How Severe is Peanut Injury from Enlist Duo Drift?

By Pratap Devkota Weed Scientist, UF/IFAS West Florida Research and Education Center

Peanuts are commonly grown in close proximity to field corn, cotton, and soybean fields in the southeastern U.S. Thus, there is potential for peanut crop exposure to herbicides applied to these crops. Cotton, soybean, and field corn are also developed with Enlist™ technology which enables the use of Enlist™ Duo (glyphosate + 2,4-D choline) and Enlist™ One (2,4-D choline) herbicides. Therefore, it is important to understand peanut response to off-target movement of these herbicides. The research was conducted to determine peanut response to low rates (simulating drift rates) of Enlist™ Duo herbicide. Treatments were applied at different times (25, 50, and 75 days after planting). The summary of results on the peanut injury, canopy width reduction, and yield loss response are presented in the table below. Response on Peanut Injury and Yield

Peanuts exposed to Enlist™ Duo herbicide at 25 days after planting (at the vegetative growth stage) showed more injury compared to exposure at 50 or 75 days after planting (at pegging and pod development stages). A similar response was observed for peanut canopy width.

* Enlist™ Duo = glyphosate (1.7 lb ae/gal) + 2,4-D choline (1.6 lb ae/gal). 1X rate is 76 oz/A.

** WAT = weeks after herbicide treatment.

*** Reduction is calculated based on the canopy width or yield of peanuts that were not exposed to Enlist™ Duo herbicide.

**** DAP = days after planting.

Peanuts exposed to Enlist™ Duo herbicide at various growth timing resulted in a reduced yield of 13-16 percent. The results suggest that Enlist™ Duo drift that occurred on peanuts at an earlier growth timing could be more severe than drift that occurred at the later growth timings of pod formation and development.

Peanut injury response is highly dependent on the Enlist™ Duo drift rate. Peanuts exposed to Enlist™ Duo at a rate ≥ 2.4 fl oz/A resulted in more significant injury and yield reductions. However, a rate below 0.348 fl oz/A showed minimal impact on peanut injury and yield (< 10 percent).

Overall, results from this study suggest that in the Enlist™ Duo drift scenario, the peanut injury assessed

Pesticide Clean Out Days

The Georgia Department of Agriculture has scheduled a Pesticide Clean Day Event for March 29, 2023, 8:00 a.m. - 3:00 p.m. at Tri County Gin in Coffee County, Georgia. Clean Day is a program that gives everyone an opportunity to discard old, unusable, or canceled pesticides to a hazardous waste contractor for disposal. Participation in the Clean Day Program remains free of charge to all private and commercial applicators with the understanding that the event is designed and intended for farmers, lawn care, golf courses, and pest control companies. at 4 weeks after drift provides a reasonable estimate for injury progression in the season and yield reduction.

The Georgia Department of Agriculture will be requiring preregistration for the events. For more information about the event please contact your local extension agent or visit the GDA website at www.agr.georgia.gov.

If a farmer only needs to recycle triple-rinsed containers, they can request pick up at the USAg Recycling website, www. usaagrecycling.com. Labels must be removed for recycling.