3015) injected through the irrigation tubing, at a rate of 12 pounds of nitrogen per acre, per week
through the growing season.
Twenty cores of soil, 2.5-cm-diam. × 25-cm-deep, were collected from each row of each
subplot on 5 September and 15 November. Soil cores were mixed, and nematodes were
extracted from a 150-cm3 sub-sample with centrifugal flotation (Jenkins, 1964).
Following final harvest on 14 November, ten plants were dug from each row and rated
for root galling by M. incognita on a 1 to 5 scale: 1 = 0%, 2 = 1% to 25%, 3 = 26% to 50%, 4 =
51% to 75%, 5 = 76% to 100% roots galled (Barker et al., 1986). All data collected was analyzed
with an analysis of variance (P = 0.05) and means were separated using Duncan’s Multiple range
test.
The injector used in this study, we refer to as the chisel injector, was specially built for
these applications. It has chisel shanks for injecting chemicals 8-10 inches deep and is equipped
with a combination rototiller for applying chemicals such as metam sodium in combination with
injectable products.
Results and Discussion
All nematicide treatments were equally effective in reducing root-knot nematode
populations (Table 1) and root galling (Table 2) compared to the non-treated control (treatment
8). All nematicide treatments improved vigor ratings (Table 2) compared to the non-treated
control. All nematicide treatments significantly increased cumulative weight of marketable
cucumbers (Table 3) and cumulative number of marketable cucumbers (Table 4). In-Line 35 EC
injected through drip tape was an effective means of nematode suppression.
All of the chemical treatments whether applied through tractor powered equipment or
through drip tape performed as well as methyl bromide for maintaining Vigor increasing yield of
cucumber.
All fumigation treatments significantly reduced the soil populations of Fusarium spp. and
Pythium spp. as compared to the untreated check in samples taken prior to transplanting. Inline
-83-
35 EC, when injected at 35 GPA, reduced populations of Fusarium spp. by greater than 90% of
those seen in plots treated with Telone II EC (18 GPA) or Inline 35 EC (20 GPA), and did not
differ from Telone C-35 chisel-injected at 35 GPA or methyl bromide chisel-injected at 200 lb
a.i./A. The combination of Inline 35 EC (20.5 GPA) and Vapam (37.5 GPA) injected
simultaneously or 3 days apart also reduced Fusarium populations as well as methyl bromide,
and performed better than Telone II at 18 GPA or Inline 35 EC at 20 GPA. Rhizoctonia solani
was not detected in soil samples taken prior to transplanting. When soil samples were taken in
late November, populations of Fusarium spp. were lowest where Inline 35 EC (20.5 GPA),
Telone C-35 (chisel injected at 35 GPA), or Inline 35 EC (20.5 GPA) injected simultaneously
with Vapam (37.5 GPA) had been applied. A similar pattern was observed with populations of
Pythium spp.
All drip-injected materials reduced the survival of inoculum of Fusarium solani and
Rhizoctonia solani, placed in the soil at the time of injection, as compared to the untreated check
or methyl bromide. A similar pattern was seen with the survival of yellow nutsedge nutlets from
plots treated with drip-applied materials. Inline 35 EC (35 GPA) or Inline 35 EC (20.5 GPA)
plus Vapam (37.5 GPA), injected simultaneously or 3 days apart, killed all nutlets that were
placed in plots at the time of injection.
Acknowledgments
The authors wish to thank Unessee Hargett, Don Hickey, Lewis Mullis, Tonya Jo
Cravens, Brandi Hogan, Bryan Horten, Eduvina McDonald, Donnie Starling, Matt McKinnon,
Thomas H. Hilton, David L. Clements, Billy Wilson, and A. Kyle Monfort for technical support.
Also, Dow Agrosciences for financial support.
-84-
Table 1. Effects of soil chemical treatments on nematode population densities in cucumbers 2001a
Treatment
Rate
Method of Application c
M.i.b
Nematodes per 150-cm3 soil
5 September
15 November
P.m.
C.o.
M.i.
P.m.
C.o.
1. Telone II EC
18 gal/A
Inject through drip tape
156
0
0
4b
0
0
2. In-Line 35 EC
20.5 gal/A
Inject through drip tape
64
0
0
10 b
0
0
3. In-Line 35 EC
35 gal/A
Inject through drip tape
44
0
0
0b
0
0
4. Telone C-35
35 gal/A
Chisel Injection
36
0
0
0b
0
0
5. In-Line 35 EC
20.5 gal/A
Inject through drip tape
496
0
0
0b
0
0
37.5 gal/A
Inject through drip tape
(3 days later)
20.5 gal/A
Inject through drip tape
simultaneously (mix
together in tank)
28
0
0
36 b
0
0
Chisel Injection
48
0
0
2b
0
0
+ Metam Sodium
6. In-Line 35 EC
+ Metam Sodium
7. Methyl Bromide
37.5 gal/A
200lbs
ai/A
8. Non-Treated Control
N/A
------------288
0
0
582 a
0
0
Data are means of five replications.
b
M.i. = Meloidogyne incognita, P.m. = Paratrichodorus, C.o. = Criconemoides
c
Treatments number 4 and 7, were chisel injected on 9 August. All other treatments were injected through the drip tape over a 6 hour
delivery period. Treatments 2, 3, and 5a were injected on 14 August. Treatments 1, and 6 were injected on 15 August. The final treatment,
5b was injected on 17 August. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
No letters indicate non-significant.
a
-85-
Table 2. Effects of soil chemical treatments on root-gall indices, Vigor and stand counts of cucumbers - 2001a
Vigor Rating
27 September
Stand
count d
17 September
1.7 b
9.6 a
17
Inject through drip tape
1.6 b
9.4 a
17
35 gal/A
Inject through drip tape
1.5 b
8.6 a
17
4. Telone C-35
35 gal/A
Chisel Injection
1.7 b
9.6 a
16
5. In-Line 35 EC
20.5 gal/A
Inject through drip tape
1.4 b
9.4 a
16
37.5 gal/A
Inject through drip tape
(3 days later)
20.5 gal/A
1.9 b
9.0 a
16
37.5 gal/A
Inject through drip tape
simultaneously (mix
together in tank)
200 lbs ai/A
Chisel Injection
1.7 b
9.0 a
17
Treatment
Rate
Method of Application
1. Telone II EC
18 gal/A
Inject through drip tape
2. In-Line 35 EC
20.5 gal/A
3. In-Line 35 EC
+ Metam Sodium
6. In-Line 35 EC
+ Metam Sodium
7. Methyl Bromide
Root-gall index
14 November
b
c
8. Non-Treated Control
N/A
-----------4.8 a
7.0 b
16
Data are means of five replications.
b
Root Gall Index 1-5 scale: 1 = no galls, 2 = 1% to 25%, 3 = 26% to 50%, 4 = 51% to 75%, and 5 = 76% to 100% of roots galled.
c
Vigor was done a 1-10 scale with 10= live and healthy plants and 1=dead plants.
d
Maximum number of plants per plot = 17.
Means in the same column followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test. No letters indicate
non-significant difference
a
-86-
Table 3. Effect of soil chemical treatments on marketable yield of cucumbers -2001a
Treatment
Weight of marketable cucumbers per plot (35 lin. ft. row)
November
October
15
24
31
7
Total
Mean
Rate
Method of Application
1. Telone II EC
18 gal/A
Inject through drip tape
12.3
62.5 a
14.2 a
9.1 ab
98.1 a
2. In-Line 35 EC
20.5 gal/A
Inject through drip tape
13.9
56.2 a
15.2 a
6.6 ab
91.8 a
3. In-Line 35 EC
35 gal/A
Inject through drip tape
10.7
67.1 a
12.5 a
4. Telone C-35
35 gal/A
Chisel Injection
14.9
64.7 a
13.8 a
10.3 a
103.8 a
5. In-Line 35 EC
20.5 gal/A
Inject through drip tape
11.4
56.9 a
15.8 a
11.2 a
95.3 a
37.5 gal/A
Inject through drip tape
(3 days later)
20.5 gal/A
12.8
55.6 a
10.6 a
9.4 a
88.5 a
37.5 gal/A
Inject through drip tape
simultaneously (mix
together in tank)
200 lbs ai/A
Chisel Injection
15.3
61.6 a
12.4 a
9.3 ab
98.6 a
+ Metam Sodium
6. In-Line 35 EC
+ Metam Sodium
7. Methyl Bromide
7.5 ab
97.9 a
8. Non-Treated Control
N/A
-----------2.6
41.9 b
4.4 b
4.8 b
53.8 b
Data are means of five replications.
Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test. No letters indicate non-significant
difference.
a
-87-
Table 4. Effect of soil chemical treatments on marketable yield of cucumbers - 2001a
Treatment
Number of marketable cucumbers per plot (35 lin. ft. row)
October
November
15
24
31
7
Total
Mean
Rate
Method of Application
1. Telone II EC
18 gal/A
Inject through drip tape
29.2 a
88.0 a
34.4 a
18.4 ab
170.0 a
2. In-Line 35 EC
20.5 gal/A
Inject through drip tape
31.6 a
81.8 a
35.2 a
13.6 ab
162.2 a
3. In-Line 35 EC
35 gal/A
Inject through drip tape
24.2 a
94.2 a
26.0 a
13.4 ab
157.8 a
4. Telone C-35
35 gal/A
Chisel Injection
31.2 a
90.8 a
29.0 a
20.0 a
171.0 a
5. In-Line 35 EC
20.5 gal/A
Inject through drip tape
24.6 a
81.6 a
35.0 a
21.0 a
162.2 a
37.5 gal/A
Inject through drip tape
(3 days later)
20.5 gal/A
30.8 a
83.0 a
25.0 a
17.2 ab
156.0 a
37.5 gal/A
Inject through drip tape
simultaneously (mix
together in tank)
200 lbs ai/A
Chisel Injection
33.4 a
83.0 a
25.4 a
18.6 ab
160.4 a
11.4 b
82.6 b
+ Metam Sodium
6. In-Line 35 EC
+ Metam Sodium
7. Methyl Bromide
8. Non-Treated Control
N/A
-----------6.8 b
55.2 b
9.2 b
Data are means of five replications.
Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
a
-88-
Table 5. Effect of soil chemical treatment on cull yield of cucumbers - 2001a
Rate
Method of Application
Weight of cull cucumbers per plot (35 lin. ft. row)
October
November
15
24
31
7
1. Telone II EC
18 gal/A
Inject through drip tape
0.1
1.2 b
0.2
1.3
2.7 ab
2. In-Line 35 EC
20.5 gal/A
Inject through drip tape
0.0
1.1 b
0.9
0.8
2.8 ab
3. In-Line 35 EC
35 gal/A
Inject through drip tape
0.1
1.3 b
0.8
1.5
3.7 a
4. Telone C-35
35 gal/A
Chisel Injection
0.1
2.5 a
0.3
1.1
4.1 a
5. In-Line 35 EC
20.5 gal/A
Inject through drip tape
0.0
1.2 b
0.9
1.0
3.0 ab
37.5 gal/A
Inject through drip tape
(3 days later)
20.5 gal/A
0.0
1.5 ab
0.9
1.0
3.0 ab
37.5 gal/A
Inject through drip tape
simultaneously (mix
together in tank)
200 lbs ai/A
Chisel Injection
0.1
0.9 b
1.2
0.9
2.9 ab
Treatment
+ Metam Sodium
6. In-Line 35 EC
+ Metam Sodium
7. Methyl Bromide
Total
Mean
8. Non-Treated Control
N/A
-----------0.0
0.4 b
0.4
0.8
1.6 b
Data are means of five replications.
Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test. No letters indicate non- significant
difference.
a
-89-
Table 6. Effect of soil chemical treatment on cull yield of cucumbers - 2001a
Treatment
Number of cull cucumbers per plot (35 lin. ft. row)
October
November
15
24
31
7
Total
Mean
Rate
Method of Application
1. Telone II EC
18 gal/A
Inject through drip tape
0.2
2.0 bcd
0.6 b
4.6
7.4 ab
2. In-Line 35 EC
20.5 gal/A
Inject through drip tape
0.0
2.0 bcd
3.8 ab
2.6
8.4 ab
3. In-Line 35 EC
35 gal/A
Inject through drip tape
0.2
2.4 abc
2.6 ab
4.0
9.2 a
4. Telone C-35
35 gal/A
Chisel Injection
0.4
4.0 a
1.6 ab
3.4
9.4 a
5. In-Line 35 EC
20.5 gal/A
Inject through drip tape
0.0
0.8 cd
3.2 ab
2.8
6.8 ab
37.5 gal/A
Inject through drip tape
(3 days later)
20.5 gal/A
0.0
2.8 ab
3.4 ab
3.0
8.6 ab
37.5 gal/A
Inject through drip tape
simultaneously (mix
together in tank)
200 lbs ai/A
Chisel Injection
0.2
1.6 bcd
4.8 a
3.2
9.8 a
2.6
4.8 b
+ Metam Sodium
6. In-Line 35 EC
+ Metam Sodium
7. Methyl Bromide
8. Non-Treated Control
N/A
-----------0.0
0.6 b
1.6 ab
Data are means of five replications.
Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
No letters indicate non-significant difference.
a
-90-
Table 7. Population densities of Pythium spp., Rhizoctonia spp., and Fusarium spp., and viability of Phytophthora capsici, Fusarium solani,
Rhizoctonia solani, and yellow nutsedge in soil after treatment with alternatives to methyl bromide in August, 2001.
Treatment
Fungal populations a
Fusarium Pythium Rhizoctonia
PC
Pathogen and weed viability b
FS
RS
YN
Rate
Method of Application
1. Telone II EC
18 gal/A
Inject through drip tape
1920 b
0.8 b
0
0
5.8 b
0.0 b
1.8 bc
2. In-Line 35 EC
20.5 gal/A
Inject through drip tape
2032 b
0.8 b
0
0
4.4 b
0.0 b
2.6 b
3. In-Line 35 EC
35 gal/A
Inject through drip tape
112 c
0.0 b
0
0
3.2 b
0.4 ab
0.0 c
4. Telone C-35
35 gal/A
Chisel Injection
144 c
0.0 b
0
0
9.6 a
0.2 b
6.8 a
5. In-Line 35 EC
20.5 gal/A
Inject through drip tape
64 c
0.0 b
0
1.8
5.2 b
0.0 b
0.0 c
37.5 gal/A
Inject through drip tape
(3 days later)
20.5 gal/A
336 c
3.2 b
0
0
5.6 b
0.0 b
0.0 c
37.5 gal/A
Inject through drip tape
simultaneously (mix
together in tank)
200 lbs ai/A
Chisel Injection
672 c
1.6 b
0
0
10.0 a
0.8 ab
8.6 a
+ Metam Sodium
6. In-Line 35 EC
+ Metam Sodium
7. Methyl Bromide
8. Non-Treated Control
N/A
-----------5504 a 34.4 a
0
0
10.0 a
1.2 a
9.2 a
Total populations of Fusarium spp., Pythium spp., and Rhizoctonia spp. expressed as the number of colony forming units per gram of soil.
b
Number of pathogen-infested grains or yellow nutsedge nutlets (out of 10 per mesh bag) that were viable after removal from treated soil prior to
transplanting of cucumbers on 5 September . PC=Phytophthora capsici, FS=Fusarium solani, RS=Rhizoctonia solani (AG-4), and YN=yellow
nutsedge.
Means followed by the same letter do not differ significantly as determined by Fisher’s protected least significant difference test (P#0.05).No letters
indicate non-significant difference.
a
-91-
Table 8. Population densities of Pythium spp., Rhizoctonia spp., and Fusarium spp. and viability of Phytophthora capsici, Fusarium solani,
Rhizoctonia solani, and yellow nutsedge in soil on November 20th after treatment with alternatives to methyl bromide in August, 2001
Treatment
Rate
Method of Application
1. Telone II EC
18 gal/A
Inject through drip tape
2064 b
19.2 b
0.0
2. In-Line 35 EC
20.5 gal/A
Inject through drip tape
1152 c
6.4 cd
0.0
3. In-Line 35 EC
35 gal/A
Inject through drip tape
6128 a
9.6 bcd
0.0
4. Telone C-35
35 gal/A
Chisel Injection
1840 c
0.0 d
0.0
5. In-Line 35 EC
20.5 gal/A
Inject through drip tape
5392 a
7.2 bcd
0.0
37.5 gal/A
Inject through drip tape
(3 days later)
20.5 gal/A
1552 c
13.6 bc
0.0
37.5 gal/A
Inject through drip tape
simultaneously (mix
together in tank)
200 lbs ai/A
Chisel Injection
1328 c
0.0 d
0.0
+ Metam Sodium
6. In-Line 35 EC
+ Metam Sodium
7. Methyl Bromide
Fusarium
Fungal populations a
Pythium
8. Non-Treated Control
N/A
-----------4784 ab
56.0 a
Total populations of Fusarium spp., Pythium spp., and Rhizoctonia spp. expressed as the number of
colony forming units per gram of soil.
Means followed by the same letter do not differ significantly as determined by Fisher’s protected
least significant difference test (P#0.05). No letters indicate non-significant difference.
a
-92-
Rhizoctonia
0.03
EFFECTS OF VYDATE AND TELONE TREATMENTS FOR MANAGEMENT
OF NEMATODES, DISEASES, AND YIELD OF CUCUMBER
A. S. Csinos, Phytopathologist, Department of Plant Pathology,
University of Georgia, Tifton Campus
K. W. Seebold, Plant Pathologist, Department of Plant Pathology,
University of Georgia, Tifton Campus
P. Timper, Crop protection and Management Research Unit,
USDA-ARS Tifton, GA
R. F. Davis, Crop protection and Management Research Unit,
USDA-ARS Tifton, GA
J. E. Laska, Agricultural Research Coordinator, Plant Pathology
University of Georgia, Tifton Campus
Introduction
Methyl bromide is a broad-spectrum biocide and is an important management tool for
controlling nematodes, soilborne diseases and other pests in a wide range of crops including
vegetable crops. The developing vegetable industry in Georgia is valued at over $635 million.
By the year 2005 all uses of methyl bromide in the United states are scheduled to be terminated.
Methyl bromide production and importation will be reduced from 1991 levels as follows: 25% in
1999, 50% in 2001, 70% in 2003, and 100% in 2005. Therefore, alternative pest management
strategies must be developed before 2005. The objective of this study was to determine the
effects of soil chemical treatments on a susceptible cultivar of cucumber on yield, nematodes,
and residual effects on cucumber.
Materials and Methods Cucumber Crop
Field plots were established 8 August 2001 at the Blackshank Research Farm in Tifton
Georgia, and maintained through November 2001 on a Tifton loamy sand (fine-loamy, siliceous
thermic Plinthic Kandiudults: 85% sand, 10% silt, 5% clay; 0.5% organic matter; pH 5.4). The
plots were naturally infested with Meloidogyne incognita, Patatrichodorus, Helicotylenchus, and
Pythium spp.
The experiment was a randomized block design with drip tape irrigation and chemical
treatments injected with chemical injection rigs and replicated five times. Initially, the soil was
disc-harrowed, plowed 10 to 12 inches deep with a moldboard plow and shaped into beds 30
inch wide and 8 inches high. Five hundred pounds per acre of 5-10-15 fertilizer was applied by
broadcast to all plots and incorporated approximately four inches deep with a tractor-powered
rototiller. Whole-plots were 30 inches wide and 25 feet long. All chisel injected treatments,
were injected on 9 August. The Vydate treatments were applied during the growing season
starting at planting and as follows. On 6 September the first Vydate (2qt/A) injection treatment,
numbers 4 and 5, was applied through the drip tape. Total injection time 2 hours for 1/3 bed
coverage (2.7ml per bed for 10 beds = 27.0 ml in 2 gal H2O). On 20 September the second
Vydate (2qt/A) injection treatment, numbers 4, 5, 6, and 7, was applied through the drip tape.
-93-
Total injection time 3 hours for 1/2 bed coverage (2.7 ml per bed for 20 beds = 54.0 ml in 3 gal
H2O). On 4 October the third Vydate (2qt/A) injection treatment, numbers 4, 5, 6, 7, and 8, was
applied through drip tape. Total injection time 6 hours for full bed coverage (2.7 ml per bed for
25 beds = 67.5 ml in 6 gal H2O). On 18 October the forth Vydate (2qt/A) injection treatment,
numbers 6, 7, and 8, was applied through drip tape. Total injection time 6 hours for full bed
coverage (2.7 ml per bed for 15 beds = 40.5 ml in 6 gal H2O). On 1 November the fifth and final
Vydate (2qt/A) injection treatment, number 8, was applied through drip tape. Total injection time
6 hours for full bed coverage (2.7 ml per bed for 5 beds= 13.5 ml in 6 gal H2O). Non-treated
plots served as controls.
