You’ve finished scouting for winter weeds and you’ve identified marestail as one of the unwelcome intruders in your field. You’ve found the problem, but what is the solution? Limiting costly yield reductions next season starts with a strong, integrated weed control program in the fall to keep uncontrolled weed populations in check.
Marestail control in corn and soybeans
Here is an overview of cultural and chemical tactics that can help you fight marestail pressure.
Cover crops and shade
Marestail struggles to emerge when faced with competition from other vegetation. Fall-planted cover crops such as cereal rye and winter wheat can suppress emerging marestail by 83 to 99%.¹ Timing is everything: Marestail that emerges before or soon after cover crop planting may not be successfully suppressed by the cover crop. Early planted or even interseeded cover crops planted into R-stage corn, for instance, can help foster better competition against marestail. That competition can potentially increase the efficacy of a preplant burndown herbicide.
Tillage to help control marestail
Pre-plant tillage can help temporarily control winter annuals like marestail, but know that vertical tillage alone seldom kills marestail plants, only injuring them while leaving root systems intact. Another downside to tillage is its ability to disperse seeds more widely across your fields.
Marestail herbicides and burndown
Learn how fall herbicide treatments can manage tough winter weeds and provide a weed-free seedbed in the spring.
Sharpen® herbicide
Sharpen herbicide for corn and soybeans drives burndown three to five times faster than 2, 4-D or glyphosate. Its rapid burndown of broadleaf weeds includes powerful control over difficult-to-manage weeds like glyphosate-resistant marestail.
Marestail herbicides for soybeans
Weeds typically begin emerging within eight to 10 days after tillage. Most herbicides should be applied in soybean fields before weeds exceed 3” to 6” high for optimal control.
Engenia® Herbicide
Engenia herbicide is designed to eradicate weeds like marestail and other winter annuals. An over-the-top early application with the lowest use rate can help you cover more acres more efficiently. Engenia carries additional site of action controls for weeds resistant to glyphosate and PPOs, and its systemic activity moves from the point of application to other parts of the plant, providing more consistent weed control. Additionally, it helps keep weeds down with two weeks of broadleaf residual control.
Marestail herbicides for corn
In fields with heavy corn residue, increase spray volume or decrease speed to increase carrier volume. Weeds can easily be shielded by residue, compromising spray coverage. Using residuals in these situations will increase the consistency of winter weed control because these products can be washed off the corn residue with precipitation and into the soil where they can be effective. The best time to apply fall herbicides is on fall days when the morning low temperature is above freezing.
Zidua® SC herbicide
Zidua SC offers broad-spectrum control that lasts up to two weeks longer than other comparable herbicides. With better soil stability to ensure performance and lower use rates, it is an efficient tool in your arsenal.
Coming in 2026: Voraxor®
BASF plans to launch this product for marestail and winter annuals to U.S. growers in 2026. Voraxor® herbicide contains a combination of Kixor® and Tirexor active ingredients. To help prevent marestail from developing resistance to another site of action, consider a mix of Voraxor® with Enlist E3® soybean seed or a mix of Voraxor with Engenia® herbicide for Xtendflex® soybean seed. Always follow label instructions and contact experts who are available to help you make your decisions. Reach out to your seed retailer, a nearby extension office agent, or a professional like your regional BASF representative.
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Endnotes
- “Cover crops help manage Marestail.” Soybean Research & Information Network, 2024, soybeanresearchinfo.com/research-highlight/cover-crops-help-manage-marestail/. Accessed 9 Mar. 2026.
