Minnesota

For timely updates on Palmer Amaranth in Minnesota, please visit the University of Minnesota crop news blog

Herbicide Resistant Weeds in Minnesota

Updated October 26, 2016. Jeff Gunsolus, University of Minnesota; www.weedscience.org – Minnesota

Reading this list: Each weed with herbicide resistant populations in this state is listed. Underneath each species is a list of the unique resistant biotypes of that weed in the state, according to the herbicide group(s) they are resistant to.

Palmer Amaranth – Highest Concern

  • Group 2 + Group 9 we have 12 known sites in west central MN-which resistant biotypes are present is currently unknown

Tall waterhemp – Highest Concern

  • Group 2
  • Group 9
  • Group 2 + Group 9
  • Group 14
  • Recent confirmation of Group 9 + Group 14 – likelihood of three-way of 2+9+14 but not confirmed

Note from Jeff Gunsolus: From a management standpoint the Amaranth species are of greatest concern due to their biological characteristics of cross-pollination; high reproductive capacity; small-seed that leads to contamination of seed lots and movement out of affected fields.

Kochia – Highest Concern

  • Group 2
  • Potential for other group resistance near the MN/North Dakota border

Common ragweed – Highest Concern

  • Group 2
  • Group 9
  • Group 2 + Group 9
  • Potential for other group resistance near the MN/North Dakota border

Giant ragweed – Highest Concern

  • Group 9
  • Group 2 + Group 9

Common lambsquarters

  • Group 5

Wild oat

  • Group 1

Redroot pigweed

  • Group 5

Common cocklebur

  • Group 2

Giant foxtail

  • Group 2

Giant green foxtail

  • Group 1
  • Group 2

Yellow foxtail

  • Group 2