The irrigation drip tubing, Toro “Aquatraxx” brand, with emitters spaced 12 inches
apart, each emitter delivering 0.30 gallons per hour at 10 psi of pressure, was placed in the
center of all beds as they were covered with 3 mil white polyethylene.
Thirteen days after the last chisel injected treatment, 5 September, holes (2 inches diam.)
were cut 18 inches apart in single rows using a mechanical-hand transplanter and a single
greenhouse-grown cucumber seedling, cultivar “General Lee”, was planted in each hole per bed.
The total number of living plants per plot was recorded on 17 September. A vigor rating
was done on 27 September, with 1 to10 scale, 10 representing live and healthy plants and 1
representing dead plants.
All cucumbers were hand-harvested, each harvest was separated into marketable and cull,
counted, and weighed. There were a total of four harvests, they were as follows; 15, 24, and 31
October, and a final on 7 November.
All plots were sprayed with Manex + Zinc (1.8 qts./A) and Kocide LF (5 pts./A) on a 7to 10- day schedule for foliage disease control and Ambush (10 oz./A), alternating with Pounce
3.2 (6 oz./A) for insect control on a 7 to 10 day interval. As per the recommendation of the
University Of Georgia Extension service, all plots received liquid fertilizer (Miracle-Gro 15-3015) injected through the irrigation tubing, at a rate of 12 pounds of nitrogen per acre, per week
through the growing season.
Twenty cores of soil, 2.5-cm-diam. × 25-cm-deep, were collected from each row of each
subplot on 5 September and 15 November. Soil cores were mixed, and nematodes were
extracted from a 150-cm3 sub-sample with centrifugal flotation (Jenkins, 1964).
Following final harvest on 14 November, ten plants were dug from each row and rated
for root galling by M. incognita on a 1 to 5 scale: 1 = 0%, 2 = 1% to 25%, 3 = 26% to 50%, 4 =
51% to 75%, 5 = 76% to 100% roots galled (Barker et al., 1986). All data collected was analyzed
with an analysis of variance (P = 0.05) and means were separated using Duncan’s Multiple range
test.
Two different injection rigs were used in this study. The first injector, we refer to as the
chisel injector, was specially built for these applications. It has chisel shanks for injecting
chemicals 8-10 inches deep and is equipped with a combination rototiller for applying chemicals
such as metam sodium in combination with injectable products. The second injection rig,
referred to as the Yetter rig, it is an injection unit designed for deep chemical injection 10-14
inches deep. It also is equipped with large 36 in. round disks which slice through field debris and
trash such as old plastic and drip tape left behind after previous film mulch plantings.
-94-
Results and Discussion
Methyl bromide and all treatments including Telone II suppressed root-knot nematode
populations (Table 1) and root galling (Table 2) better than the control (treatment 1) or
treatments receiving only Vydate (treatments 5 and 7). Vigor ratings (Table 2), cumulative
weight of marketable cucumbers (Table 3), and cumulative number of marketable cucumbers
(Table 4) generally were lower with treatments that had higher root-knot nematode populations
and gall ratings.
The combination of Telone II chiseled in, plus Vydate applied through drip tape provided
yields equivalent to the methyl bromide standard (tables 3-6).
Methyl bromide, chisel-injected at 200 lb a.i./A, was the only treatment to reduce
populations of Fusarium spp. in soil samples taken prior to transplanting. By late November,
Fusarium populations remained lowest in methyl bromide-fumigated plots and in those injected
with Vydate at 2 qt./A at 2, 4, and 6 weeks after planting. The greatest reductions of Pythium
spp. prior to transplanting were seen in plots treated with methyl bromide, Telone II (18 GPA),
Telone II (18 GPA) followed by Vydate (2 qt/A) at 0, 2, and 4 weeks after transplanting, Vydate
(2 qt/A) applied at 2, 4, and 6 weeks after transplanting, and Telone II (18 GPA) followed by
Vydate (2 qt/A) applied at 4, 6, and 8 weeks after transplanting. A similar pattern was seen in
samples taken in late November; however, Vydate applied alone at 2, 4, and 6 weeks after
transplanting did not reduce Pythium populations as compared to the untreated check.
Populations of Rhizoctonia spp. were lowest in methyl bromide-fumigated plots and in those
injected with Vydate at 2 qt./A at 2, 4, and 6 weeks after planting. No differences were seen
between any treatment and the untreated check in samples taken at the end of the season.
Acknowledgments
The authors wish to thank Unessee Hargett, Don Hickey, Lewis Mullis, Tonya Jo
Cravens, Brandi Hogan, Bryan Horten, Eduvina McDonald, Donnie Starling, Matt McKinnon,
Thomas H. Hilton, David L. Clements, Billy Wilson, and A. Kyle Monfort for technical support,
Cindy H. LaHue for typing. Also, DuPont Chemical for financial support.
-95-
Table 1. Effects of soil chemical treatments on nematode population densities in cucumbers 2001a
Treatment
1. Control
a
b
Rate
N/A
Method of Applicationc
Nematodes per 150-cm3 soil
5th September
P.m.
C.o.
15th
M.i.
November
P.m.
M.i.b
C.o.
68
4
32
132 a
8
0
0
4
0
0b
2
0
12
0
64
10 b
6
0
36
0
16
6b
2
0
------------------
2. Methyl
Bromide 98%
200lbs ai/A
Chisel Inject
(shallow application at 8")
3. Telone II
18 gal/A
W/ Yetter Rig
application at 12")
4. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
+ Vydate
2qts/A
0, 2 & 4 weeks post plant
5. Vydate
2qts/A
0, 2 & 4 weeks post plant
12
8
16
140 a
2
0
6. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
12
0
48
0b
2
0
+ Vydate
2qts/A
2, 4 & 6 weeks post plant
7. Vydate
2qts/A
2, 4 & 6 weeks post plant
236
16
20
160 a
4
0
8. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
252
20
20
24 b
6
0
+ Vydate
2qts/A
(deep
4, 6 & 8 weeks post plant
Data are means of five replications.
M.i. = Meloidogyne incognita, P.m. = Paratrichodorus, C.o. = Criconemoides.
Chisel injected treatments were injected on 9 August, the Vydate treatments were applied through the drip tape as follows; 6 September (delivery time 2 hrs), and
20 September (delivery time 3 hrs), 4 October (delivery time 6 hrs), and 18 October (delivery time 6 hrs), and the final on 1 November (delivery time 6 hrs).
Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test. No letters indicate non-significant.
c
-96-
Table 2. Effects of soil chemical treatments on root-gall indices, Vigor and stand count of cucumbers - 2001a
Treatment
1. Control
Rate
N/A
Method of Application
Root-gall index b
14 November
Vigor Rating c
September 27
Stand
count d
September 17
------------------
4.4 a
8.4 ab
17
2. Methyl
Bromide 98%
200lbs ai/A
Chisel Inject
(shallow application at 8")
1.3 b
9.4 a
17
3. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
1.7 b
7.8 ab
17
4. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
1.4 b
8.4 ab
17
+ Vydate
2qts/A
0, 2 & 4 weeks post plant
5. Vydate
2qts/A
0, 2 & 4 weeks post plant
3.7 a
8.4 ab
17
6. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
1.3 b
9.0 a
17
+ Vydate
2qts/A
2, 4 & 6 weeks post plant
7. Vydate
2qts/A
2, 4 & 6 weeks post plant
4.7 a
7.0 b
17
8. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
1.6 b
9.4 a
17
+ Vydate
2qts/A
4, 6 & 8 weeks post plant
Data are means of five replications.
Root Gall Index 1-5 scale: 1 = no galls, 2 = 1% to 25%, 3 = 26% to 50%, 4 = 51% to 75%, and 5 = 76% to 100% of roots galled.
c
Vigor was done a 1-10 scale with 10= live and healthy plants and 1=dead plants.
d
Maximum number of plants per plot = 36.
Means in the same column followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test. No letters indicate nonsignificant difference.
a
b
-97-
Table 3. Effect of soil chemical treatments on marketable yield of cucumbers -2001a
Treatment
1. Control
a
Rate
N/A
Method of Application
------------------
Weight (lbs.) of marketable cucumbers per plot (35 lin. ft. row)
November
Total
October
15
24
31
7
Mean
9.1 c
50.5 ab
11.0 ab
6.5 cd
77.2 bc
2. Methyl
Bromide 98%
200lbs ai/A
Chisel Inject
(shallow application at 8")
20.4 a
58.7 a
15.8 ab
10.2 abc
105.2 a
3. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
16.2 ab
45.1 ab
17.9 ab
8.3 bcd
87.4 abc
4. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
15.2 abc
46.1 ab
19.3 a
12.8 a
93.4 ab
+ Vydate
2qts/A
0, 2 & 4 weeks post plant
5. Vydate
2qts/A
0, 2 & 4 weeks post plant
13.2 bc
39.2 b
13.7 ab
6.7 cd
72.8 cd
6. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
16.6 ab
55.9 a
17.8 ab
12.3 ab
102.5 a
+ Vydate
2qts/A
2, 4 & 6 weeks post plant
7. Vydate
2qts/A
2, 4 & 6 weeks post plant
3.1 d
40.5 b
10.0 b
4.1 d
57.7 d
8. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
14.5 abc
50.5 ab
16.0 ab
9.8 abc
+ Vydate
2qts/A
4, 6 & 8 weeks post plant
90.8 abc
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
Table 4. Effect of soil chemical treatments on marketable yield of cucumber - 2001a
-98-
Treatment
1. Control
a
Rate
N/A
Method of Application
Number of marketable cucumber per plot (35 lin. ft. row)
October
November
Total
15
24
31
7
Mean
------------------
21.6 c
64.4 abc
21.0 ab
13.8 bcd
120.8 b
2. Methyl
Bromide 98%
200lbs ai/A
Chisel Inject
(shallow application at 8")
39.6 a
79.2 a
33.4 a
20.8 ab
173.0 a
3. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
36.3 ab
62.3 abc
34.3 a
19.0 abc
151.8 a
4. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
31.8 abc
60.4 bc
34.8 a
23.8 a
150.8 a
+ Vydate
2qts/A
0, 2 & 4 weeks post plant
5. Vydate
2qts/A
0, 2 & 4 weeks post plant
24.8 bc
52.2 c
27.6 ab
13.0 cd
117.6 b
6. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
36.4 ab
74.6 ab
35.2 a
22.2 a
168.4 a
+ Vydate
2qts/A
2, 4 & 6 weeks post plant
7. Vydate
2qts/A
2, 4 & 6 weeks post plant
7.8 d
53.6 c
16.8 b
8.2 d
86.4 c
8. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
31.0 abc
66.8 abc
29.8 ab
21.4 a
149.0 a
+ Vydate
2qts/A
4, 6 & 8 weeks post plant
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
-99-
Table 5. Effect of soil chemical treatment on cull yield of cucumbers - 2001a
Treatment
1. Control
Rate
N/A
Method of Application
------------------
Weight (lbs.) of cull cucumbers per plot (35 lin. ft. row)
October
November
15
24
31
7
Total
Mean
0.0
1.6
0.7
1.0 b
3.3 abc
2. Methyl
Bromide 98%
200lbs ai/A
Chisel Inject
(shallow application at 8")
0.0
0.4
0.6
1.2 b
2.2 c
3. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
0.0
0.9
1.6
1.9 ab
4.4 ab
4. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
0.1
0.9
0.7
2.9 a
4.6 a
+ Vydate
2qts/A
0, 2 & 4 weeks post plant
5. Vydate
2qts/A
0, 2 & 4 weeks post plant
0.1
0.5
1.2
1.2 b
2.9 bc
6. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
0.1
0.6
0.9
1.5 b
3.1 abc
+ Vydate
2qts/A
2, 4 & 6 weeks post plant
7. Vydate
2qts/A
2, 4 & 6 weeks post plant
0.0
0.3
1.4
1.8 ab
3.5 abc
8. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
0.1
1.0
0.9
2.2 ab
4.1 ab
+ Vydate
2qts/A
4, 6 & 8 weeks post plant
a
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test. No letters
indicate non- significant difference.
-100-
Table 6. Effect of soil chemical treatment on cull yield of cucumbers - 2001a
Treatment
1. Control
Rate
N/A
Method of Application
------------------
Number of cull marketable cucumbers per plot (35 lin. ft. row)
October
November
Total
15
24
31
7
Mean
0.0
1.2
3.4
4.2 b
8.8 abc
2. Methyl
Bromide 98%
200lbs ai/A
Chisel Inject
(shallow application at 8")
0.0
0.8
2.2
3.4 b
6.4 c
3. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
0.0
1.5
5.5
5.3 ab
12.3 ab
4. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
0.4
1.2
2.6
9.0 a
13.2 a
+ Vydate
2qts/A
0, 2 & 4 weeks post plant
5. Vydate
2qts/A
0, 2 & 4 weeks post plant
0.4
0.8
3.8
3.2 b
8.2 bc
6. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
0.2
1.2
3.8
3.6 b
8.8 abc
+ Vydate
2qts/A
2, 4 & 6 weeks post plant
7. Vydate
2qts/A
2, 4 & 6 weeks post plant
0.0
0.4
5.6
4.4 b
10.4 abc
8. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
0.2
1.4
2.8
6.4 ab
10.8 abc
+ Vydate
2qts/A
4, 6 & 8 weeks post plant
a
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
Means followed by the same letter do not differ significantly as determined by Fisher’s protected least significant difference test (P#0.05). No letters
indicate non- significant difference.
-101-
Table 7. Population densities of Pythium spp., Rhizoctonia spp., and Fusarium spp. in soil after treatment with alternatives to methyl bromide in
August, 2001 (cucumber test).
Treatment
1. Control
Rate
N/A
Method of Application
------------------
Fungal populations (9-11-01)a
Fusarium
Pythium Rhizoctonia
Rhizoctonia
Fungal populations(11-20-01)
Fusarium Pythium
6128 c
36.8 a
0.16 ab
13584 b
25.6 c
0.03
2. Methyl
Bromide 98%
200lbs ai/A
Chisel Inject
(shallow application at 8")
2128 d
4.0 d
0.0 c
8448 c
2.4 e
0.0
3. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
7520 bc
12.0 cd
0.05 bc
13392 b
11.2 de
0.03
4. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
6880 bc
8.0 d
0.05 bc
17408 a
4.0 e
0.03
+ Vydate
2qts/A
0, 2 & 4 weeks post plant
5. Vydate
2qts/A
0, 2 & 4 weeks post plant
10784 a
25.6 ab
0.29 a
14944 ab
37.6 b
0.08
6. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
8688 b
24.8 abc
0.0 c
15936 ab
19.2 cd
0.0
+ Vydate
2qts/A
2, 4 & 6 weeks post plant
7. Vydate
2qts/A
2, 4 & 6 weeks post plant
7248 bc
21.6 bc
0.05 bc
8544 c
51.2 a
0.03
8. Telone II
18 gal/A
W/ Yetter Rig
(deep application at 12")
11248 a
12.8 bcd
0.08 bc
14576 ab
5.6 e
0.03
+ Vydate
2qts/A
4, 6 & 8 weeks post plant
a
Total populations of Fusarium spp., Pythium spp., and Rhizoctonia spp. expressed as the number of colony forming units per gram of soil.
Means followed by the same letter do not differ significantly as determined by Fisher’s protected least significant difference test (P#0.05).
No letters indicate non- significant difference.
-102-
EVALUATION OF CHISEL PLACEMENT OF TELONE PRODUCTS AND DRIP
INJECTION FOR EFFICACY AND YIELD IN BELL PEPPER
A. S. Csinos, Phytopathologist, Department of Plant Pathology,
University of Georgia, Tifton Campus
K. W. Seebold, Plant Pathologist, Department of Plant Pathology,
University of Georgia, Tifton Campus
P. Timper, Crop Protection and Management Research Unit,
USDA-ARS Tifton, GA
J. E. Laska, Agricultural Research Coordinator, Plant Pathology
University of Georgia, Tifton Campus
Introduction
Methyl bromide is a broad-spectrum biocide and is an important management tool for
controlling nematodes, soilborne diseases and other pests in a wide range of crops including
vegetable crops. The developing vegetable industry in Georgia is valued at over $635 million.
By the year 2005 all uses of methyl bromide in the United states are scheduled to be terminated.
Methyl bromide production and importation will be reduced from 1991 levels as follows: 25% in
1999, 50% in 2001, 70% in 2003, and 100% in 2005. Therefore, alternative pest management
strategies must be developed before year 2005. The objective of this study was to determine the
effects of soil chemical treatments on a susceptible cultivar of bell pepper on yield, nematodes,
and residual effects on bell pepper.
Materials and Methods Bell Pepper Crop
The study was located at the Blackshank Farm, CPES, Tifton, GA. The area had a history
of soybeans, tobacco, and assorted vegetables. The area was prepared using all current
University of Georgia Extension Service recommendations. The plot design was a randomized
complete block consisting of single bed plots replicated five times. Each plot was 35 feet long.
On 27 March, chisel injection treatments, 2, 3, 4a, and 5a were applied to the test plot
area as indicated in footnotes of table 1. On 9 April chisel injection treatments 1, 4b, 5b, 6, and 8
were then applied. All plots were then shaped to a 30 in. wide X 8 in. high bed then covered with
6 mil black polyethylene with drip tape in the center of the bed approximately 1in. deep. The
final treatment number 7, 1,3-D-C35 “Inline”, an emulsifiable concentrate, was applied through
drip tape on 11 April using a Milton Roy injection pump over a 6 hour period at 12 psi pressure
with Aquatraxx brand dripline with emitters spaced 12 inches apart, each emitter delivering 0.30
gallons per hour at 10 psi of pressure.
Two different injection rigs were used in this study. The first injector, we refer to as the
chisel injector, was specially built for these applications. It has chisel shanks for injecting
chemicals 8-10 inches deep and is equipped with a combination rototiller for applying chemicals
such as metam sodium in combination with injectable products. The second injection rig,
referred to as the Yetter rig, it is an injection unit designed for deep chemical injection 10-14
-103-
inches deep. It also is equipped with large 36 in. round disks which slice through field debris and
trash such as old plastic and drip tape left behind after previous film mulch plantings.
Bell pepper, cultivar “Capistrano”, a variety susceptible to M. incognita, seedlings were
produced in nutrient tray system to the 4-leaf stage. A single pepper plant was transplanted into
holes cut into the center of the plastic bed adjacent to the drip tape on 19 April. Stand counts
were made to record live plants on 26 May. A vigor rating was done on 1 June and rated with 1
to 10 scale, 10 representing live and healthy plants and 1 representing dead plants.
As per the recommendation of the University Of Georgia Extension service, all plots
received 145 lbs. of N, and 145 lbs. of K, in the form of liquid fertilizer
(Miracle-Gro15-0-14) injected through the irrigation tubing during the growing season. All
pepper plots were sprayed with Manex with Zinc (2.4 qt/A) plus Kocide LF (0.5 gal/A) for
control of foliar diseases and Ambush (10 oz./A), alternating with Pounce 3.2 (6 oz./A) for
insect control on a 7 to 10 day interval.
Twelve cores of soil, 2.5-cm-diam× 25-cm-deep, were collected from each row of each plot on
26 March, 20 April, and 3 August, 2001.Replications for treatments on each data were mixed,
and nematodes were extracted from a 150-cm3 sub-sample using a centrifugal flotation
technique.
All pepper pods were hand-harvested, each harvest was separated into marketable and
cull, counted, and weighed. There were a total of six harvests, they were as follows; 26 June,
and 5, 11, 18, and 24 July, and a final on 1 August. Following final harvest on 1 August, ten
plants were dug from each row and rated for root galling by M. incognita on a 1 to 5 scale: 1 =
0%, 2 = 1% to 25%, 3 = 26% to 50%, 4 = 51% to 75%, 5 = 76% to 100% roots galled. All data
collected was analyzed with an analysis of variance (P = 0.05) and means were separated using
Duncan’s Multiple range test.
Results and Discussion
Not all chemical treatments were effective in reducing root gall indices or nematode
populations (tables 1-3). Only Telone C-17 plus metam sodium had superior vigour ratings and
yield aspects equaled to methyl bromide.
Soil populations of Fusarium spp., Pythium spp.
and Rhizoctonia spp. at transplanting were significantly reduced by applications of Telone C-17
at 10 GPA in combination with Vapam at 37.5GPA 3 weeks prior to transplanting. Application
depth of Telone C-35 did not affect the ability of the fumigant to suppress populations of
Fusarium and Rhizoctonia spp.; however, populations of Pythium were higher when Telone C35 was injected at 12 inches compared to 8 inches. No differences in fungal populations were
seen between plots treated with Telone II (no chloropicrin) followed by chloropicrin and Telone
C-17 followed by chloropicrin. Telone C-35 Inline reduced fungal populations as effectively as
methyl bromide. At three months after fumigation, no differences were observed between any
treatment and the untreated check with regard to populations of Rhizoctonia spp. All fumigation
treatments had significantly lower populations of Pythium spp. than the untreated check. Only
those plots treated with Telone C-17 in combination with Vapam and Telone C-35 Inline had
Fusarium populations greater than or equal to the untreated check.
