It look like dieback and gummosis disease caused by fungal pathogen Lasiodiplodia theobromae (earlier Botryodiplodia theobromae). The main symptoms are characteristic drying of twigs from top downwards, especially in older trees which is followed by drying of the leaves. On young green twigs you will see darker patches. The infected branches exhibit cracks and exudes gum like substance from this cracks. Eventually the infected branch dies. Also the infection in a nodal region of growing point leads to death of twigs.

The pathogen also attack fruits during storage.

According to Indian Council of Agriculture Reserach "the disease can be reduced by pruning of infected plant parts from 7- 10 cm below the infection site and pasting the cut ends with clay mixed cow dung or Copper oxychloride or Bordeaux mixture. In case of gummosis diseased parts may be cleaned / removed and pasted either with Bordeaux or Copper oxychloride paste. Application of Copper sulphate (500 g t -1 ) in soil around the tree trunk is also found effective in reducing gummosis. The stem end rot can be minimized by pre-harvest spray of Carbendazim or Thiophanate methyl (0.1%) 15 days prior to fruit harvest. Fruit should be harvested with stalk (5 cm), if not, the opening must be sealed with wax. Post-harvest phase of the disease can also be controlled by dipping the fruit in hot water (52 ± 10°C) with Carbendazim for 5 minutes. Covering fruits with brown or news paper bags and use of bio-control agent, Streptisporangium pseudovulgare have also been found effective in management of stem end rot."

http://mangifera.org/disease.php