On July 23, the U.S. Environmental Protection Agency (EPA) opened a 30‑day public comment period for its proposed decision on over-the-top (OTT) use in dicamba-tolerant soybeans and cotton, which would only become possible if EPA completes its review and issues a final decision—potentially in time to allow use during the 2026 growing season.

The EPA’s proposal also includes more stringent rules around application timing, rates, and environmental conditions. For example, under the proposed registration, dicamba would be limited to two applications per season, with a single-use maximum of 0.5 lb. acid equivalent (a.e.) dicamba per acre and a total seasonal maximum of 1 lb. a.e. per acre. Aerial applications would be prohibited, and a 240-foot downwind buffer would be required—though certain drift-reduction practices may result in a reduced buffer in some cases, depending on label specifications.

Temperature limits also come into play. Applications would be banned when temperatures exceed 95°F. Between 75°F and 95°F, use of drift and volatility reduction agents would be required in increasing amounts, or growers would need to reduce application by 40% on a field during higher temperatures, potentially requiring the application to a single field to be split over multiple days.

The proposed rule includes additional requirements related to drift, runoff, and endangered species protections. Applicators would be required to adopt specific practices for compliance, including implementing multiple conservation practices to limit runoff. In areas with sensitive species, additional mitigation steps would be required. Applicators would also be responsible for checking the EPA’s “Bulletins Live! Two” system for region-specific limitations.

In addition to increased federal rules, the Illinois Department of Agriculture (IDOA) currently plans to leave Illinois specific rules in place – including the June 20 and 85-degree application cutoffs. Growers can review these rules at the IDOA Dicamba website. There is an understanding at IDOA that there will be a learning curve, and they are making plans to keep applicators informed.

The proposal leaves open the possibility of OTT dicamba use in 2026, subject to tighter restrictions. Illinois growers are encouraged to review the proposal and share comments, questions or concerns with the Illinois Soybean Association. The comment period on the proposed dicamba registration will run from July 23 to Aug. 22.