Soybeans: 5 Tips to Stay Ahead of Resistant Weeds

According to the Weed Science Society of America (WSSA), without the use of herbicides to control weeds, soybean and corn farmers would lose about half their crop, costing them about $43 billion every year.

To maintain the usefulness of herbicides, farmers must diversify their weed-management plans beyond just herbicides, according to Kansas State University weed scientist Anita Dille, Ph.D., who led this research project.

“It also drives home the importance of taking steps to mitigate the development of herbicide resistance,” Dille said in a WSSA news release. “When a single herbicide is used repeatedly to the exclusion of other controls, weeds can become resistant and can grow unchecked.”

Now is a critical time for soybean farmers to manage against yield-robbing weeds. Here are five tips to help.

1. Spring Cleaning. Any weeds that have emerged before the crop starts coming up will have a huge advantage, says University of Tennessee associate professor and row-crop weed specialist Larry Steckel, Ph.D. Weeds grow much faster than soybean plants, giving them an edge in competing for nutrients, sunlight and water.

2. Proactive Control. The faster your soybean plants can form a canopy, the better they’ll be able to hold out weeds all season long. Apply a pre-emergence herbicide to give them a head start. Read more ways to help keep your soybeans ahead of weeds.

Our Newsletter

3. Weed Warm-Up. Some weed species can survive the winter and then spring back to life once the weather turns warmer. Split-spring herbicide applications – one prior to planting and one after emergence – can help control these species, which include marestail, Italian ryegrass, henbit and more.

4. Take Action Now. The soy checkoff helped build a program that gives farmers the tools they need to battle weeds this season. It’s called Take Action, and more than two dozen organizations from throughout agriculture are involved. The program encourages farmers to diversify their plan of attack against weeds, such as using crop rotation, residual herbicides and multiple modes and sites of action. It’s not too late to build your diverse weed-management plan for this season.

5. Chart Your Success. Under Take Action, the checkoff develops materials to introduce farmers to some of the biggest weed threats, as well as ways to control them. For example, the Herbicide Classification chart helps farmers diversify herbicide applications based on mode and site of action. And the Weed Out Resistance chart lists the herbicide groups to which the 11 most threatening weed species have developed resistance.