Relationships Between Inoculum Concentrations of Three Decay Fungi and Pear Fruit Decay. R. A. Spotts, Associate Professor, Oregon State University, Mid-Columbia Experiment Station, Hood River 97031. Plant Dis. 70:386-389. Accepted for publication 4 November 1985. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-386.

The relationships between inoculum concentrations of Botrytis cinerea, Mucor piriformis, and Penicillium expansum and decay of Anjou pear fruits were nonlinear and best described by quadratic regression equations. At each inoculum concentration up to 2,000 conidia per milliliter, P. expansum caused more decay of wounded fruits than B. cinerea or M. piriformis. However, when fruits were inoculated by immersion of stem ends, M. piriformis caused the highest incidence of decay. Less decay developed in spray-rinsed fruits than in nonrinsed fruits. Decay developed when pear fruits were inoculated with B. cinerea, M. piriformis, or P. expansum at various times up to 7 days at 20 C or 24 wk at –1.1 C after harvest.