Occurrence of Puccinia graminis subsp, graminicola in Chewings Fescue in Oregon. Ronald E. Welty, Agricultural Research Service, U.S. Department of Agriculture, National Forage Seed Production Research Center, Corvallis, Oreg. 97331-7102. Mark D. Arevedo, Agricultural Research Service, U.S. Department of Agriculture, National Forage Seed Production Research Center, Corvallis, OR 97331-7102. Plant Dis. 79:1014-1016. Accepted for publication 20 July 1995. 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, 1995. DOI: 10.1094/PD-79-1014.

Stem rust was" found on Chewings fescue throughout seed production areas of the Willamette Valley of Oregon in 1993. Stem rust developed in greenhouse-grown seedlings of cultivar Jamestown when inoculated with isolates of stem rust collected from three locations in the Willamette Valley. No difference in plant response was observed among isolates. Twelve cultivars of Chewings fescue and four other species of cool season grasses used for turf (red fescue, tall fescue, sheep fescue, and perennial ryegrass) were inoculated with the same mixture of isolates of stem rust and incubated for infection in a controlled environment chamber. Among the cultivars of Chewings fescue inoculated, stem rust pustules developed on 624 of 673 seedlings; 49 seedlings remained free of stem rust. This is believed to be the first report of Puccinia graminis subsp, graminicola on Chewings fescue in Oregon. Puccinia g. subsp, graminicola infected 28 of 60 seedlings of red fescue, which was less susceptible than Chewings fescue. Five of 46 seedlings of sheep fescue and one of 60 seedlings of perennial ryegrass became infected by P. g. subsp, graminicola. Pustules of stem rust did not develop in tall fescue inoculated with this collection of isolates.