Susceptibility of Pear Cultivars to Blossom Blast Caused by Pseudomonas syringae

Abstract

Conditions were established for inducing pear (Pyrus communis L.) blossom blast caused by Pseudomonas syringae (Ps) on detached shoots. Highest incidence of infection followed occurrence of a major exotherm in the presence of Ps suspended in water drops on blossom tissue. Eight pear cultivars were evaluated for susceptibility to blossom blast, with the red-fruited `Beurré d'Anjou' sports `Gebhart' and `Columbia' least susceptible and `Doyenné du Cornice', `Beurré d'Anjou', and `Beurré Bosc' most susceptible.