Weed Management in Alfalfa
Here are some guideline recommendations for managing weeds in Alfalfa from Dr. Sarah Lancaster, K-State Research and Extension Weed Specialist:
-In Roundup Ready alfalfa, one could consider glyphosate, if the pigweed population is still susceptible.
Another alternative is Raptor, if the pigweed population is still susceptible to ALS-inhibiting herbicides.
-Some of the better options for established alfalfa would be to use dormant applications of a product that contains diuron (such as Karmex or AlfalfaMax). Metribuzin or Sharpen could also be used as a dormant application. Another alternative for established stands would be Paraquat (Gramoxone) applied immediately after cutting.
-In a first-year stand, bromoxynil (Moxy, etc.) or 2,4-DB (Butyrac 200, etc.) can be effective. The key is to apply herbicides to small pigweeds. In addition, application is limited by alfalfa growth stage and weather for these herbicides.