Natural Infection Period and Susceptibility of Vegetative Seedlings of European Hazelnut to Anisogramma anomala. J. K. Stone, Research Associate, Department of Botany and Plant Pathology, Oregon State University, Corvallis 97331-2902. K. B. Johnson, J. N. Pinkerton, and J. W. Pscheidt. Assistant Professor, Department of Botany and Plant Pathology, Oregon State University, Corvallis 97331-2902; Research Plant Pathologist, Agricultural Research Service, U.S. Department of Agriculture, Horticultural Crops Research Laboratory; and Assistant Professor, Department of Botany and Plant Pathology, Oregon State University, Corvallis 97331-2902. Plant Dis. 76:348-352. Accepted for publication 18 November 1991. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0348.

Infection of European hazelnut (Corylus avellana) by Anisogramma anomala, the cause of eastern filbert blight, was investigated in artificial inoculation experiments and by sequentially exposing potted trees for 1 wk to natural inoculum in an orchard severely infected with the disease. In the orchard exposure experiment, European hazelnut was found to be susceptible to infection in the spring during leaf emergence and new shoot elongation but not before vegetative budbreak, as previously reported. Artificial inoculation experiments confirmed the susceptibility of vegetative buds and shoots over a range of phenological stages of development. In other experiments, 3-wk-old hazelnut seedlings were found to be highly susceptible to infection by A. anomala after ascospores of the fungus were placed on vegetative tissues. Established infections were detected in freehand sections of the cambium and outer xylem tissues 1–3 mo after inoculation.

Keyword(s): Corylus americana.