Twigs and branches are dry causing dieback and defoliation. Leaves becomes dark colored and margins roll up. Twigs may die and fall from the tree. Cankers appear around the infection point that will later cause necrosis (darkening of affected plant part) and dieback of the wood. Branches may also exude gum droplets that later can cover most of the branch. Fruit rot is mostly observed postharvest and begins at the stem end. The affected part becomes grey at first and later turns black. Under severe infestation the fruit can become completely rotton and mummified. The fruit flesh also becomes discolored. In fruits, the pedicarp darkens near the base of the pedicel. The affected area enlarges to form a circular, black patch which extends rapidly under humid temperature and turns the whole fruit completely black within two or three days. The pulp becomes brown and softer.
The damage is caused by the soil-borne fungus Lasiodiplidia theobromae, which has a wide host range and is found throughout the tropics and subtropics. It damages the crop on the field and in storage. It survives as pycnidia on crop residues. The spores can be dispersed by wind and rain splashes and enter the host through freshly cut or damaged plant parts. Water stressed plants show more severe symptoms. High temperatures and high rainfall favors the disease.
Bacillus subtilis and Xanthomonas oryzae pv. oryzae can be used to manage the disease. Trichoderma Harzianum can also be applied.
Always consider an integrated approach with preventive measures together with biological treatments if available. To prevent the disease outbreak you can apply fungicides (paints, pastes) on large cuts after pruning. Spray carbendazim (50 WP) or thiophanate-methyl (70 WP) at 1 ppm a.i. or more to reduce the disease severity. 15 days pre harvest spray application of Carbendazim (0.05%) and propiconazol (0.05%) has shown to be very effective in the reduction of stem end rot. Post harvest treatment with hot water and carbendazim is partially effective against sem end rot. For control of stem end rot during controlled atmosphere storage, a dual treatment of hot carbendazim followed by prochloraz is necessary.