BALTIMORE, Md. — The normal practice at farm conferences is for a panel of experts to discuss a significant issue for an hour, or 90 minutes at the most.
At the Weed Science Society of America’s annual meeting in Baltimore Feb. 5, however, 15 scientists on three separate panels talked about herbicide resistance for more than four hours.
The weed experts, agricultural economics professors and one sociologist discussed ways to manage herbicide resistant weeds, particularly weeds that glyphosate will no longer kill.
However, Kevin Bradley, a weed expert at the University of Missouri, said the crisis is much larger than glyphosate resistance.
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“The bigger issue right now for me, and many of my colleagues, is multiple resistance. These types are be-coming more and more common.”
He said several weed species in the U.S. Midwest are now resistant to a rainbow of herbicides, which presents an expensive challenge because those super weeds dictate how farmers grow their crops.
“Kochia is developing into a driver weed in the western region of the corn belt,” he said.
“Waterhemp … has many types of herbicide resistance, and the degree to which we have multiple resistance now is really changing a lot of our (production) systems.”
The scientists also spent hours at the conference discussing grower behaviour and choices, specifically how to persuade producers to adopt best management practices to prevent resistance.
“It’s not just science, it’s human behaviour that dictates outcomes,” said Jodie Holt, a weed scientist from the University of California Riverside.
Amy Asmus, an owner of Asmus Farm Supply in Iowa, said she prepared for the panel discussion by surveying certified crop advisers in the United States, Canada and Mexico to assess attitudes and perceptions regarding herbicide resistance and the best management practices to delay resistance.
When asked when they would adopt alternative practices to fight herbicide resistance, 40 percent of respondents said they would take appropriate action when it appeared in their fields.
“That number was a little higher than I (expected),” she said.
Asmus said the reluctance to prevent a problem shouldn’t be surprising because producers are pressed for time and must cope with other on-farm troubles.
“They have good intentions but sometime that falls to time or weather constraints.”
Ray Jussaume, a Michigan State University sociologist, said scientists are too focused on the science of herbicide resistance. Instead, they need to consider the science of personal choice.
“You are facing a human problem.”
