WEED OF THE MONTH: Marestail

Trends:

  • In 2012, 24 percent of growers reported the presence of glyphosate-resistant marestail on their farm, which is 8 percent more than in 2011, according to Stratus data.6
  • The germination window has expanded and now includes summer. Marestail can germinate eight to nine months out of the year.5

Resistance statistics:

According to WeedScience.org:

  • Herbicide classes:
  • Multiple resistances confirmed in:
    • OH:
        • ALS inhibitors, glyphosate
    • MS:
      • PSI electron diverter, glyphosate
    • DE:
      • ALS inhibitors, glyphosate

Weed management tips:

According to Joe Armstrong, field scientist, Dow AgroSciences:

  • Learn to identify marestail in the small rosette stage and scout for it in the spring, early summer and fall.
  • An early spring burndown controls winter marestail. A preemergence herbicide will open a wider window to apply a postemergence herbicide to control any remaining marestail.
  • Apply a residual herbicide to control marestail and prevent later germination. Follow up with a fall application to keep fields clean going into winter.

Dow AgroSciences weed control solutions:

Corn:

*Regulatory approvals are pending for the Enlist herbicide solution and crops containing Enlist herbicide tolerance traits. This is not an offer for sale of Enlist.

Soybean:

**Regulatory approvals are pending for the Enlist herbicide solution and crops containing Enlist herbicide tolerance traits. This is not an offer for sale of Enlist.

Additional Information:

1Everman, W., C. Sprague, S. Gower, and R. Richardson. 2010. An IPM Pocket Guide for Weed Identification in Field Crops.
2PLANTS Profile. United States Department of Agriculture Natural Resources Conservation Service website. http://plants.usda.gov
3MSU Weed Science website. http://www.msuweeds.com/worst-weeds/marestail/
4Understanding and Managing Marestail. http://www.agprofessional.com/resource-centers/corn/news/understanding_and_managing_marestail_120009894.html
5University of Illinois Extension. Controlling Marestail (Horseweed) After Crop Emergence. http://web.extension.illinois.edu/state/newsdetail.cfm?NewsID=29274
6Stratus Agri-Marketing Inc. Glyphosate Resistance Tracking USA 2012.

®™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow. Cobalt, Cobalt Advanced, FulTime NXT, Keystone LA NXT and Keystone NXT are federally Restricted Use Pesticides. State restrictions on the sale and use of Hornet WDG apply. Consult the label before purchase or use for full details. Cobalt, Cobalt Advanced, Duramax, Durango DMA, FirstRate, FulTime NXT, Instinct II, Keystone LA NXT, Keystone NXT, Sonic, SureStart, Surpass NXT and Surveil Co-pack are not registered for sale or use in all states. FulTime NXT, Keystone LA NXT, Keystone NXT, SureStart and Surpass NXT are not available for sale, distribution or use in Nassau and Suffolk counties in the state of New York. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Do not fall-apply anhydrous ammonia south of Highway 16 in the state of Illinois. Enlist E3 soybeans are being jointly developed by MS Technologies and Dow AgroSciences. Regulatory approvals are pending for the Enlist herbicide solution and crops containing Enlist herbicide tolerance traits. The information presented here is not an offer for sale. Always read and follow label directions. ©2014 Dow AgroSciences LLC