Susceptibility of European Hazelnut Clones to Eastern Filbert Blight

Abstract

In the springs of 1989 and 1990, 2- to 3-yr-old hazelnut trees representing 19 cultivars were exposed to ascospores of Anisogramma anomala, which causes eastern filbert blight. The trees were potted and randomly arranged under wire mesh platforms elevated 1.8 m from the ground. Diseased hazelnut branches were placed on top of the platforms in low, medium, or high numbers to provide three levels of inoculum. During periods of rain, ascospores of the pathogen were released from the diseased branches and deposited on the potted trees. External disease symptoms developed at 16 and 28 mo after initial exposure to inoculum, at which times disease responses were evaluated. Cultivars differed significantly in disease incidence, mortality, number of cankers per tree, proportion of wood cankered, and proportion of dead wood (.)