Weed Control in Established Dryland Alfalfa (Medicago sativa)

Abstract

Fall-applied herbicides were evaluated in field studies conducted in 1978 through 1980 in western Nebraska for selective weed control in nonirrigated, established alfalfa (Medicago sativaL. ‘Ranger’). All herbicides effectively controlled downy brome (Bromus tectorumL.). Broadleaf weeds were differentially controlled by the herbicides tested. All herbicide treatments increased forage production and protein content over that produced in the untreated check. Increasing the rate of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] and simazine [2-chloro-4,6-bis(ethylamino)-s-triazine] above amounts needed for effective weed control caused an increase in the protein content of alfalfa forage above that resulting from normal use rates.