On June 3, the U.S. Court of Appeals for the 9th Circuit vacated the registrations of three dicamba products — XtendiMax, Engenia and FeXapan — labeled for over-the-top use in Xtend soybean systems.
In response to the court’s decision, an Environmental Protection Agency order on June 8 stated that private and commercial applicators could use existing stocks that were acquired prior to June 3. Applications of these products are permitted until July 31.
The EPA order limits further distribution and sales of these products to only existing stocks that were in possession of commercial applicators prior to June 3.
So, what are growers to do and what other options are available? Here are some things to think about:
Label restrictions. Although the July 31 deadline will permit postemergence use of these dicamba products in full-season soybeans, keep in mind that the label restricts applications of these products to 45 days after planting, or the R1 growth stage of soybeans.
Keep sensitive crops in mind. Although it was not mentioned in the ruling, we do not recommend using dicamba as a burndown in double-crop soybeans since it can be risky. At that time of year, many sensitive crops and ornamentals are very susceptible to dicamba, and weather conditions favor dicamba drift.
Tavium still available. Tavium, which is a premix of dicamba and S-metolachlor that can be applied up to the V4 growth stage in Xtend soybeans, was not part of the ruling and will continue to be sold. Supply is likely to be limited, though.
Avoid illegal sprayings. Other dicamba-containing products such as Clarity, Banvel, Status and the many generics cannot be legally sprayed over the top of Xtend soybeans.
2,4-D products unaffected. Enlist E3 soybean varieties have not been affected by this lawsuit, and thus registered 2,4-D choline products (Enlist One and Duo) can be used in that system. However, these 2,4-D products cannot be used in Xtend soybean systems because major crop damage will occur.
Lingenfelter is the Extension weed specialist for Penn State Cooperative Extension and Wallace is a professor of weed science for Penn State.