Peanut Response to Dicamba (Clarity) E.P. Prostko, T.L. Grey, M. - PowerPoint PPT Presentation

Peanut Response to Dicamba (Clarity) E.P. Prostko, T.L. Grey, M. Marshall, J.A. Ferrell, D.L. Jordan, B.J. Brecke, P.A. Dotray, W.J. Grichar APRES 2009

2007 Contaminated 2,4-DB Symptomology

2007 Contaminated 2,4-DB (> 250 ppm or 0.025%) Lot # Dicamba (%) 2,4-D (%) FB-01 0 0.294 0.091 (MCPA) EC-16 0.170 0.110 0.079 (MCPA) EC-16 0.198 0.104 EL-31 0 0.011 EL-31 0 0.010 EL-31 0 0.012 CE-04 0 0.006

Dicamba-Resistant Crops • Behrens et al. 2007 Science 316:1185- 1188. (Nebraska) dicamba acid • Transferred gene from Pseudomonas maltophila into tobacco, soybeans, tomatoes dicamba DGA salt • Monsanto in hot pursuit

Dicamba Drift on Soybeans • 14-93% yield reduction (V3) – Anderson et al. 2004 (SD) • 15%-22% yield loss (V3); 12-28% yield loss (V7) – Kelley et al. 2005 (IL) Photo: Purdue University Weed Science

Objectives • Determine the influence of Clarity rate and timing of application on peanut yield • Develop a predictive model for future use

Materials and Methods • 8 locations across Peanut Belt – GA(2), FL(2), SC(1), NC(1), TX (2), • RCB design • 3 X 6 factorial arrangement – Timing (30, 60, 90 DAP) – Rate (0, 1, 2, 4, 8, 16 oz/A Clarity) • 4 replications • Weed-free

Site Descriptions Soil Characteristics OM Sand Silt Clay Planting Digging Harvest (%) (%) (%) (%) State Location Variety Date Date Date FL1 Citra Georgia April 23 August 25 August 28 0.5 97 1 2 Green FL2 Jay Florida-07 May 12 September 19 September 18 2.1 69 16 15 GA1 Ty Ty AP-3 May 12 September 26 September 29 1.07 94 2 4 GA2 Plains Georgia-02C May 13 October 3 October 7 1.0 40 25 34 NC1 Rocky VA-98R May 20 October 8 October 14 Mount SC1 Blackville Champs May 19 October 8 October 15 TX1 Lamesa Flavor April 30 October 27 November 5 0.40 67 14 19 Runner 458 TX2 Yoakum Tamrun OL02 June 16 November 3 November 5 1.0 70 16 14

Results • 5 locations had significant rate X timing interaction – Lamesa, Yoakum, Rocky Mount, Blackville, and TyTy • 3 locations had no interaction – Plains, Jay, Citra – Rate and timing were significant

Figure 1. Peanut Yield Response to Clarity, Ty Ty, GA (2008). 30 DAP 60 DAP 90 DAP 6000 5000 5047 5037 4898 4891 4800 4481 4000 lbs/A . 4136 3841 3777 3780 3523 3509 3000 2469 2000 2198 1714 1622 1000 955 664 0 NTC 1 2 4 8 16 Clarity Rate/A (oz) LSD 0.10 = 472

Figure 2. Peanut Yield Response to Clarity, Lamesa, TX (2008). 30 DAP 60 DAP 90 DAP 7000 6555 6000 6292 6281 6239 6079 5820 5823 5000 5380 5327 5282 lbs/A . 4795 4744 4634 4000 4294 4136 3000 2944 2651 2000 1939 1000 0 NTC 1 2 4 8 16 Clarity Rate/A (oz) LSD 0.10 = 620

Figure 3. Peanut Yield Response to Clarity, Yoakum, TX (2008). 30 DAP 60 DAP 90 DAP 3500 3000 3153 3098 2980 2500 2676 2551 lbs/A . 2365 2238 2233 2199 2000 1977 1729 1500 1000 910 774 761 500 505 512 476 454 0 NTC 1 2 4 8 16 Clarity Rate/A (oz) LSD 0.10 = 210

Figure 4. Peanut Yield Response to Clarity, Rocky Mount, NC (2008). 30 DAP 60 DAP 90 DAP 4500 4000 3894 3500 3540 3550 3550 3528 3420 3325 3000 lbs/A . 3136 3020 3000 2919 2500 2570 2000 2241 1805 1500 1000 1016 500 649 303 351 0 NTC 1 2 4 8 16 Clarity Rate/A (oz) LSD 0.10 = 466

Figure 5. Peanut Yield Response to Clarity, Blackville, SC (2008). 30 DAP 60 DAP 90 DAP 8000 7964 7620 7420 6654 6557 6000 6394 6336 6319 6230 5798 lbs/A . 5256 4858 4000 3906 3551 3316 2485 2000 1608 1456 0 NTC 1 2 4 8 16 Clarity Rate/A (oz) LSD 0.10 = 1208

Figure 6. Peanut Yield Response to Clarity Rate (2008). (pooled over 3 timings) NTC 1 oz 2 oz 4 oz 8 oz 16 oz 6000 5000 4764 lbs/A . 4000 4352 4310 4083 4044 4030 3931 3636 3427 3381 3000 3247 2567 2510 2000 2345 2038 1972 1000 1325 1060 0 Plains Jay Citra Location Plains LSD 0.10 = 467 Jay LSD 0.10 = 599 Citra LSD 0.10 = 330

Figure 7. Peanut Yield As Influenced by Clarity Timing (2008). (pooled over 6 rates) 30 DA P 60 D A P 90 DA P 5000 4000 4236 lbs/A > 3874 3851 3750 3606 3569 3000 2000 2286 1945 1394 1000 0 Plains Jay Citra Tim ing (DA P) Plains LSD 0.10 = 349 Jay LSD 0.10 = 422 Citra LSD 0.10 = 203

Peanut Response to Clarity (dicamba) 4SC @ 16 ozs/A Applied 90 DAP Applied 30 DAP Applied 60 DAP (2198 lb/A – 56% loss) (664 lb/A – 87% loss) (955 lb/A – 81% loss) Photo 107 DAP NTC (4994 lb/A) Ty Ty, GA

Peanut Response to Clarity (dicamba) 4SC @ 8 ozs/A Applied 90 DAP Applied 30 DAP Applied 60 DAP (3509 lb/A – 30% loss) (1622 lb/A – 67% loss) (1714 lb/A – 66% loss) Photo 107 DAP NTC (4994 lb/A) Ty Ty, GA

Peanut Response to Clarity (dicamba) 4SC @ 1 oz/A Applied 30 DAP Applied 90 DAP Applied 60 DAP (4481 lb/A – 10% loss) (4891 lb/A – 2% loss) (3841 lb/A – 33% loss) Photo 107 DAP NTC (4994 lb/A) Ty Ty, GA

Summary • Increase Clarity rate = increase peanut yield loss • Increase peanut age = decreased peanut yield loss – Some locations (13/25) 60 DAP more sensitive (R3-R4 stage of growth) • Can get significant peanut yield reductions with as little as 1 oz/A Clarity – 13% average (0%-low, 25%-high) • Growers need to avoid contamination/drift problems

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