Puccinia graminis subsp. graminicola Identified on Tall Fescue in Oregon. R. E. Welty, USDA-ARS, National Forage Seed Production Research Center, Corvallis, OR 97331-7102. Mark E. Mellbye, Oregon State University Extension Service, Oregon Agricultural Experiment Station, Corvallis 97331. Plant Dis. 73:775. Accepted for publication 18 May 1989. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0775A.
Stem rust on tall fescue (Festuca arundinacea Schreb.) was sporadic
throughout seed production fields in the Willamette Valley of Oregon
in spring of 1987. In 1988, the disease was widespread and rated as
moderate to severe in 22 of 29 cultivars evaluated. Urediniospores
of the fungus were recovered from cv. Bonanza and used to inoculate
Bonanza in the greenhouse. Leaves of Bonanza with pustules of
urediniospores were deposited in the stem rust collection at the USDAARS
Cereal Rust Laboratory, St. Paul, Minnesota. In 1942 (1), stem
rust was recorded on F. pratensis Hudson (= F. elatior L.) in
Washington and northeastern and western Oregon and on F. arundinacea
(F. elatior var. arundinacea (Schreb.) Wimm.) in Washington.
No cases of stem rust occurring on tall fescue are recorded in disease
clinic files at Oregon State University. To our knowledge, this is the
first report of Puccinia graminis Pers. subsp. graminicola Urban being
a serious and widespread pathogen on F. arundinacea in the Willamette
Valley in Oregon.