GROWMARK FS released on May 4 new information about the requirements and best management practices for using dicamba over-the-top herbicides in soybeans during the 2026 growing season.
The update matters to soybean growers who rely on dicamba-tolerant crops as a tool against difficult weeds, as new federal labels bring changes that affect application timing, equipment, and environmental compliance. The goal is to help farmers achieve effective weed control while meeting regulatory standards.
According to GROWMARK FS, Engenia, Stryax and Tavium were approved by the United States Environmental Protection Agency in February for two years of use with new application guidelines. These products are intended to help manage tough-to-control weeds such as waterhemp and marestail. The company emphasized that spraying small weeds with proper adjuvants, nozzles, and carrier volume provides the best results. “Follow all federal and state approved labels to ensure applications are made according to appropriate guidelines,” GROWMARK FS said.
Best management practices from the updated labels include selecting nozzles that produce coarse or larger droplets to minimize drift. Ultra-coarse droplets may further reduce off-target movement but might require increased carrier volume for better coverage. Adjuvants remain essential; oil emulsion drift reduction adjuvants (DRA) at specified rates are required along with volatility reduction adjuvants (VRA). Water conditioning agents should be used if hard water is present.
Application windows have also changed: Engenia or Stryax can be applied through R1 growth stage while Tavium can be used through V4 stage. There are temperature-based restrictions—only half of a grower’s dicamba-tolerant acres may be sprayed when temperatures range between 85°F and less than 95°F; no applications are allowed above 95°F. Additional measures must be taken under Endangered Species Act mitigation rules regarding runoff, erosion points, spray buffers, and recordkeeping.
GROWMARK FS advises an integrated approach using preemergence herbicides alongside post-emergence applications with overlapping residuals for continued weed control throughout crop establishment: “When we take this chemical approach, along with cultural and mechanical control measures, we can start clean and stay clean throughout the season.” Growers are encouraged to contact local FS Crop Specialists with questions about best practices or purchasing dicamba-tolerant seeds.
GROWMARK FS consists of locally owned cooperative retailers working together under GROWMARK—a regional agricultural cooperative governed by farmers—serving areas across the Midwest, Northeast and Mid-Atlantic regions of the United States as well as Ontario in Canada according to its official website. The company operates through more than 38 local cooperatives providing over 1,000 agronomy and energy products according to its official website. Its services aim at maximizing yields for growers while supporting fleet owners’ efficiency needs according to its official website.
Looking ahead, GROWMARK FS says it will continue offering comprehensive solutions—including high-yield seed varieties, crop performance products, grain marketing services as well as fuels—for agriculture customers seeking expert knowledge backed by a reliable supply chain according to its official website.
