Research Highlights

Research Highlights
Scientists supply farmers with know-how to combat herbicide-resistant weeds

Photo: United Soybean Board

By Carol Brown

A group of researchers is equipping farmers across the Midwest with the knowledge they need to fight herbicide-resistant weeds.

Weed scientists in 10 states are informing farmers and crop advisors on the proper use and stewardship of herbicides including 2,4-D, dicamba and glyphosate. The group is the collective expertise behind Take Action, a multi-media campaign through the United Soybean Board (USB). The campaign began several years ago with collaborative efforts across the ag industry to combat herbicide-resistant weeds. In 2016, Take Action expanded to include fungicide- and insect-resistance issues.

“Our group of extension weed scientists has been collaborating for some time,” said Bill Johnson, professor of weed science at Purdue University. “This project has enabled us to use resources to broaden our expertise and make recommendations across a bigger geographical area.”

Johnson is the lead project investigator on the project supported by USB. He collaborates with peers at universities in Illinois, Iowa, Kansas, Kentucky, Michigan, Missouri, North Dakota, Ohio, Tennessee, and Wisconsin.

Take Action includes a website, print materials, a mobile app, social media, and presentations by experts at field days and seminars. Currently, the weed scientists are hosting a weekly webinar series to discuss pertinent topics.

“We are conducting seven webinars, which are live each Thursday morning, continuing through the end of March,” Johnson said. “These are great sources of information for farmers, crop advisers, and for those teaching weed science or pest management classes at universities and community colleges.”

Several weed species have shown resistance to glyphosate and some weeds are resistant to more than one herbicide. Until farmers have weed issues, they aren’t thinking much about them, Johnson said. The research team developed materials to help farmers identify problematic weeds along with providing them best management practices for weed termination while maintaining the cash crop’s integrity. These materials, and much more, can be found on the Take Action website.

One publication the team developed is “11 That Threaten,” which can be downloaded from the website. It covers details on the 11 most problematic weeds for soybean production including identification tips, herbicide groups and sites of action, and strengths and weaknesses for each.

“This guide highlights the top weeds that are issues in at least half of the states that grow soybeans,” Johnson said. “Each of these weeds covers a broad geographical area, but each one is not a problem in all 30 or so states where soybeans are grown.”

The website also houses numerous resources for managing insect, fungicide and herbicide resistance. Website visitors can get help with weed identification, look up modes of action, read articles penned by experts, sign up for the webinars and email updates, watch past webinars and more.

Johnson said the project is the product of two research areas coming together. The extension and outreach portion that he leads, and the research component led by Bryan Young, Purdue University weed science professor. Young has been exploring best management tactics and issues including off-target dicamba drift. Johnson said these two efforts began at the same time and involved many of the same people, so it made good sense to work together.

“We’re putting our outreach emphasis on how to use the new technologies to the best of our abilities while minimizing the off-target movement,” he said. “We’re bringing more research results to growers and we’re incorporating it into the Take Action program.”

Their efforts seem to be working. Johnson said there’s a heightened awareness of weed problems by farmers, and his group has seen use of alternative management practices go up dramatically. The group’s funding continues through 2020 to extend their research and outreach to farmers.


For more resources on weeds, go to the resource library on this website:

Take Action website:

Previously recorded webinars, located on the Take Action website, managed by USB:

Published: Apr 16, 2020

The materials on SRIN were funded with checkoff dollars from United Soybean Board and the North Central Soybean Research Program. To find checkoff funded research related to this research highlight or to see other checkoff research projects, please visit the National Soybean Checkoff Research Database.