More research should be done on the effects of weeds on alfalfa quality, suggests Kevin Bradley, plant scientist, University of Missouri.

Missouri studies have shown increases in crude protein content in harvested alfalfa after spraying weeds with herbicides compared to untreated areas. Yet, looking at in vitro true digestibility of the harvested forage, very little difference was seen between weed-free and weedy alfalfa, he adds.

The effects of weeds on the total alfalfa harvested forage quality will be dependent on 1) the weed in question and 2) what stage the weed is in at harvest. “It is not, in my opinion, a simple answer,” Bradley says.