Telone C-35 Inline was the only treatment to reduce the survival of Fusarium solani,
Rhizoctonia solani AG-4, and Cyperus esculentus (yellow nutsedge). No differences in viability
of propagules were seen between any fumigation treatment and the untreated check.
-104-
Acknowledgments
The authors wish to thank Unessee Hargett, Don Hickey, Lewis Mullis, Tonya Jo
Cravens, Bryan Horten, Eduvina McDonald, Donnie Starling, Matt McKinnon, Thomas H.
Hilton, David L. Clements, Billy Wilson, and A. Kyle Monfort for technical support, Cindy H.
LaHue for typing. Also, Dow Agrosciences for financial support.
-105-
Table 1. Effects of soil chemical treatments on nematode population densities in bell pepper 2001a
Treatment
c
Rate
Nematodes per 150-cm3 soil
Method of
Application
26 March
P.m.
C.o.
M.i.
50
14 ab
0
2b
2
0
146 b
0
0
b
M.i.
1. Telone C-17
20 April
P.m.
C.o.
3 August
M.i. P.m. C.o.
10 gal/A
Chisel Injected 8 in.
37.5 gal/A
Rototilled 4 in.
2. Telone C-35
35 gal/A
Chisel Injected 8 in.
46
4 ab
0
0b
2
0
28 b
2
0
3. Telone C-35
35 gal/A
Yetter d Injected 12 in.
38
4 ab
0
0b
0
0
26 b
2
2
4. Telone II
18 gal/A
Yetter Injected 12 in.
38
6 ab
0
0b
4
4
24 b
2
0
9 gal/A
Chisel Injected 8 in.
14 days later
21.6 gal/A
Yetter Injected 12 in.
20
2b
0
0b
2
2
308 a
0
0
9 gal/A
Chisel Injected 8 in.
14 days later
6. Methyl Bromide 89%
200 lb ai/A
Chisel Injected 8 in.
10
26 a
0
2b
4
0
50 b
2
0
7. In-Line (C-35 EC)
35 gal/A
Through Drip Tape
34
8 ab
0
2b
4
2
8b
0
0
8.Non-Treated Control
N/A
------------------------
36
20 ab
0
8a
4
0
424 a
0
0
+ Metam Sodium
+ Chloropicrin
5. Telone C-17
+ Chloropicrin
a
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
No letters indicate non-significant.
b
M.i. = Meloidogyne incognita, P.m. = Paratrichodorus, C.o. = Criconemoides
c
Treatments 2, 3, 4a, and 5a were applied on 27 March, treatments 1, 4b, 5b, 6 and 8 were all applied 14 days later on 9 April. The final treatment
7, “Inline”, an emulsifiable concentrate, was applied through the drip system on 11 April using a Milton Roy injection pump over a 6 hour period
at 10 psi pressure with Aquatraxx brand dripline with emitters spaced 12 inches apart, each emitter delivering 0.30 gallons per hour at 10 psi of
pressure.
d
Yetter rig is an injection unit designed for deep chemical injection 10-14 inches deep. It also is equipped with large 36 in. round disks which slice
through field debris and trash such as old plastic and drip tape left behind after previous plantings.
-106-
Table 2. Effects of soil chemical treatments on root-gall indices, Vigor and stand count of bell pepper - 2001a
Method of Application
Treatment
1. Telone C-17
Rate
Root-gall index
3 August
10 gal/A
Chisel Injected 8 in.
37.5 gal/A
Rototilled 4 in.
2. Telone C-35
35 gal/A
3. Telone C-35
4. Telone II
b
Vigor Rating
1 June
d
Stand
count c
26 May
3.1 a
9.0 a
36
Chisel Injected 8 in.
1.4 b
6.8 c
35
35 gal/A
Yetter Injected 12 in.
1.6 b
7.0 bc
36
18 gal/A
Yetter Injected 12 in.
1.6 b
8.8 ab
36
9 gal/A
Chisel Injected 8 in.
14 days later
21.6 gal/A
Yetter Injected 12 in.
2.8 ab
7.6 abc
36
9 gal/A
Chisel Injected 8 in.
14 days later
6. Methyl Bromide 89%
200 lb ai/A
Chisel Injected 8 in.
2.0 ab
8.0 abc
36
7. In-Line (C-35 EC)
35 gal/A
Through Drip Tape
1.3 b
6.4 c
36
+ Metam Sodium
+ Chloropicrin
5. Telone C-17
+ Chloropicrin
8.Non-Treated Control
N/A
-----------------------3.2 a
6.2 c
36
Data are means of five replications. Means in the same column followed by the same letter are not different (P = 0.05) according to
Duncan’s multiple range test. No letters indicate non-significant difference.
b
Root Gall Index 1-5 scale: 1 = no galls, 2 = 1% to 25%, 3 = 26% to 50%, 4 = 51% to 75%, and 5 = 76% to 100% of roots galled.
c
Maximum number of plants per plot = 36.
d
Vigor was done a 1-10 scale with 10= live and healthy plants and 1=dead plants.
a
-107-
Table 3. Effect of soil chemical treatments on marketable yield of bell pepper -2001a
Treatment
1. Telone C-17
Rate
Method of
Application
10 gal/A
Chisel Injected 8 in.
37.5 gal/A
Rototilled 4 in.
2. Telone C-35
35 gal/A
3. Telone C-35
4. Telone II
Weight (lbs.) of
June
26
5
marketable bell pepper per plot
July
11
18
24
(35 lin. ft. row)
August
1
Total
Mean
23.9 a
4.4 a
5.2 b
7.0 ab
7.3 b
6.7
54.6 a
Chisel Injected 8 in.
10.4 c
1.1 b
4.2 b
3.8 b
5.4 b
5.4
30.3 d
35 gal/A
Yetter Injected 12 in.
10.2 c
2.0 ab
4.3 b
6.5 ab
5.3 b
5.6
33.9 cd
18 gal/A
Yetter Injected 12 in.
13.9 bc
2.7 ab
6.5 ab
6.1 ab
6.4 b
7.7
43.4 bc
9 gal/A
Chisel Injected 8 in.
14 days later
21.6 gal/A
Yetter Injected 12 in.
11.4 c
2.2 ab
6.4 ab
5.8 ab
14.0 a
8.4
48.2 ab
9 gal/A
Chisel Injected 8 in.
14 days later
6. Methyl Bromide 89%
200 lb ai/A
Chisel Injected 8 in.
22.2 ab
4.2 a
9.26 a
5.0 b
6.2
55.9 a
7. In-Line (C-35 EC)
35 gal/A
Through Drip Tape
6.1 c
2.5 ab
6.0 ab
4.4 b
5.6 b
8.6
33.1 cd
8.Non-Treated Control
N/A
------------------------
11.2 c
2.5 ab
6.1 ab
6.0 ab
5.1 b
8.5
39.5 bcd
+ Metam Sodium
+ Chloropicrin
5. Telone C-17
+ Chloropicrin
a
8.96 a
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
No letters indicate non-significant difference.
Table 4. Effect of soil chemical treatments on marketable yield of bell pepper - 2001a
-108-
Treatment
Rate
Method of
Application
Number of marketable bell pepper per plot
July
June
26
5
11
18
(35 lin. ft. row)
August Total
24
1
Mean
80.0 a
15 a
22.6 ab
35.8
ab
41.0 ab
54.2
248.6 a
Chisel Injected 8 in.
44.6 b
4.2 b
21.4 ab
20.2 b
30.6 b
34.2
155.2 d
35 gal/A
Yetter Injected 12 in.
41.8 b
8.6 ab
18.8 b
30.6 b
29.0 b
41.0
169.8 cd
18 gal/A
Yetter Injected 12 in.
49.4 ab
10.6 ab
26.2 ab
32.6 b
34.0 b
54.4
207.2 abc
9 gal/A
Chisel Injected 8 in.
14 days later
21.6 gal/A
Yetter Injected 12 in.
8.4 ab
27.0 ab
66.6 a
53.8
224.0 ab
9 gal/A
Chisel Injected 8 in.
14 days later
28.4
b
6. Methyl Bromide 89%
200 lb ai/A
Chisel Injected 8 in.
77.8 a
38.0 a
52.2 a
28.8 b
42.0
253.6 a
7. In-Line (C-35 EC)
35 gal/A
Through Drip Tape
26.2 b
9.6 ab
30.2 ab
21.8 b
35.4 b
40.4
163.6 cd
8.Non-Treated Control
N/A
------------------------
43.0 b
10.0 ab
26.6 ab
29.0 b
26.0 b
48.6
183.2 bcd
1. Telone C-17
10 gal/A
Chisel Injected 8 in.
37.5 gal/A
Rototilled 4 in.
2. Telone C-35
35 gal/A
3. Telone C-35
4. Telone II
+ Metam Sodium
+ Chloropicrin
5. Telone C-17
+ Chloropicrin
39.8 c
a
14.8 a
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range
test. No letters indicate non-significant difference.
-109-
Table 5. Effect of soil chemical treatment on cull yield of bell pepper - 2001a
Treatment
1. Telone C-17
Rate
Method of
Application
10 gal/A
Chisel Injected 8 in.
37.5 gal/A
Rototilled 4 in.
2. Telone C-35
35 gal/A
3. Telone C-35
4. Telone II
Weight (lbs.) of cull bell pepper per plot
July
June
26
5
11
18
(35 lin. ft. row)
August
24
1
Total
Mean
0.5 b
0.3 ab
0.8 bc
0.5 ab
1.9 a
1.0
5.0 ab
Chisel Injected 8 in.
0.3 b
0.1 ab
0.5 c
0.7 ab
0.7 b
0.4
2.7 b
35 gal/A
Yetter Injected 12 in.
0.1 b
0.1 ab
0.1 c
0.4 ab
0.8 b
0.3
1.8 b
18 gal/A
Yetter Injected 12 in.
3.0 a
0.6 a
2.0 ab
1.1 ab
0.7 b
1.0
8.2 a
9 gal/A
Chisel Injected 8 in.
14 days later
21.6 gal/A
Yetter Injected 12 in.
1.6 ab
0.4 ab
2.3 a
1.3 a
1.9 a
0.6
8.1 a
9 gal/A
Chisel Injected 8 in.
14 days later
6. Methyl Bromide 89%
200 lb ai/A
Chisel Injected 8 in.
1.1 b
0.2 ab
0.8 bc
0.8 ab
0.7 b
0.8
4.4 ab
7. In-Line (C-35 EC)
35 gal/A
Through Drip Tape
0.2 b
0.2 ab
0.4 c
0.7 ab
1.1 ab
0.6
3.1 b
8.Non-Treated Control
N/A
------------------------
0.1 b
0.1 b
0.4 c
0.2 b
0.2 b
0.5
1.4 b
+ Metam Sodium
+ Chloropicrin
5. Telone C-17
+ Chloropicrin
a
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
No letters indicate non- significant difference.
-110-
Table 6. Effect of soil chemical treatment on cull yield of bell pepper - 2001a
Treatment
Rate
Method of
Application
Number of Cull bell pepper per plot
(35 lin. ft. row)
July
June
26
5
11
18
24
August Total
1
Mean
3.4 b
1.4 ab
5.8 abc
4.0 ab
15.4 a
8.0
38.0 ab
Chisel Injected 8 in.
1.6 b
.4 b
3.8 bc
5.2 ab
4.8 bc
3.2
19.0 bc
35 gal/A
Yetter Injected 12 in.
.4 b
.6 ab
0.8 c
2.2 ab
5.4 bc
1.8
11.2 bc
18 gal/A
Yetter Injected 12 in.
16.0 a
3.2 a
12.2 ab
7.2 ab
5.4 bc
7.2
51.2 a
9 gal/A
Chisel Injected 8 in.
14 days later
21.6 gal/A
Yetter Injected 12 in.
7.8 ab
1.8 ab
13.4 a
9.8 a
12.2 ab
4.0
49.0 a
9 gal/A
Chisel Injected 8 in.
14 days later
6. Methyl Bromide 89%
200 lb ai/A
Chisel Injected 8 in.
6.0 b
1.0 ab
4.8 abc
6.6 ab
7.0 bc
5.2
30.6 abc
7. In-Line (C-35 EC)
35 gal/A
Through Drip Tape
1.0 b
1.0 ab
3.0 bc
5.0 ab
8.8 abc
5.0
23.8 abc
8.Non-Treated Control
N/A
------------------------
1.2 b
0.2 b
2.2 c
1.0 b
1.8 c
3.2
9.6 c
1. Telone C-17
10 gal/A
Chisel Injected 8 in.
37.5 gal/A
Rototilled 4 in.
2. Telone C-35
35 gal/A
3. Telone C-35
4. Telone II
+ Metam Sodium
+ Chloropicrin
5. Telone C-17
+ Chloropicrin
a
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range
test.
No letters indicate non-significant difference.
-111-
Table 7. Population densities of Pythium spp., Rhizoctonia spp., and Fusarium spp., and viability of Pythium irregulare, Fusarium solani,
Rhizoctonia solani, and yellow nutsedge in soil 3 weeks after treatment with alternatives to methyl bromide in April, 2001 (pepper test).
Treatment
1. Telone C-17
Rate
Method of
Application
10 gal/A
Chisel Injected 8 in.
37.5 gal/A
Rototilled 4 in.
2. Telone C-35
35 gal/A
Chisel Injected 8 in.
3. Telone C-35
35 gal/A
Yetter Injected 12 in.
4. Telone II
18 gal/A
Yetter Injected 12 in.
9 gal/A
Chisel Injected 8 in.
14 days later
21.6 gal/A
Yetter Injected 12 in.
9 gal/A
Chisel Injected 8 in.
14 days later
6. Methyl Bromide 89%
200 lb ai/A
7. In-Line (C-35 EC)
8.Non-Treated Control
+ Metam Sodium
+ Chloropicrin
5. Telone C-17
+ Chloropicrin
Fungal populations a
Fusarium Pythium Rhizoctonia
Pathogen and weed viability b
PI
FS
RS
YN
272 d
0d
0b
36 a
100 a
100 a
82 a
992 bc
22 c
0.05 b
38 a
100 a
80 a
74 a
40 b
0.11 b
40 a
100 a
82 a
78 a
960 bc
0d
0b
46 a
100 a
100 a
78 a
464 cd
0d
0.03 b
42 a
100 a
100 a
54 a
Chisel Injected 8 in.
608 cd
0.8 d
0.03 b
30 a
100 a
100 a
72 a
35 gal/A
Through Drip Tape
720 cd
3.2 d
0b
34 a
72 b
18 b
14 b
N/A
------------------------
64 a
0.45 a
42 a
100 a
86 a
62 a
1536 b
5232 a
Means followed by the same letter do not differ significantly as determined by Fisher’s protected least significant difference test (P#0.05).
a
Total populations of Fusarium spp., Pythium spp., and Rhizoctonia spp. expressed as the number of colony forming units per gram of soil.
b
Percentage of pathogen-infested grains or yellow nutsedge nutlets that were viable after removal from treated soil prior to transplanting of peppers.
PI=Pythium irregulare, FS=Fusarium solani, RS=Rhizoctonia solani (AG-4), and YN=yellow nutsedge.
-112-
Table 8. Population densities of Pythium spp., Rhizoctonia spp., and Fusarium spp. in soil 3
months after treatment with alternatives to methyl bromide in April, 2001 (pepper test).
Treatment
1. Telone C-17
Rate
Method of
Application
10 gal/A
Chisel Injected 8 in.
37.5 gal/A
Rototilled 4 in.
2. Telone C-35
35 gal/A
Chisel Injected 8 in.
3. Telone C-35
35 gal/A
4. Telone II
Fusarium
Rhizoctonia
4b
0.03 a
368 cd
0b
0.03 a
Yetter Injected 12 in.
176 d
4b
0.05 a
18 gal/A
Yetter Injected 12 in.
144 d
2.4 b
0.05 a
9 gal/A
Chisel Injected 8 in.
14 days later
21.6 gal/A
Yetter Injected 12 in.
208 d
0b
0.03 a
9 gal/A
Chisel Injected 8 in.
14 days later
6. Methyl Bromide 89%
200 lb ai/A
Chisel Injected 8 in.
608 cd
3.2 b
0.03 a
7. In-Line (C-35 EC)
35 gal/A
Through Drip Tape
1824 ab
3.2 b
0.05 a
8.Non-Treated Control
N/A
------------------------
1136 bc
11.2 a
0.11 a
+ Metam Sodium
+ Chloropicrin
5. Telone C-17
+ Chloropicrin
2160 a
Fungal populations a
Pythium
Means followed by the same letter do not differ significantly as determined by Fisher’s protected
least significant difference test (P#0.05).
a
Total populations of Fusarium spp., Pythium spp., and Rhizoctonia spp. expressed as the number of
colony forming units per gram of soil.
-113-
-114-
TELONE C-17, METAM SODIUM COMBINATIONS FOR EFFICACY AND
EVALUATION OF PHYTOTOXICITY IN SQUASH
A. S. Csinos, Phytopathologist, Department of Plant Pathology,
University of Georgia, Tifton Campus
K. W. Seebold, Plant Pathologist, Department of Plant Pathology,
University of Georgia, Tifton Campus
P. Timper, Crop Protection and Management Research Unit,
USDA-ARS Tifton, GA
J. E. Laska, Agricultural Research Coordinator, Plant Pathology
University of Georgia, Tifton Campus
Introduction
Methyl bromide is a broad-spectrum biocide and is an important management tool for
controlling nematodes, soilborne diseases and other pests in a wide range of crops including
vegetable crops. The developing vegetable industry in Georgia is valued at over $635 million.
By the year 2005 all uses of methyl bromide in the United states are scheduled to be terminated.
Methyl bromide production and importation will be reduced from 1991 levels as follows: 25% in
1999, 50% in 2001, 70% in 2003, and 100% in 2005. Therefore, alternative pest management
strategies must be developed before year 2005. The objective of this study was to determine
how soon greenhouse produced transplants could be safely transplanted into a chemically
injected plastic covered bed, also the effects of soil chemical treatments on yield of squash,
nematodes, and plant vigour on squash.
Materials and Methods Squash Crop
The study was located at the Blackshank Farm, CPES, Tifton, GA. The area had a history
of soybeans, tobacco, and assorted vegetables. The area was prepared using all current
University of Georgia Extension Service recommendations. The plot design was a randomized
complete block consisting of single bed plots replicated five times. Each plot was 35 feet long.
On 8 March, the first of the chisel injection treatments, 1, 5, 6, and 7 were applied to the
test plot area as indicated in tables. On 19 March chisel injection treatment 2 was then applied
followed by treatment 3 on 26 March. The final treatment 4 was applied on 9 April. At the time
of each injection, the specific plots were then shaped to a 30 in. wide X 8 in. high bed then
covered with 6 mil black polyethylene with drip tape in the center of the bed approximately 1in.
deep.
The injector used in this study, we refer to as the chisel injector, was specially built for
these applications. It has chisel shanks for injecting chemicals 8-10 inches deep and is equipped
with a combination rototiller for applying chemicals such as metam sodium in combination with
injectable soil fumigant products.
Squash, cultivar “Prelude”, a variety susceptible to M. incognita, seedlings were
produced in nutrient tray system to the 4-leaf stage. A single squash plant was transplanted into
holes cut into the center of the plastic bed adjacent to the drip tape on 19 April. Stand counts
were made to record live plants on 26 April. Two vigor ratings were done on 25 April and 14
May and rated with 1 to 10 scale, 10 representing live and healthy plants and 1 representing dead
plants.
-115-
As per the recommendation of the University Of Georgia Extension service, all plots
received 145 lbs. of N, and 145 lbs. of K, in the form of liquid fertilizer
(Miracle-Gro15-0-14) injected through the irrigation tubing during the growing season. All
squash plots were sprayed with Manex with Zinc (2.4 qt/A) plus Kocide LF (0.5 gal/A) for
control of foliar diseases and Ambush (10 oz./A), alternating with Pounce 3.2 (6 oz./A) for
insect control on a 7 to 10 day interval.
Twelve cores of soil, 2.5-cm-diam. × 25-cm-deep, were collected from each row of each
plot on 8 March, 13 April, and 15 July, 2001. Replications for treatments on each data were
mixed, and nematodes were extracted from a 150-cm3 sub-sample using a centrifugal flotation
technique.
