Mango scab is a fungal disease that affects mango trees in many tropical and subtropical regions around the world. The disease is caused by the fungus Elsinoë mangiferae, also known in its asexual stage as Denticularia mangiferae. Although it is less widely known than anthracnose, mango scab remains an important problem for growers because it damages leaves, fruits, and young stems, reducing both fruit quality and market value.
The disease is especially common in areas with warm, humid, and rainy weather. Moisture plays a major role in the spread of the fungus because fungal spores germinate and infect plant tissues more easily under wet conditions. Young leaves and developing fruits are particularly vulnerable. Unlike anthracnose fungi, which can survive on dead plant material, Elsinoë mangiferae is an obligate biotrophic pathogen. This means it survives only on living plant tissue, making active mango trees essential for the fungus to continue its life cycle.
The symptoms of mango scab vary depending on the age of the infected tissue and the severity of the infection. On leaves, the disease first appears as tiny dark or black spots. As these lesions enlarge, the leaves may become distorted, curled, or crinkled. Corky growths can also develop on the underside of leaves, and severe infections may cause premature leaf drop. Defoliation weakens the tree and reduces its ability to produce healthy fruit.
Fruit symptoms are often the most economically damaging. Infected mangoes develop rough, corky, and scab-like lesions on their skin. These blemishes may crack as the fruit grows, producing scar tissue that reduces the fruit’s appearance and commercial value. In severe cases, infected fruits may fall from the tree before ripening. Even when the flesh inside remains edible, consumers are less likely to purchase blemished fruit, leading to financial losses for growers and exporters.
Mango scab can also affect young stems and twigs. Grey or brown lesions may appear on tender shoots, eventually becoming corky and enlarged. Heavy infections can slow shoot growth and reduce tree vigor over time.
Managing mango scab requires an integrated approach. Farmers often improve air circulation within orchards through pruning, which helps leaves and fruit dry more quickly after rain. Removing infected plant material can also reduce sources of fungal spores. Fungicide sprays, especially copper-based products, are commonly used during flowering and early fruit development when trees are most susceptible. In addition, planting resistant or less susceptible mango varieties can help limit disease outbreaks.
Although mango scab is sometimes overshadowed by other mango diseases, it remains a serious challenge in humid growing regions. Effective disease monitoring and proper orchard management are essential to maintaining healthy trees and producing high-quality mangoes for local and international markets.Mango Scab: A Hidden Threat to Mango Production
