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2007 Peanut Weed Management Update for County Agents. Eric P. Prostko Extension Weed Specialist Department of Crop & Soil Sciences The University of Georgia. Extension Agent Training – December 2006. Changes in 2007 Pest Control Handbook – Peanut Weed Control. - PowerPoint PPT Presentation
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2007 Peanut Weed Management Update for County Agents
Eric P. ProstkoExtension Weed Specialist
Department of Crop & Soil SciencesThe University of Georgia
Extension Agent Training – December 2006
Changes in 2007 Pest Control Handbook – Peanut Weed Control• Added Firestorm (generic paraquat) where
appropriate
• Included Aim in burndown sections
• Added generic metolachlors but still included the following warning: The generic formulations of metolachlor (Parallel, Stalwart, Me-Too-Lachlor) have not provided the same length of residual control of certain weeds as similar rates of Dual Magnum formulations in some UGA field trials.
• Added a specific control rec for tropical spiderwort
• Table for ALS/GR-resistant pigweed control
• Added Propel (generic Outlook)
• Zorial to Solicam
Firestorm
• Chemtura – Great Lakes Chemical Corp. + Crompton Corp.
• 3 lb/gallon of paraquat• Similar formulation as Gramoxone Max• 5.4 to 10.8 ozs/A = normal rates
• preplant burndown up to 24 hours after planting
• Up to 2 ozs/A– $5.00/oz
• Tank-mix with glyphosate
IMPOSE
• Generic liquid Cadre• From Makhteshim Agan of North America
(MANA)
How/Why do we let pigweeds get this big????
Will these herbicides control large pigweeds?
Cobra 2EC @ 12.5 ozs/A + COC @ 1% v/v applied to 17” tall pigweed
1 DAT 4 DAT
7 DAT 16 DAT
Cadre @ 4 ozs/A + 2,4-DB @ 1.1 pt/A + COC @ 1% v/v – 34 DAT
Applied to 17” tall pigweed
2,4-DB/Cobra Test – 2006
POST: June 5 (17” tall pigweed)POST2: June 9Photos taken 24 days after POST application
Untreated Cobra 2EC @ 12.5 oz/AAgrioil @ 1% v/v
POST
2,4-DB 1.75SL @ 1.1 pt/A +Agrioil @ 1% v/v (POST)
fbCobra 2EC @ 12.5 oz/A
Agrioil @ 1% v/vPOST2
Palmer Amaranth Control with Cobra and 2,4-DB
0
20
40
60
80
4 DAT 7 DAT 10 DAT 16 DAT 24 DAT 34 DAT
Time
Con
trol
- %
Cobra 2,4-DB Cobra + 2,4-DB 2,4-DB fb Cobra
Cobra @ 12.5 ozs/A2,4-DB @ 1.1 pts/ACOC @ 1% v/v Applied to 17” tall pigweed
How do we manage ALS-resistant Palmer amaranth?
• Need to start using more PRE’S– Valor, Dual Magnum/generics, Outlook– Goal?????
• POST Herbicides– Timeliness– Cobra, Ultra Blazer, Paraquat– Over reliance on PPO’s
• Will need both PRE’s and POST’s• Increased production costs
GR-Pigweed/Soybean Test – II (2006)7 WAP
Untreated Valor @ 2 oz/A (PRE)RUWM (POST)
RUWM (POST)
What if we do not control Palmer amaranth?
Crop
(State) Density Yield Loss Source
Corn
(KS)
0.5-8 plants/m 11-91% Weed Sci.
2001
49:202-208
Soybean
(AK)
0.33-10 plants/m 17-68% Weed Sci.
1994
42:523-527
Grain sorghum
(OK)
1-18 plants/15 m 4-63% Weed Tech.
2004
18:23-29
Peanut
(NC)
1-5 plants/m 28-66% Burke and Wilcut
(in-press)
Cotton
(TX)
1-10 plants/9.1 m 13-54% Weed Tech.
2001
15:408-412
Does Cobra reduce yields??
Peanut (GA Green) Response to Cobra78 DAP - 2006
Untreated Cobra @ 12.5 ozs/AAgrioil @ 1% v/vApplied 30 DAP
3556 lbs/A – Tifton4450 lbs/A - Plains
4003 lbs/A – Tifton4319 lbs/A - Plains
Classic Use in GA Peanuts
0
5
10
15
20
25
30
1993
1995
1997
1999
2001
2003
Year
Acres-%
Classic @ 0.5 ozs/A Applied 62 DAE
7 DAT
AP-3
GA-02C
Classic Effects on TSWV (2000-2006)
-40-32-24-16-808
16243240
50 60 70 80 90 100 110
Classic Timing (DAC)
Ch
ang
e in
TS
WV
- %
11 weed-free field trials in GA
31 data points77% ≤ 8%23% > 8%
Classic Effects on Peanut Yield - 2006
4689
3750
4429
3195
45764211
4459
3564
4546
3266
0
1000
2000
3000
4000
5000
AP-3 GA-02C
Variety
LB
S/A
Untreated 62 DAE 75 DAE 90 DAE 105 DAE
(P = 0.66) (P = 0.37)
Classic @ 0.5 oz/A + 80/20 @ 0.25% v/vWeed-free
Gramoxone Still Works!!!! (for me)
Untreated Gramoxone Inteon (12 oz/A) +Storm (1.5 pt/A) + 80/20 (0.25% v/v)
PE-26-0623 DAT
Speed, Nozzle Tip, GPA Effects7 MPH Tractor Speed
22
3236
1215
21
0
10
20
30
40
50
10 15 20
GPA
Cov
erag
e - %
FF WJ
LSD 0.10 = 3
Gramoxone Inteon (GI) and Basagran (B) Effects on Peanut Yield - 2006
3275 3352 3384
0
1000
2000
3000
4000
Untreated GI @ 8 oz/A GI @ 12 oz/A + B @8 oz/A
Treatment
lbs/
A
GA-02CAveraged over 4 timings (7, 14, 22, 28 DAC)Included 80/20 @ 0.25% v/vWeed-free
P = 0.63
Cadre or Gramoxone fb Cadre???
• 4 field trials conducted in 2005-2006
• 477 lb/A average yield increase when Gramoxone + Basagran was used prior to Cadre compared to Cadre alone
• It only takes a 64 lbs/A increase of peanuts to pay for this treatment
Peanut (GA-02C) Response to Roundup Weathermax – 112 DAP
Roundup Weathermax @ 12 ozs/A Applied 71 DAP
8 DAT
Peanut Yield Loss Caused by Roundup WeatherMax
0
10
20
30
40
50
60
0 2 4 6 8 12
Rate/A (oz)
Yie
ld L
oss
- %
71 DAP 89 DAP 105 DAP
GA-O2CPonder Farm - 2006
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