Dodder Control in Alfalfa by Dichlobenil

Abstract

The herbicide, 2,6-dichlorobenzonitrile (dichlobenil), applied to the soil surface at 2 lb/A controlled dodder ( Cuscuta spp.) and other weeds for 4 to 6 weeks in the field, and did not injure established alfalfa ( Medicago sativa L.) significantly. Soil incorporation increased the herbicidal effect of dichlobenil on alfalfa and dodder, but alfalfa injury was increased more than dodder control. Dichlobenil was effective when applied just before sprinkler irrigation, or on moist soil after irrigating. In the greenhouse, dichlobenil vapors moved from a wettable powder formulation mixed with moist soil or from granules on the surface of moist soil, and killed dodder in adjacent untreated soil.