Evaluating Soybean Cultivars for Resistance to Sclerotinia sclerotiorum Under Field Conditions. G. J. Boland, Assistant Professor, Department of Environmental Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1. R. Hall, Professor, Department of Environmental Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1. Plant Dis. 71:934-936. Accepted for publication 23 February 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0934.

Forty-two soybean (Glycine max) cultivars were evaluated for resistance to Sclerotinia sclerotiorum in field conditions. The most resistant cultivars in four field trials were Maple Arrow and Ace, but Maple Presto and McCall appear promising. The wide range in cultivar reactions indicated that breeding for resistance to this pathogen is possible. Disease incidence at harvest was correlated with cultivar height, lodging severity, and maturity as well as number of apothecia under the canopy. These results suggest that disease escape may be an important consideration in Sclerotinia stem rot of soybean.