Diversity of Pathogens and Symptoms Associated with Dieback on Passion Fruit in Kenya

Abstract

Passion fruit is very important in Kenya as a source of nutrition and income. Currently, local demand for the fruit highly exceeds its supply. Diseases and pests are the most important constraints to passion fruit production. Among diseases, dieback has constantly been listed as one of the disease that requires highest priority in terms of management. The disease causes over 70% of total fruit losses in the country. With the goal of addressing the impact of dieback constraint on passion fruit production, research was carried out on the etiological and epidemiological aspects of the disease. The objective of this study was to identify the causal organisms of die-back. Samples of dieback infected passion fruit were collected from some passion fruit growing regions in Kenya and and transported to the laboratory for pathogen isolation. The most frequently occurring fungi were tested for pathogenicity on passion fruit. Of the fungi found associated with diseased passion fruit, Fusarium oxysporum, Fusarium semitectum, Fusarium solani, Phytophthora nicotianae, Alternaria passiflorae and Ascochyta spp. caused symptoms similar to those in the fields. These findings lay a foundation for identifying the passion fruit die-back complex and designing its managememt approach.