Infection of Photinia Leaves by Entomosporium mespili. A. B. A. M. Baudoin, Assistant Professor, Department of Plant Pathology, Physiology, and Weed Science, Virginia Polytechnic Institute and State University, Blacksburg 24061. Plant Dis. 70:191-194. Accepted for publication 13 August 1985. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-191.

Young, expanding leaves of Photinia × fraseri were highly susceptible to Entomosporium leaf spot, but few spots formed on fully expanded leaves. Infection took place on both surfaces of the young leaf, the abaxial surface being penetrated about twice as frequently as the adaxial surface. The fungus usually penetrated directly through the cuticle and cell wall; stomatal penetration was uncommon. At 25 C, penetration into epidermal cells could be detected within 12 hr of inoculation. Conidia germinated and produced appressoria on mature leaves, but penetration through the thick cuticle and cell wall was uncommon. Most penetrations of mature leaves occurred on the abaxial surface, through guard cells or stomata.

Keyword(s): Diplocarpon maculatum, Entomosporium maculatum, Fabraea maculata.