Palmer amaranth resistant to atrazine and HPPD inhibitors (Callisto, Laudis, Impact) in a seed corn production field in Fillmore County, Nebraska.
Palmer amaranth resistant to atrazine and HPPD inhibitors (Callisto, Laudis, Impact) in a seed corn production field in Fillmore County, Nebraska.

A team of weed scientists, economists and sociologists led by Mike Owen, an Iowa State University agronomy professor, is working to develop effective approaches to address an increase in herbicide resistant weeds.

"The spread of herbicide resistant weeds is a growing problem in many parts of the U.S. While herbicide resistance has existed for decades, the number of weed species with resistance to glyphosate and other herbicides has risen dramatically in recent years," Owen said.

"As a result, more time and money are being spent on weed control, and farmers are faced with the likelihood of lower yields and profits unless changes in their weed management are implemented. Further, some conservation gains made with reduced or no tillage systems may be reversed."

The team seeks to better understand the causes and consequences of herbicide resistant weeds, and the strategies farmers use to cope with them. The project, which is supported by a U.S. Department of Agriculture Agriculture and Food Research Initiative grant, also addresses barriers farmers face in adopting more diverse strategies for herbicide-resistant weed management.

Beginning this month, the team will conduct a survey of farmers who manage a wide range of corn, soybean, cotton and sugar beet enterprises. As the people on the front lines of herbicide resistance, farmers have a unique experience and understanding of the problem and the opportunities for cost-effective approaches, which makes the information they can provide so critical for effectively responding to the herbicide resistant weed problem.

"The survey will help the team better understand the human dimensions of herbicide resistance as well as how herbicide resistant weeds are spreading," Owen, a University Professor, said. "It will determine how farmers manage weeds on their farms, including the use of herbicides, tillage systems, crop rotation and other practices that have significant impacts on herbicide resistance."

Another focus of the survey is to identify social, economic and technological barriers that prevent farmers from using different weed management approaches.

Team members include Raymond Jussaume and Katherine Dentzman, Michigan State University; David Ervin, Portland State University; Wes Everman, North Carolina State University; George Frisvold, University of Arizona; Jeffrey Gunsolus and Terry Hurley, University of Minnesota; Jason Norsworthy, University of Arkansas; and David Shaw, Mississippi State University.