The best way to control weeds is to know what you are dealing with.
A herbicide-resistant biotype of a weed species is a population of plants that is not controlled by the normal application rate of a herbicide. It is not controlled by a given herbicide because it has a genetic change that prevents the herbicide from working as it should. A herbicide-susceptible biotype of a weed species is a population of plants that is controlled by the normal application of a herbicide.
A number of weed species in Kansas' crops have developed resistance to different herbicides, and some to multiple herbicides. Weed species in Kansas that have known resistance include: Kochia (Kochia scoparia), Marestail / Horseweed (Conyza canadensis), Mustard species (Bushy wallflower (Erysimum repandum) and flixweed (Descurainia pinnata or Descurainia sophia)), and Pigweed species (Palmer amaranth, common waterhemp, redroot pigweed).
Below is a list of Weeds, Herbicide Resistance/Mode of Action, and the year the resistance was discovered.
Herbicide Modes of Action
|Type of herbicide resistance/|
Mode of Action
|3-way multiple resistance|
(triazine, ALS- and PPO-inhibitors)
- Glyphosate-resistant Palmer amaranth spreading rapidly in Kansas
- Glyphosate-resistant Palmer amaranth in Kansas?
- Kochia - The Basics
- Glyphosate Resistance: How Widespread is the Problem?
- Kochia Control in Corn and Sorghum
- Kochia Control in Sunflowers and Soybeans
- Kochia Control in Wheat
- Fall Control of Bindweed