2015 Status of herbicide resistant weeds in Michigan

Erin Hill, and Christy Sprague, Michigan State University Extension, Department of Plant, Soil and Microbial Sciences -

Glyphosate and other herbicide-resistant weeds continue to spread across Michigan.

Horseweed or marestail. Photo credit: Steve Gower
Horseweed or marestail. Photo credit: Steve Gower

Each fall we receive several weed seed samples from around the state to test for resistance to various herbicides. All testing is conducted by the weed science group within the Department of Plant, Soil, and Microbial Sciences at Michigan State University and is sponsored by the Michigan Soybean Promotion Committee. In 2014, we received samples of redroot pigweed (1), Palmer amaranth (2), common waterhemp (5), common ragweed (7), common lambsquarters (2), and horseweed/marestail (15). Each sample received is tested for resistance to five or six herbicide Sites of Action.

We will again be conducting free herbicide resistance testing in the fall of 2015. Please view “How to submit a sample to MSU Diagnostic Services” in the back of the 2015 Weed Control Guide for Field Crops (E0434) for more information on submitting a sample. Submission of several mature seedheads/plants by early November will ensure enough time for our team to break seed dormancy and conduct the screenings. If you have any questions regarding weed seed collection, please contact Christy Sprague (sprague1@msu.edu) for more information. Below is the update published by Michigan State University Extension.

New county locations and/or incidents of resistance confirmed from 2014

Redroot pigweed

  • ALS-resistant: Shiawassee Co.

Palmer amaranth

  • ALS-resistant: Shiawassee Co. [multiple (glyphosate/ALS)-resistant was reported in 2011]

Common waterhemp

  • ALS-resistant: Shiawassee Co.
  • Multiple-resistant (glyphosate/ALS): Berrien, Saginaw, Shiawassee, St. Joseph Co.

Common ragweed

  • ALS-resistant: Branch, Montcalm Co.
  • Multiple-resistant (glyphosate/ALS): Isabella, Shiawassee Co.

Common lambsquarters

  • ALS-resistant: Branch Co.

Horseweed/marestail

  • ALS-resistant: Isabella Co.
  • Multiple-resistant (glyphosate/ALS): Berrien, Cass, Gratiot, Montcalm Co.

View maps of Michigan counties with these resistant weeds.

This article was published by Michigan State University Extension. For more information, visit https://extension.msu.edu. To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464).

Did you find this article useful?

You Might Also Be Interested In

Tag List
  • agriculture,
  • corn,
  • dry beans,
  • field crops,
  • forages,
  • grazing crops,
  • hops,
  • msu extension,
  • small grains,
  • soybeans,
  • sugarbeets,
  • wheat
  • follow us on youtube
  • follow us on linkedin
Michigan State University
  • Spartans Will.
  • © Michigan State University

MSU is an affirmative-action, equal-opportunity employer, committed to achieving excellence through a diverse workforce and inclusive culture that encourages all people to reach their full potential.

Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status. Issued in furtherance of MSU Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Quentin Tyler, Director, MSU Extension, East Lansing, MI 48824. This information is for educational purposes only. Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned.

The 4-H Name and Emblem have special protections from Congress, protected by code 18 USC 707.

We comply with the Federal Trade Commission 1998 Children’s Online Privacy Protection Act (COPPA).