Marestail, also known as horseweed, can follow a winter or summer lifecycle and grows rapidly - and once this troublesome weed grows above 5 inches, it can be difficult to control with herbicides alone.1,2
This annual broadleaf weed is native to North America but can now be found worldwide.3
Failure to rein in its growth early can reduce yield by 40%.4
Up to 90% of fall emerged seedlings can survive winter and "bolt" in spring.5
Leaves are entirely without petioles, and solid stems can reach 6 feet, while root systems consist of short taproots with fibrous secondary roots.6
Seeds are numerous as each plant can produce up to 200,000 SEEDS, and 80% of these seeds can germinate immediately after falling from the mature plant.7
The evolution of herbicide-resistant and tough-to-control marestail is widespread. Keep weeds from affecting your bottom line by using well-designed best management practices, including a fall and spring burndown treatment, as well as residual herbicides to control weeds after planting. An integrated approach combining different sites and modes of action along with cultural practices can protect fields now and help prevent resistance in the future.
to diversify herbicide programs and weed control strategies.
with a burndown herbicide or tillage.
using a residual product within 2 weeks before planting or prior to crop emergence.
before weeds grow taller than 4 inches.
If weeds escape, use tillage or physically remove them before plants produce seed.
1 Crop Science (June 27, 2019). Keep crops safe from broadleaf weeds. Retrieved from http://www.cropscience.bayer.us
2 Lingenfelter, D., Klood, A., Curran, W. S. Pennsylvania State University Extension (November 13, 2017). Marestail (horseweed) management. Retrieved from http://www.extension.psu.edu
3 University of Wisconsin-Madison Integrated Pest and Crop Management (Sep. 4, 2019). A horseweed population in Wisconsin is confirmed resistant to glyphosate. Retrieved from http://www.ipcm.wisc.edu
4 Klingaman, G. University of Arkansas Division of Agriculture (August 5, 2005). Plant of the week: marestail (horseweed). Retrieved from http://www.uaex.edu
5 Crop Science (Sep. 4, 2019). Fighting glyphosate-resistant marestail? Get the facts. Retrieved from http://www.cropscience.bayer.us
6 University of Missouri Division of Plant Sciences (June 27, 2019). Weed ID Guide, Horseweed. Retrieved from http://www.weedid.missouri.edu
7 Jhala, A., Elmore, R. University of Nebraska ï¿½ Lincoln Institute of Agriculture and Natural Resources (October 25, 2018). Management of glyphosate-resistant marestail in fall. Retrieved from http://wwww.cropwatch.unl.edu