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Disease Note Basal Rot of Onion Caused by Fusarium oxysporum f. sp. cepae in Georgia. D. R. Sumner, Department of Plant Pathology, Coastal Plain Station and Cooperative Extension Service, University of Georgia, Tifton 31793. D. R. Sumner and J. D. Gay, Department of Plant Pathology, Coastal Plain Station and Cooperative Extension Service, University of Georgia, Tifton 31793. Plant Dis. 68:450. Accepted for publication 27 January 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-450a. Basal rot and stem plate discoloration were observed on 90% of maturing bulbs of the onion (Allium cepa L.) cultivar Granex 33 in three fields in Tattnall and Candler counties during May and June 1983. Only Fusarium oxysporum f. sp. cepae (Hanz.) Snyd. & Hans. (pink-colony type) was isolated from bulbs. Yellow Granex onion was seeded into heat-treated soil infested with single-spore cultures and into soils from problem fields. Seedling blight and bulb rot were significantly greater in infested and field soils, and F. oxysporum f. sp. cepae was reisolated from rotted seedlings. This is the first identification of F. oxysporum f. sp. Cepae in onion grown in Georgia. |