All squash were hand-harvested, each harvest was separated into marketable and cull,
counted, and weighed. There were a total of eight harvests, they were as follows;15, 18, 22, 25,
29, May, 1, 5, and a final on 8 June. Following final harvest on 8 June, ten plants were dug from
each row and rated for root galling by M. incognita on a 1 to 5 scale: 1 = 0%, 2 = 1% to 25%, 3
= 26% to 50%, 4 = 51% to 75%, 5 = 76% to 100% roots galled. All data collected was analyzed
with an analysis of variance (P = 0.05) and means were separated using Duncan’s Multiple range
test.
Results and Discussion
Root gall indices and nematode numbers were high in all treatments including the methyl
bromide standard. Vigour ratings were highest in treatments which were allowed to fumigate the
longest, suggesting either phytotoxicity or lack of pest control. All treatments were effective in
increasing yield over the control and all treatments performed as well as or better than the methyl
bromide standard (tables 3-6). In general, soil populations of Pythium spp. and Rhizoctonia spp.
at transplanting were significantly reduced by applications of Telone C-17 at 10 GPA in
combination with Vapam at 37.5GPA, regardless of the interval between application and
transplanting. Total populations of Fusarium spp. were reduced in comparison to the untreated
control at all fumigation-transplant intervals except 35 days. Combinations of Telone C-17 plus
Vapam, and chloropicrin plus Vapam, performed as well as methyl bromide in reducing
populations of Pythium spp. and Rhizoctonia spp. at transplanting. Populations of Pythium spp.
and Rhizoctonia spp. remained low for all fumigants three months after transplanting, and were
significantly lower than in the untreated controls. However, populations of Fusarium spp. were,
for the most part, highest where fumigants had been applied. It is likely that the “biological
vacuum” created by soil fumigation created a non-competitive environment for the species of
Fusarium present and allowed for rapid population growth.
Time of exposure to the combination of Telone C-17 and Vapam affected the survival of
Fusarium solani, Rhizoctonia solani AG-4, and Cyperus esculentus (yellow nutsedge).
Propagules of these organisms were least viable when exposed to the Telone/Vapam
combinations for 22 and 35 days. Viability of propagules was higher as the exposure interval
decreased, indicating that longer (> 3 weeks) periods of exposure are needed for maximum
efficacy.
-116-
Acknowledgments
The authors wish to thank Unessee Hargett, Don Hickey, Lewis Mullis, Tonya Jo
Cravens, Bryan Horten, Eduvina McDonald, Donnie Starling, Matt McKinnon, Thomas H.
Hilton, David L. Clements, Billy Wilson, and A. Kyle Monfort for technical support. Also Cindy
H. LaHue for typing.
-117-
Table 1. Effects of soil chemical treatments on nematode population densities in Prelude Yellow Crook Neck Squash 2001c
Treatment / Rate
Method b / Time before Planting
a
M.i.
1. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
2. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
3. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
4. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
5. Vapam, 37.5gal/A
+ Chloropicrin, 9 gal/A
6. Methyl Bromide 98%,
200 lbs. ai/A
8 March
P.m.
C.o.
Nematodes per 150-cm3 soil
13 April
15 July
M.i.
P.m.
C.o.
M.i.
P.m.
C.o.
Chisel Injected 8" / 35 days
rototilled 4" to 6"
106 a
2
0
8
0
0
110
0
0
44 ab
8
0
2
0
0
28
0
0
20 b
2
0
2
0
0
74
0
0
24 b
0
0
2
0
0
24
6
0
22 b
12
0
2
2
0
48
0
0
16 b
6
0
6
0
0
94
4
0
Chisel Injected 8" / 22 days
rototilled 4" to 6"
Chisel Injected 8" / 17 days
rototilled 4" to 6"
Chisel Injected 8" / 5 days
rototilled 4" to 6"
rototilled 4" to 6"
Chisel Injected 8" / 35 days
Chisel Injected 8" / 35 days
7. Non-treated Control
NA / 35 days
20 b
0
0
2
0
0
144
0
0
M.i. = Meloidogyne incognita, P.m. = Paratrichodorus, C.o. = Criconemoides
b
The injector used in this study, we refer to as the chisel injector, was specially built for these applications. It has chisel shanks for injecting chemicals
8-10 inches deep and is equipped with a combination rototiller for applying chemicals such as metam sodium in combination with injectable soil
fumigant products.
a
c
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
indicate non-significant.
-118-
No letters
Table 2. Effects of soil chemical treatments on root-gall indices, Vigor and stand count of Prelude Yellow Crook Neck Squash- 2001e
Treatment / Rate
1. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
2. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
3. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
4. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
5. Vapam, 37.5gal/A
+ Chloropicrin, 9 gal/A
Method d / Time before
Planting
Stand
count b
26 April
Root-gall index a
18 June
Vigor Ratingc
25 April
Vigor Ratingc
14 May
4.8 a
9.0 a
9.4 a
36
4.3 ab
6.4 b
6.6 b
36
3.5 b
6.2 b
5.2 bc
36
3.6 b
3.8 b
4.4 c
36
4.9 a
9.2 a
10.0 a
36
Chisel Injected 8" / 35 days
rototilled 4" to 6"
Chisel Injected 8" / 22 days
rototilled 4" to 6"
Chisel Injected 8" / 17 days
rototilled 4" to 6"
Chisel Injected 8" / 5 days
rototilled 4" to 6"
rototilled 4" to 6"
Chisel Injected 8" / 35 days
6. Methyl Bromide 98%,
200 lbs. ai/A
Chisel Injected 8" / 35 days
4.6 a
8.8 a
5.0 bc
36
7. Non-treated Control
NA / 35 days
4.9 a
8.6 a
4.0 c
36
a
Root Gall Index 1-5 scale: 1 = no galls, 2 = 1% to 25%, 3 = 26% to 50%, 4 = 51% to 75%, and 5 = 76% to 100% of roots galled.
Maximum number of plants per plot = 36.
c
Vigor was done a 1-10 scale with 10= live and healthy plants and 1=dead plants.
d
The injector used in this study, we refer to as the chisel injector, was specially built for these applications. It has chisel shanks for injecting chemicals 8-10
inches deep and is equipped with a combination rototiller for applying chemicals such as metam sodium in combination with injectable soil fumigant products.
e
Data are means of five replications. Means in the same column followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range
test. No letters indicate non-significant difference.
b
-119-
Table 3. Effect of soil chemical treatments on marketable yield of Prelude Yellow Crook Neck Squash -2001b
Treatment / Rate
1. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
2. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
3. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
4. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
5. Vapam, 37.5gal/A
+ Chloropicrin, 9 gal/A
a
Method / Time before
Planting
Chisel Injected 8" / 35 days
rototilled 4" to 6"
Chisel Injected 8" / 22 days
rototilled 4" to 6"
Chisel Injected 8" / 17 days
rototilled 4" to 6"
Chisel Injected 8" / 5 days
rototilled 4" to 6"
rototilled 4" to 6"
Chisel Injected 8" / 35 days
15
Number of marketable Yellow Crook Neck Squash plot (35 lin. ft. row)
May
_______
June______
18
22
25
29
1
5
8
Total
Mean
38.8 ab
27.2 a
21.4 ab
21.4 ab
25.4 a
20.6 ab
21.6 a
21.6 a
198.0 ab
26.0 bc
24.8 a
19.0 ab
19.2 ab
20.8 abc
20.6 ab
23.8 a
20.6 a
174.8 bc
18.0 c
20.4 ab
14.0 bc
17.4 b
19.4 abc
14.4 bc
23.0 a
19.6
ab
146.2 cd
2.8 d
14.4 b
19.0 ab
15.0 bc
15.8 c
17.4 abc
26.4 a
13.4
bc
124.2 d
50.0 a
28.4 a
27.2 a
26.6 a
23.0 ab
26.4 a
26.0 a
14.6
abc
222.2 a
6. Methyl Bromide 98%,
200 lbs. ai/A
Chisel Injected 8" / 35 days
27.4 bc
21.4 ab
14.0 bc
13.6 bc
17.2 bc
22.0 ab
21.2 a
10.4 c
147.2 cd
7. Non-treated Control
NA / 35 days
15.8 cd
13.2 b
5.4 c
8.2 c
18.6 bc
10.4 c
13.2 b
11.0 c
95.8 e
a
The injector used in this study, we refer to as the chisel injector, was specially built for these applications. It has chisel shanks for injecting chemicals
8-10 inches deep and is equipped with a combination rototiller for applying chemicals such as metam sodium in combination with injectable soil
fumigant products.
b
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
Table 4. Effect of soil chemical treatments on marketable yield of Prelude Yellow Crook Neck Squash - 2001b
-120-
Treatment / Rate
1. Telone C-17, 10
gal/A
+ Vapam, 37.5gal/A
2. Telone C-17, 10
gal/A
+ Vapam, 37.5gal/A
3. Telone C-17, 10
gal/A
+ Vapam, 37.5gal/A
4. Telone C-17, 10
gal/A
+ Vapam, 37.5gal/A
a
Method / Time
before Planting
Chisel Injected 8" /
35 days
15
Weight (lbs.) of marketable Yellow Crook Neck Squash plot (35 lin. ft. row)
May
June
18
22
25
29
1
5
8
___
Total
Mean
15.2 a
9.6 a
8.3 ab
6.0 ab
10.5 a
8.9 ab
11.7 ab
8.9 ab
77.7 a
6.1 b
5.9 b
4.8 bc
4.9 abc
7.6 b
7.2 abc
11.4 ab
9.3 a
57.0 b
3.6 bc
4.4 bc
3.6 c
4.2 bcd
6.3 bc
4.1 cd
9.1 abc
7.5 ab
43.0 c
0.4 c
2.7 c
3.9 c
2.8 cd
4.5 c
5.5 bcd
14.1 a
5.5 bc
39.4 c
18.6 a
10.4 a
10.4 a
6.6 a
8.1 ab
10.7 a
11.4 ab
6.4 abc
82.6 a
rototilled 4" to 6"
Chisel Injected 8" /
22 days
rototilled 4" to 6"
Chisel Injected 8" /
17 days
rototilled 4" to 6"
Chisel Injected 8" / 5
days
rototilled 4" to 6"
5. Vapam, 37.5gal/A
rototilled 4" to 6"
+ Chloropicrin, 9
gal/A
Chisel Injected 8" /
35 days
6. Methyl Bromide
98%,
200 lbs. ai/A
Chisel Injected 8" /
35 days
6.6 b
5.4 bc
3.6 c
2.4 cd
4.7 c
7.4 abc
8.9 bc
4.1 c
43.1 c
7. Non-treated Control
NA / 35 days
3.3 bc
2.6 c
1.1 c
2.0 d
5.9 bc
3.1 d
4.5 c
3.7 c
26.2 d
a
The injector used in this study, we refer to as the chisel injector, was specially built for these applications. It has chisel shanks for injecting chemicals 8-10 inches
deep and is equipped with a combination rototiller for applying chemicals such as metam sodium in combination with injectable soil fumigant products.
b
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
-121-
Table 5. Effect of soil chemical treatment on cull yield of Prelude Yellow Crook Neck Squash - 2001b
Treatment / Rate
1. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
2. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
3. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
4. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
5. Vapam, 37.5gal/A
+ Chloropicrin, 9 gal/A
Method a / Time before
Planting
15
May
18
Number of Cull Yellow Crook Neck Squash plot (35 lin. ft. row)
June
Total
22
25
29
1
5
8
Mean
Chisel Injected 8" / 35 days
rototilled 4" to 6"
1.0
0.0 b
0.0
0.8
0.2
1.2
0.2
1.8 a
5.2 abc
1.0
0.2 ab
0.8
1.6
0.2
0.0
0.6
1.6 ab
6.0 ab
0.0
0.2 ab
0.0
1.0
1.6
0.0
0.2
0.4 ab
3.4 bc
0.6
0.6 ab
1.0
1.0
1.0
0.2
0.6
0.0 b
5.0 abc
0.6
0.8 ab
1.8
1.0
2.2
1.0
0.2
0.8 ab
8.4 a
Chisel Injected 8" / 22 days
rototilled 4" to 6"
Chisel Injected 8" / 17 days
rototilled 4" to 6"
Chisel Injected 8" / 5 days
rototilled 4" to 6"
rototilled 4" to 6"
Chisel Injected 8" / 35 days
6. Methyl Bromide 98%,
200 lbs. ai/A
Chisel Injected 8" / 35 days
0.0
1.0 a
1.0
1.8
0.2
0.2
1.0
1.2 ab
6.4 ab
7. Non-treated Control
NA / 35 days
0.0
0.0 b
0.2
0.6
0.6
0.0
0.6
0.0 b
2.0 c
a
The injector used in this study, we refer to as the chisel injector, was specially built for these applications. It has chisel shanks for injecting chemicals
8-10 inches deep and is equipped with a combination rototiller for applying chemicals such as metam sodium in combination with injectable soil
fumigant products.
b
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test. No letters
indicate non- significant difference.
-122-
Table 6. Effect of soil chemical treatment on cull yield of Prelude Yellow Crook Neck Squash - 2001b
Treatment / Rate
1. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
2. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
3. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
4. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
5. Vapam, 37.5gal/A
+ Chloropicrin, 9 gal/A
6. Methyl Bromide 98%,
200 lbs. ai/A
Method a / Time before
Planting
15
Weight (lbs) of Cull Yellow Crook Neck Squash plot (35 lin. ft. row)
May
June
Total
18
22
25
29
1
5
8
Mean
Chisel Injected 8" / 35 days
rototilled 4" to 6"
0.14
0.0 b
0.0
0.06
0.02
0.2 a
0.04
0.24
5.2 abc
0.08
0.02 b
0.1
0.1
0.02
0.0 b
0.04
0.2
6.0 ab
0.0
0.06 ab
0.0
0.06
0.12
0.0 b
0.08
0.06
3.4 bc
0.06
0.12 ab
0.14
0.14
0.14
0.04 b
0.14
0.0
5.0 abc
0.12
0.22 a
0.32
0.2
0.12
0.06 b
0.02
0.26
8.4 a
0.0
0.14 ab
0.16
0.1
0.02
0.02 b
0.08
0.22
6.4 ab
Chisel Injected 8" / 22 days
rototilled 4" to 6"
Chisel Injected 8" / 17 days
rototilled 4" to 6"
Chisel Injected 8" / 5 days
rototilled 4" to 6"
rototilled 4" to 6"
Chisel Injected 8" / 35 days
Chisel Injected 8" / 35 days
7. Non-treated Control
NA / 35 days
0.0
0.0 b
0.02
0.12
0.1
0.0 b
0.04
0.0
2.0 c
a
The injector used in this study, we refer to as the chisel injector, was specially built for these applications. It has chisel shanks for injecting chemicals
8-10 inches deep and is equipped with a combination rototiller for applying chemicals such as metam sodium in combination with injectable soil fumigant
products.
b
Data are means of five replications. Means followed by the same letter are not different (P = 0.05) according to Duncan’s multiple range test.
No letters indicate non-significant difference.
-123-
Table 7. Population densities of Pythium spp., Rhizoctonia spp., and Fusarium spp., and viability of Pythium irregulare, Fusarium solani, Rhizoctonia
solani,
and yellow nutsedge in soil 3 weeks after treatment with alternatives to methyl bromide in April, 2001 (Prelude Yellow Crook Neck Squash).
d
Treatment / Rate
1. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
2. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
3. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
4. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
5. Vapam, 37.5gal/A
+ Chloropicrin, 9 gal/A
6. Methyl Bromide 98%,
200 lbs. ai/A
Method b / Time before
Planting
Chisel Injected 8" / 35 days
Fusarium
Fungal populations a
Pythium Rhizoctonia
PI
Pathogen and weed viability c
FS
RS
YN
528 ab
4.0 b
0.03 b
0b
48 b
10 c
0c
112 cd
0.8 b
0.05 b
0b
20 b
0c
0c
320 bc
0b
0b
0b
64 ab
52 ab
10 c
32 d
0b
0b
0b
64 ab
86 a
68 b
16 d
6.4 b
0.05 b
0b
18 b
0c
0c
16 d
0b
0.08 b
0b
100 a
20 bc
2c
rototilled 4" to 6"
Chisel Injected 8" / 22 days
rototilled 4" to 6"
Chisel Injected 8" / 17 days
rototilled 4" to 6"
Chisel Injected 8" / 5 days
rototilled 4" to 6"
rototilled 4" to 6"
Chisel Injected 8" / 35 days
Chisel Injected 8" / 35 days
7. Non-treated Control
NA / 35 days
608 a
140 a
0.5 a
80 a
100 a
74 a 88 a
Total populations of Fusarium spp., Pythium spp., and Rhizoctonia spp. expressed as the number of colony forming units per gram of soil.
b
The injector used in this study, we refer to as the chisel injector, was specially built for these applications. It has chisel shanks for injecting chemicals
8-10 inches deep and is equipped with a combination rototiller for applying chemicals such as metam sodium in combination with injectable soil fumigant
products.
c
Percentage of pathogen-infested grains or yellow nutsedge nutlets that were viable after removal from treated soil prior to transplanting of peppers.
PI=Pythium irregulare, FS=Fusarium solani, RS=Rhizoctonia solani (AG-4), and YN=yellow nutsedge.
d
Data are means of five replications. Means followed by the same letter do not differ significantly as determined by Fisher’s protected least significant
difference test (P#0.05).
a
-124-
Table 8. Population densities of Pythium spp., Rhizoctonia spp., and Fusarium spp. in soil 3 months after treatment with alternatives to methyl
bromide in April, 2001 (Prelude Yellow Crook Neck Squash.)c
Treatment / Rate
Method b / Time before Planting
Fungal populations a
Pythium
Rhizoctonia
8672 bc
4.8 b
0b
9408 ab
2.4 b
0b
11488 a
0.8 b
0b
9840 ab
0.8 b
0b
11056 a
2.4 b
0b
10960 ab
2.4 b
0b
Fusarium
1. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
2. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
3. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
4. Telone C-17, 10 gal/A
+ Vapam, 37.5gal/A
5. Vapam, 37.5gal/A
+ Chloropicrin, 9 gal/A
6. Methyl Bromide 98%,
200 lbs. ai/A
Chisel Injected 8" / 35 days
rototilled 4" to 6"
Chisel Injected 8" / 22 days
rototilled 4" to 6"
Chisel Injected 8" / 17 days
rototilled 4" to 6"
Chisel Injected 8" / 5 days
rototilled 4" to 6"
rototilled 4" to 6"
Chisel Injected 8" / 35 days
Chisel Injected 8" / 35 days
7. Non-treated Control
NA / 35 days
6496 c
45.6 a
0.08 a
Total populations of Fusarium spp., Pythium spp., and Rhizoctonia spp. expressed as the number of colony forming units per gram of soil.
b
The injector used in this study, we refer to as the chisel injector, was specially built for these applications. It has chisel shanks for injecting
chemicals 8-10 inches deep and is equipped with a combination rototiller for applying chemicals such as metam sodium in combination with
injectable soil fumigant products.
c
Data are means of five replications. Means followed by the same letter do not differ significantly as determined by Fisher’s protected least
significant difference test (P#0.05).
a
-125-
Effects of Tomato Spotted Wilt Virus on Plant Growth, Yield and Fruit Quality
of Drip-Irrigated Tomato Plants
Juan C. Diaz-Perez, Dean Batal, Denne Bertrand and David Giddings
Dept of Horticulture, Coastal Plain Experiment Station, Tifton, GA 31794
Introduction
Tomato spotted wilt virus (TSWV) can cause serious damage to tomato, pepper, lettuce
and other crops. The virus is transmitted by several species of thrips. Because the virus has
wide host range, it is difficult to eliminate the disease.
Chemical control of the vector is often used as a means to reduce the incidence of
TSWV. However, chemical control may not fully control TSWV. Besides excessive use of
pesticides increases the cost of production and may have an impact on the environment.
Effective strategies of disease management require an understanding of the relationship between
the host (tomato plant) and the vector (thrips). The objective of this study was to determine the
effect of the time after transplanting when TSWV symptoms first appeared on tomato plant size,
fruit yield and fruit quality.
Materials and Methods
This study was conducted at the Horticulture Farm, Coastal Plain Experiment Station,
Tifton, Georgia during the spring of 1999. Tomato (cv. ‘Florida-47',Asgrow) plants were dripirrigated and planted over black plastic mulch. Fumigation, fertilization and irrigation were
performed according to standard practices (University of Georgia, Extension Service). Six-week
old transplants were planted in 0.9-m beds, formed on 1.8-m centers. Transplants were planted
in a single row per bed and a 60-cm spacing between transplants.
Determination of TSWV incidence
Tomato plants acquired TSWV under conditions of natural infection. During the season,
there was a high incidence of thrips and TSWV in the region. Individual plants were visually
monitored every 4-7 d for TSWV symptoms for the whole season, and the date when each plant
first showed TSWV symptoms was determined. The presence of TSWV in symptomatic plants
was confirmed through ELISA. The percent of asymptomatic plats was not determined.
