Herbicide-resistant weeds continue to be a major issue for crop farmers in Iowa and across the Midwest. Recognizing the challenges related to this problem, Iowa State Extension staff recently surveyed farmers about their perspectives and practices related to weed and resistance management.

Through the Iowa Farm and Rural Life Poll, they surveyed more than 850 row crop farmers. Farmers were asked about their herbicide resistance management practices. Preliminary results found the percentages used for these practices:

In other words, farmers are using multiple strategies, which matches expert recommendations. Staff asked the same questions in 2013, and most areas show considerable increases in adoption.

Tackling weed resistance

The goal of the poll was to gain insight on farmer attitudes and responses related to weed and herbicide resistance management. Across the industry, experts and farmers alike are concerned about the increased numbers of weeds that have evolved resistance to one or more classes of herbicide, as documented by a growing body of research. The new report summarizes the findings to help inform farmers, crop advisers and researchers to choose strategies to tackle resistance effectively.

“Most farmers were both aware of and concerned about herbicide-resistant weeds,” says J. Arbuckle, an Iowa State University rural sociologist and director of the Iowa Farm and Rural Life Poll.

“The results show that the use of the recommended management practices is increasing over time. Although they are currently not at the levels we want, they are definitely trending in a positive direction,” he adds.

Trying new strategies

Over the past five years, 84% of farmers have changed their weed management program due to concern over herbicide resistance. That’s up from 77% in 2017 and 52% in 2013.

Only 36% develop their own herbicide program, which means most farmers are relying on chemical suppliers or agronomists for herbicide decisions.

“One of the biggest things I see in the survey results is the increase in behavior changes over time,” says Katherine Dentzman, ISU assistant professor in rural sociology and co-author of the survey. “We saw a massive increase in the past nine years or so in the percent of respondents who said they changed a farm management practice in response to herbicide-resistant weeds.

“To me, that says people are starting to react proactively to this issue.”

Although farmers appear to be taking herbicide resistance seriously, it’s an ongoing issue that continues to plague agriculture, even as new herbicides are developed. In the survey, 90% of farmers said pest management feels like a “never-ending technology treadmill.”

Need to work together

Another challenge is the need to work cooperatively. Weeds can easily spread from one farm to another. Decisions made on one farm can easily affect another. “One thing we know about managing herbicide-resistant weeds is it’s a lot more effective if it’s community-wide or regional,” Dentzman says.

Of the farmers surveyed, 87% said they are concerned about herbicide-resistant weeds spreading from nearby farms, and nearly half (47%) said that a farmer-led collaboration would be effective. However, nearly 40% also reported they don’t discuss weed resistant issues with neighbors, citing concerns over privacy and the right to make individual decisions.

“The survey provides important information to help Extension specialists and researchers understand farmer perspectives on the issue,” Arbuckle says. “We see a lot of positive trends, but there is still a lot of work to do to get evolution of resistance under control.”

Dentzman is encouraged that farmers are actively engaging in this issue. “They aren't just sitting back and letting it happen, or denying it’s a problem,” she says. “It’s on their doorsteps now, and they’re doing what they can in order to deal with it. That’s huge, and also presents an opportunity to engage with farmers, and provide support and information so they can use the most appropriate management approaches.”

Survey results are available online at Farmers’ Attitudes and Behaviors Related to Weed and Herbicide Resistance Management.