Palmer Amaranth

Glyphosate-resisant Palmer amaranth spreading rapidly in Kansas

Populations of Palmer amaranth resistant to glyphosate were first documented in Kansas three years ago. At that time, these populations were limited in range to isolated areas of south central Kansas. Glyphosate resistant Palmer amaranth has gradually expanded the last couple of years, and now appears to be increasing rapidly, especially through the central part of the state.

Glyphosate-resistant Palmer amaranth in Kansas?

Glyphosate-resistant weeds continue to be an increasing problem in Kansas. Glyphosate-resistant marestail, common waterhemp, common ragweed, giant ragweed, and kochia have been previously confirmed in Kansas and have become very problematic in certain areas of the state.

Glyphostate-resistant Palmer amaranth is a serious problem in the Southeast U.S. and has dramatically impacted weed control programs and even cropping systems. Palmer amaranth is also a serious weed problem in Kansas, but glyphosate-resistant Palmer amaranth has not been previously confirmed in the state. The hot, dry weather the last couple of years, has made it difficult to assess herbicide performance and resistance problems, but poor control of Palmer amaranth with glyphosate has raised questions about whether glyphosate-resistant Palmer amaranth populations are now showing up in Kansas.