Determination of TSWV severity in fruit
Severity of TSWV symptoms in fruit was determined visually based on a 5-point scale
(see below). Fruit were graded according to USDA standards. Those fruit with a TSWV score
of < 3 were considered marketable.
Effect of TSWV on quality of ripe fruit
-126-
Fruit from individual plants were harvested and graded. Marketable fruit with TSWV severity of
# 3 were allowed to ripen at 20 °C (68 °F). After ripening, fruit were graded again for TSWV
severity.
TSWV Severity Scale in Fruit
1 = NO SYMPTOMS.
2 = MILD. Small specks or irregular discoloration in <10% fruit surface; fruit
surface free from scars or other defects.
3 = MODERATE. More than 10% fruit surface with specks or patches of
different skin color; <10% fruit surface with minor scars on fruit surface).
4 = MODERATELY SEVERE. More than 10% fruit surface with specks or
patches of different skin color and scars; concentric rings in the skin (bull’s
eye); moderate fruit deformation.
5 = SEVERE. Fruit are small, highly deformed with abundant necrotic area.
Results and Discussion
Dynamics of TSWV symptoms appearance
The first plants with TSWV symptoms where found 28 DAT. The incidence of TSWV was close
to 100% by 70 DAT. High populations of thrips were detected since early stages of plant
development, which were probably associated to the high incidence of TSWV.
Effect of TSWV on plant growth
Plant fresh weight was higher the later in plant development TSWV symptoms first appeared.
Plants infected 30 DAT reached a final weight of 0.5 kg, while those infected 70 DAT weighed
about 5.0 kg (Fig. 1). Plant leaf area was also positively correlated with the time of first
symptom expression (data not shown).
Effect of TSWV on fruit yield
The time of first symptom expression was also positively correlated with total fruit yield (Fig. 1),
marketable yield, and fruit number and size (Table 1). This decrease in fruit number and size
associated to early TSWV infection was probably a result of a reduced capacity of the infected
plants to produce enough photosynthates to sustain fruit growth.
Effect of TSWV on fruit quality after ripening
Fruit from TSWV-infected plants ripened abnormally, showing irregular red color development
of the skin. TSWV scores after ripening were 3.15, 3.34, and 3.57 for fruit previously graded as
1, 2, and 3 respectively. This indicates that fruit from TSWV-infected plants with no apparent
TSWV symptoms before ripening, may not ripen properly during storage or at the retail level
and thus be of poor quality.
Conclusions
-127-
TSWV infection was deleterious to plant growth and fruit production. Plants were
susceptible to damage from TSWV infection from transplanting to harvest.
The impact of TSWV on plant growth and fruit yield was more severe the sooner after
transplanting tomato plants first showed TSWV symptoms.
Presence of TSWV in the plant was associated with a reduction in fruit quality (fruit
deformation and irregular fruit ripening). Irregular ripening was observed in several
mature-green fruit with no TSWV symptoms at harvest time.
Table 1. Correlation coefficients (r) for the relationships of time (DAT) for TSWV symptom
expression with various tomato plant growth and fruit yield attributes (n = 214 plants).
Plant attribute
r
p>F
0.805
< 0.0001
Total
0.798
< 0.0001
Marketable
Large
Medium
Small
Culls
0.713
0.640
0.512
0.457
0.756
< 0.0001
< 0.0001
< 0.0001
< 0.0001
< 0.0001
0.824
0.704
0.223
0.640
0.523
0.477
0.741
< 0.0001
< 0.0001
0.021
< 0.0001
< 0.0001
< 0.0001
< 0.0001
Plant growth
Plant fresh weight
Number of fruit per plant
Fruit yield per plant
Total
Marketable
Extra-large
Large
Medium
Small
Culls
-128-
Plant fresh weight (Kg)
6
y = 0.0885x - 1.7484
2
R = 0.648
5
4
3
2
1
0
0
20
40
60
80
40
60
80
Fruit yield per plant (kg)
12
y = 0.2679x - 8.8358
2
R = 0.679
10
8
6
4
2
0
0
20
Time of TSWV symptom expression (DAT)
Figure 1. Effect of time of TSWV symptom expression on
tomato plant weight and fruit yield.
-129-
Evaluation of Fungicides and Biological Control Materials for Control of
Cercospora Leaf Spot of Turnip
D. B. Langston, Jr.1, R. T. Boland, Jr.2, J. G Price3
Cercospora Leaf Spot; Cercospora brassicicolaUniv. of Georgia Coop. Ext. Ser., Depts. 1Plant
Pathology, Tifton, GA 31793, 2Brantley Co. CEC,
Nahunta, GA 31553 and Camden Co. CEA,
Woodbine, Ga, 31569
Introduction
Leaf spot diseases directly affect leafy green crops because the plant part that is marketed
is the part that is affected. According to the U.S. Department of Agriculture standards for
mustard and turnip greens, leaves with more than 10% of the surface area discolored are
unsalable. Also, most leafy greens are harvested mechanically by once-over cutting which
means that all foliage must be removed. Hand separation of unacceptable leaves and decayed
tissue is time-consuming and expensive. Fungicides that can be used to control foliar diseases of
leafy greens are few. Benlate had been an excellent option for control of Cercospora leaf spot of
turnip greens and has been used under a Section 24C in several southeastern states. DuPont has
recently voluntarily removed Benlate from the market within the past 2 years. Maneb has a
Section 24C state label for Georgia and Tennessee for leafy greens. However, Maneb is only
partially effective in controlling these leaf spot diseases under high disease pressure. Quadris
has recently received a full federal label for use on leafy greens and has been shown to be an
excellent fungicide for control of many foliar pathogens. However, fungicide resistance to
Quadris is becoming more of a problem and there exists no effective rotational fungicide
partners in leafy greens to aid in resistance management. New, effective fungicide options must
be labeled soon to provide adequate protection for leafy green production in the southeast.
Materials and Methods
Turnip seed were planted in 36 in rows at 4 lb/A on 24 Oct in Hortense, GA. Standard
practices for management of fertility, weeds, nematodes and insects were followed throughout
the season. The experiment utilized a randomized complete block design with 4 replications.
Each fungicide plot consisted of two 15-ft long rows that utilized a 3-ft buffer zone between plot
ends. Foliar fungicide treatments were initiated at the first symptoms of disease (26 Nov).
Fungicides were applied using a CO2-pressurized backpack sprayer calibrated to deliver 40 gal/A
at 75 psi through TX-18 hollow cone nozzles.
Results
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Weather during the experiment was warm and very dry with rainfall accumulations
during the test period of only 0.92 in. Treatments that significantly reduced leaf spot compared
to the non-treated check on the 04 Dec rating date were both BAS500 treatments, BAS516,
Quadris at 5.0 fl oz/A, and Benlate (Table 1). All fungicide treatments significantly reduced leaf
spot by 17 Dec. No phytotoxicity was observed with any of the treatments.
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Table 1.
Leaf Spot Ratings2
Treatment, rate/A and spray timing1
04 Dec
17 Dec
BAS500 20WG, 0.75 lb/A (2, 4) . . . . . . . . . . . . . . . . . . 5.5 d3
2.0 e
BAS500 20WG, 1.0 lb/A (2, 4) . . . . . . . . . . . . . . . . . . . 4.5 d
2.3 e
BAS516 38WG, 0.66 lb/A (2, 4) . . . . . . . . . . . . . . . . . 7.8 cd
4.8 de
Quadris 2.08F, 5.0 fl oz/A (2, 4) . . . . . . . . . . . . . . . . . 14.0 b-d
13.8 cd
Quadris 2.08F, 8.0 fl oz/A (2, 4) . . . . . . . . . . . . . . . . . 19.0 a-c
15.0 cd
Benlate 50WP, 0.5 lb/A (2, 4) . . . . . . . . . . . . . . . . . . . . 9.3 cd
9.4 de
Bravo Weatherstik 720F, 1.5 pt/A (2, 4) . . . . . . . . . . . 26.5 a
23.8 c
Maneb 75DF, 2.0 lb/A (2, 4) . . . . . . . . . . . . . . . . . . . . 24.0 ab
35.0 b
Serenade 10WP, 4.0 lb/A (2, 4) . . . . . . . . . . . . . . . . . . 21.3 ab
45.0 b
Non-treated check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30.0 a
60.0 a
1
Spray dates are as follows: 1=26 Nov; 2=4 Dec.
2
Percent leaf area affected by leaf spot.
3
Means in columns with letter(s) in common are not significantly different according to Fisher’s
Protected LSD test at P
-132-
Evaluation of Fungicides and Spray Programs for Control of
Gummy Stem Blight of Watermelon.
D. B. Langston, Jr. and K.W. Seebold, University
of Georgia Dept. of Plant Pathology, CPES, Tifton, GA 31793
Introduction
Gummy stem blight, caused by the fungus Didymella bryoniae is the most widespread and
destructive disease of watermelon in Georgia. Management options for this disease are rotation,
deep turning diseased tissue, avoiding irrigating that prolongs leaf wetness, and preventive fungicide
applications. Of these management options, preventive fungicide applications is the most effective.
Fungicides labeled for control of gummy stem blight are primarily ethylenebisdithiocarbamates
(Dithane, Maneb, Manzate, Penncozeb, ect), chlorothalonil (Bravo, Echo, Equus), benomyl
(Benlate), thiophanate methyl (Topsin M), and just recently, the strobilurin azoxystrobin (Quadris).
Benomyl or thiophanate methyl tank-mixed with EBDC’s and alternated with chlorothalonil
products had proven to offer good control of gummy stem blight until resistance to the
benzimidazoles (benomyl and thiophanate methyl) was observed in the early 1990's. Chlorothalonil
products have shown good efficacy on gummy stem blight but are not used because they have been
implicated in causing phytotoxicity to mature watermelon rinds. Azoxystrobin was shown to have
excellent efficacy on gummy stem blight by several researchers in the early 1990's and was granted
Section 18 emergency exemption status in Georgia in 1997 and 1998 specifically for gummy stem
blight control. A full Section 3 national label was granted for azoxystrobin use on the cucurbit crop
grouping in March of 1999 which led to the widespread and routine use of the fungicide to control
a broad spectrum of foliar cucurbit diseases. However, resistance to azoxystrobin in gummy stem
blight has been documented across Georgia. Studies that evaluate the efficacy of new and emerging
products along with the strobilurins are needed to develop effective spray programs for watermelons.
Materials and Methods
Watermelon seed (Citrullus lanatus ‘Stargazer’) were planted on 6 Jun in a bare-ground field
every 42 in. rows spaced 6-ft apart. Experimental plots were 30-ft long, utilized 10-ft borders
between plot ends, and were arranged in a randomized complete block with 4 replications. Each
treated plot was alternated with a non-treated row. Standard practices for management of fertility,
weeds, nematodes and insects were followed throughout the season. Fungicides were applied using
a CO2-pressurized backpack sprayer calibrated to deliver 40 gal/A at 40 psi through TX-26 hollow
cone nozzles. Plots were harvested on 13 Sep.
Results
Rainfall accumulation from Jun through Sep was 4.1 in. above normal, which was conducive to
disease development. Gummy stem blight was first observed on 8 Aug and completely defoliated
some plots by 4 Sep. Bravo Weatherstik alone, Folicur applied alone at 8.0 oz/A, Folicur applied
-133-
at 8.0 oz/A alternated with Bravo Weatherstik, and TD 2435-01 applied at the 1.75 lb/A rate
significantly reduced gummy stem blight severity on 4 Sep and the AUDPC compared to the nontreated check (Table 1). Folicur at 8.0 oz/A was the only treatment to significantly improve yield
over the non-treated check.
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Table 1.
Gummy Stem
Blight2 AUDPC3
Treatment, rate/A, spray timing1
Yield
lbs/plot
Bravo Weatherstik 720 6F, 2.0 pt/A (1, 2, 4, 5, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78.8 d4
39.7 h
67.9 a-c
Folicur 3.6F, 6.0 fl oz/A + Induce, 6.4 fl oz/A (1, 2, 4, 5, 6) . . . . . . . . . . . . . . . . . . . . . . . . 97.8 ab
49.7 e-h
45.2 c-h
Folicur 3.6F, 8.0 oz/A + Induce, 6.4 fl oz/A (1, 2, 4, 5, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . 86.0 b-d
40.3 h
74.5 a
Folicur 3.6F, 6.0 fl oz/A + Induce, 6.4 fl oz/A (1, 4, 6)
Bravo Weatherstik 720 F, 2.0 pt/A (2, 5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90.0 a-d
42.7 gh
51.6 a-e
Folicur 3.6F, 8.0 fl oz/A + Induce, 6.4 fl oz/A (1, 4, 6)
Bravo Weatherstik 720 F, 2.0 pt/A (2, 5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83.3 cd
41.4 h
69.0 ab
Dithane Rainshield 75DF, 3.0 lb/A (1, 2, 4, 5, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99.5 a
60.5 b-f
45.4 b-h
Topsin M 70WP, 0.5 lb/A, (1, 2, 4, 5, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97.8 a
64.2 a-d
31.3 d-i
Topsin M 70WP, 0.5 lb/A + Dithane Rainshield 75DF, 2.0 lb/A (1, 4, 6)
Bravo Weatherstik 720 6F, 2.0 pt/A (2, 5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97.0 ab
61.3 b-e
43.9 d-h
TD 2435-01 90DF, 0.75 lb/A (1, 2, 4, 5, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99.5 a
62.7 a-e
49.6 b-f
TD 2435-01 90DF, 1.25 lb/A (1, 2, 4, 5, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96.0 ab
60.6 b-f
47.0 b-g
TD 2435-01 90DF, 1.75 lb/A (1, 2, 4, 5, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82.3 cd
40.3 h
51.1 a-e
Switch 62.5WG, 13.5 oz/A (1, 2, 4, 5, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90.0 a-d
48.6 e-h
54.0 a-d
Nova 40WP, 5.0 oz/A (1, 2, 4, 5, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98.7 a
52.6 d-h
52.2 a-e
Flint 50WG, 2.0 oz/A (1, 2, 4, 5, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96.0 ab
62.6 a-e
22.7 hi
Flint 50WG, 4.0 oz/A (1, 2, 4, 5, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99.3 a
70.4 a-c
26.2 f-i
BAS500 20WG, 12.0 oz/A (1, 2, 4, 5, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99.0 a
65.5 a-d
25.4 g-i
-135-
Table 1. continued
Gummy Stem
Blight
AUDPC
Yield
lbs/plot
BAS500 20WG, 12.0 oz/A (1, 4, 6)
Bravo Weatherstik 720 6F, 2.0 pt/A (2, 5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93.0 a-c
46.8 f-h
41.9 d-h
Quadris 2.08SC, 12.3 fl oz/A (1, 2, 4, 5, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.0 a
70.7 a-c
25.8 g-i
Quadris 2.08SC, 12.3 fl oz/A (1, 4, 6)
Bravo Weatherstik 720 6F, 2.0 pt/A (2, 5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99.5 a
71.5 ab
46.7 b-g
Quadris 2.08SC, 6.2 fl oz/A + Actigard 50WG, 0.5 oz/A (1, 6)
Bravo Weatherstik 720 6F, 2.0 pt/A (4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99.5 a
69.0 a-c
25.8 g-i
Quadris 2.08SC, 6.2 fl oz/A + Actigard 50WG, 0.5 oz/A (1, 8)
Bravo Weatherstik 720 6F, 2.0 pt/A (5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99.0 a
60.1 b-f
41.4 d-h
Quadris 2.08SC, 9.2 fl oz/A + Actigard 50WG, 0.5 oz/A (1, 4)
Bravo Weatherstik 720 6F, 2.0 pt/A (3, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.0 a
60.0 b-f
29.1 e-i
Quadris 2.08SC, 9.2 fl oz/A + Actigard 50WG, 0.5 oz/A (1, 6)
Bravo Weatherstik 720 6F, 2.0 pt/A (4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99.3 a
75.9 a
35.9 d-h
Quadris 2.08SC, 6.2 fl oz/A + Actigard 50WG, 0.5 oz/A (1, 4, 6)
Bravo Weatherstik 720 6F, 2.0 pt/A + Actigard 50WG, 0.5 oz/A (2, 5) . . . . . . . . . . . . . . 100.0 a
61.7 b-e
13.9 i
Quadris 2.08SC, 6.2 fl oz/A + Actigard 50WG, 0.5 oz/A (1, 4)
Switch 62.5WG, 13.5 oz/A (2, 5)
Bravo Weatherstik 720 6F, 2.0 pt/A (6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.0 a
62.2 a-e
41.4 d-h
Non-treated check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99.8 a
56.6 c-g
47.4 b-g
Treatment, rate/A, and spray timing
1
Fungicide treatments were applied on the following dates: 1=23 Jul; 2=31 Jul; 3=3 Aug; 4=8 Aug; 5=14 Aug; 6=21 Aug; 7=23 Aug; and 8=28 Aug.
2
Percentage of leaf area affected by gummy stem blight on 4 Sep.
3
Area under the disease progress curve for gummy stem blight calculated from four weekly evaluations beginning on 8 Aug to 4 Sep.
-136-
4
Means in columns with letter(s) in common are not significantly different according to Fisher’s protected
LSD test at P
Evaluation of Actigard, Messenger, and Vacciplant for
Suppression of Bacterial Spot of Tomato
1
D. B. Langston, Jr.1, and J. T. Flanders2,
University of Georgia Coop. Ext. Ser., Dept. Plant Pathology,
Tifton, GA 31793 and 2Grady Co. CEC., Cairo, GA 31728
Introduction
Bacterial spot, caused by the bacterium Xanthomonas campestris pv. vesicatoria, is one of
the most troublesome diseases of tomato in Georgia. Warm weather coupled with wet conditions
are favorable for development of this disease. Standard control practices are using disease-free
seed and transplants, avoiding working in wet foliage, and weekly copper sprays. However,
severe losses to bacterial spot are still observed despite these measures. Part of the problem is
resistance of the bacterium to copper. Copper tank-mixed with maneb or mancozeb has helped
overcome some of the resistance problem but some isolates have become less sensitive to this
strategy as well. New biological control materials and plant activators have shown promise
against bacterial pathogens in other systems. This study was conducted to determine the
effectiveness of those compounds when added to a normal copper + maneb spray program.
Materials and Methods
A commercial tomato field in Grady Co. GA was chosen for this study. Tomato plants
(Lycopersicon esculentum “Florida 47”) were treated in the field with Actiguard, Messenger and
Vacciplant using a CO2 pressurized backpack sprayer calibrated to deliver 40 GPA at 75 psi.
Plots were arranged in a randomized complete block design, replicated 4 times, were 50-ft long
× 6-ft apart, contained approximately 25 plants/plot.
Results
The weather during the experiment was warm and dry but was favorable enough to support a
natural epidemic of bacterial spot in the field. Actigard at 0.75 oz/acre was the only treatment to
significantly reduce the severity of bacterial spot by the 9 September rating date. No differences
in yield or disease severity were noted in later assessments.
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Treatment, rate/A and spray timing1
Bacterial Spot
Ratings2
9/09
9/27
Bacterial Spot
No.3
9/27
Total4
Yield
Actigard, 0.75 oz/A (1, 3, 5, 7) . . . . . . . . . . . . 5.0 b3
40.0 a
35.5 a
109.3 a
Messenger, 30 ppm, (1-10) . . . . . . . . . . . . . . 11.3 a
57.5 a
48.0 a
104.1 a
Vacciplant, 12.8 fl oz/A (1, 3, 5, 7) . . . . . . . 15.0 a
47.5 a
46.8 a
106.0 a
Vacciplant, 25.6 fl oz/A (1, 3, 5, 7) . . . . . . . . 15.0 a
61.2 a
37.3 a
100.3 a
Industry Standard (copper + maneb weekly) . 11.3 a
57.5 a
75.3 a
96.1 a
1
Spray dates are as follows: 1=27 Jul; 2=3 Aug; 3=11 Aug; 4=17 Aug; 5=25 Aug; 6=1 Sep; 7=10 Sep;
8=18 Sep; 9=25 Sep; 10=2 Oct.
2
Percent leaf area affected by leaf spot.
3
Number of spots per 5 leaves per plot.
4
Total marketable yield from 10 Oct, 24 Oct, 21 Nov.
5
Means in columns with letter(s) in common are not significantly different according to Fisher’s Protected
LSD test at P=0.05.
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Evaluation of Fungicides and Biological Control Materials for
Control of Powdery Mildew in Transgenic Yellow Crookneck Squash
D. B. Langston, Jr.1 and W. T. Kelley2,
Univ. of Georgia Coop. Ext. Ser., Depts. 1Plant Pathology and 2Horticulture,
Tifton, GA 31793.
