Tackling weed resistance contentious

Caleigh Irwin of Vive Crop Protection in Guelph, Ont., was one of hundreds of experts who attended the Weed Science Society of America annual meeting in Baltimore Feb. 4-7. She was taking a look at the poster presentations organized for the conference.  |  Robert Arnason photo

Compensating farmers who overused glyphosate is ‘rewarding bad management,’ says scientist

BALTIMORE, Md. — Carol Mallory-Smith, a weed scientist from Oregon State University, couldn’t help herself.

Two experts on a panel discussing herbicide resistance during the Weed Science Society of America’s annual meeting in Baltimore Feb. 4-7 had just suggested the U.S. government offer financial incentives to growers who adopt alternative practices as part of an effort to slow the development of resistant weeds.

For Mallory-Smith, however, compensating farmers who overused glyphosate in the past and now have resistant weeds on their land is absurd.

“I think that’s just rewarding bad management,” she said after rising from her chair in the audience to make her point.

“If a farmer didn’t have good practices on his farm, I don’t see how it’s the public’s (responsibility) to fix it. If I make bad decisions in my life, nobody’s going to give me incentives to fix those decisions.”

Mallory-Smith’s comments were part of a lively debate at the conference about what can be done to encourage North American farmers to preserve existing herbicides and delay the development of resistance.

She said government regulations are contentious, but they might be necessary to deal with herbicide resistance in North America.

“I think regulation should be the last avenue, but we are sort of at the last avenue because nobody has come up with any great solutions,” she said.

Lee Van Wychen, the association’s director of science policy, disagreed, saying regulations would fail miserably.

He said if a grower in a particular county in Wisconsin, for example, wasn’t allowed to use glyphosate in a particular year, he would drive to the next state or county and buy glyphosate from his brother-in-law.

“Farmers will find ways to get around it.”

Harold Coble of the U.S. Department of Agriculture in Raleigh, North Carolina, agreed with Van Wychen, saying farmers will strongly object to rules governing herbicide use.

“He will tell you where to shove that regulation,” he said.

Instead, Coble supports a successful model from Arkansas, where growers banded together to fight glyphosate resistant Palmer amaranth (pigweed) in their region.

Led by the University of Arkansas, the goal of the Zero Tolerance program is to keep all fields free of pigweed to prevent seed production.

“If we look back over the last 15 years, the mindset has been that we wanted to see a weed before we chose to kill a weed,” said Jason Norsworthy, a University of Arkansas weed scientist.

“We’ve got to move off of that (philosophy) and minimize weed seed production…. That has to be the mindset, to go into the cropping system trying to prevent seed production.”

Farmers in parts of Arkansas employ multiple strategies on their Roundup Ready cotton and soybeans to achieve zero tolerance, including residual herbicides, tillage and removing pigweed by hand.

“At the community level, we’ve had growers that have come to-gether and implemented this, across 50,000 or 100,000 acres,” Norsworthy said. “That’s basically self-imposed regulation.”

The labour costs of hand weeding cotton fields can exceed $100 per acre. Strong cotton prices offset the costs, as do incentives from Mon-santo for applying another herbicide on top of glyphosate.

Mallory-Smith said she has no problem with biotech companies offering financial incentives to preserve their technology.

However, she objects to taxpayers offsetting farmers’ costs for programs such as the Zero Tolerance initiative.

The National Resources Conservation Service in the U.S. is running a pilot program in three states that offers financial incentives to growers who adopt resistance management programs.

Taxpayer funded payments are controversial, but Norsworthy said farmers in Arkansas, at least those in regions where pigweed is highly resistant to glyphosate, are willing to spend money to control weeds.

“If the person is not going to be proactive or at least follow some of these strategies (BMPs), at the end of the day … they’re not going to continue to farm.”

However, the challenge is to convince farmers who aren’t dealing with glyphosate resistant pigweed to take action.

Norsworthy said the best pitch is selling farmers on the long-term financial benefits.

As an example, he knows of a 9,000 acre cotton grower in Arkansas who started chopping pigweed and employing other tactics to prevent resistance in the mid-2000s.

“(The grower) today lives in the heart of what we would call pigweed country,” Norsworthy said.

“I’ve done some surveys in that area and they (farmers) are spending $150 per acre chopping pigweed so they can grow a crop of cotton.”

The proactive grower does have glyphosate resistant pigweed on his farm, but he spends only $6 per acre on labour to chop the weed, he said.

“That’s the message we’ve got to take and get in front of (growers). Are you going to completely prevent this from happening? No. But obviously there is some benefit to being proactive.”

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