FORB RESPONSE TO HERBICIDES FOR
SEED PRODUCTION AND RANGELAND
RESTORATION
Corey Ransom and Kim Edvarchuk
Objective – Seed Production
Identify herbicides for
weed management in
forb seed production.
- Astragalus filipies
- Dalea ornata
- Dalea searlsiae
Postemergence Herbicide Screening, 2009
Conducted on fields established in
2005 as transplants from conetainers.
Plants were spaced 0.5 m.
Herbicide treatments applied May 12,
15, and 21, 2009.
Applications made with a shielded
bicycle sprayer at 20 gpa and 30
psi.
Multiple accessions and inconsistent
plant vigor prior to treatment add
to variability in these trials.
Herbicide Treatments on Astragalus filipies
Herbicide
Rates
lb ai/A
product
Buctril
0.25
1.0 pt
2,4-DB
0.25
1.0 pt
Transline
0.124
0.33 pt
Paramount + MSO
0.248
0.33 lb
Raptor + MSO
0.078
10.0 oz
MSO at 1.0% v/v
• Application made May 15.
• Injury evaluated May 26 (11 DAT) and June 23 (41 DAT).
• Biomass taken July 23.
Astragalus Injury on May 23 and June 25
70
60
11 DAT
41 DAT
Injury (%)
50
40
30
20
10
0
Buctril
2,4-DB
Transline
Paramount
Raptor
Treatment
• Transline again caused significant season long injury
• 2,4-DB , Paramount, and Raptor had among the least injury
Astragalus Plant Weight in Response to Herbicides
25
a
Biomass (g/plant)
20
15
a
a
a
b
10
b
5
0
Untreated
Buctril
2,4-DB
Transline Paramount Raptor
Treatment
• Buctril and Transline significantly reduced plant biomass.
Astragalus Flowering in Response to Herbicides
12
a
Flowering (plants/plot)
10
8
6
ab
4
bc
bc
2
bc
c
0
Untreated
Buctril
2,4-DB
Transline Paramount Raptor
Treatment
Herbicide Injury in Astragalus filipies
Herbicide Treatments on Dalea ornata
Herbicide
Rates
lb ai/A
product
Prowl H2O
0.71
1.5 pt
Outlook
0.84
18.0 oz
Goal
0.25
0.66 lb
0.064
1.0 pt
Sencor + NIS
0.5
0.66 lb
Buctril
0.25
1.0 pt
2,4-DB
0.25
1.0 pt
Transline
0.124
0.33 pt
Paramount + MSO
0.248
0.33 lb
Raptor + MSO
0.078
10.0 oz
Milestone
0.047
3.0 oz
Chateau + NIS
NIS at 0.25% v/v
MSO at 1.0% v/v
• Applied May 21.
• Injury evaluated
May 26 (5 DAT) and
June 25 (35 DAT).
• Plant biomass and
seed head biomass
August 6.
Herbicide Treatments on Dalea ornata
Injury
Herbicide
5 DAT
Biomass
35 DAT
----------------%--------------
Veg.
Seed head
----------g/plot----------
Untreated
-
-
520
243
Prowl H2O
10
1
545
203
6
4
616
189
Goal
64
26
513
218
Chateau + NIS
56
18
479
203
Sencor + NIS
21
5
571
140
Buctril
13
14
337
126
2,4-DB
23
10
393
150
Transline
41
44
416
32
Paramount + MSO
25
10
704
191
Raptor + MSO
38
18
446
185
Milestone
35
63
257
2
Outlook
Herbicide Injury in Dalea
Herbicide Treatments on Dalea searlsie
Herbicide
Rates
lb ai/A
product
Prowl H2O
0.71
1.5 pt
Goal
0.25
0.66 lb
Chateau + NIS
0.064
1.0 pt
Sencor + NIS
0.5
0.66 lb
Buctril
0.25
1.0 pt
2,4-DB
0.25
1.0 pt
Transline
0.124
0.33 pt
Paramount + MSO
0.248
0.33 lb
Raptor + MSO
0.078
10.0 oz
NIS at 0.25% v/v
MSO at 1.0% v/v
• Applied May 12.
• Injury evaluated
May 26 (14 DAT)
and June 25 (44
DAT).
• Plant biomass and
seed head biomass
August 6.
Herbicide Treatments on Dalea searlsie
Injury
Herbicide
14 DAT
Biomass
44 DAT
----------------%--------------
Veg.
Seed head
----------g/plot----------
Untreated
-
-
423
99
Prowl H2O
9
8
401
102
Goal
65
16
489
146
Chateau + NIS
58
21
403
97
Sencor + NIS
28
19
405
102
Buctril
13
6
508
110
2,4-DB
16
5
518
110
Transline
33
44
410
32
Paramount + MSO
25
16
472
80
Raptor + MSO
36
15
547
89
Impact of Application Timing
• No herbicide injury was
evident in 2008 when
applications were made while
Dalea was dormant.
• Significant injury appeared
when actively growing Dalea
was treated in 2009.
Issue of crop selectivity vs.
weed efficacy.
Conclusions – Seed Production
1. 2,4-DB warrants further investigation for
postemergence use in Astragalus filipies.
2. Established Dalea ornata and Dalea searlsie appear
to tolerate postemergence treatments of several
herbicides, but impact on seed yield and viability
has not been determined.
3. Transline if definitely one of the most injurious
herbicides on all the species tested.
4. Likely, the use of soil active herbicides will continue
to cause minimal damage to established plants.
Objective – Rangeland Restoration
Evaluate native species
response to herbicides
applied to control
downy brome.
How will they handle
exposure to these
herbicides when
germinating?
Initiation of Field Establishment Trials, 2009
Locations in Nephi and Cache Junction.
Application timings:
Spring and Fall 2009
Herbicides:
Plateau 1, 2, 4, 6, 8, 10, and 12 fl oz
Olympus, Outrider, Matrix, Oust
Planting timings:
Fall 2009 and Fall 2010
Initiation of Field Establishment Trials, 2009
Species planted at Cache Junction:
First Strike
Slender wheatgrass
Anatone
Bluebunch wheatgrass
Magnar
Basin wildrye
Valvalov II
Siberian wheatgrass
Sherman
Big bluegrass
Rimrock
Indian Ricegrass
Initiation of Field Establishment Trials, 2009
Species planted at Nephi:
Lupinus sericeus
Globe mallow
Sphaeralcea
Sulfur flower BW
Eriogonum umbellatum
Big blue penstemon
Penstemon cyaneus
Prairie clover
Dalea ornata
Searle’s Prairie Clover Dalea searlsie
Utah sweetvetch
Astragalus filipies
Silky lupine
Anatone
Bluebunch wheatgrass
Sherman
Big bluegrass
USDI BLM Great Basin Restoration
Initiative, GBNPSIP, and
USDA FS Rocky Mountain Research
Station