Application of Epicoccum purpurascens Spores to Control White Mold of Snap Bean. Ting Zhou, Graduate Student, Department of Plant Science, Macdonald College of McGill University, Ste. Anne de Bellevue, Quebec, Canada H9X 1C0. R. D. Reeleder, Assistant Professor, Department of Plant Science, Macdonald College of McGill University, Ste. Anne de Bellevue, Quebec, Canada H9X 1C0. Plant Dis. 73:639-642. Accepted for publication 29 January 1989. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0639.

The efficacy of Epicoccum purpurascens in controlling white mold of snap bean, caused by Sclerotinia sclerotiorum, was assessed in greenhouse and field trials in 1987 and 1988. Treatments were applied to plants during flowering, and plants were subsequently sprayed with ascospores of S. sclerotiorum. In two field trials in 1987, applications of an iprodione-tolerant strain of E. purpurascens (in 1% malt extract) and/or iprodione (0.5 kg a.i./ha) significantly reduced disease incidence and disease index relative to control plots. In two field trials in 1988, three applications of E. purpurascens in 1% malt extract and two applications of iprodione significantly reduced disease incidence, disease index, and percentage of diseased pods. Similar results were obtained in greenhouse studies.

Keyword(s): biocontrol, Phaseolus vulgaris.