A court ruling last week threw the legality of dicamba applications on soybeans into question just as many farmers began post-emergence weed control. 

The U.S. Court of Appeals for the Ninth Circuit vacated the registrations of three dicamba herbicides formulated for over-the-top applications on dicamba-tolerant soybeans and cotton. The court ruled that the Environmental Protection Agency (EPA) substantially understated the risks related to the use of dicamba...