Daily News Archive
From March 15, 2001

University Finds Horseweed Resistent to Roundup

The Indianapolis Star reported that horseweed (Conyza Canadensis) is developing resistance to the herbicide Roundup in some East Coast farm fields, according to research released by the University of Delaware. Until now, horseweed, wasn't known to resist Monsanto's popular herbicide outside Delaware and New Jersey. Experts say the news will prompt farmers to manage fields differently.

However, Rae Schnapp of the Hoosier Environmental Council pointed to the discovery as evidence of wrong-headed thinking. "It's a kind of a symbol of our pest-control policies and our pest-control practices," he told The Indianapolis Star. "Our pests are becoming resistant about as fast as we can develop chemicals."

According to the story, Delaware farmers last summer complained of horseweed surviving Roundup treatments in soybean fields. Seeds gathered from the surviving weeds were germinated in greenhouses. Then the plants were doused with as much as 10 times the amount of Roundup typically used in fields.