Modes of Penetration of Young Cocoa Leaves by Crinipellis perniciosa. T. N. Sreenivasan, Cocoa Research Unit, The University of the West Indies, St. Augustine, Trinidad. S. Dabydeen, Plant Science and Biochemistry, The University of the West Indies, St. Augustine, Trinidad. Plant Dis. 73:478-481. Accepted for publication 25 November 1988. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0478.

Young attached and detached leaves of the cocoa cultivar ICS 43 were inoculated with basidiospores of Crinipellis perniciosa to investigate the modes of entry of the pathogen. Light and scanning electron microscopy after 6, 12, and 48 hr of incubation showed that the pathogen enters the leaf by direct penetration and also through stomata. In both modes of penetration either single or multiple germ tubes entered the leaf. Basidiospore germination also resulted in hyphal growth on the lamina.