Introduction
Powdery mildew, caused by the fungus Sphaerotheca fuliginea, is on of the most costly
diseases of cucurbits both in yield loss and cost of control. Several fungicides have been
developed through the years which have been used to suppress losses to powdery mildew but
have become ineffective due to a shift towards more aggressive, less fungicide sensitive
pathogen populations and because of development of resistance to certain fungicidal modes of
action. Cucurbit growers have few fungicide options open to them that provide adequate
powdery mildew suppression that can also serve as alternative modes of action for fungicide
resistance management. Several fungicides with high levels of efficacy against powdery mildew
and with different modes of action are needed to provide adequate disease control and to
maintain the effectiveness of powdery mildew fungicides.
Materials and Methods
Squash seed (‘Destiny III’) were planted on 30 Aug black plastic-mulched beds that had
been previously been planted to bell pepper in Tifton, GA. Seed were planted every 18 in. in
rows spaced 6 ft apart. Standard practices for management of fertility, weeds, nematodes and
insects were followed throughout the season. The experiment utilized a randomized complete
block design with 4 replications. Each fungicide plot consisted of a single 15-ft long row that
utilized a 3-ft buffer zone between plot ends. Foliar fungicide treatments were initiated at
anthesis (27 Sep). Fungicides were applied using a CO2-pressurized backpack sprayer calibrated
to deliver 40 gal/A at 75 psi through TX-18 hollow cone nozzles.
Results
Weather during the experiment was cool with rainfall accumulations from Sep through
Oct near the 77 year average of 5.6 in. Powdery mildew was first observed on 10 Oct and
increased to high levels by the 26 Oct rating date. Disease assessments on 16 Oct indicated that
none of the treatments fungicides significantly reduced powdery mildew severity on the upper
leaf surface (ULS) (Table 1). Lower leaf surface (LLS) assessments on 16 Oct indicated that all
treatments significantly reduced powdery mildew severity compared to the non-treated check
with the exception of the biological material, Serenade, applied at the 2.0 lb/A rate. All
fungicides and fungicide/Serenade combinations significantly outperformed Serenade applied
alone at 4.0 lb/A. Serenade alternated with Nova significantly reduced disease severity
compared to Serenade alternated with Flint. Disease assessments recorded on 26 Oct
-139-
demonstrated that all fungicide treatments significantly reduced disease on the ULS and LLS
except the 2.0 rate of Serenade. Treatments containing Procure, Nova or Flint either alone or in
combination demonstrated the greatest levels of control. However, when applied alone, both
Procure and Nova significantly outperformed Flint. Nova also significantly outperformed Flint
when alternated with Serenade.
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Table 1.
Powdery Mildew Ratings2
16 Oct
26 Oct
Treatment, rate/A and spray timing1
ULS
LLS
ULS
LLS
Procure 50WS, 6.0 oz/A (1, 3)
Flint 50WG, 2.0 oz/A (2, 4) . . . . . . . . . . . . . . . . . . . . . . . . 0.0 a3
3.8 cd
0.0 b
3.1 de
Procure 50WS, 6.0 oz/A + Silwet L-77, 0.05% v/v (1, 3)
Flint 50WG, 2.0 oz/A (2,4) . . . . . . . . . . . . . . . . . . . . . . . . 0.0 a
3.1 cd
0.0 b
1.8 de
Procure 50WS, 8.0 oz/A (1, 3)
Flint 50WG, 2.0 oz/A (2, 4) . . . . . . . . . . . . . . . . . . . . . . . 0.0 a
4.0 cd
0.0 b
3.6 de
Nova 40W, 5.0 oz/A (1, 3)
Flint 50WG, 2.0 oz/A (2, 4) . . . . . . . . . . . . . . . . . . . . . . . . 0.0 a
3.4 cd
0.0 b
2.1 de
Procure 50WS, 6.0 oz/A (1, 2, 3, 4) . . . . . . . . . . . . . . . . . 0.0 a
1.0 d
0.0 b
1.0 e
Nova 40W, 5.0 oz/A (1, 2, 3, 4) . . . . . . . . . . . . . . . . . . . . 0.0 a
1.0 d
0.0 b
1.0 e
Flint 50WG, 2.0 oz/A (1, 2, 3, 4) . . . . . . . . . . . . . . . . . . . . 0.0 a
5.0 cd
0.0 b
15.3 d
Serenade 10WP, 2.0 lb/A (1, 2, 3, 4) . . . . . . . . . . . . . . . . . 5.8 a
35.0 a
19.4 a
77.5 a
Serenade 10WP, 4.0 lb/A (1, 2, 3, 4) . . . . . . . . . . . . . . . . . 2.5 a
26.3 b
6.5 b
61.3 b
Serenade 10WP, 2.0 lb/A (1, 3)
Flint 50WG, 2.0 oz/A (2, 4) . . . . . . . . . . . . . . . . . . . . . . . . 0.3 a
9.4 c
6.3 b
42.5 c
Serenade 10WP, 2.0 lb/A (1, 3)
Nova 40W, 5.0 oz/A (2, 4) . . . . . . . . . . . . . . . . . . . . . . . . . 0.0 a
2.1 d
0.9 b
13.1 de
Non-treated check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6 a
38.8 a
25.0 a
91.3 a
1
Spray dates are as follows: 1=27 Sep; 2=5 Oct; 3=15 Oct; 4=22 Oct.
Percent leaf area affected by powdery mildew on both upper (ULS) and lower (LLS) leaf surfaces.
3
Means in columns with letter(s) in common are not significantly different according to Fisher’s Protected
LSD test at P=0.05.
2
-141-
Evaluation of Fungicides and Biological Materials for Control of Downy Mildew and
Plectosporium Blight of Pumpkin
D. B. Langston, Jr. and K.W. Seebold, University of
Georgia Dept. of Plant Pathology, CPES, Tifton, GA 31793
Introduction
Downy Mildew (Pseudoperonospora cubensis) and Plectosporium blight (Plectosporium
tabacinum) are two of the most destructive diseases plauging pumpkin growers in North
Georgia. Fungicide trials were conducted at the Mountain Branch Research Station in
Blairsville Georgia to evaluate certain fungicides for efficacy against both of these pumpkin
diseases.
Materials and Methods
Pumpkin seed (‘Oz’) were planted on 13 Jun in a bare-ground field every 2 ft in rows spaced
8 ft apart. Experimental plots were 16-ft long and utilized a randomized complete block design
with 4 replications. Standard practices for management of fertility, weeds, nematodes and
insects were followed throughout the season. Nova 40WP was applied at 5.0 oz/A on 4 and 11
Aug to suppress powdery mildew. Fungicides were applied using a CO2-pressurized backpack
sprayer calibrated to deliver 40 gal/A at 40 psi through TX-26 hollow cone nozzles. Plots were
harvested on 1 Oct.
Results
Rainfall accumulation from Jul through Sep was only 0.36 in. below normal. Downy mildew
was first observed on 16 Aug and increased rapidly to cause complete defoliation in some plots
by harvest. Microdochium blight was observed first on 30 Aug and progressed rapidly until
harvest. Microdochium blight severity was significantly reduced compared to the non-treated
check by most treatments except the Ranman/Silwet tank-mix, KP 481at 8.0 oz/A tank-mixed
with Dithane Rainshield, QRD 282 applied alone, and Aliette. Applications of BAS500, Flint,
Quadris and Bravo Weatherstik produced the lowest Microdochium blight ratings. Significant
suppression of downy mildew was achieved by all fungicides and fungicide programs compared
to the non-treated check except Aliette and two rates of QRD 282 applied alone. The greatest
reductions in downy mildew severity and AUDPC were observed in plots treated with BAS500,
Ranman, Omega 500, Tattoo C, and KP 481 + Dithane Rainshield.
-142-
Table 1.
Plectosporium Downy
blight2
mildew3
Treatment, rate/A, spray timing1
BAS500 20WG, 8.0 oz/A (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 hi5
34.0 g-j
BAS 500 20WG, 12.0 oz/A (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 i
19.0 j
Flint 50WG, 4.0 oz/A (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 g-i
AUDPC4
Yield
(tons/A)
17.0 h-l
11.2 b-f
9.1 kl
13.5 a-c
60.0 cd
37.7 de
6.1 h-k
Quadris 2.08SC, 15.0 oz/A (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 g-i
51.8 d-f
27.1 e-i
10.7 b-g
Acrobat MZ 69WP, 2.25 lb/A (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 d-f
60.0 cd
34.3 d-f
7.4 f-j
Gavel 75DF, 2.25 lb/A (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.9 c-f
51.3 d-g
23.1 f-j
12.3 a-d
Ridomil Gold Bravo 76WP, 2.0 lb/A (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8 e-g
59.3 cd
28.0 e-i
8.3 e-i
Bravo Weatherstik 720F, 2.0 pt/A (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 g-i
62.5 cd
33.6 d-f
10.0 c-h
Dithane Rainshield 75DF, 3.0 lb/A (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1 f-h
58.3 cd
31.9 d-g
7.1 g-k
Omega 500F, 1.0 pt/A (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 d-f
18.8 j
8.9 kl
10.5 b-g
Tattoo C, 2.5 pt/A (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6 c-f
22.5 ij
10.1 kl
11.2 b-f
Ranman 400SC, 2.1 fl oz/A + Silwett L-77, 4:3 Ranman:Silwet (1-7) . . . . . . 8.1 ab
37.8 e-i
17.7 h-l
9.1 d-h
Ranman 400SC, 2.75 fl oz/A + Silwett L-77, 4:3 Ranman:Silwett (1-7) . . . . 8.1 ab
34.3 f-j
17.5 h-l
8.5 d-h
BAS 500 20WG, 8.0 oz/A (1, 3, 5, 7)
Ranman 400SC, 2.1 fl oz/A + Silwett L-77, 4:3 Ranman:Silwet (2, 4, 6) . . . 5.6 c-f
25.3 ij
12.6 j-l
11.1 b-f
BAS 500 20WG, 16.0 oz/A (1, 3, 5, 7)
Ranman 400SC, 2.75 fl oz/A + Silwett L-77, 4:3 Ranman:Silwet (2, 4, 6) . . 4.1 f-h
16.8 j
7.9 l
14.2 ab
BAS 500 20WG, 8.0 oz/A (1, 3, 5, 7)
Ranman 400SC, 2.1 fl oz/A + Silwett L-77, 4:3 Ranman:Silwet
+ Bravo Weatherstik 720F, 1.0 pt/A (2, 4, 6) . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 e-h
27.0 ij
13.4 j-l
15.1 a
BAS 500 20WG, 16.0 oz/A (1, 3, 5, 7)
Ranman 400SC, 2.75 fl oz/A + Silwett L-77, 4:3 Ranman:Silwet
+ Bravo Weatherstik 720F, 1.0 pt/A (2, 4, 6) . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 i
21.3 ij
10.3 kl
12.1 a-e
KQ 667 68.75WG, 24 oz/A (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1 c-e
51.3 d-g
29.0 e-h
8.0 f-i
-143-
Plectosporium
Blight
Mildew
Table 1. continued
Downy Yield
AUDPC
(tons/A)
KQ 667 68.75WG, 32.1 oz/A (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6 c-f
45.3 d-h
21.2 g-k
15.4 a
KP 481 50WG, 8.0 oz/A + Dithane Rainshield 75DF, 2.0 lb/A (1-7) . . . . . . . 6.9 a-d
52.0 de
28.1 e-i
6.6 h-k
KP 481 50WG, 12.2 oz/A + Dithane Rainshield 75DF, 2.0 lb/A (1-7) . . . . . . 5.3 d-f
31.8 h-j
15.9 i-l
9.3 d-h
Aliette 80WDG, 3.0 lb/A (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 a-c
91.7 a
52.9 bc
4.4 i-k
QRD 282 AS, 1% v/v (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.6 ab
88.8 a
60.3 ab
3.4 jk
QRD 282 AS, 2% v/v (1-7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8 a
94.5 a
65.8 a
4.0 jk
QRD 282 AS, 1% v/v (1, 3, 5, 7)
Ridomil Gold Bravo 76WP, 2.0 lb/A (2, 4, 6) . . . . . . . . . . . . . . . . . . . . . . . . . 6.8 b-d
70.8 bc
43.9 cd
8.2 f-i
Non-treated check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.7 a
87.7 ab
60.7 ab
3.3 k
1
Fungicide treatments were applied on the following dates: 1=24 Jul; 2=31 Jul; 3=8 Aug; 4=16 Aug; 5=22 Aug; 6=30 Aug; and 7=6
Sep.
2
Microdochium blight was evaluated on 12 Sep using a 0-10 scale where 0=no symptoms and 10=total infestation of crowns and
stems.
3
Percentage of leaf area with symptoms of downy mildew.
4
Area under the disease progress curve for downy mildew calculated from four weekly evaluations beginning on 22 Aug to 12 Sep.
5
Means in columns with letter(s) in common are not significantly different according to Fisher’s protected LSD test at P=0.05.
-144-
Evaluation of Fungicides and Protection Intervals for Control of Alternaria Leaf Spot of
Carrot Using Two Nitrogen Fertility Regimes
D. B. Langston, Jr.1 and J. E. Hudgins 2,
Univ. of Georgia Coop. Ext. Ser., Depts. 1Plant Pathology,
Tifton, GA 31793. and 2CEA, Decatur Co., Bainbridge , GA 31718
Introduction
Carrot production has become very significant in Georgia in recent years. In 2001,
approximately 5,328 acres of carrot were grown in Georgia that were valued at 25,796,788. The
soil types and climatic conditions in Georgia are conducive for production of high yielding, good
quality carrots. Like most vegetable crops, carrots are susceptible to attack by several diseases.
The primary disease of carrots in Georgia is Alternaria leaf blight (caused by Alternaria dauci).
This disease causes a foliar blight of carrot tops which reduces root size and harvesting
efficiency. The main controls for this disease have been rotation, using disease-free seed, and
applying fungicides in a preventive manner. Fungicides that are labeled on carrot for
suppressing Alternaria leaf blight are chlorothalonil (Bravo, Echo, Equus), azoxystrobin
(Quadris), pyraclostrobin (Cabrio), and iprodione (Rovral). It has been hypothesized that overfertilization with nitrogen can cause increased susceptibility of carrot tops to Alternaria leaf
blight.
Materials & Methods
Carrot seed (‘Choctaw’) were planted on 6 Nov 00 on 6-ft beds in Bainbridge, GA. Seed
were planted every 1.5 in. in rows spaced 8 in. apart. Standard practices for management of
irrigation, weeds, nematodes and insects for carrots grown in Georgia were followed throughout
the season. The experiment utilized a split plot design with 4 replications, with fertility
treatments as the main plots and fungicide treatments as sub-plots. The standard nitrogen (N)
fertility regime received 173 lbs of N/A which consisted of a pre-plant application of 15 lbs/A of
5-20-20 (5 Nov 00), 50 lbs of 14-4-14 (12 Dec 00), 30 lbs/A of 28-0-0-5 (5 Jan 01 and 15 Feb
01), and 48 lbs/A of 28-0-0-5 (8 Mar 01). The high N regime received 223 lb of N/A and
differed from the standard only by applying an extra 50 lb/A of 14-4-14 on 23 Jan, 01.
Fungicide plots were 20-ft long with a 10-ft buffer between tiers and a 15-ft buffer between
replications. Fungicides were applied using a CO2- pressurized backpack sprayer calibrated to
deliver 40 gal/A at 75 psi through TX-18 hollow cone nozzles.
Results
Weather conditions during the experiment were dry with rainfall accumulations of 8.3 in.
below the 99 year average for Nov through Apr. The onset of Alternaria leaf blight occurred late
and symptom development was not severe until after the last application of fungicide. No
significant differences in disease severity were noted between fertility regimes and no significant
interactions were detected between fungicide treatment and fertility regime. Therefore fungicide
treatments were averaged across fertility regimes. All fungicide treatments significantly reduced
disease severity compared to the non-treated check (Table 1). Generally, fungicide programs
utilizing the shortest protection interval received more fungicide sprays and had the lower
disease ratings for Alternaria leaf spot.
-145-
Table 1.
Alternaria
Treatment, rate/A and spray timing1
leaf spot2
Bravo Weatherstik 720 6L, 1.5 pt/A (1-8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 b-f3
Bravo Weatherstik 720 6L, 1.5 pt/A. (1, 3, 5, 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7 b-e
Bravo Weatherstik 720 6L, 1.5 pt/A (1, 4, 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.8 b-e
Bravo Weatherstik 720 6L, 1.5 pt/A (1, 3, 5, 7)
Quadris 2.08 SC, 15 oz/A (2, 4, 6, 8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 ef
Bravo Weatherstik 720 6L, 1.5 pt/A (1, 5)
Quadris 2.08 SC, 15 oz/A (2, 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7 b-e
Bravo Weatherstik 720 6L, 1.5 pt/A (1, 7)
Quadris 2.08 SC 15 oz/A, (4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.9 b-d
Quadris 2.08 SC, 15 oz/A (1-8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 f
Quadris 2.08 SC, 15 oz/A (1, 3, 5, 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 bc
Quadris 2.08 SC, 15 oz/A (1, 4, 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6 b-e
Rovral 4F, 1.5 pt/A (1-8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4 c-f
Rovral 4F, 1.5 pt/A (1, 3, 5, 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7 b-e
Rovral 4F, 1.5 pt/A (1, 4, 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6 b-e
Bravo Weatherstik 720 6L, 1.5 pt/A (1, 3, 5, 7)
Rovral 4F, 1.5 pt/A (2, 4, 6, 8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 d-f
Bravo Weatherstik 720 6L, 1.5 pt/A (1, 5)
Rovral 4F, 1.5 pt/A (2, 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7 b-e
Bravo Weatherstik 720 6L, 1.5 pt/A (1, 7)
Rovral 4F, 1.5 pt/A (4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3 b
Non-treated check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 a
1
Spray dates are as follows: 1=8 Feb; 2=15 Feb; 3=23 Feb; 4=8 Mar; 5=17 Mar; 6=23 Mar;
7=2 Apr; 8=10 Apr.
2
Alternaria leaf blight ratings recorded on 8 May according to a 0-10 scale where 0=no
symptoms and 10=total defoliation.
3
Means in columns with letter(s) in common are not significantly different according to Fisher’s
Protected LSD test at P=0.05.
-146-
Screening Fungicides for Control of Phytophthora capsici in Summer Squash
Kenneth W. Seebold, Jr., David B. Langston, Jr., and T. Bryan Horten
University of Georgia, Dept. of Plant Pathology, Tifton GA
Introduction
An experiment was conducted at the Blackshank Research Farm in Tifton, GA in a field that
had previously been inoculated with Phytophthora capsici to establish a disease nursery. The
soil was a Fuquay loamy sand, and was prepared with a rototiller prior to planting. Guidelines
established by the University of Georgia Cooperative Extension Service were followed for land
preparation, fertility, weed management, and insect control. Summer squash (cv. ‘Dixie’) were
planted on 23 April 01 into non-mulched, raised beds with a Stanhay vegetable seeder set to
deliver seed every 12 in. Each plot consisted of two 20 ft rows, spaced 36 in. apart, with 5 ft
borders between blocks. The experiment was laid out in a randomized complete-block design
with 4 replications. The number of plants emerged at 21 days after planting (DAP) was counted
immediately prior to initiation of fungicide applications. Fungicides were applied over the rows
with a CO2-powered backpack sprayer through a 4-nozzle boom (18 in. spacing) fitted with
TSX-26 hollow cone nozzles and set to deliver 40 gallons at 40 psi. Fungicide applications were
initiated at 21 DAP and continued weekly until maximum disease incidence was reached in the
untreated check (total of 4 sprays). Supplemental overhead irrigation was applied to the test site
after planting (0.5 in.), and daily thereafter to achieve optimal moisture conditions for
development of disease. Plant mortality was recorded in plots weekly beginning on 8 June 01
and ending on 22 June 01, when maximum mortality was observed in untreated plots.
Results and Discussion
The combination of warm temperatures, frequent irrigation, and late-season rain resulted in
severe damage to fruit by Phytophthora capsici, Pythium spp. (cottony leak), Sclerotium rolfsii, and
Choanephora cucurbitarum. Yields were therefore not taken for the experiment. Incidence of
crown rot was heaviest at the final evaluation in the untreated checks and in plots treated with
Quadris 2.08F (1 pt/A) (Table 1). The combination of Ranman 400SC (2.75 fl oz/A), BAS500
21.9WG (9 oz/A), and Silwet (2.1 fl oz/A) gave significantly better control of Phytophthora crown
rot than Ridomil Gold Bravo at 2 lb/A, Ranman 400SC (2.75 fl oz/A) tank-mixed with Penetrator
Plus (1 pt/A), and Ranman 400SC (2.75 fl oz/A) plus BAS550 50WP (6.4 oz/A) tank mixed with
Silwet (2.1 fl oz/A). No phytotoxicity was observed in the experiment.
