Herbicides for Legumes

Butyrac 200

• Butyrac is safe for use on forage legumes like alfalfa, clovers and birdsfoot trefoil, but isn't for use on sweet clover. This herbicide effectively controls velveltleaf, ragweeds, lambsquarter, buttercup, pigweed. It also works on nightshade and mustard to a lesser extent. This herbicide is also known as 2, 4-DB and should be applied only during the first cutting of the pasture.

Buctril

• This herbicide works by inhibiting photosynthesis, and works best when sprayed on weeds during their most active growth stages. While technically safe for use on small grains and alfalfa, this dust inhibits the alfalfa in the same way as the weeds. While it may not kill the alfalfa outright, it stands a good chance of reducing crop yield if applied after cultivation.

MCPA

• Like Buctril, this chemical is technically safe to use around legumes, but isn't particularly good for them. You'll need to cover the legume plants with a tarp before applying this herbicide to pigweed, morning glory, broadleaf and any number of annual weed species. Apply this herbicide to annual weeds while they're young, while the soil is moist and several hours before you expect rain.

2, 4-D Amine

• This herbicide is safe for use on white clover and lespedeza but isn't for use on red (crimson) clover or arrowleaf. Amine works only on ragweed and bitterweed, and can be applied at any stage during the weeds' development.

Pronamide

• Pronamide (aka Kerb 50WP) is safe for birdsfoot, alfalfa, trefoil, landino and red clover after the plants reach their trifoliate stage. Pronamide effectively controls volunteer grains, downy brome and chickweed, but it will also kill any desirable grasses caught in the treatment area. Apply at least 120 days before the scheduled harvest.

Limazamox

• Sold under the trade name Raptor 1AS, this chemical is specifically designed to treat broadleaf, lambsquarter and annual grass infestations in alfalfa. This is a short-acting herbicide, and works best when applied right after rain while the weeds are growing very quickly. Raptor can cause yellowing or stunted growth in alfalfa, so you should try to apply it while the alfalfa is in its dormant stage during the winter. However, it won't work at temperatures below 50 degrees Fahrenheit, so wait until you know that the temperature will maintain 51 degrees Fahrenheit or higher for at least 10 hours after the application period.