Preplant Burndowns for Peanut (Prostko)

I have been getting a few calls about preplant burndown options for strip-till peanut fields.  They say a picture is worth a 1000 words so see below for a few options.  As a reminder, the plant-back restriction for peanut after 2,4-D is 7 days and 0 days (1 oz/A) or 7 days (2 oz/A) for Reviton.  Also, remember that Reviton has no soil residual activity.

Figure 1.  Preplant burndown with Roundup PowerMax3 + 2,4-D amine + Valor EZ, March 27, 2026 (7 DAT), UGA Ponder Farm.

Figure 2. Preplant burndown with Roundup PowerMax3 + Reviton, March 27, 2026 (7 DAT), UGA Ponder Farm.

Droplet Sizes for Contact POST Herbicides (Prostko)

When visiting with your growers, please remind them to use a nozzle/pressure combination that produces COARSE droplets (VMD₅₀ = ≥ 270 microns) when applying contact herbicides such as Basagran (bentazon), Cobra (lactofen), Gramoxone (paraquat), Liberty (glufosinate), and Reflex (fomesafen).  COARSE droplets provide a reasonable balance of drift protection and coverage.  Droplets larger than coarse provide better drift protection but less coverage. Coverage is extremely important for contact herbicides especially when application conditions are not favorable (large weeds, cold temperatures, drought). Various nozzle types and pressures can be used to obtain COARSE droplet sizes (green color on TeeJet chart listed below).

Not playing favorites here with this TeeJet chart but a recent UGA Extension survey indicated that 68% of Georgia farmers use TeeJet nozzles. Other nozzle purveyors include the following:

Greenleaf Technologies: https://greenleaftech.com/

Pentair Hypro: https://www.pentair.com/en-us/flow/hypro/hypro-products/hypro-spraying-products/hypro-spray-nozzles.html

John Deere: https://cdn.prod.website-files.com/66e9e33a09ceaffe3ed4b8dd/66fef97547cff80b92845bf6_JD-Sprayer-Parts-Catalog-2019.pdf

Paraquat Trainings (Prostko)

Since Syngenta recently announced that they will no longer be manufacturing the active ingredient paraquat (https://www.syngenta.com/media/syngenta-cease-paraquat-production-uk-2026), I have received numerous inquires about the future of the US EPA required paraquat safety trainings (https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training-certified-applicators#q4).  The following is information that I received from Syngenta on March 13 regarding the issue of paraquat safety training:  

"Syngenta will continue to provide paraquat training via its online training portal while channel inventories of Gramoxone® Herbicide still exist. Our commitment to stewardship, safe use, and regulatory compliance remains unchanged, and we recognize how essential this training is for certified applicators across the country.

 

As we look ahead, Syngenta is actively evaluating options to transition the paraquat training program to an alternative host to ensure continuity beyond our direct involvement. We will share updates as soon as a viable path is confirmed.

 

Thank you for your continued dedication to safe and responsible pesticide application. If you need assistance accessing the training, please reach out to your Syngenta representative or visit the paraquat training portal.  Gramoxone Herbicide is a Restricted Use Pesticide.  Always read and follow label instructions."

Dicamba Preplant in Field Corn (Prostko)

It has come to my attention that the recommendations for preplant/burndown applications of dicamba for field corn in the UGA Pest Control Handbook are NOT sufficiently described.  After closer review of the product labels, there needs to be some adjustment.  Please review the following with any grower who desires to use dicamba for preplant/burndown weed control prior to planting field corn.

1) The newer formulations of dicamba (Stryax®, Engenia®) are NOT labeled for this particular use.

2) Older formulations of dicamba (Clarity®, Rifle®, Sterling Blue®) are labeled for this use depending upon tillage system and soil type as follows:

a) PREPLANT AND PREEMERGENCE APPLICATION IN NO TILLAGE CORN: Rates: Apply 16 fluid ounces of Clarity®, or Rifle®, or Sterling Blue® per acre on medium-or fine-textured soils containing 2.5% or greater organic matter. Use 8 fluid ounces per acre on coarse soils (sand, loamy sand, and sandy loam) or medium-and fine-textured soils with less than 2.5% organic matter.  

b) PREEMERGENCE APPLICATION IN CONVENTIONAL OR REDUCED TILLAGE CORN: Rates: Apply 16 fluid ounces of Clarity®, or Rifle® or Sterling Blue® per treated acre to medium- or fine-textured soils that contain 2.5% organic matter or more. DO NOT apply to coarse-textured soils (sand, loamy sand, or sandy loam) or any soil with less than 2.5% organic matter until after corn emergence.  

c) Failure to follow these recommendations could result in excessive crop injury.  If a grower applies dicamba as a burndown in a field intended to be planted to dicamba-tolerant cotton or soybean and changes their mind and wants to plant field corn, please contact me ASAP. 

3) Everyone always asks me what my preferred burndown is for field corn.  Lots of good choices.  But, I prefer Roundup or Gramoxone + atrazine because these combos will control most of our common winter weeds and field corn can be planted immediately without concern for crop injury.  See below.