Incidence and Distribution of Septoria Diseases of Wheat in California. D. G. Gilchrist, Department of Plant Pathology, University of California, Davis 95616. K. H. Brownell, and A. N. Martensen, Department of Plant Pathology, University of California, Davis 95616. Plant Dis. 66:513-515. Accepted for publication 31 December 1981. Copyright 1982 American Phytopathological Society. DOI: 10.1094/PD-66-513.

Septoria tritici, cause of speckled leaf blotch of wheat (Triticum aestivum), was first recognized as an important pathogen in California in 1975. Results of a survey of 17 counties in 1978, coupled with additional observations in 1979, 1980, and 1981, confirmed that the disease was widespread in the northern two-thirds of the Central Valley, with relative incidence and severity increasing in a south-to-north gradient. Severity of speckled leaf blotch, where it occurred annually, represented a significant economic impact to spring wheat production. The presence of S. nodorum, cause of glume blotch of wheat, although limited in distribution, is reported for the first time in California.

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