The U.S. Environmental Protection Agency (EPA) has announced what it calls the “strongest protections in agency history” for the over-the-top (OTT) application of dicamba on dicamba-tolerant cotton and soybean crops. The new regulatory framework introduces tighter controls while maintaining access to a tool many farmers say is critical for combating herbicide-resistant weeds.
According to an EPA press release, “President Trump has remained deeply committed to supporting America’s farmers and rural communities. This action reflects his administration’s commitment to ensuring farmers have the tools they need to succeed while protecting the environment with the strongest safeguards ever imposed on OTT dicamba use. Cotton farmers across the southern United States have been particularly vocal about why they need OTT dicamba as herbicide-resistant weeds like Palmer amaranth have become nearly impossible to control with other available tools, threatening crop yields and farm viability. These “super weeds” can grow 3 inches per day and destroy entire fields. Without effective weed management during the growing season, these producers face devastating economic losses. This temporary approval reflects the voices of farmers who depend on this tool using informed restrictions and safety measures.”
Dicamba has long been a point of contention due to concerns over volatility and off-target drift. In response, the EPA emphasized that compliance with the new rules is mandatory, stating that “these restrictions are not optional suggestions,” but enforceable legal requirements subject to oversight and penalties.
Under the updated registration, new restrictions for OTT dicamba use include cutting the maximum application rate in half, doubling the required use of volatility reduction agents, implementing mandatory conservation practices, and enforcing temperature-based application limits designed to reduce drift risk.
Several safeguards from previous registrations remain in place. These include restricted use pesticide designation, annual mandatory applicator training, required personal protective equipment, a 24-hour restricted entry interval, mandatory drift reduction agents, a 240-foot downwind spray drift buffer, strict application timing restrictions, proximity restrictions, wind speed requirements, droplet size specifications, low spray height mandates, a prohibition on aerial application, tank mixing prohibitions, and mandatory record keeping.
The EPA’s approach seeks to balance environmental protection with agricultural productivity, reinforcing enforcement while acknowledging the ongoing challenges farmers face from herbicide-resistant weeds like Palmer amaranth. As implementation begins, growers and applicators will need to closely follow the updated dicamba regulations to remain compliant and avoid enforcement action.
Audio Reporting by Dale Sandlin for Southeast AgNet.