Races of Phytophthora megasperma f. sp. glycinea on Soybeans in Eastern Nebraska. Dennis M. White, Research Technologist, Department of Agronomy, University of Nebraska, Lincoln 68583-0722. J. E. Partridge, Assistant Professor, Department of Plant Pathology, and J. H. Williams, Professor, Department of Agronomy, University of Nebraska, Lincoln 68583-0722. Plant Dis. 67:1281-1282. Accepted for publication 18 July 1983. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-1281.

Soil samples were collected in 1980 from soybean fields in 39 countries in eastern Nebraska to identify races of Phytophthora megasperma f. sp. glycinea (Pmg) in the state. In 1981, 300 fields were sampled in three counties. Race 1 was isolated from Seward and Butler counties, races 1 and 3 from Richardson County, races 9 and 14 from Nemaha County, and races 1 and 18 from Saunders County. A new physiologic race distinct from the 22 known races of Pmg was isolated from Saunders, Otoe, Nemaha, and Richardson counties. It is proposed as race 23.