Incidence of Barley Yellow Dwarf Viruses in California Cereals. J. A. Griesbach, Plant Division, Oregon Department of Agriculture, 635 Capitol St. N.W., Salem 97310-0110. B. W. Falk, and R. A. Valverde. Department of Plant Pathology, University of California, Davis 95616; and Department of Plant Pathology and Crop Physiology, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803. Plant Dis. 74:111-114. Accepted for publication 29 August 1989. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/PD-74-0111.

An ELISA survey of barley yellow dwarf virus (BYDV) in four major cereal-producing areas showed regional and year-to-year differences in the frequency of BYDV types detected. PAV types were most commonly detected in the 1,115 oat, wheat, and barley samples assayed, followed by MAV and RPV types. Replicated field trials also were conducted in 1986 and 1987 to assess and compare the incidence of BYDV types in randomly collected and symptomatic samples. Chi-square analysis showed that symptomatic sampling overestimated the amount of PAV and RPV types relative to their incidence in random samples.