Managing Palmer amaranth to manage resistance
Manage to Reduce Development of Herbicide Resistance
Palmer amaranth growing on your farm may already be resistant to some herbicide families. Triazine-resistant Palmer amaranth has already been identified in Nebraska and UNL researchers are testing for additional resistance development. As is always recommended, avoid relying on a single herbicide mode of action for weed control.
- Use production practices that do not spread the weed.
- Rotate herbicide modes of action to reduce the potential for resistance development.
In the south Palmer amaranth has developed resistance to the following herbicide families: dinitroanilines (Prowl, Sonalan), imidazolinones (Pursuit, Raptor), triazines (atrazine), PPO inhibitors (Reflex) and most recently EPSP synthetase inhibition (glyphosate).
In the Panhandle, Palmer amaranth has been most noticeable in corn. Corn and weeds such as kochia, common lambsquarters, and hairy nightshade emerge earlier in the spring than Palmer amaranth. Using a herbicide with soil residual such as atrazine, Balance Flexx, Callisto, Dual Magnum, Outlook, Prowl, Permit, Verdict, or Warrant at corn planting will help control early season emergence. Following with a postemergence weed control program with herbicides such as dicamba, 2,4-D, glyphosate, Impact, or Laudis will help control later emerging plants.
In dry bean, herbicides applied at planting such as Dual Magnum, Outlook, Prowl, Sonalan, or Permit can provide early season control while Raptor and Reflex will provide postemergence control.