Waterhemp is the big bad wolf that can – and will – blow soybean yields down. 

But the Minnesota Soybean Research & Promotion Council (MSR&PC) is the house made of bricks that invests Minnesota soybean checkoff dollars to stand up to waterhemp’s huffs and puffs. 

“Waterhemp is a very devastating weed if it takes over a soybean field,” MSR&PC Director Gene Stoel said. “If we don’t figure out how to control it, we’ll lose yield and lose profits for the Minnesota – and U.S. – soybean farmer.” 

Continually planting for the future, MSR&PC is funding an agronomic research project through the University of Minnesota investigating waterhemp’s resistance to glufosinate this fiscal year, after seemingly Liberty-resistant waterhemp was found in Dodge County last growing season. 

“This is early in the game,” MSR&PC Director of Research David Kee said. “There has never been a documented Liberty-resistant waterhemp, though there is Liberty-resistant Palmer amaranth, which is a close relative to waterhemp. We’re not 100 percent sure it’s resistant but we’re suspicious and I wouldn’t be surprised if resistance is confirmed.” 

The project has two objectives – to confirm glufosinate resistance in the collected samples and explicate the genetic and physiological mechanisms of glufosinate resistance. With recent soybean traits – like Enlist E3, XtendFlex, LLGT27 and Liberty Link – engineered for glufosinate resistance, getting ahead of the problem is crucial. 

“They’re going to try to tease some of the details out of the samples,” Kee said. “That, in turn, can help determine next steps, whether that be switching the mixture, changing the timing or developing a new product. We need to know what we have to change to keep Liberty as an effective tool.” 

As the most problematic weed in Minnesota soybean fields, this isn’t the first time the Council has gotten its hands dirty with waterhemp research. In 2021, MSR&PC funded a three-year study that showed that 86 percent of waterhemp populations surveyed in Minnesota were resistant to glyphosates, such as Roundup and Touchdown. The same study confirmed the presence of waterhemp resistance to six herbicide sites of action including auxin mimics like 2, 4-D and dicamba. In the meantime, many soybean growers across Minnesota have adopted the use of glufosinate to combat waterhemp. 

“We want to stay in front of these problems and that takes a group effort,” Kee said. “If you’re a soybean grower and spray Liberty and notice that the waterhemp is resistant, please contact the Minnesota Soybean office.” 

Though it’s not a widespread problem quite yet, it’s an issue coming down the pipeline. MSR&PC is jumping into action to find solutions before farmers across the state have their hands tied.  

“MSR&PC has a history of being the leading research agency for Minnesota soybean growers,” said Stoel, who also represents the Council on the North Central Soybean Research Program (NCSRP). “When soybean aphids were first becoming an issue, Council investments in NCSRP helped determine the thresholds and treatment methods. The same went for soybean rust. These types of checkoff investments save growers a lot of money.” 

This study is just one example of the Council’s checkoff investments toward addressing future problems. Stay tuned throughout the summer to learn more about the many avenues Minnesota soybean checkoff dollars are invested in to mitigate problems that are on the horizon.