1. Peanut Agent Training - 2008
Eric P. Prostko
Extension Weed Specialist
Department of Crop & Soil Sciences
The University of Georgia

2. Topic For Discussion Resistance Update Modes of Action Info
Aim – Harvest Aid label
Palmer Amaranth
Provost Issues
2,4-DB Issues
Classic Update
15 locations
6 varieties

3. 2005 ALS-Resistant Pigweed Survey Results
61 peanut fields in 21 counties
All populations had some level of resistance to Cadre.
Populations were also cross-resistant to Staple and Classic.
None were resistant to glyphosate

4. GA Confirmed Glyphosate-Resistant Palmer Sites
2005
2006
Current
Testing
2007
May 8, 2007

5. Herbicide Modes of Action Info
New Table in 2008 Pest Control Handbook
MOA’s listed in crop sections

6. Harvest Aid Label September 2007 1-2 oz/A NIS or COC 7 day PHI
Morningglory
Pigweed
Spiderwort

7. Managing Palmer Amaranth
Know the enemy
Lots of seed
Grows 1-2”/day
Very competitive
Resistant or not??
ALS or GR
Residual herbicide
Activation
irrigation or incorporation
Timely POST’s
Avoid overusing PPO’s

8. Palmer Amaranth Control in Peanuts Macon County, GA – 2007 (38 DAT)
NTC
Valor SX 3 oz/A

9. Palmer Amaranth Control in Peanuts Macon County, GA – 2007 (38 DAT)
NTC
Dual Magnum 7.62EC
@ 1 pt/A

10. Strongarm + Valor (PRE) fb
PE (13 days after POST, 42 DAP)
NTC
Strongarm + Valor (PRE) fb
Cobra (POST
ALS-susceptible population

11. Residual Herbicides Must Be Activated!!!!!!
Rainfall
Irrigation
Herbicide incorporation
Conventional tillage
Dryland fields
No chance of rain
will help but not a guarantee
2X, angle
Some herbicides should not be incorporated
Valor

12. This is what a 2” pigweed looks like!!!!

14. Provost (10.7 oz/A) + Fulbor + Penatrator Plus + 2,4-DB
Richard McDaniel, 2007

15. Peanut Phytotoxicity and Provost (# trials)
Source: Herb Young
Bayer CropScience
11/20/07

16. Probable Provost Label Changes
No surfactants
No tank-mixes with 2,4-DB
No tank-mixes with EC pyrethroids
Others??

19. Contaminated Lots Contamination if exceeds 250 ppm Tested Lots
FB-01 = 2,4-D acid (0.294%)
EC-16 = dicamba (0.17%) + 2,4-D acid (0.11%)
EC-16 = Dicamba (0.198%) + 2,4-D acid (0.104%)
EL-31 = ppm 2,4-D (3 samples)
CE-04 = 56 ppm of 2,4-D

20. What will 2,4-D and dicamba do to peanuts????
Research in GA conducted over the past few years would suggest that 2 oz/A of 2,4-D would not cause many problems.
If contaminated product was applied at 24 oz/A then 2,4-D rate would only be oz/A.

21. Why is this important? Peanut response to dicamba
Dicamba resistant crops are in the pipeline
More contamination/drift problems are likely

23. The Influence of Classic on the Incidence of TSWV (2000-2007)* * *
0.5 oz/A % v/v
Averaged over 6 varieties and 15 locations
*Significantly different from NTC (P = 0.05.)

24. The Influence of Classic on Peanut Yield (2000-2007)
0.5 oz/A % v/v
Averaged over 6 varieties and 15 locations
P =