The epidemiology of anthracnose disease of mango: inoculum sources, spore production and dispersal

Abstract

SUMMARY Anthracnose disease spreads within mango trees by water‐borne conidia of Colletotrichum gloeosporioides var. minor. Conidia were produced in lesions on leaves, defoliated branch terminals, mummified inflorescences and flower bracts. Conidia were trapped from these sources in the orchard during periods when anthracnose disease was developing both in flush growth and in flowers. The majority of conidia were trapped from lesions in young leaves. Conidia were produced in the laboratory from acervuli in leaf lesions over a wide temperature range (10–30°C) both in wet and humid (95–97% r.h.) conditions. Conidia would be present for dispersal within the tree throughout the entire season. Large numbers of conidia were trapped during prolonged periods of rain, and when these occurred during active growth or flowering, severe outbreaks of disease were recorded. No conidia were trapped following dews. Ascospores of Glomerella cingulata var. minor were not trapped while the disease was active in the orchard. These spores do not appear to contribute to the infection cycle of mango anthracnose.