Susceptibility of Selected European Pear Cultivars to Infection by Stemphylium vesicarium and Influence of Leaf and Fruit Age. Emilio Montesinos, Professor of Microbiology; Department of Chemical Engineering, Agronomy and Food Technology, Crop Sciences Section, University of Girona, Avgda. Lluis Santalo s/n, 17003 Girona, Spain. Concepcio Moragrega, Graduate Student, Isidre Llorente, Grad-uate Student, and Pere Vilardell, Research Agronomist, Department of Chemical Engineering, Agronomy and Food Technology, Crop Sciences Section, University of Girona, Avgda. Lluis Santalo s/n, 17003 Girona, Spain; and Mas Badia Agricultural Experiment Station, La Tallada, Girona, Spain. Plant Dis. 79:471-473. . Accepted for publication 30 January 1995. Copyright 1995 The American Phytopathological Society. DOI: 10.1094/PD-79-0471.

Nonwounded fruit of 16 European pear cultivars (Pyrus communis) and potted Conference pear plants were inoculated with conidia of Slemphylium vesicarium. Cultivars Passe Crassane, Alexandrine, Conference, Doyenne du Cornice, Due de Bordeaux, Abate Fetel, and General Leclerc were highly susceptible. Cultivars Williams, Blanquilla, BeurTe Hardy, Louis Bonne, Grand Champion, and Highland were slightly or not sus-ceptible. The susceptibility of fruit decreased logarithmically from fruit set to harvest in very susceptible cultivars. Younger leaves developed 1.8-3 times more disease than older leaves.