Q.mango
I have mango tree in Dubai which is full grown. many green mangoes are hanginging from it. when the mango gets ripe ie slowly yellow — it (the mango) develops a black spot . then the mango slowly gets rotten. (we don’t spray too much pesticicde cause the skin of mango is very thin) . How to stop the mango from developing the black spot and get rotten . appreciate ur help.
s_kazim@hotmail.com . thanku.

This looks like it could be sap burn.
These articles have more information.
https://www.gardeningknowhow.com/edible/fruits/mango/mango-fruit-harvest.htm
https://www.gardeningknowhow.com/edible/fruits/mango/mango-tree-not-producing.htm