Resistant Weeds a Growing Concern for Soybean Farmers


Tom Peters (right) and Dave Nicolai (left) address farmers on current weed issues.

Herbicide resistant weeds are a growing concern for many farmers and this past Wednesday, around 40 Minnesota soybean farmers took initiative to learn more about the problem and possible solutions.

“It is our responsibility to learn about the products and do a good job,” said farmer Tommy Young, who has been battling weed resistance issues on his farm in Arkansas.

The Weed Resistance Meeting held in Olivia, Minn., on Aug. 12, was filled with informative tours and speakers including Dow AgroSciences, Extension Agronomist Tom Peters, speakers from Dekalb/Asgrow and Young.

“Pre-emergents aren’t the total answer,” said Brian Pettis, a farmer from Winthrop, Minn. “I’m concerned about residue carry over from one year to the next.”

The meeting began at the Dow AgroSciences plots, where Ryan Keller, Enlist Specialist – Midwest, spoke on the new Enlist Weed Control System. The Enlist system combines 2,4-D and glyphosate and has benefits regarding volatility, tank contamination and drift. Participants then visited the Dow AgroSciences Research and Development facility to learn how varieties are developed.

Tom Peters, Extension Agronomist for North Dakota State University and the University of Minnesota, along with Dave Nicolai, University of Minnesota Extension Educator, presented weeds that were common problems in Minnesota and addressed farmers concerns. Peters encouraged farmers to scout their fields, develop a strategy, manage field borders, have zero tolerance for weed escapes, utilize an integrated approach and adjust strategy as needed.

Young began his presentation by explaining that he didn’t mean to be an expert, but because he’s been a farmer his whole life, he became one. In 2010, he began facing major weed resistance problems on his farm.

“It’s not if I have resistance, but when,” Young said, as he had learned from his experience.

Palmer Amaranth is a weed that has caused a problem on his farm and in many areas of the United States. However, it does not currently exist in Minnesota.

“If you see one of these, call the extension agronomists, call ghostbusters, call somebody,” Young said. “It’s that big of a deal.”

At the Dekalb/Asgrow plant, Technical Agronomist Greg Haubrich gave an update on the soybean growing season and soybean fertility. Soybean Breeder Roger Lussenden also spoke about current and new products. Ross Recker, Weed Management Technology Development rep for Monsanto also covered sustainable weed management.

Recker summarized his main points for farmers to remember to reduce risk of herbicide resistance:

  1. Use a diversified approach and integrate chemical, cultural, biological and mechanical practices.
  2. Apply correct rate of chemicals at appropriate weed sizes.
  3. Use multiple herbicide mechanisms of action.
  4. Emphasize cultural practices that suppress weeds by using crop competitiveness.
  5. Incorporate new methods and technology.

“Weed resistance is a numbers game, and the name of the game is overlapping methods,” Recker said. “The future of weed control can be sustainable.”