Common Root Rot of Cereals in California. S. C. Scardaci, Farm Advisor, University of California Cooperative Extension, Davis 95616. R. K. Webster, Professor, Department of Plant Pathology, University of California, Davis 95616. Plant Dis. 66:31-34. Accepted for publication 15 April 1981. Copyright 1982 American Phytopathological Society. DOI: 10.1094/PD-66-31.

Fusarium culmorum, F. graminearum, Bipolaris sorokiniana, and Microdochium bolleyi were frequently isolated from crowns and subcrown internodes of wheat and barley showing common root rot symptoms. M. bolleyi was also isolated from oat. The frequency of isolation of these fungi varied with the area from which infected plants were obtained. Most isolates of F. culmorum, F. graminearum, and B. sorokiniana were moderately to highly virulent on the barley cultivar CM72, although a few isolates were not pathogenic. All isolates of M. bolleyi were less virulent than isolates of the other fungi. The barley cultivar CM72 was more susceptible than the wheat cultivar Anza to F. culmorum, F. graminearum, and B. sorokiniana at a relatively low inoculum level (200 propagules per gram of soil); however, differences among wheat and barley cultivars were not as apparent at a higher inoculum level (900 propagules per gram). Isolates of F. culmorum, F. graminearum, and B. sorokiniana obtained from either wheat or barley showed no evidence of host specificity on wheat or barley.

Keyword(s): cereal foot rot, Fusarium roseum, Helminthosporium sativum.