The prevalence of marestail in crop production systems has steadily increased over the last 20 years due, in part, to a corresponding increase in reduced tillage practices.1 Before this time, it was typically found in field edges and roadsides. Marestail has grown in complexity to control due to a few challenges:
- A single plant can produce 200,000 plus seeds (Figure 1).
- Small seeds are easily spread by wind.
- 80% of the seeds can germinate immediately.
Marestail seed can germinate year-round if soil conditions are adequate. The seeds generally germinate in late fall and survive the winter in a basal rosette stage. An extended spring emergence period makes burndown applications difficult to plan.
A few marestail management tips include:
- Marestail is most effectively controlled in the seedling or rosette stage (less than 4 inches), apply spring burndowns before bolt or stem elongation to control large populations.
- Herbicide programs should include a burndown to help ensure a clean start at planting and soil-applied residuals for an additional six to eight weeks of control.
- Marestail populations have become resistant to glyphosate, ALS inhibitors, triazines and paraquat. Because of this, consult your local crop protection specialist to help determine an effective PRE and POST herbicide program that combines multiple sites of action for corn or soybean.
- Use full labeled herbicide rates.
- Herbicide product labels MUST be read to help prevent crop injury or carryover.
1Jhala, A. 2018. Management of glyphosate-resistant Marestail in fall. CROPWATCH. University of Nebraska-Lincoln. https://cropwatch.unl.edu/.
Website verified 2/22/20
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