Abstract
Growth of Cercospora arachidicola Hori, the causal agent of early leaf spot disease on peanuts, was completely inhibited on Czapek-Dox broth medium amended with the acaricide cyhexatin (Plictran) at ≤ 73.5 μg/ml; however, at 14.7 μg/ml traces of growth occurred after 6 weeks of incubation at 27±2C and continuous fluorescent light (800 lux). Aqueous preparations of cyhexation at ≤ 147.0 μg/ml completely inhibited the germination of conidia of C. arachidicola. At a concentration of cyhexatin ≤ 73.5 and 14.7 μg/ml, less than two percent of the conidia germinated as compared with more than 95 percent germination in distilled water. Misting of aqueous preparations of cyhexatin at ≤ 147.0 μg/ml on the adaxial or both surfaces of peanut leaflets with mature leafspot lesions was very effective in reducing the sporulating potential of C. arachidicola.
Author notes
1Cooperative investigations of Agr. Res., Science and Ed. Admin., USDA and Oklahoma State University. Journal Article No. 3803, Oklahoma Agricultural Experiment Station, Oklahoma State University, Stillwater, OK 74078.
This is a report on the current status of research concerning use of a chemical that requires registration under the Federal Insecticide, Fungicide, and Rodenticide Act, as amended by the Federal Environmental Pesticide Control Act. Cyhexatin is not presently registered on peanuts with the Environmental Protection Agency. No recommendations for use of this chemical are implied in this report.