Illinois

Herbicide Resistant Weeds in Illinois

Updated October, 2016. Aaron Hager, University of Illinois; www.weedscience.org – Illinois

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.

Tall waterhemp – Highest concern

  • Group 2
  • Group 5
  • Group 2 + Group 5
  • Group 2 + Group 9
  • Group 2 + Group 5 + Group 14
  • Group 2 + Group 5 + Group 27
  • Group 2 + Group 5 + Group 9 + Group 14
  • Group 2 + Group 4 (dicamba) + Group 5 + Group 14 + Group 27

Horseweed/marestail – Second highest concern

  • Group 2
  • Group 9

Palmer Amaranth – Third highest concern

  • Group 2
  • Group 9
  • Group 2 + Group 9
  • Group 9 + Group 14

Common Lambsquarters

  • Group 5 (atrazine)

Kochia

  • Group 5
  • Group 2 + Group 5

Smooth pigweed

  • Group 2
  • Group 5
  • Group 2 + Group 5

Common ragweed

  • Group 2

Giant ragweed

  • Group 2

Common cocklebur

  • Group 2

Giant foxtail

  • Group 1
  • Group 2

Eastern black nightshade

  • Group 2

Shattercane

  • Group 2