VIEW ARTICLE

Studies with Benomyl and Thiabendazole on Control of Cotton Diseases. C. D. Ranney, Research Plant Pathologist, Plant Science Research Division, ARS, USDA, in cooperation with the Delta Branch of the Mississippi Agricultural Experiment Station, Stoneville, Mississippi, Present address: Plant Industry Station, Beltsville, Maryland 20705; Phytopathology 61:783-786. Accepted for publication 5 February 1971. DOI: 10.1094/Phyto-61-783.

Field studies indicate that losses due to seedling disease, Verticillium wilt, and boll rot were slightly reduced with moderate rates of either methyl 1-(butylcarbamoyl)-2-benzimidazolecarbamate (benomyl) or 2-(4-thiazolyl) benzimidazole (thiabendazole). Only a slight degree of seedling disease control was obtained with either material. Thiabendazole was more phytotoxic than benomyl, particularly when applied on, or adjacent to, the cottonseed. A combination of seed, soil, and early-season foliage applications of both systemic fungicides significantly reduced incidence of Verticillium wilt and increased yield. When applied as foliage sprays late in the season, both fungicides significantly reduced loss due to boll rot. A higher level of disease control and higher yields were consistently obtained with benomyl than with an equal rate of thiabendazole. However, the results do not indicate economic control of cotton diseases with these fungicides using the rates and methods of application evaluated.