A New Physiologic Race of Phytophthora megasperma f. sp. glycinea. B. L. Keeling, Research Plant Pathologist, U.S. Department of Agriculture, Agricultural Research Service, Southern Region, Stoneville, MS 38776. Plant Dis. 68:626-627. Accepted for publication 26 March 1984. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1984. DOI: 10.1094/PD-68-626.

A new physiologic race of Phytophthora megasperma f. sp. glycinea was recovered from diseased soybeans (Glycine max) in the Delta of Mississippi in 1982. Isolates of the new race were recovered from soybeans grown at two locations (Stoneville and near Shelby, MS). The differential soybean cultivars Harosoy 63, Mack, and PI 103091 were resistant. Harosoy, Sanga, Altona, PI 171442, and Tracy were susceptible. This new race is proposed as race 24.