Blueberry Twig Blight Caused by Phomopsis vaccinii. R. D. Milholland, Professor, Department of Plant Pathology, North Carolina State University, Raleigh 27650. Plant Dis. 66:1034-1036. Accepted for publication 1 March 1982. Copyright 1982 American Phytopathological Society. DOI: 10.1094/PD-66-1034.

In North Carolina, Phomopsis vaccinii causes a blighting of 1-yr-old blueberry twigs with flower buds, resulting in reduced fruit production. The primary mode of infection was found to be through flower buds from budbreak through bloom. The fungus apparently entered the stem through the vascular tissue and progressed down the stem 50–150 mm. The entire stem was not killed. Systemic invasion also occurred when the fungus infected the leaf margins and progressed down the petiole into the stem. Infection of unwounded succulent stems resulted in small, raised lesions that failed to develop further. Rain-dispersed conidia of P. vaccinii were collected in traps throughout the growing season, the largest number being caught from blossom budbreak through bloom.

Keyword(s):