Weeds resistant to Roundup are beginning to spread from Midwest to other states

Weeds in key farming states—Kansas, Missouri, Nebraska and Illinois—are showing a strong resistance to glyphosate, brand name Roundup, which "is a worrisome sign as weed resistance spreads from the southern U.S. into the Midwest and Plains farming states," Carey Gillam reports for Reuters. "As the key ingredient in Monsanto Co's Roundup herbicide products as well as about 700 other products, glyphosate is widely used on farms as well as residential lawns."

Dallas Peterson, a weed scientist at Kansas State University and president of the Weed Science Society of America, "said Kansas soybean farmers in particular are experiencing weed problems, particularly with a type known as Palmer amaranth," Gillam writes. "Wet weather along with the weed resistance contributed to the problem, he said."

"Weeds can choke off nutrients to crops hurting production and raise costs for farmers who often use added chemicals or other means to combat the troublesome weeds," Gillam writes. The House agriculture committee has scheduled a Dec. 4 briefing to discuss the problem.

"The U.S. Department of Agriculture said that reliance on glyphosate by many farmers is the primary factor for the problem," Gillam writes. "Fourteen glyphosate-resistance weed species have so far been documented in U.S. crop production areas, according to USDA." Monsanto and DowAgroSciences, a unit of Dow Chemical, have said they are introducing new herbicides to the market, but Peterson warned that KSU tests "showed that these combinations still had trouble controlling Palmer amaranth weeds." (Read more)