Leaf Blight Disease and Persimmon Trees

Disease Identification

• Leaf blight or leaf spot is a fungal disorder of many trees including persimmon. Numerous fungi cause leaf blight on persimmon trees. These include the Cercospora, Coniothyrium, Elsinoe, Sphaceloma, Gloeosporium, Mycosphaerella, Phyllosticta and the Physalospora fungi. The majority of leaf blight fungal infections are aesthetic in nature and do little harm to tree health.

Symptoms

• Leaf blight or leaf spot infection in persimmon trees starts with the appearance of scattered, small, round to oval dead areas in leaves. These spots may be tan, dark brown, gray, yellow, purple or black. Certain fungi cause raised, shiny, black spots. Some spots develop darker margins. With disease progression, the spots enlarge and merge to create larger patches. Infected leaves gradually yellow, wither and start to drop. Repeated infection and heavy defoliation weaken trees and increase susceptibility to other pests.

Favorable Conditions

• Persimmon trees that are growing in shade and in poorly ventilated areas are more prone to infection. Trees that are crowded together are also more likely to suffer from leaf blight. Leaf blight disorders usually start appearing on trees between late June and August. Fungal growth is favored by cool weather temperature, high humidity, extended periods of dew and frequent and light summer rains.

Management

• Keeping trees in good health is among the best preventative strategies against leaf blight disorders. Prune the persimmon trees regularly to thin heavy crown and remove any diseased, dead or weak branches. Fertilize trees during early spring to encourage healthy growth. The use of fungicides is not recommended for control unless the disease is severe enough to endanger tree health seriously, cites the University of Illinois Extension.