-147-
Table 1. Effect of fungicides on the severity of Phytophthora crown rot in yellow squash, 2001.
Final disease
Treatment and rate/A
(6/22/01)a
AUDPCa
Ranman 400SC 2.75 fl oz + Silwet 2.1 oz ………………………………
21.14 cd
0.99 b
Ranman 400SC 2.75 fl oz + Penetrator Plus 1 pt ……………………….
49.32 bc
3.38 ab
Ranman 400SC 2.75 fl oz + BAS550 50WP 6.4 oz + Silwet 2.1 oz ……
39.95 bc
2.23 ab
Ranman 400SC 2.75 fl oz + BAS500 21.9WG 1 lb + Silwet 2.1 oz ……
19.82 cd
0.90 b
Ranman 400SC 2.75 fl oz + BAS500 21.9WG 9 oz + Silwet 2.1 oz …...
3.56 d
0.12 b
Omega 500F 1 pt ………………………………………………………..
18.13 cd
0.80 b
Ridomil Gold Bravo 76WP 2.0 lb ………………………………………
41.06 bc
1.99 b
BAS 500 21.9WG 1 lb …………………………………………………..
18.66 cd
1.12 b
Quadris 2.08F 1 pt ………………………………………………………
64.74 ab
5.50 a
Ridomil Gold 4EC 1 pt ………………………………………………….
22.87 cd
0.84 b
Untreated check …………………………………………………………
84.95 a
5.44 a
Means followed by the same letter do not differ significantly as determined by Fisher’s protected least
significant difference test (P#0.05).
a
Final disease rating (incidence of plants with symptoms of Phytophthora crown rot) taken on
6/22/01; AUDPC=area under the disease progress curve, constructed from evaluations taken on
6/08/01, 6/15/01, and 6/22/01.
-148-
Evaluation of Experimental Fungicides for the Control
of Phytophthora Crown rot of Summer Squash
Kenneth W. Seebold, Jr., David B. Langston, Jr., and T. Bryan Horten.
University of Georgia, Dept. of Plant Pathology, Tifton GA
Introduction
An experiment was conducted at the Blackshank Research Farm in Tifton, GA in a field that
had previously been inoculated with Phytophthora capsici to establish a disease nursery. The
soil was a Fuquay loamy sand, and was prepared with a rototiller prior to planting. Guidelines
established by the University of Georgia Cooperative Extension Service were followed for land
preparation, fertility, weed management, and insect control. Summer squash (cv. ‘Dixie’) were
planted on 23 April 01 into non-mulched, raised beds with a Stanhay vegetable seeder set to
deliver seed every 12 in. Each plot consisted of two 20 ft rows, spaced 36 in. apart, with 5 ft
borders between blocks. The experiment was laid out in a randomized complete-block design
with 4 replications. The number of plants emerged at 21 days after planting (DAP) was counted
immediately prior to initiation of fungicide applications. Fungicides were applied over the rows
with a CO2-powered backpack sprayer through a 4-nozzle boom (18 in. spacing) fitted with
TSX-26 hollow cone nozzles and set to deliver 40 gallons at 40 psi. Fungicide applications were
initiated at 21 DAP and continued weekly until maximum disease incidence was reached in the
untreated check (total of 4 sprays). Supplemental overhead irrigation was applied to the test site
after planting (0.5 in.), and daily thereafter to achieve optimal moisture conditions for
development of disease. Plant mortality was recorded in plots weekly beginning on 8 June 01
and ending on 22 June 01, when maximum mortality was observed in untreated plots.
Results and Discussion
High rainfall, supplemental irrigation, and warm temperatures resulted in high incidence of
Phytophthora crown rot in the experiment. Fruit rots caused by Pythium spp. and Choanephora
cucurbitarum severe and widespread, resulting in a total loss of yield. All treatments reduced
disease incidence early in the course of the epidemic, with KQ 667 68.75WG (2 lb/A), KP 481
(0.5 and 0.75 lb/A) + Dithane 75DF (2 lb/A), and Ridomil Gold 4EC (1 pt/A) giving highest
levels of suppression (Table 1). At the final evaluation, no significant differences in disease
control were found between any treatment. None of the experimental fungicides performed as
well as Ridomil Gold 4EC (1 pt/A). Area under the disease progress curve was lowest for
Ridomil Gold 4EC. No phytotoxicity was observed with any fungicide treatment.
-149-
Table 1. Effects of experimental fungicides on the severity of Phytophthora crown rot on yellow
squash, 2001.
Treatment and rate/A
KQ 667 68.75WG 1.5 lb
KQ 667 68.75WG 2.0 lb
Percent incidence of diseased plants
6/08/2001
6/22/2001
AUDPCa
33.8 a
92.4 a
10.8 a
1.3 c
84.7 a
8.6 ab
KP 481 50WG 0.5 lb + Dithane 75DF 2 lb
9.5 bc
81.8 a
8.6 ab
KP 481 50WG 0.75 lb + Dithane 75DF 2 lb
7.6 bc
89.2 a
8.6 ab
Ridomil Gold 4EC 1 pt
1.5 c
66.9 a
5.9 b
Untreated check
23.8 ab
87.6 a
9.9 a
Means followed by the same letter do not differ significantly as determined by Fisher’s protected
least significant difference test (P=0.05).
a
AUDPC=area under disease progress curve, calculated from plant mortality counts made on 08
June, 15 June, and 22 June 01.
-150-
-151-
Insect Control
-152-
-153-
INSECT PEST CONTROL TRIALS IN VEGETABLES IN 2000-2001
David G. Riley
Coastal Plain Experiment Station
Dept. Entomology, P.O. Box 748
Tifton, GA 31793
Introduction
In 2000-2001, several insecticide efficacy trials were conducted to evaluate various
chemicals for the control of insect pests of vegetable crops in Tift County, Georgia. The
following results summarizes efficacy data for insect pests Which occurred in significant
numbers in two snap bean tests, two cabbage tests, a pepper test and a tomato test. Insects cause
millions of dollars in damage to Georgia vegetable crops each year and the use of effective
insecticides is essential to the short term viability of the vegetable industry.
Materials and Methods
Evaluation of Insecticide Treatments in Snap Bean Against Whitefly, 2000: Snap
beans were planted into two 6-ft beds by 30 ft length on 1 Aug 2000 and maintained with
standard cultural practices at the Lang Farm, Georgia Coastal Plain Experiment Station at Tifton.
A total of 275 lbs of 10-10-10 and 150 lbs of 34-0-0 were applied to Tift sandy clay loam field
plots and irrigation regularly with an overhead sprinkler system. Scouting was initiated on 9
Aug and continued weekly until 27 Sep. Four foliar applications of insecticide were made on 11,
22, 31 Aug and11 Sep and the drench applications of Admire and Platinum were made on 9 Aug.
Three 1 mm dia. leaf disks from 3 leaf samples were taken for whitefly egg and nymph counts
and 3 randomly sampled leaf turn counts were scouted on 8/21, 8/23, 9/15, 9/27. Eggs, small
(1st + 2nd instar), and large (3rd +4th instar) larvae of SLWF were recorded per 0.8 mm2 of leaf
area sample. Beans were harvested in a single picking from 5 plants at the center of the 30 ft
plot on 28 Sep and were categorized as marketable or unmarketable and the weight of fresh plant
tops, cut at ground level, was also recorded.
Evaluation of Insecticide Treatments in Snap Bean Against Whiteflies, 2001: Snap
beans were planted similar to the 2000 snap bean test. A total of 250 lbs of 5-10-15 were applied
to Tift sandy clay loam field plots and irrigation regularly with an overhead sprinkler system.
Scouting was initiated on 21 Aug and continued weekly until 25 Sep. Four foliar applications of
insecticide were made on 23, 30 Aug and 6, 13 Sep and the drench applications of Admire and
Platinum were made on 9 Aug. Three 1 mm dia. leaf disks from 3 leaf samples were taken for
whitefly egg and nymph counts and 3 randomly sampled leaf turn counts were scouted on 8/21,
8/28, 9/4, 9/11, 9/18, 9/25. Eggs, small (1st + 2nd instar), and large (3rd +4th instar) larvae of
SLWF were recorded per 0.8 mm2 of leaf area sample. Beans were harvested in a single picking
-154-
from 5 plants at the center of the 30 ft plot on 28 Sep and were categorized as marketable or
unmarketable and the weight of fresh plant tops, cut at ground level, was also recorded.
Evaluation of Insecticide Treatments in Cabbage, 2000: Cabbage was transplanted
into 2 rows per 6-ft beds on 21 Feb 2000. A total of 500 lbs of 10-10-10 was applied to Tift
sandy clay loam field plots and irrigation regularly with an overhead sprinkler system. Scouting
was initiated on 8 Mar and continued weekly until harvest. Five weekly applications of
insecticide were made from 21 Mar to17 May and 1 sample of 6 plants were scouted per plot
approximately 24-48 h after weekly applications. Small (1st - 3rd instar) and large (4th - 6th
instar) larvae of DBM, CL, and ICW were recorded per 3-plant sample. Cabbage was harvested
from 10 ft of row (10 heads) on 25 May and heads and wrapper leaves were categorized as
severely, slightly, or not damaged and percent marketable was estimated as the percent of
cabbage heads with no damage (% marketable). Damage ratings for cabbage heads (0=none,
3=severe) and weight (lbs) of marketable heads were reported. Data was analyzed using GLM
and LSD tests for separation of means (SAS Institute 1985).
Evaluation of Insecticide Treatments in Cabbage, 2001: Cabbage was transplanted
into 2 rows per 6-ft beds on 21 Feb 2001 and a total of 500 lbs of 10-10-10 was applied to Tift
pebbly clay loam field plots and irrigated regularly. Scouting was initiated on 13 Mar and
continued weekly until harvest. Seven applications of insecticide were made from 21 Mar to25
May and 1 sample of 6 plants were scouted per plot approximately 48 h after weekly
applications. Small (1st - 3rd instar) and large (4th - 6th instar) larvae of DBM, CL, and ICW
were recorded per 3-plant sample. Cabbage was harvested from 10 ft of row (10 heads) on 23
May to 4 Jun and heads and wrapper leaves were categorized as severely, slightly, or not
damaged and the average weight of heads was measured. Damage ratings for cabbage heads
(0=none, 3=severe) and weight (lbs) of marketable heads were reported.
Evaluation of Insecticide Treatments in Pepper, 2000: Pepper was transplanted into 2
rows per 6-ft beds on 10 Aug 2000 and maintained with standard cultural practices at the Lang
Farm, Georgia Coastal Plain Experiment Station at Tifton. A total of 500 lbs of 8-8-13 per acre
was applied to Tift sandy clay loam field plots and irrigation regularly with an overhead
sprinkler system. Scouting was initiated in Aug and continued weekly until harvest. Eight
applications of insecticide were made from 16 Aug to31 Oct and 1 sample of 6 plants were
scouted per plot approximately 24-48 h after weekly applications. Lepidoptera larvae and other
insects were recorded per 6-plant sample. Pepper was harvested from 35 ft of row (60-70 plants)
on 23 Oct and 16 Nov and fruit were categorized as marketable or unmarketable and all fruit
were cut to inspect for pepper weevil larvae or pupae inside the pod.
Evaluation of Insecticide Treatments in 2001: Tomato, hyb. Florida 47, was
transplanted with 2-ft spacing into 1 row per 6-ft wide beds in 30-ft long plots on 15 Aug and
maintained with standard cultural practices at the Georgia Coastal Plain Experiment Station at
Tifton. A total of 350 lbs of 8-8-13 was applied to Tift pebbly clay loam field plots and irrigated
-155-
regularly with drip irrigation system. Scouting was initiated on 5 Sep and continued weekly
until harvest. All plots were on metallic-silver mulch (ReflecTek Foils, Inc. Lake Zurich, IL)
except treatment 10 which was white-painted plastic mulch. Nine applications of insecticide
were made from 31 Aug to 24 Oct and 1 sample of 6 plants were scouted per plot after weekly
applications. Tomatoes were harvested from 10 ft of row (5 plants) on 1 Nov and fruit were
categorized as marketable or unmarketable (primarily Lepidoptera larval damage) and the
average weight was measured. Composite (all species) measurements of Lepitoptera damage
were reported.
In all of the above tests, each treatment was replicated four times in a randomized
complete block design and data were analyzed using ANOVA and LSD tests for separation of
means (SAS Institute 1985). Results were summarized in Tables 1-6.
Results and Discussion
In the 2000 Snap Bean Trial, the lowest number of total whitefly nymphs and adults
occurred in the Knack and Knack plus Admire treatments. At the end of the season Knack
provided very good control, but there did not appear to be a rate response. The best treatments in
terms of percent marketable weight were the Admire plus Warrior/Monitor, Admire plus Knack,
high rates of Admire alone, the Warrior/Monitor and low rate of Knack. In the 2001 trial, the
best treatments in terms of lowest number of total whitefly nymphs at the end of the season, were
the high rate of Knack, Knack plus Admire and Thiodan treatments. Knack provided good
control of whitefly nymphs and there appeared to be a slight rate response.
In the 2000 Cabbage Trial the best treatments in terms of percent marketable heads were
the Novaluron, Spintor-Dipel rotation, Avaunt, Avaunt-Spintor-Dipel rotation, Avaunt-DipelSpintor rotation, and Spintor. In terms of lowest number of total Lepidoptera larvae, the best
treatments were the same. Avaunt, Spintor and Novaluron treatments all had the lowest damage
to heads. In the 2001 trial, the best treatments in terms of undamaged heads were the Avaunt,
Novaluron, Spintor, and Proclaim treatments. These treatments also had the lowest damage to
wrapper leaves. In terms of lowest number of total Lepidoptera larvae, the best treatments were
Avaunt, Karate, Spintor, Proclaim and Novaluron treatments. Avaunt, Spintor, and Karate
treatments significantly reduced small (1st and 2nd instar) diamondback moth compared to the
untreated check. The pest pressure from all Lepidoptera larvae was moderate (averaged
approximately one per plant over the sampling period in the untreated check).
The Pepper Trial treatments that had the lowest cucumber beetle numbers were the high
rates of S-1812 plus Orthene and Admire plus Confirm. The treatments that had the lowest
pepper weevil infestation were S-1812 at 0.2 lb ai, TD 2344 at 0.03 lb ai, but treatment effects
were not significantly different from the untreated check.
-156-
All of the insecticide treatments in the Tomato Trial treatments provided good
Lepidoptera control. The untreated checks were severely damaged by various species of
Lepidoptera larvae, producing less than 50% of the yield of the treated plots. The spray
treatments that also had the lowest damage from Lepidoptera were the S-1812 combination
treatments. In terms of lowest number of total whitefly, all metallic silver mulch treatments had
lower numbers compared to the one white mulch check. Also, the white mulch treatment had
significantly greater THW larvae. The best treatment in terms of the highest yield was the S1812 plus Asana XL treatment, followed by the high rate of Baythroid, then the S-1812 plus
Dipel DF treatment.
-157-
Table 1a. Snap Bean 2000 trial results.
Treatments (application method)
Rate lb
ai/a
SLWF
eggs 8/21
SLWF
eggs 9/15
Small
nymphs
9/15
Large
nymphs
9/15
SLWF
eggs 9/27
Small
nymphs
9/27
Large
nymphs
9/27
1. Admire 2SC (drench)
0.25
23.17cd
106.83a
63.17ab
5.92a
43.75cde
84.67a
1.17abc
2. Admire 2SC (drench)
0.375
3.33d
63.17c
24.67cd
0.42b
32.17de
40.50bc
0.92bc
3. Admire 2SC (drench)
0.50
1.67d
74.33abc
8.50de
0.42b
65.58abcd
58.00abc
0.00c
4. Platinum 2SC (drench)
0.14
8.08d
78.67abc
43.17bc
1.50b
30.58de
57.42abc
4.83ab
5. Admire 2SC (drench),
0.25
21.92cd
109.25a
7.25de
0.58b
80.42abc
2.75d
0.00c
Knack 0.86 EC (foliar spray)
0.067
6. Warrior 1EC (foliar spray),
0.015
102.25a
88.33abc
34.17c
0.08b
47.75bcd
51.58bc
0.33c
Monitor 4 L (foliar spray)
0.75
7. Admire 2SC (drench),
0.25
11.00cd
65.83bc
0.83e
0.08b
9.25e
32.83cd
0.58c
Warrior 1EC (foliar spray),
Monitor 4 L (foliar spray)
0.015
8. Knack 0.86 EC (foliar spray)
0.054
66.50b
64.08c
10.83de
0.67b
84.58ab
2.00d
0.00c
9. Knack 0.86 EC (foliar spray)
0.067
37.42c
103.00ab
5.17de
1.67b
86.92a
4.92d
0.42c
10. Untreated check
-
70.92b
86.00abc
72.25a
2.83ab
40.42de
65.92ab
5.25a
0.75
* Means within columns followed by the same letter are not significantly different (LSD, P<0.05).
-158-
Table 1b. Snap Bean 2000 trial results.
Treatments (application method)
Rate lb
ai/a
SLWF
adults 8/21
SLWF
adults 8/23
SLWF
adults 9/15
SLWF
adults 9/27
Bean
marketable
wt (lb)
Cut bean
plant top
wt (lb)
1. Admire 2SC (drench)
0.25
20.58a
15.08abc
34.58a
0.75bc
0.226b
1.969abc
2. Admire 2SC (drench)
0.375
7.67d
9.92abc
32.58a
1.83abc
0.332ab
2.594a
3. Admire 2SC (drench)
0.50
8.00cd
14.58abc
34.33a
2.33ab
0.273ab
2.594a
4. Platinum 2SC (drench)
0.14
13.67abcd
16.08abc
37.75a
1.33bc
0.177b
2.063abc
5. Admire 2SC (drench),
0.25
16.58ab
18.47ab
44.08a
0.58bc
0.353ab
2.219abc
Knack 0.86 EC (foliar spray)
0.067
6. Warrior 1EC (foliar spray),
0.015
15.83abc
9.17cd
38.58a
3.33a
0.275ab
1.875bc
Monitor 4 L (foliar spray)
0.75
7. Admire 2SC (drench),
0.25
13.33abcd
4.67d
30.08a
1.17bc
0.496a
2.563ab
Warrior 1EC (foliar spray),
Monitor 4 L (foliar spray)
0.015
8. Knack 0.86 EC (foliar spray)
0.054
19.67a
21.17a
39.58a
0.00c
0.254ab
1.969abc
9. Knack 0.86 EC (foliar spray)
0.067
9.25bcd
17.08abc
36.17a
0.50bc
0.169b
1.875bc
10. Untreated check
-
14.75abcd
17.67abc
30.42a
0.92bc
0.109b
1.594c
0.75
* Means within columns followed by the same letter are not significantly different (LSD, P<0.05).
-159-
Table 2. Snap Bean 2001 trial results.
Treatments (application method)
Rate lb
ai/a
SLWF
eggs on
8/28/01
SLWF
eggs on
9/11/01
SLWF
nymphs on
8/21/01
SLWF
nymphs on
9/18/01
SLWF
nymphs
overall
SLWF
adults
overall
1. Knack 0.86 EC (foliar spray)
0.054
0.38bc
3.08bc
0.21b
0.13b
0.26abc
1.89a
2. Knack 0.86 EC (foliar spray)
0.067
0.96ab
3.38ab
0.21b
0.04b
0.15bc
1.51a
3. Admire 2SC (drench),
0.187
0.75bc
2.92bc
0.00b
0.00b
0.07c
1.57a
Knack 0.86 EC (foliar spray)
0.067
4. Admire 2SC (drench)
0.187
1.54a
2.08bc
0.25b
0.67a
0.42ab
1.74a
5. Thiodan 3EC
1.0
0.17c
0.58c
0.21b
0.00b
0.12bc
1.47a
6. Untreated check
-
0.54bc
6.00a
0.88a
0.63a
0.52a
1.98a
Treatments (application method)
Rate lb
ai/a
SLWF adults
on 8/28/01
SLWF adults
on 9/04/01
SLWF adults
on 9/25/01
Bean
marketable wt
(lb)
Number of
light-colored
beans
1. Knack 0.86 EC (foliar spray)
0.054
2.21a
2.29a
0.96b
7.3a
5.25a
2. Knack 0.86 EC (foliar spray)
0.067
1.08a
2.67a
0.92b
3.8a
4.25a
3. Admire 2SC (drench),
0.187
1.58a
1.38a
0.08b
1.5a
2.00a
Knack 0.86 EC (foliar spray)
0.067
4. Admire 2SC (drench)
0.187
1.42a
2.92a
0.96b
3.8a
2.75a
5. Thiodan 3EC
1.0
1.46a
2.13a
1.21b
11.1a
8.00a
6. Untreated check
-
1.63a
2.71a
2.50a
4.1a
7.25a
-160-
* Means within columns followed by the same letter are not significantly different (LSD, P<0.05).
