Farmers and commercial ap­­plicators can use existing supplies of three dicamba herbicides on soybeans in certain specific circumstances through July 31, the Environmental Protection Agency (EPA) said last week.

The EPA said its cancellation order, which resulted from the Ninth Circuit Court of Appeals’ decision vacating the registrations for XtendiMax with VaporGrip Technology, Engenia and FeXapan, provides clarity and mitigates economic consequen­ces for farmers. 

However, the groups that prevailed in the dicamba lawsuit filed an emergency motion on June 11 asking a federal court to halt all dicamba use and hold the EPA in contempt for its decision to allow farmers to use existing stocks of the herbicides.

BASF, which makes Engenia, countered by filing an emergency motion to intervene in the case, saying the court ruling poses a sudden and severe negative impact for farmers.

“Taking this action during the height of the application season gives no regard to the significant investments farmers have made in their businesses and leaves them without viable options for the growing season,” said Paul Rea, senior vice president for BASF Agricultural Solutions North America. 

U.S. farmers this year planted an estimated 60 million acres of dicamba-tolerant soybeans and cotton compatible with post-emergence use of the three products.

The EPA said growers and commercial applicators may use supplies that were "in their possession on June 3," the effective date of the court decision. Such use must be consistent with the product’s previously approved label and may not continue after July 31, the EPA said. 

In response to questions re­­garding “possession” of the herbicides, the EPA clarified that farmers and certified applicators can use products that were purchased but in storage at another location such as a retailer, distributor or cooperative.

Distribution or sale of the products is generally prohibited except for ensuring proper disposal or return to the registrant.

Syngenta’s Tavium dicamba postemergence soybean herbicide isn't affected by the court ruling since it received registration after the lawsuit was filed. 

Dicamba alternatives
Farmers who aren’t able to make planned dicamba applications on soybeans have relatively few good options for controlling resistant water hemp, said Iowa State University Extension weed specialists Bob Hartzler and Prashant Jha. They recommend a tank mix including a Group 14 herbicide and glyphosate to broaden the spectrum of control, plus a Group 15 herbicide for residual control.

“Unfortunately, this court ruling came at a bad time for Iowa soybean farmers,” they said in a blog post. “Now is the time to determine what products are av­­ailable and begin scouting fields to prioritize which fields need treated earliest. This is a shocking wake-up call showing how fragile our herbicide-based production system is.”

Mechanical cultivation could also be an option for 30-inch row soybeans that are very weedy, they said. 

New registrations
BASF and Bayer, which makes XtendiMax, said they will continue to pursue registrations of their dicamba herbicides for the 2021 season and beyond. The current registrations were due to expire at the end of this year.