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Host Range and Survival in Soil of Pyrenochaeta lycopersici. G. G. Grove, Postdoctoral Plant Pathologist, Department of Plant Pathology, University of California, Davis 95616. R. N. Campbell, Professor, Department of Plant Pathology, University of California, Davis 95616. Plant Dis. 71:806-809. Accepted for publication 13 April 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0806.

A semiselective medium (corky root medium) was developed for isolation, host range, and survival studies of Pyrenochaeta lycopersici, the causal agent of corky root of tomato. The host range of the fungus was tested by growing seedlings in infested vermiculite and by collecting plants growing in infested soils. Four new hosts (squash, Datura stramonium, spinach, and safflower) were identified in the seedling tests, and the last two were also found naturally infected. Other known hosts confirmed in the seedling test were pepper, eggplant, cucumber, and melon. Beet was a symptomless host. All hosts may occur in rotations in tomato production areas in California and therefore act as increase hosts for the fungus. An isolation technique was developed in which diseased tissue was blended and the fungus was isolated from the extract. The fungus was recovered from tomato roots buried for 6, 27, and 43 wk. Furthermore, P. lycopersici survived as microsclerotia in buried tissue, as was proven by removing single, viable microsclerotia from the extract of buried tissue.