VIEW ARTICLE

Letter to the Editor

Dynamic Pathogen Distribution and Logistic Increase of Plant Disease. X. B. Yang and D. 0. TeBeest. Department of Plant Pathology, University of Arkansas, Fayetteville 72701. Phytopathology 82:380-383. Accepted for publication 8 January 1992. Copyright 1992 The American Phytopathological Society.

Random distribution of propagules is one of the basic assumptions of logistic growth models of plant disease. Numerous investigations on the spatial patterns of plant diseases commonly. have found clustered distributions for soilborne fungal diseases, virus diseases vectored by insects, bacterial disease spread by rain, and fungal disease spread by air or by mycelial growth. In a theoretical study, Waggoner and Rich found that aggregation should slow the rate of disease development if the degree of aggregation remains constant over the course of the epidemic.