Production of Pseudocercosporella herpotrichoides Spores. G. W. Bruehl, Plant Pathologist, Washington State University, Pullman 99164-6430. R. Machtmes, Research Technologist, Washington State University, Pullman 99164-6430. Plant Dis. 69:862-863. Accepted for publication 30 May 1985. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-862.

Incubation on oat kernels in the laboratory for longer than 30 days diminished the ability of Pseudocercosporella herpotrichoides to produce conidia when these oats were placed outdoors. Heaviest sporulation occurred on oats colonized for fewer than 30 days. P. herpotrichoides used easily digestible substrates for spore production on naturally infected wheat stems but apparently did not compete saprophytically for tissue not colonized during the parasitic phase or not easily digested.