Algal Leaf Spot
Algal leaf spot is a plant disease associated with parasitic algae such as Cephaleuros species. On mango foliage, affected areas may appear as raised or textured spots with rusty or orange coloration, though appearance changes with age and conditions. It is not the same as an insect infestation or every brown leaf patch. Tree vigor, moisture conditions, and accurate identification matter when deciding whether management is needed. A few old spots do not automatically justify broad chemical treatment.