Number of Roundup-resistant weeds is rising

We most recently reported the increase of Roundup Ready-resistant weeds in early May, and now some of the specific problems arising from the resistance affecting farmers are coming to light. In the South, Roundup-resistant pigweed is choking out cotton, Tom Beyerlein of the Dayton Daily News reports. Ohio has just three resistant weed species, marestail, giant and common ragweed, but they are spreading. The International Survey of Herbicide Resistant Weeds has identified 346 different resistant species worldwide, Beyerlein reports. (Daily News graphic showing number of resistant species by year)

"We can go back to the old ways, but do we want to do it, environmentally?" Jeff Stachler, who led several Ohio weed studies, told Beyerlein. "How do we want to harm the environment the least?" In addition to the cost-saving and productivity benefits of using Roundup Ready seeds, many Roundup advocates say the herbicide is more environmentally friendly that other older weed killers. (Read more)