Alternaria alternata: A New Pathogen on Stored Potatoes. S. Droby, Division of Fruit and Vegetable Storage, Agricultural Research Organization, Volcani Center, P.O.B. 6, Bet Dagan. D. Prusky, Division of Fruit and Vegetable Storage, Agricultural Research Organization, Volcani Center, P.O.B. 6, Bet Dagan; A. Dinoor, Department of Plant Pathology, Hebrew University of Jerusalem, Faculty of Agriculture, P.O.B. 12, Rehovot 76100; and Rivka Barkai-Golan, Division of Fruit and Vegetable Storage, Agricultural Research Organization, Volcani Center, P.O.B. 6, Bet Dagan 50250, Israel. Plant Dis. 68:160-161. Accepted for publication 30 September 1983. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-160.

The agent responsible for a black pit disease on potato tubers was identified as the fungus Alternaria alternata. A significantly greater incidence of disease was observed in mechanically harvested tubers (twofold to sixfold greater than in manually harvested tubers). Iprodione sprays at a concentration of 1,000 μg a.i./ml significantly decreased Alternaria incidence on newly harvested tubers after 4 mo of storage. The data support the conclusion that A. alternata infestation occurs during harvesting and is enhanced in damaged potato tubers. Fungicide treatment after mechanical harvesting reduces disease incidence during storage.