University Expert Talks Resistance in Southern Illinois at 2009 Farm Progress Show
Dr. Bryan Young, weed scientist at Southern Illinois University, spoke on the impact glyphosate-resistant weeds are having throughout southern Illinois at the Syngenta Farm Progress Show booth this week.
The southern 2/3 of the state is currently dealing with some type of glyphosate-resistant weed. Young commented on fields he has worked closely with, saying a loss of over $50 per acre in soybeans due to glyphosate-resistant weeds is realistic. Fields have even seen as much as a 50 percent reduction in soybean yield due to resistance pressure. Young is dealing with one field with giant ragweed, waterhemp and horseweed that cannot be controlled with glyphosate herbicides.
The keys weeds to watch moving forward are waterhemp and lambsquarters, according to Young. Waterhemp and marestail accounted for what growers felt was their biggest weed challenge in 2008.
Escaped waterhemp and marestail. Photo courtesy of Southern Illinois University.
Young recommends the use of a soil-residual herbicide, starting clean, avoiding glyphosate-only programs, and the inclusion of multiple modes of action (at least two during burndown). There aren’t a lot of good options for post-emergence control in soybeans once weeds get some height on them, said Young. Spraying when weeds are small (less than 6 inches) and more manageable is key.
At Syngenta, this problem is too easy to see beyond the borders of Illinois. Unfortunately, plenty of other states across the U.S. are facing similar, if not worse, problems. The projected acreage for glyphosate-resistant weeds is at 38 million U.S. acres just four years from now. That’s one in four acres that will be impacted. Visit the Solution Builder module on resistancefighter.com to create a personalized plan so you don’t get caught with a problem too big to control.