VIEW ARTICLE

Comparative Pathogenicity of Pythium aphanidermatum and Pythium myriotylum to Twelve Plant Species and Intraspecific Variation in Virulence. S. M. McCarter, Assistant Professor, University of Georgia, Athens 30601, Former affiliation of senior author: Crops Research Division, ARS, USDA, Tifton; R. H. Littrell, Assistant Professor, Georgia Coastal Plain Experiment Station, Tifton 31794. Phytopathology 60:264-268. Accepted for publication 5 September 1969. DOI: 10.1094/Phyto-60-264.

Tomato, bean, cucumber, rye, oats, wheat, peanut, sorghum, soybean, cotton, corn, and tobacco were inoculated with 14 isolates each of Pythium aphanidermatum and Pythium myriotylum. The crops differed greatly in susceptibility to the two organisms, tomato, bean, and rye being most susceptible, cotton and corn most resistant. The two Pythium spp. often differed in pathogenicity on a given plant species, and individual isolates of each organism varied markedly in virulence on susceptible crops.