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Midway District

Midway Extension District #15

Ellsworth Office:
210 N. Kansas
Suite #1, Courthouse
Ellsworth, KS 67439
785-472-4442  

Russell Office:
309 S. Fossil
Russell, KS 67665
785-483-3157

Hours: Monday-Friday
8:00 a.m. - 5:00 p.m.
(Closed for lunch 12-1)

Weed Control

The best way to control weeds is to know what you are dealing with. 

Herbicide Guide

Weed Identification

Herbicide Resistance

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
Weed SpeciesYear
Discovered
ALS-inhibitorskochia1987
ALS-inhibitorsRussian thistle1988
ALS-inhibitorscommon waterhemp1993
ALS-inhibitorsPalmer amaranth1994
ALS-inhibitorscommon cocklebur1997
ALS-inhibitorscommon sunflower1997
ALS-inhibitorsshattercane1997
ALS-inhibitorsbushywallflower2005
ALS-inhibitorsflixweed2006
ALS-inhibitorsjapanese brome2007
ALS-inhibitorscheat2007
Triazineskochia1976
Triazinesdowny brome1977
TriazinesPalmer amaranth1994
Triazinesredroot pigweed1996
Triazinescommon waterhemp1997
Glycinesmarestail2005
Glycinescommon waterhemp2006
Glycinesgiant ragweed2006
Glycinescommon ragweed2006
Glycineskochia2007
PPO-inhibitorcommon waterhemp2001
3-way multiple resistance
(triazine, ALS- and PPO-inhibitors)
common waterhemp2002

Palmer Amaranth: A Problem Weed?

  • Glyphosate-resistant Palmer amaranth spreading rapidly in Kansas
  • Glyphosate-resistant Palmer amaranth in Kansas?

Marestail: Biology and Control

Mustard: Biology and Control

Kochia: A Problem Weed?

  • 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

Bindweed Control

  • Fall Control of Bindweed

Resources

 

Michelle Buchanan

Ag and Natural Resources
210 N Kansas, Suite #1
Ellsworth, KS 67439
785-472-4442
mbuchanan@ksu.edu

palmer

Palmer Amaranth

marestailrosebud

Marestail - Rosette growth stage

Marestail

Marestail

mustard

Mustard

binweed

Bindweed 

kochia

Kochia