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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. |