Races of Puccinia hordei in the United States from 1979 Through 1982. M. W. Andres, Former Graduate Research Assistant, Department of Plant Pathology, University of Minnesota, St. Paul 55108. R. D. Wilcoxson, Professor, Department of Plant Pathology, University of Minnesota, St. Paul 55108; A. P. Roelfs, Research Plant Pathologist, Cereal Rust Laboratory, Agricultural Research Service, U.S. Department of Agriculture, University of Minnesota, St. Paul 55108; and Z. A. Pretorius, Agricultural Researcher and Rotary Scholar, Small Grain Center, Bethlehem, 9700 South Africa. Plant Dis. 67:1336-1337. Accepted for publication 8 June 1983. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-1336.

Barley leaf rust was moderately severe in the Upper Midwest in 1979, nearly absent in 1980, severe in late-planted barley fields in 1981, and light in 1982. Isolates of Puccinia hordei from 93 field collections from 16 states and Mexico were studied and 6 races identified. Race 8 was present in 98% of the collections. Race 4 was the second most common but was found only in 1979 and 1980. Races 13, 19, 40, and 42 were found only in trace amounts. The cultivars Abyssinian (Pa 9), Aim (Pa 3), Cebada Capa (Pa 7), and Quinn (Pa 2 and Pa 5) were resistant to all six races.