Extension Response to Contaminated 2,4-DB/Peanut Problems in 2007

1. Extension Response to Contaminated 2,4-DB/Peanut Problems in 2007 Eric P. Prostko*, J. Tim Flanders, and Scott N. Brown The University of Georgia SWSS/WSSA - 2009

2. UGA Eric Prostko County Extension Agents Scott Brown – Colquitt Tim Flanders – Berrien Dealers Joe Dixon – Berrien Growers At least 48 Industry Jim Shue (NuFarm) J.W. Christiansen (Aceto) Private Consultant Tim Adcock (Diligene Technologies) GA Department of Agriculture The Players

3. 2,4-DB in Peanuts • One of the most commonly used herbicides • 50% of acres • 1-3 applications/year • From 2 WAP until 30 DBH • Annual morningglory, sicklepod, pigweed (?)

4. Typical 2,4-DB Injury Symptoms

5. 2007 Symptomology

6. Berrien County – Dixon FarmAugust 23, 2007 (14 DAT) 2005 2,4-DB @ 1 pt/A Butoxone 175 @ 1 pt/A

8. Contaminated Lots(> 250 ppm or 0.025%)

9. 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 (0.778 oz ai/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 0.025-0.071 oz ai/A (0.03-0.09X)

10. What will 2,4-D and dicamba do to peanuts???? • No data exists for peanut response to dicamba. • Peanuts are more sensitive to dicamba than 2,4-D. • Dicamba rate was equivalent to 0.041-0.048 oz ai/A • Normal dicamba (Banvel) rate for corn is 8 oz/A (3.08 oz ai/A) • 0.013-0.016X rate

11. What happened at harvest?

12. Table 1. Peanut Pod Numbers and Weights as Influenced by 2,4-DB formulation, Berrien County, September 14, 2007. 1Contaminated and Non-Contaminated samples collected from same field. 2Average of 10 plants.

13. Table 2. Peanut yield (cv. Georgia Green) as influenced by 2,4-DB formulation, P.H. Danforth Farm, Berrien County, October 12, 2007. 1Contaminated and Non-Contaminated samples collected from same field. Plot size was 6’ X 130’. 2Adjusted to 10% moisture.

14. Berrien County, 2007

15. What did the company do? • Hired consultant to manage complaints • Information request form was mailed to all growers • Monies were distributed based upon comparison of 2007 yields to historical yields • Growers were happy and I was curious. • 2007 was a dry year • May to September: -6.54” deficit • Was yield loss due to product or dry weather?

16. 2008 ResearchI just had to know for sure!!!! • Small plot research • Contaminated 2,4-DB • 24 oz/A + COC @ 1% • Applied at various stages (28, 45, 62, 78, 91, and 105 DAP) • Irrigated peanuts • Weed-free • Twin-row • AP-3 • Visual observations • yield

17. Peanut Yield Response to Contaminated 2,4-DB, 2008 24 oz/A + 1% Peptoil P = 0.2142 CV = 8

18. Peanut Pod Weights in Response to Contaminated 2,4-DB, 2008 24 oz/A + 1% Peptoil P = 0.3239 CV = 6

19. 100 Seed Weights in Response to Contaminated 2,4-DB, 2008 24 oz/A + 1% Peptoil LSD 0.10 = 7 CV = 9

20. Why is this important? • Peanut response to dicamba • Dicamba resistant crops are in the pipeline • More contamination/drift problems are likely • Dicamba/peanut tolerance studies were conducted in 7 locations in 2008 across peanut belt

21. Peanut Response to Clarity (dicamba) 4SC @ 16 ozs/A Applied 30 DAP Applied 59 DAP Applied 91 DAP Photo 107 DAP

22. www.gaweed.com