Discussion of resistant weeds

“U.S. farmers are heading for a crisis,” says Stephen Powles of the University of Western Australia, Crawley. Powles is an expert on herbicide resistance, a worsening problem in U.S. fields. Weeds resistant to glyphosate—the world’s most popular herbicide—are now present in the vast majority of soybean, cotton, and corn farms in some U.S. states.