VIEW ARTICLE

Disease Control and Pest Management

Effects of Three Herbicides on Selected Pathogens and Diseases of Turfgrasses. Guy W. Karr, Jr., Former graduate teaching assistant, Department of Botany and Microbiology, Auburn University Agricultural Experiment Station, Auburn, AL 36830, Present address of senior author: Division of Plant Industry, Alabama State Department of Agriculture and Industries, Montgomery, 36109; Robert T. Gudauskas(2), and Ray Dickens(3). (2)Professor, Department of Botany and Microbiology, Auburn University Agricultural Experiment Station, Auburn, AL 36830; (3)Associate professor, Department of Agronomy and Soils, Auburn University Agricultural Experiment Station, Auburn, AL 36830. Phytopathology 69:279-282. Accepted for publication 5 September 1978. Copyright 1979 The American Phytopathological Society. DOI: 10.1094/Phyto-69-279.

The effects of the herbicides 2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulphonate (NC8438); 0, 0-diisopropyl phosphor-odithioate S-ester with N-(2-mercaptoethyl) benzenesulfonamide (bensulide), and N-butyl-N-ethyl-α,a,α,-trifluoro-2,6-dinitro-p-toluidine (benefin) on radial growth of Drechslera cynodontis, Pythium aphanidermatum, Rhizoctonia solani, and Sclerotinia homoeocarpa on artificial media were determined at 18, 26, and 35 C. Fungal growth was inhibited proportionally by most herbicide concentrations (1, 2, and 10× recommended field rates) at all temperatures. Growth of R. solani at 35 C was stimulated by the lowest rate of bensulide and the two lowest rates of NC8438. Pot-grown bermudagrass and annual ryegrass plants were sprayed with 1× and 3× the recommended field rates of the herbicides and inoculated with one of the four fungi. The 1× rate of benefin increased the severity of brown patch and dollar spot caused by R. solani and S. homoeocarpa, respectively. NC8438 reduced severity of these diseases and also Pythium blight caused by P. aphanidermatum.