Palmer Amaranth

Palmer Amaranth (Amaranthus palmeri)

This weed is showing up more often in the High Plains and was found to be the most common weed in Kansas sunflower fields in the 2008 NSA survey. Other common names for this weed are palmer pigweed and carelessweed. It is an erect annual that closely resembles other pigweed species. Of most concern is its development of ‘resistance' to Glyphosate (found in Georgia) and ALS herbicide resistance. This greatly complicates control in sunflower.

palmer amaranth grown — Palmer amaranth grown

Control Strategies

1. Pre-plant burn down using Glyphosate tank mixed with products such as 2-4D and/or Aim to eliminate any Glyphosate resistant plants

2. Spartan has good to excellent activity on Palmer Amaranth

3. Sonalan, Trifluralin, Prowl are rated as fair to good

4. Both Beyond¹ and Express² have good to excellent activity but good stewardship must be practiced to reduce the potential of spreading ALS resistant plants

5. Between row cultivation or hooded sprayer herbicide application

Links of Interest

Kansas State University Dept of Agronomy

NDSU Crop Production and Marketing

South Dakota Pest Management Guides (sdstate.edu)

Footnotes

(1) Beyond herbicide is specific to CLEARFIELD® hybrids only. Clearfield hybrids have been developed with a resistant gene to Beyond herbicide. Applying Beyond herbicide on non-Clearfield hybrids will result in extensive damage.

(2) Express herbicide is specific to ExpressSun® hybrids only. ExpressSun hybrids have been developed with a resistant gene to Express herbicide. Applying Express herbicide on non-ExpressSun hybrids will result in extensive damage.

Glyphosate and Aim are labeled for between row hooded sprayer applications.