Disease Note

First Report of Soybean Stem Canker in Maryland. M. M. Kulik, USDA-ARS, Seed Research Laboratory, Beltsville, MD 20705. P. R. Thomison, Department of Agronomy, University of Maryland, College Park 20742. Plant Dis. 69:811. Accepted for publication 6 May 1985. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-811a.

Soybean plants (Glycine max (L.) Merr.) with symptoms of stem canker were observed during mid- to late September 1984 in small patches in fields in the Maryland Eastern Shore counties of Dorchester (cv. Essex), Queen Anne’s (cv. Verde), and Wicomico (experimental breeding line). Plants in affected areas were killed during early pod formation (R3). The causal fungus, Diaporthe phaseolorum (Cke. & Ell.) Sacc. f. sp. caulivora (Athow & Caldwell) Kulik (≡ var. caulivora Athow & Caldwell), was isolated from infected stem tissue. Koch’s postulates were completed using plants of cv. Essex in the greenhouse. This is the first report of soybean stem canker in Maryland. Resistance to this disease in cultivars in maturity groups III, IV, and V is currently being evaluated in the greenhouse.