April 28, 2020
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.
Figure 1. Marestail seed head.
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.
Sources
1Jhala, A. 2018. Management of glyphosate-resistant Marestail in fall. CROPWATCH. University of Nebraska-Lincoln. https://cropwatch.unl.edu/.
Website verified 2/22/20
ALWAYS READ AND FOLLOW PESTICIDE LABEL DIRECTIONS. Performance may vary, from location to location and from year to year, as local growing, soil and weather conditions may vary. Growers should evaluate data from multiple locations and years whenever possible and should consider the impacts of these conditions on the grower’s fields. Tank mixtures: The applicable labeling for each product must be in the possession of the user at the time of application. Follow applicable use instructions, including application rates, precautions and restrictions of each product used in the tank mixture. Not all tank mix product formulations have been tested for compatibility or performance other than specifically listed by brand name. Always predetermine the compatibility of tank mixtures by mixing small proportional quantities in advance. Channel® and the Arrow Design® and Seedsmanship At Work® are registered trademarks of Channel Bio, LLC. All other trademarks are the property of their respective owners. ©2020 Bayer Group. All rights reserved.