Farmers Concerned about Herbicide-Resistant Weeds

Survey shows farmers are concerned about resistant weeds

December 4, 2023, 10:48 am | J. Gordon Arbuckle Jr., Katherine Dentzman

AMES, Iowa – Herbicide-resistant weeds continue to be a major issue for crop farmers in Iowa and across the Midwest. Recognizing the challenges related to this issue, the 2022 Iowa Farm and Rural Life Poll asked farmers about their perspectives and behaviors related to weed and resistance management.

Results were gathered from more than 850 row crop farmers and were published in November 2023, in an extension report called Farmers’ Attitudes and Behaviors Related to Weed and Herbicide Resistance Management.

Farmers were asked about their herbicide resistance management practices. Ninety-seven percent of those surveyed said they use crop rotation, followed by 84% who use multiple modes of herbicide action each season, 81% who use multiple herbicide application timings, 73% who use tillage and 42% who use cover crops. Some 43% report that they use hand-weeding done by themselves, and 44% report using crop cultivars that are resistant to herbicides other than glyphosate. In other words, farmers are using multiple strategies, which matches expert recommendations.

Field of cover crops in Iowa.The same practices were examined in 2013 and most show considerable increases in adoption.

“Most farmers were both aware of and concerned about herbicide-resistant weeds,” said J. Arbuckle, rural sociologist with Iowa State University Extension and Outreach 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 would want, they are definitely trending in a positive direction.”

The survey also shows that over the last five years, 84% of farmers have changed their weed management program due to concern over herbicide resistance. This is 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 that stuck out to me was the increase in behavior changes over time,” said Katherine Dentzman, assistant professor in rural sociology at Iowa State 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 that 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. Ninety percent of farmers said that pest management feels like a “never-ending technology treadmill.”

Another challenge is the need to work cooperatively. Since weeds can easily spread from one farm to another, the decisions made on one farm can easily affect another.

“One of the things we know about management of herbicide-resistant weeds is that it’s a lot more effective if it’s community-wide or regional,” said Dentzman.

Eighty-seven percent of farmers reported 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 did not discuss resistant issues with neighbors, citing concerns over privacy and the right to make individual decisions.

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

According to Dentzman, it’s encouraging to see that farmers are actively engaging this issue.

“They aren't just sitting back and letting it happen, or denying it's a problem,” she said. “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.”

Shareable photo: Field of cover crops in Iowa.

About the Authors: