Herbicide-Crop Rotation for Witchweed Control

Abstract

Corn, cotton, peanuts, and soybeans in various rotations received six separate herbicidal treatments in a 5-year rotation from 1959 through 1963. Several of the combination treatments were highly effective in controlling witchweed (Striga spp.). Land heavily infested with witchweed required 3 to 4 years of herbicidal treatments before the competition of witchweed was eliminated and normal corn yields were produced. The most effective treatment for the control of witchweed without crop injury was postemergence applications of ½ lb/A 2,4-dichlorophenoxyacetic acid (2,4-D) as needed in continuous corn. At the end of the 5-year study, all plots were planted to corn, Using corn yields as a criteria, there were no differences in witchweed competition in herbicide treated plots with continuous corn and herbicide treated plots in which corn was rotated with other crops.