Sounds like it could be The soil-borne fungal pathogen known as Verticillium albo-atrum attacks mango trees planted in infected soil. It enters through the roots and compromises the tree’s vascular system, which causes symptoms similar to water stress. Typically, one side of the tree will develop wilted leaves that die but cling to the infected branches. Twig dieback occurs, and the mango begins to decline. Making longitudinal cuts into infected branches will reveal vascular discoloration.