Dicamba decision

The future of dicamba use is once again in ques­tion after the EPA issued a revised report on the herbi­cide’s risks in August. The agency is now seeking public comment by Oct. 17 for consideration in making an interim decision about dicamba’s registration in 2023.

The EPA’s most recent ecological risk assessment said that dicamba potentially adversely affects birds, mam­mals, bees, freshwater fish and aquatic vascular plants with the “primary risk of concern” for non-target plants through spray drift and volatilization. In addition, the agency said it found no evidence new measures put in place have helped reduce off-target incidents.

“Despite the control measures implemented in EPA’s October 2020 dicamba registration decision, the 2021 incident reports showed little change in number, severity or geographic extent of dicamba-related incidents when compared to the reports it received before the 2020 con­trol measures,” the agency said. “EPA is currently working with states and affected stakeholders to gather available incident information for the 2022 growing season.”

Draft risk assessments are part of EPA’s routine registra­tion review process, which dicamba is now undergoing. EPA said it is evaluating whether over-the-top dicamba “can be used in a manner that does not pose unreason­able risks” to non-target crops and other plants or to listed species and their designated habitats. EPA is also looking at non-approved over-the-top dicamba formula­tions, which are often applied prior to planting to control existing vegetation or early post emergence in corn.

Products approved for over-the-top use in dicamba-tol­erant crops include XtendiMax with VaporGrip Technol­ogy, Engenia, and Tavium Plus VaporGrip Technology. Dicamba is also an active ingredient in a range of other agricultural and non-agriculture weed control products.

To read EPA’s full risk assessment and submit com­ments, visit online at bit.ly/dicamba_review.