A History Lesson in Herbicide Resistance
The evolution and spread of glyphosate resistant weeds has increased people’s awareness of the threat of herbicide resistance. Participants at a recent series of meetings were asked their perspective of the prevalence of resistance to several herbicide classes in fields they managed. In the survey, 60 percent of farmers reported that waterhemp resistant to Group 2 herbicides (ALS inhibitors) was not present in their fields or they were unsure of its presence. Industry representatives were somewhat more aware of Group 2 resistance, with 38 percent saying resistance was widespread and 42 percent reporting it was isolated in their territories. Both groups reported that glyphosate (Group 9) resistance was more common than Group 2 resistance.