Disease affected Mango Tree!

Hey Guys,

                I am new to this forum. I live in India and I have five Mango trees and a single mango plant. We water the plants everyday and supply it with natural fertilizers from time to time. But out of the five, one has seem to have been diseased. I have uploaded an image indicating the four stages of the disease, which is mainly observed in the mango fruit and beginning symptoms in raw mango. So guys, I would like your help guys. I would like to know, how to treat the diseased plant, guys. By the way, which receive the same shelter bear very good fruits. Thanks in advance for your help.