NAAA Fights for Aerial Applications of Dicamba on Dicamba Tolerant Crops

Last week NAAA submitted comments to the EPA opposing the prohibition of aerial applications of three low-volatility formulations of dicamba on dicamba tolerant (DT) soybean and cotton varieties. The saga of DT crops began in 2016 when EPA first registered the newer low volatility dicamba products for over-the-top applications on DT crops. Since then, registration of these products for use on DT crops has been terminated twice by court action, the last time in early 2024. One thing that has been consistent in the registration history of DT crops is that aerial application has been prohibited since the very beginning.

The latest action by EPA and the three registrants with formulations for DT crops – Bayer, BASF, and Syngenta – came in late July of 2025, when EPA proposed to once again register the uses of dicamba on DT cotton and soybean. As in all prior registrations, this proposal prohibited aerial applications. Based on success NAAA has had working with EPA on recent Endangered Species Act strategies, NAAA decided to submit comments to EPA opposing the aerial ban.

NAAA’s comments, which can be read here, focused on two main points. The first dealt with the speed of aerial applications over all other types of applications, and why this speed is critical for making both successful and safe dicamba applications on DT crops. The labels for the three dicamba products are very restrictive regarding wind speed, temperature, and inversions. NAAA pointed out that these restrictions severely limit the application hours available to a grower if they are forced to only use ground application. In many cases they risk ineffective weed control and the further spread of herbicide resistant weeds.

The second point was proposed requirements for making aerial applications of dicamba on DT crops. These included a larger droplet size, a boom length restricted to 50% of the wingspan or rotor diameter, and a 400-foot downwind buffer for protection of sensitive areas. NAAA used AgDRIFT to point out that these suggested aerial requirements result in estimated drift just slightly greater than the estimated drift from ground rigs. The success of NAAA’s request is uncertain; what is certain is that growers and the environment always benefit when fast and timely pesticide applications are available from ag aircraft.