Black spot disease is a fungal disease called Phyllosticta citricarpa. It primarily affects citrus trees and fruits most especially sweet oranges and tangerines. This fungi disease affects citrus plants in tropical and subtropical climates, causing the fruits to crack, rot and decay. It makes citrus leaves and fruits have a black spot that makes them decay and rot if not treated.

In Nigeria and the West African region citrus, the black spot caused big damages and losses in the citrus business. It has destroyed many commercial citrus farms in Nigeria and all over the world when the disease is not properly managed. https://aefarmtech.com/pest-and-diseases/citrus-black-spot-disease-treatment-and-management/