Effect of Apple Cultivar on Venturia inaequalis Ascospore Emission in California. W. J. Moller, Plant Pathologist, Cooperative Extension Service, University of California, Davis 95616. Plant Dis. 64:930-931. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1980. DOI: 10.1094/PD-64-930.

Six apple cultivars growing in the interior region of central California were compared for spring ascospore productivity from infected leaves after an unexpected epidemic in 1978 when leaves and fruits became severely infected. There were distinct differences between cultivars in ascospore productivity, although overall levels were less than those reported from New York State, where an identical sampling procedure has been used for many years. Ascospore emission in this location in 1979 lasted only 4–5 wk; it began in late dormancy and was virtually complete before any of the cultivars reached full bloom.