Seasonal Periodicity and Distribution of Bacterial Blight of Coffee in Kenya. A. H. Ramos, Senior Plant Pathologist, National Agricultural Laboratories, Nairobi, Kenya. R. E. Kamidi, Biometrician, National Agricultural Laboratories, Nairobi, Kenya. Plant Dis. 65:581-584. Copyright 1981 American Phytopathological Society. DOI: 10.1094/PD-65-581.

The inherent growth and flowering rhythm of Coffea arabica trees, governed by the annual rainfall pattern, strongly influenced seasonal periodicity of bacterial blight, caused by Pseudomonas syringae pv. garcae. During extension growth and flowering, abundant avenues of infection and rainfall (duration and intensity) provided conditions for epiphytic growth, dispersal, entry, and internal spread of the pathogen. During reduced growth, avenues of infection and epiphytic inoculum became limiting, resulting in low disease incidence. Based on these findings, disease development in coffee-growing areas east and west of the Rift Valley of Africa is discussed.