Increased Severity of Sclerotinia Blight in Peanuts Treated with Captafol and Chlorothalonil. D. M. Porter, Plant Pathologist, AR, SEA, USDA, Tidewater Research and Continuing Education Center, Suffolk, VA 23437. Plant Dis. 64:394-395. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1980. DOI: 10.1094/PD-64-394.

Captafol, applied at rates recommended for control of Cercospora leaf spot of peanut, significantly increased the severity of blight caused by Sclerotinia minor. Increases were similar with chlorothalonil, another leaf spot fungicide. Disease severity was similar in all plots at the time of the first fungicide treatment, but at the end of the growing season, disease was significantly more severe in plots treated with captafol and chlorothalonil than in untreated control plots or plots treated with benomyl. At the end of the growing season, two and four times more plants were dead in plots treated with chlorothalonil and captafol, respectively, than in untreated controls. Pod yields and values were significantly lower in plots receiving four applications of captafol and chlorothalonil than in untreated control and benomyl-treated plots.