Farmers will have a new weapon to fight herbicide-resistant weeds after the Environmental Protection Agency (EPA) last week approved a new dicamba herbicide formulation for post-emergence applications on dicamba-tolerant crops.

The EPA approved Monsanto’s XtendiMax herbicide with VaporGrip Technology for in-crop use with Roundup Ready 2 Xtend soybeans and Bollgard II XtendFlex cotton beginning next year. However, the herbicide approval comes with a number of restrictions designed to manage weed...