The moisture content of soils is frequently reported to have an important effect upon the phytotoxicity of herbicides. Yet, specific experimental results establishing such relationships are, for the most part, lacking. Most moisture studies with herbicides have been designed to evaluate the effect of applied water on leaching and its indirect effect on volatilization and breakdown by exposure to sunlight. Some studies have shown the effect of moisture content on the rate of herbicide breakdown. Research on the fate of herbicides in soils has been summarized by Hill et al. and Ogle and Warren. The experiments reported here were designed to establish the effect of soil-moisture content per se upon the response of cotton to 3–(3,4–dichlorophenyl)–1,1-dimethylurea (diuron), isopropyl–N–(3–chlorophenyl) carbamate (CIPC) and 4,6–dinitro ortho secondary butylphenol (DNBP) as the alkanolamine salts.