Maryland

Herbicide Resistant Weeds in Maryland

Updated October, 2016. Source: www.weedscience.org – Maryland

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

  • Group 2 + Group 9

Horseweed/marestail

  • Group 9

Smooth pigweed

  • Group 5

Redroot pigweed

  • Group 2

Common lambsquarters

  • Group 5

Common ragweed

  • Glyphostate
  • ALS

Barnyardgrass

  • Group 5

Velvetleaf

  • Group 5

Yellow foxtail

  • Group 5

Giant foxtail

  • Group 5

Italian ryegrass

  • Group 1 (ACCase inhibitors)

Common cocklebur

  • Group 2

Common chickweed

  • Group 2