Table 3. Cabbage 2000 trial results.
Total
Lep.
DBM
total
DBM
large
CL
ICW
total
Damage
rating
for
heads
Damage
rating
for
wrapper
leaves
Wt.
Good
Heads
per 10 ft
of row
Percent
marketable
total
16.Untreated Check
6.50 a
3.19 a
1.81 a
0.31
2.88 a
1.78 a
2.75 a
5.40 f
0.10 f
9.Pounce 3.2EC 0.1 lb ai/a
1.31 b
0.69 b
0.56 b
0.19
0.13 b
0.60 b
1.40 b
25.0 cde
0.50 e
10. Confirm 2F 0.094ai +
Ketch Bt 8oz prod
0.88 b
0.44 b
0.13 bc
0.25
0.00 b
0.30 cd
1.20 bc
33.0 cde
0.73 d
3. Proclaim 5SG 0.01 lb ai/a
0.81 b
0.38 b
0.13 bc
0.06
0.25 b
0.25 de
0.98 cd
43.9 ab
0.75 cd
13.RH-2485 80WP 0.10 ai
+Ketch Bt 8oz prod
0.81 b
0.50 b
0.25 bc
0.06
0.00 b
0.23 de
0.98 cd
36.1 cd
0.78 bcd
12.RH-2485 80WP 0.05 ai
+Ketch Bt 8oz prod
0.69 b
0.56 b
0.31 bc
0.00
0.00 b
0.53 bc
1.33 bc
18.6 ef
0.50 e
11. Confirm 2F 0.125ai
+Ketch Bt 8oz prod
0.56 b
0.38 b
0.19 bc
0.00
0.19 b
0.68 b
1.28 bc
24.7 de
0.53 e
8. Spintor 0.067, Dipel 1
0.50 b
0.19 b
0.00 c
0.06
0.13 b
0.05 e
0.48 efg
39.7 bcd
0.95 ab
15. Novaluron 0.833EC 0.08
0.50 b
0.25 b
0.06 bc
0.00
0.25 b
0.15 de
0.63
defg
39.9 bc
0.90
abcd
14. Novaluron 0.833EC 0.04
0.44 b
0.13 b
0.06 bc
0.13
0.06 b
0.03 e
0.78 de
57.3 a
0.98 a
Treatment
-161-
Total
Lep.
DBM
total
DBM
large
CL
ICW
total
Damage
rating
for
heads
Damage
rating
for
wrapper
leaves
Wt.
Good
Heads
per 10 ft
of row
Percent
marketable
total
7. Avaunt 0.065, Spintor,
Dipel 2
0.44 b
0.19 b
0.13 bc
0.06
0.00 b
0.10 de
0.48 efg
37.5 bcd
0.90
abcd
2.Avaunt 30WDG 0.065
0.44 b
0.13 b
0.13 bc
0.00
0.06 b
0.08 de
0.28 g
40.5 b
0.93 abc
4. Spintor 2SC 0.067 lb ai/a
0.31 b
0.06 b
0.00 c
0.06
0.00 b
0.15 de
0.38 fg
38.5 bcd
0.88
abcd
1. Avaunt 30WDG 0.045
0.25 b
0.06 b
0.06 bc
0.00
0.06 b
0.13 de
0.55 efg
39.5 bcd
0.88
abcd
5. Avaunt 0.065, Dipel,
Spintor 3
0.25 b
0.06 b
0.00 c
0.00
0.06 b
0.13 de
0.73 def
40.0 bc
0.90
abcd
6. Avaunt 0.045, Spintor,
Dipel 4
0.13 b
0.00 b
0.00 c
0.06
0.06 b
0.15 de
0.70 def
42.8 ab
0.85
abcd
Treatment
lbs ai/a
lbs ai/a
* Means within columns followed by the same letter are not significantly different (LSD, P<0.05).
SPRAY ROTATIONS:
1
alternate a) and b): a)Spintor 2SC 0.067 lb ai/a, b)Dipel Df 1lb prod/a
2
1 of a),1 of b), 2 of c),1 of a),1 of b),1of a),1of b): a)Avaunt 30WDG 0.065lbs ai/a, b)Spintor 2SC 0.067lb ai/a, c)Dipel Df 1lb prod/a
3
2 of a), 2 of b), 2 of c), then 2 of a): a)Avaunt 30WDG 0.065lbs ai/a, b)Dipel Df 1lb prod/a, c)Spintor 2SC 0.047lb ai/a
4
2 of a), 2 of b), 2 of c), then 2 of a): a)Avaunt 30WDG 0.045lbs ai/a, b)Dipel Df 1lb prod/a, c)Spintor 2SC 0.047lb ai/a
-162-
Table 4. Cabbage 2001 trial results.
small
Damage
rating for
heads
Damage
rating for
wrapper
leaves
Avg. wt.
(lb) heads
each
0.14a
0.11ab
1.85a
1.30a
3.87bc
0.25cd
0.08a
0.00b
0.75fgh
0.35efgh
4.55a
0.03c
0.31bcd
0.00a
0.00b
1.20cd
0.90bc
4.30ab
0.78bc
0.00c
0.33bcd
0.06a
0.19a
1.13cde
0.65cde
4.31a
5. Baythroid 20WP - 0.025 lb ai
1.67a
0.28a
0.36bcd
0.14a
0.19a
1.13cde
0.85cd
4.64a
6. Baythroid 20WP - 0.05 lb ai
0.83bc
0.08bc
0.44bcd
0.06a
0.08ab
1.30bc
0.93bc
4.33a
7. Leverage 2.7SC - 0.08 lb ai
1.22ab
0.08bc
0.92a
0.06a
0.00b
1.55ab
1.20ab
3.64c
8. Novaluron 0.833EC - 0.039 ai
0.75bc
0.03c
0.39bcd
0.03a
0.00b
0.22ij
0.13gh
3.47c
9. Novaluron 0.833EC - 0.059 lb ai
1.00ab
0.17ab
0.67abc
0.00a
0.06b
0.43hij
0.20fgh
3.78c
10. Novaluron 0.833EC - 0.078 lb ai
0.94bc
0.03c
0.58abcd
0.11a
0.00b
0.53ghi
0.35efgh
4.70a
11. Karate Z - 0.03 lb ai
0.56bc
0.06bc
0.22d
0.06a
0.00b
0.80efg
0.43efg
4.50a
12. Avaunt 30WDG 0.065 lb ai/a
0.50c
0.05bc
0.25cd
0.08a
0.06b
0.18j
0.10h
4.70a
13. Proclaim 5SG - 0.0075 lb ai
0.833bc
0.00c
0.33bcd
0.03a
0.00b
0.95def
0.48ef
4.38a
14. Proclaim 5SG - 0.01 lb ai
0.67bc
0.08bc
0.36bcd
0.06a
0.03b
0.60gh
0.55de
4.31a
CL
Treatment - rate per acre
Total
Lep.
DBM
ICW
total
DBM
small
large
1.Untreated Check
1.19ab
0.05bc
0.69ab
2. Intrepid (RH 2485) 80WP - 0.10
ai/a then Spintor 2SC - 0.067 ai
0.67bc
0.05bc
3. Confirm 2F - 0.125 ai then
Spintor 2SC - 0.067 ai
0.801bc
4. Baythroid 2EC - 0.025 lb ai
-163-
15. Spintor 2SC - 0.067 lb ai
0.64bc
0.11bc
0.22d
0.03a
0.00b
0.48ghij
0.40efgh
4.64a
* Means within columns followed by the same letter are not significantly different (LSD, P<0.05) except for total Lep. (P<0.1).
Table 5. Pepper 2001 trial results.
Treatments
BAW per 6 plants
CB per 6 plants
PW in harvested fruit
1. Avaunt 30WDG 0.045 lbs ai/a
0.000a
0.03bc
0.25a
2. Avaunt 30WDG 0.065 lbs ai/a
0.000a
0.03bc
0.25a
3. Proclaim 5SG 0.01 lb ai/a
0.031a
0.13ab
0.38a
4. Spintor 2SC 0.067 lb ai/a
0.000a
0.03bc
0.88a
0.000a
0.03bc
0.25a
0.000a
0.00c
0.13a
0.063a
0.09abc
0.13a
0.063a
0.06abc
0.38a
9. TD2344-03 0.83E 0.03 lb ai/a
0.094a
0.03bc
0.00a
10. S-1812 35WP 0.1 lb ai/a
0.000a
0.03bc
0.38a
11. S-1812 35WP 0.15 lb ai/a
0.000a
0.03bc
0.13a
5. Platinum 0.140 lb ai/a drench
+Confirm 2F 0.125 ai
6. Admire 2F 0.25 lb ai/a drench
+Confirm 2F 0.125 ai
7. Kryocide 96W 7.68 lb ai/a (first 3 sprays then
spray TD2344-03 0.83E 0.03 lb ai/a)
8. Kryocide 96W 11.52 lb ai/a (first 2 sprays then
spray TD2344-03 0.83E 0.03 lb ai/a)
-164-
12. S-1812 35WP 0.2 lb ai/a
0.000a
0.16a
0.00a
0.000a
0.00c
2.38a
0.000a
0.16a
1.63a
15. Orthene 90SP 0.5 lb ai/a
0.000a
0.06abc
0.50a
16. UNTREATED CHECK
0.000a
0.03bc
0.75a
13. S-1812 35WP 0.1 lb ai/a
+Orthene 90SP 0.5 lb ai/a
14. S-1812 35WP 0.1 lb ai/a
+Orthene 90SP 0.75 lb ai/a
* Means within columns followed by the same letter are not significantly using LSD Test (P>0.10)
-165-
Table 6. Tomato 2001 trial results.
SAW
larvae
overall
TFW
larvae
overall
CL
larvae
overall
Total
Lep.
overall
Whitefly
adults
Predators
Treatment - formulation (lb
AI/a)
THW
larvae +
eggs
overall
(mainly
spiders)
Yield
(lbs/5
plants)
Lepidoptera
Damaged
fruit
1. S1812 - 35WP (0.15)
0.13c
0.00b
0.04
0.08b
0.13b
1.21b
0.04ab
25.19abc
13.50bc
2. S1812 - 35WP (0.20)
0.21c
0.00b
0.00b
0.00b
0.08b
1.17b
0.00b
27.99abc
5.50bc
3. S1812 - 35WP (0.15) +
Orthene - 97PE (0.63)
0.04c
0.00b
0.00b
0.04b
0.42b
2.58b
0.00b
23.09bc
4.42c
4. S1812 - 35WP (0.15) +
Asana XL - 0.66EC (0.02)
0.13c
0.04b
0.00b
0.17b
2.00b
2.46b
0.08ab
36.33a
3.75c
5. S1812 - 35WP (0.15) +
Dipel DF (1 lb product)
0.13c
0.00b
0.00b
0.63b
0.63b
1.96b
0.08ab
28.31ab
4.50c
6. V10101 - 2.25 EC (0.18)
0.33c
0.00b
0.00b
0.21b
0.75b
0.96b
0.04ab
26.75abc
7.75bc
7. Baythroid - 2 EC (0.02)
0.21c
0.00b
0.42ab
0.33b
0.42b
2.08b
0.04ab
28.20ab
7.50bc
8. Baythroid - 20WP (0.04)
0.38c
0.00b
0.00b
0.33b
0.88b
1.83b
0.00b
32.34ab
7.75bc
9. Untreated Check (silver
mulch)
1.04b
12.25a
0.13a
1.75a
15.08a
2.25b
0.04ab
8.66d
34.75a
10.Untreated Check (white
mulch)
1.54c
19.21a
0.13a
1.54a
21.83a
7.88a
0.13a
15.52cd
20.00ab
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* Means within columns followed by the same letter are not significantly different (LSD,
P<0.05).
ABBREVIATIONS:
Silverleaf whitefly (SLWF); Bemisia argentifolii Bellows&Perring
Diamondback moth (DBM); Plutella xylostella (L.)
Cabbage looper (CL); Trichoplusia ni (Hübner)
Imported cabbageworm (ICW); Artegeia rapae (L.)
Pepper weevil (PW); Anthonomus eugenii
Beet armyworm (BAW); Spodoptera exigua
Cucumber beetles (CB); Diabrotica spp.
Beet armyworm (BAW); Spodoptera exigua (Hübner)
Tomato fruitworm (TFW); Helicoverpa zea (Boddie)
Cabbage looper (CL); Trichoplusia ni (Hübner)
Southern armyworm (SAW); Spodoptera eridania (Stoll)
Tobacco hornworm (THW); Manduca sexta (Linnaeus)
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ECONOMICS
AND
MARKETING
-168-
-169-
COMMERCIAL VEGETABLE PRICE OUTLOOK
Greg E. Fonsah
Assistant Professor and Extension Economist
Fruits, Vegetables and Pecans
Department of Agricultural and Applied Economics
University of Georgia, P.O. Box 1209 – RDC
Tifton, Ga 31793
Tel: 229 386 3512 Fax: 229 386 3440
Introduction
Commercial vegetable production is on the rise in Georgia with about 33 different vegetables
crops currently being produced. More-so, fruits and vegetables are amongst the fastest growing
sector in the consumer-related high value products industry. As any other agricultural
commodity, commercial vegetable production requires several inputs such as, seeds or plants,
fertility, insecticides, fungicides, nematicides, herbicides, labor, irrigation, packaging material,
machinery, brokers commissions, transportation and freight. All these inputs cost several
dollars to the farmer and eventually increase cost of production. An increased production cost
reduces profit margin and renders commercial vegetables less competitive in the market place.
However, one of the major factors in determining profit margin is the price obtained by the
growers of vegetables. If the prices are good, the gap caused by the high cost of production is
narrowed and profitability is improved. The reverse is true when depressing prices are obtained.
The primary objective of this research is to investigate price trend for commercial vegetables.
The specific objective are: (a) to analyze Georgia vegetable 5 years average prices; (b) to
analyze wholesales prices for selected fresh market vegetables at shipping-point; and (c) to
analyze the 5 years monthly-average f.o.b. prices for selected US fresh vegetables.
Material and Methods
Descriptive statistics such as graphs and/or time-series will be used to illustrate price trend for
the enumerated specific objectives. Secondary data will be collected from various sources of
the Economic Research Service, USDA and Georgia Statistics respectively.
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Results and Discussions
Prices for Georgia commercial vegetables have been fluctuating for the past five. Snap beans,
cucumber, eggplant, and carrot experience an increase in price from 1998 and 1999, a drop in
year 2000, and another increase in 2001 as shown in fig. 1. Prices for corn dropped in 1998 and
2000. There was a slight increase in the price of corn in 1999 but year 2001 was much better.
Incidentally, cantaloupe prices have remained constant for the past five years.
Fig
1
Georgia Vegetables 5 Years Average Prices: 1997-2001
14
12
10
dollars
8
6
4
2
0
1997
1998
1999
2000
2001
5YR AVG
Years
Bean, snap
Cabbage
Cantaloupe
Cucumber
Eggplant
Okra
Source: Eastern Vegetable and Fruit Report (USDA), various issues
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Carrots
Corn
Figure 2 shows that Vidalia onion experienced a price boom from 1998 to 1999, a drastic fall in
price in 2000 and another increase in 2001. Prices for Vidalia onion is expected to escalate in
year 2002 due to production shortages experienced by Southeast Georgia growers, due to
fluctuating climate during the growing season that caused serious damage to the crop (Torrance
and Dasher, 2002). Incidentally, the anticipated price hike will not be enough to upset the loss in
productivity. Squash, zucchini and pepper continue to encounter depressing prices.
Fig. 2
Georgia Vegetables 5 Years Average Prices Cont.:1997-2001
18
16
14
Dollars
12
10
8
6
4
2
0
1997
1998
1999
2000
2001
5YR AVG
Pepper
Potatoes
Squash
Sw eet Potatoes
Tomatoes
Vidalia Onion
Watermelon
Zuccini
Source: Eastern Vegetable and Fruit Report (USDA), various issues (1997-2001)
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Figure 3 below shows that wholesales price per bushel/cartons in Chicago shipping point for
Florida, Georgia and Michigan snap bean (round green, handpicked) was erratic. Prices as high
as $40 per bushel/carton were observed from February 2001 with worse prices in June of the
same year. Prices for greens (collards, turnips), onion and tomatoes were not as erratic. The
greens from California and Georgia were sold in cartons of 24s whereas green onions from
California and Mexico were sold in cartons or bunched of 48s. Tomatoes (mature green and
large) prices were sold in 25 lb/carton containers.
Fig 3.
Selected Wholesales prices for Fresh Market Vegetables in Chicago: 2001 2002
45.00
40.00
35.00
$/bu/ctn
30.00
25.00
20.00
15.00
10.00
5.00
0.00
2- 25611- 2-Jul 64153Jan Feb Mar Apr May Jun
Aug Sep Oct Nov Dec
Jan 4622 Feb Mar Apr
Months
Snap beans
Greens, Collards
Onion, green
Tomatoes
Source: Fruit & Vegetable Market News, Agricultural Marketing Service, USDA (2002) Vegetable and Melon
Outlook/VGS-290/April 18.
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Figure 4 shows the price trend for US selected fresh vegetables, 5 years monthly average, f.o.b.
shipping point from 1997 to 2002. Cauliflower, sweet corn and broccoli are extremely erratic.
The average price for year 2002 is only for three months (January, February and March), thus is
expected to level off in subsequent months.
Fig 4.
Selected Fresh Vegetables 5 Years Monthly-Average F.O.B. Shipping-Point
Prices: 1997-2002
60
50
(dollars/ cwt)
40
30
20
10
0
1997
1998
1999
2000
2001
2002
Years
Fig. 4
Broccoli
Cantaloups
Carrots
Cauliflower
Corn Sweet
Source: Economic Research Service, USDA (2002) Vegetables and Melons Outlook/VGS-290, April, 18.
Figure 5 shows that the average price for cucumbers for year 2002 is the price recorded for
March. Onions, snap beans and tomatoes are for three months averages (January, February and
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March), and does not reflect or represent the whole year. The twelve months average is expected
to follow the same trend as previous years.
Fig. 5
Selected Fresh Vegetables Prices: U.S. 5 Years-Average F.O.B. Shipping-Point:
1997-2002 Cont.
60
50
(Dollars/Cwt)
40
30
20
10
0
1997
1998
1999
2000
2001
2002
Years
Cucumbers
Onions
Snap beans
Tomatoes
Source: Economic Research Service, USDA (2002) Vegetables and Melons Outlook/VGS-290, April, 18.
Conclusion
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The Georgia 5 years average price for most commercial vegetables is downward slopping and
this price trend is expected to maintain status-quo due to the erratic nature. The wholesales
prices for fresh market vegetable in the Chicago shipping point shows no significant
improvement either. The US 5 years average f.o.b. shipping-point prices show a similar pattern.
Price trend for commercial vegetables will remain the same in the years to come except new
market outlets (export) are developed.
Reference
1
Atlanta Wholesale Fruit and Vegetable Report, USDA (1997-2002).
2
Economic Research Service, USDA (2002). Vegetables and Melon
Outlook/VGS- 290/April 18.
3
Eastern Vegetable and Fruit Report, USDA (1997-2002).
4
Torrance, R. and S. Dasher (2002) “Growers Lose Most of Vidalia Onion Crop”
CAES News Center, UGA College of Agricultural and Environmental Sciences.
Author Index
Page Number
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Batal, D.......................................................................................................................................125
Bertrand, D................................................................................................................................. 125
Boland, R.T................................................................................................................................ 129
Boyhan, G.............................................................................................................................. 19, 21
Csinos, A. S.......................................................................................................71, 82, 93, 103, 114
Curry, D. .................................................................................................................................32, 45
Davis, R.F..........................................................................................................................71, 82, 93
Diaz-Perez, J................................................................................................................................125
Flanders, J.T.................................................................................................................................136
Fonsah, G.....................................................................................................................................169
Giddings, D..................................................................................................................................125
Granberry, D............................................................................................................................19, 21
Hardison, G..............................................................................................................................32, 45
Hill, R.......................................................................................................................................19, 21
Horten, T.B......................................................................................................................... 146, 148
Hudgins,J.E..................................................................................................................................144
Johnson,W.C..................................................................................................................................51
Kelley, W.T............................................................................11, 13, 15, 19, 21, 24, 28, 32, 45, 138
Langston, D.B................................................................. ....129, 132, 136, 138, 141, 144, 146, 148
Laska, J.E...........................................................................................................71, 82, 93, 103, 114
Price,J.G.......................................................................................................................................129
Riley,D.........................................................................................................................................153
Seebold, K.W.....................................................................71, 82, 93, 103, 114, 132, 141, 146, 148
Sumner,P..........................................................................................................................................3
Timper, P............................................................................................................71, 82, 93, 103, 114
Webster, T.M. .........................................................................................................................51, 65
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