Researchers Offer Weed Management Advice for 2021

Agricultural researchers from across the U.S. agree that the time for corn growers to set a weed management strategy for 2021 is now.

"The end of the season is the time to take inventory of whatever you did, how well it worked and then consider how you might improve on that for next year,” says Wayne Keeling, Ph.D., professor in the Department of Soil and Crop Sciences at the Texas A&M AgriLife Research Center at Lubbock.

For corn, early-season weed control is especially important because key elements of yield potential are determined early in the growing season. Any limitations created by weeds during that time will limit the yield potential of the crop.

Early-Season Weed Control Is Key

Across the board, the researchers agree that early-season weed control is the path to maximize yield potential. “For corn, early-season weed control is especially important because key elements of yield potential are determined early in the growing season,” says Sarah Lancaster, Ph.D., assistant professor and extension specialist at Kansas State University. “Any limitations created by weeds during that time will limit the yield potential of the crop.”

The researchers underscore the significance of weed control during this early-season timing. “Control is mostly emphasized on weeds that germinate before or shortly after corn emergence, because controlling those weeds plays a large role in preserving yield potential within that crop,” says Erin Burns, Ph.D., assistant professor and extension weed scientist at Michigan State University.

This crucial control period is defined as the vegetative stages between V3 and V12. “If you let weeds stay in the field past the V2 stage of corn growth, you start to see 10% to 20% yield reductions,” says Bill Johnson, Ph.D., professor of weed science at Purdue University. “If you leave them out there until the corn is knee- to waist-high, you can start seeing 20% to 50% yield reductions.”

Weeds Are Plants, Too

In addition to the physical competition for resources, the physiology of weed presence in the field also has an impact.

“We discovered that plants can actually detect their neighbors. They know who's around them, and they respond,” says Clarence Swanton, Ph.D., professor emeritus at the University of Guelph, Canada. “Even without touching the plant, a weed can reduce that plant’s capability to photosynthesize. The plant has to expend energy to heal itself after it experiences the presence of a weed, and that's part of why the yield potential changes so dramatically. What you and I as humans experience under stress, a plant does, too.”

Aaron Hager, Ph.D., associate professor of extension weed science at the University of Illinois, agrees. “We call them weeds, but they're plants,” he says. “They have a lot of the same requirements that the crop has — moisture, nutrients, sunlight — and the resources that the weeds use up become resources that the crop does not have access to.”

Unique Chemistry Can Help Increase Yield Potential

Syngenta is committed to developing solutions to manage these troublesome weeds that impact yield potential. “We want to provide our growers with the knowledge and tools they need to effectively manage their top weed pressures so they can maximize their yield potential next season and for many seasons to come,” says Steve Gomme, herbicide product marketing lead for Syngenta. “And we have a robust portfolio of premixes, like Acuron^® corn herbicide, that enable us to offer weed management solutions for every acre.”

Acuron contains four active ingredients, including the Syngenta-exclusive bicyclopyrone, and three effective sites of action.

“This combination delivers long-lasting residual weed control with built-in resistance management,” Gomme says. “Because of its powerful weed control, longest-lasting residual and proven crop safety, Acuron outyields all other corn herbicides by 5 to 15 more bushels an acre when used preemergence at full labeled rates.*”

Bicyclopyrone allows Acuron to provide greater consistency across various weed spectrums, weather conditions and soil types. This unique chemistry enhances control of more than 70 broadleaf and grass weeds. It also provides built-in burndown control and the longest-lasting residual to minimize the weed seed bank for the next year’s crop.

“The bottom line is less weed competition means more nutrients, sunlight and water are available for the growing corn crop,” Gomme says. “This leads to stronger, healthier plants that produce more bushels and, ultimately, more revenue potential at harvest.”

To calculate how much more revenue potential Acuron offers, visit the Revenue Calculator.

* When applied preemergence and at full label rates. Acuron yield advantage range based on 2016 Syngenta and University trials comparing Acuron to Corvus^®, Resicore^®, SureStart^® II and Verdict^®. For more information on Acuron versus an individual product, ask your Syngenta representative.

Performance assessments are based upon results or analysis of public information, field observations and/or internal Syngenta evaluations. Trials reflect treatment rates commonly recommended in the marketplace.