*This article was previously published by Corteva Agriscience
Farmers often face challenges with weed control due to varying weather and field conditions. These challenges can increase weed pressure, especially from tough-to-manage winter and summer annuals like marestail and waterhemp.
A fall burndown can reduce winter weed populations and give crops a healthier start by preventing early season competition. It helps to eliminate tough-to-control weeds like marestail before they become resistant or grow too large in the spring.
What you need to know
- Spring weed pressure: Wet conditions this spring led to a surge in weed growth, with many farmers unable to apply burndown treatments until late May or early June. This delayed start allowed winter annuals and summer weeds to flourish, making them harder to control later in the season.
- Winter annuals’ impact: Weeds like marestail and henbit grow during the fall, remain dormant over winter and then emerge stronger in the spring. These weeds can delay soil warming, compete for nutrients and impact seed placement during planting. Henbit and purple deadnettle also provide a haven for pests like soybean cyst nematodes. Marestail is troublesome due to its wide germination window and herbicide resistance. By the time it “bolts” in the spring, it’s much harder to control.
- In-season pressure: In-season moisture can also lead to new flushes of summer annual weeds such as waterhemp and Palmer amaranth, which thrive as preemergence residuals wear off. Overlapping residual herbicides and adopting a full-season weed control program can help combat these issues. Fall burndown is a proactive way to reduce weed pressure before the next growing season.
Action steps to get the most from a fall burndown
- Assess your fields: If weed pressure was high this season, consider a fall burndown application to get ahead of next year’s problems.
- Target problem weeds: Focus on controlling winter annual weeds like marestail and henbit while still small. This will make eliminating and preventing future issues with resistant weeds easier.
- Use the right herbicide: Consider using Elevore® herbicide, which offers excellent control of winter annuals like marestail and henbit. Elevore is also tank-mix-compatible with commonly used burndown and residual partners to control many ALS- and glyphosate-resistant species, plus marestail up to 8″ tall. Elevore herbicide has a low use rate of 1 oz/A, making it an excellent fit in reduced- and no-till production systems.
