It could be anthracnose disease caused by fungal pathogen, Colletotrichum gloeosporioides. The pathogen infect all parts of plant. On stem it causes dieback symptom, where the stem dies backward from tip of the branches (green growing tip will change to dark brown and then to black due to necrosis). It results in immature falling of leaves, fruits and young shoots.
On leaves, the fungus causes large, irregular dead spots at the tip or on the margin. This spot may become pinkish color due to spore masses.
On fruits you will see circular sunken brown to black spots which later enlarge as the disease progress. May also infect buds and flowers.
Generally removing of infected parts and plant debris and disposing them properly reduces the disease spread. Also disease is favored by leaf wetting so avoid overhead application of water.
Spraying of copper is found to be effective against this pathogen.