Herbicide-resistant waterhemp populations will challenge weed management practices and practitioners during the 2012 growing season.
University of Illinois associate professor of weed science Aaron Hager said that the increasing occurrence of waterhemp populations that possess resistance to herbicides spanning more than one site of action further complicates management because the efficacy of multiple herbicides is compromised.
Last year, University of Illinois weed science specialists published the results of a herbicide-resistance screening program for waterhemp samples submitted during the 2010 growing season. The program uses molecular biology techniques to detect herbicide-resistance traits (glyphosate, PPO inhibitors, and ALS inhibitors) in waterhemp. In 2011, a total of 408 plants from 97 different fields suspected of having glyphosate-resistant waterhemp were submitted.
Hager explained that distinguishing between multiple herbicide resistance at the field and individual plant levels is important and can impact management options.
“Field-level multiple resistance is when resistance to herbicides from more than one site of action is present within the population growing in any particular field,” he said.… Continue readingRead More »