The over-wintering growth of weeds in alfalfa generally can be spotted as soon as the snow melts. Weed's presence lowers alfalfa yields, reduces its quality, lessens its palatability and slows hay dry-down.
Proper treatment of these weeds leads to cleaner, healthier alfalfa at the first cutting. The best way to control them is with herbicides. To control weeds in alfalfa without damaging it, apply herbicides when warmer spring weather first appears and the alfalfa has not yet turned green.
Weeds such as pennycress, downy brome, shepherd's purse, mustard and chickweed are common in first-cut alfalfa and are hard to control once the alfalfa starts growing. If weeds are sprayed when alfalfa shoots are green, alfalfa growth might be set back two to three weeks.
Herbicide options and application rates can be found in the 2005 Guide for Weed Management (EC04-130) available at your local Cooperative Extension office.
Dave Varner is an Extension Educator with the University of Nebraska Cooperative Extension office in Dodge County. Dave may be contacted at 727-2775, 1206 West 23rd Street in Fremont, or at dvarner1@unl.edu
