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Disease Note.

First Report of Verticillium Wilt of Alfalfa in Maryland. A. P. Grybauskas, Department of Botany, University of Maryland, College Park 20742. E. M. Dutky, Department of Botany, University of Maryland, College Park 20742. Plant Dis. 71:376. Accepted for publication 13 January 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0376E.

Alfalfa (Medicago sativa L.) plants with wilting leaflets typical of Verticillium wilt were discovered in May 1986 in Baltimore and Carroll counties, Maryland. Isolations from symptomatic shoots, 6-8 cm above the soil line, yielded cultures that were identified morphologically and culturally as Verticillium albo-atrum Reinke & Berth. (1). Voucher cultures have been deposited with the National Fungus Collection at Beltsville (BPI 71955). Koch's postulates were completed in the greenhouse by both root-dip and cut-stem inoculation techniques using 4- to 6-wk-old plants of the alfalfa cultivar Saranac AR. Additional field visits, isolations, and greenhouse tests for pathogenicity confirmed Verticillium wilt in six stands of 2- to 6-yr-old plants of the cultivars Arc, Classic, and Saranac AR grown from seeds purchased from two dealers. This is the first report of Verticillium wilt of alfalfa in Maryland and the second report (2) of this disease below 4()o north latitude in the United States. This extends the range of Verticillium wilt of alfalfa to USDA plant hardiness lone 7, a milder climate than previously reported.

References: (1) A. A. Christen and R. N. Peaden. Plant Dis. 65:319, 1981. (2) D. L. Stuteville et al. Plant Dis. 70:475, 1986.