The mode of infection ofColletotrichum musae (Cke. and massee) causing tip rot of banana fruits in the plantation

Abstract

The mode of infection ofColletotrichum musae, the main causal agent of tip rot of banana fruits in the Jordan Valley, was investigated. Immature, apparently healthy banana fruits cv. Dwarf Cavendish were inoculated by spraying spore suspensions on the distal end of the fruit. A correlation was found among type of flowers, age of fruits at inoculation time, concentration of spores in the inoculum, and the development of tip rot in the fruits. An infection rate of 100% was obtained with suspensions at a concentration of at least 5x10⁴ spores/ml on fruit with persistent flower parts, not older than 3 weeks after the curling of the hand bract. On fruits with deciduous flower parts, only inoculations of very young fruits still under bracts was successful. Penetration of the fungus through the perianths was assessed. Virulent inoculum was found to be present in the plantation; 100% infection was obtained by using a suspension prepared from dry leaves and debris collected around banana plants.