First symptoms appear as concentric rings with circular sunken lesions. In moist conditions, soft to dark brown fruit rot occurs. In dry conditions, fruit dehydrates and mummifies. In both cases, fruits fall prematurely. These symptoms mostly become visible when fruits ripen.
The fungus Glomerella cingulata can be dormant in plant tissue, and then becomes activated under very moist or dry environmental conditions. warm and humid weather conditions favor the development of Glomerella cingulata, especially during the flowering stage and pre-harvest. The pathogen survives on mummified fruits, leaves that remained on the tree or infected woody tissue.
Some endophytic strains of Aureobasidium pullulans have been shown to provide high protection levels against Colletotrichum spp. when applied at the pre-flowering and berry-ripening stages.
Always consider an integrated approach with preventive measures together with biological treatments if available. Apply one or two sprays with fungicides such as strobilurins, mancozeb or copper-based fungicides, one before flowering and one in the early fruit set. Two applications may be necessary if infection is left after the previous spray. Apply after pruning to ensure the cuts and tissues left behind on the tree prevent reinfection.