The University of Illinois Extension has received many questions about applying herbicides post-harvest to control emerged marestail plants. Fall-applied herbicides often provide more effective and consistent control of emerged marestail as compared with spring-applied (i.e., burndown) herbicides, says Aaron Hager, weed specialist with U of IL Extension. Here are tips from the Extension service for fall-applying herbicide to control emerged marestail.
Like what you're reading? Subscribe to CSD Extra and get the latest news right to your inbox!
1. We suggest applying 2,4-D (1.0 lb acid equivalent per acre) anytime between mid-October and late November to control emerged marestail. This treatment should not be expected to provide much soil-residual activity, so marestail plants that emerge after application will most likely not be controlled.
2. Do not rely solely on glyphosate (either in the fall or spring) to control emerged marestail.
3. Do not simply assume that fields treated with fall-applied herbicides will be free of marestail next spring. Be sure to scout fall-treated fields before spring planting and take appropriate measures (i.e., supplemental herbicides, tillage, etc.) to control any existing marestail plants.
4. Do not plant soybean into an existing marestail population. Residual herbicides should be applied close to soybean planting to control summer annual species, including spring-emerging marestail.
5. If a soil-residual herbicide will be part of a fall herbicide application, we suggest selecting an application rate that will provide control of winter annuals throughout the remainder of 2013, and recommend against increasing the application rate in hopes of obtaining control of summer annual species next spring.
You might also like: