Source credit: www.farmprogress.com
The battle against herbicide-resistant Palmer amaranth continues unabated in North Carolina. Charlie Cahoon says growers must integrate a broader system to better control troublesome weeds.
“Folks it’s time to circle the wagons. Herbicide resistance issues are not going away. We have to start thinking about resistance from a complete weed management standpoint. There has been a big push for integrated weed management in response to herbicide-resistant weeds and it’s high time we got on board,” said Cahoon, North Carolina State University Extension weed specialist for cotton and corn.
Speaking at the Cotton Field Day at the Upper Coastal Plain Research Station in Rocky Mount Sept. 19, Cahoon emphasized cover crops as an important tool for North Carolina cotton farmers to battle Palmer amaranth, horseweed, and other herbicide-resistant weeds. He stressed that cover crops won’t replace herbicides for controlling problem weeds, but they will work in tandem with and take a lot of pressure off herbicides.
At the field day, Cahoon gave a rundown of herbicide-resistant pigweed across the country. He noted there are pigweed species resistant to the Group 15 herbicides, such as Warrant, Dual Magnum, Zidua and Outlook, in the Midwest and Mid-South. In addition, reports from Tennessee say dicamba was much less effective on Palmer amaranth this year compared to the first two years of the system. In addition, 2,4-D resistance has been reported in Kansas and the Midwest.
“Right now, we (cotton farmers in North Carolina) are two to three steps ahead of pigweed. We don’t have dicamba and 2, 4-D resistance. We don’t have Group 15 resistance. We don’t have Liberty resistance. Those folks in the Mid-South and Midwest are not as fortunate. We have to find a way to avoid the same fate,” Cahoon said.