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Diplocarpon mespili

Quince leaf blight

Description

Diplocarpon mespili is a pathogenic fungus responsible for quince leaf blight, a disease affecting primarily Cydonia oblonga (quince) but also other members of the Rosaceae family, such as Amelanchier, Aronia, Chaenomeles, Cotoneaster, Crataegus, Malus, Pyracantha, Pyrus, and Sorbus. This fungus thrives in wet and humid conditions, particularly during rainy summers. It overwinters in plant debris like fallen leaves and branches, producing spores in spring that spread via wind, rain, or pollinators to infect new plants.

The fungus causes significant damage to quince trees by creating dark spots on leaves and fruits, leading to premature defoliation and reduced fruit quality. Severe infections can weaken trees, reducing their aesthetic value and productivity. Though it can also infect other Rosaceae species, the damage is generally less severe compared to quince.

Symptom

Small black spots appear on leaves, expanding as the leaf yellows or browns. Infected fruits show dark, black spots and can be deformed seriously. Severely infected leaves fall prematurely, and black specks may appear on necrotic tissue.

Tree Species: Black chokeberry, Quince, Flowering quince, Hawthorn, Firethorn, Apple Tree, Rowan, Whitebeam, Shadbush, Cotoneaster

Part of a plant- attacked: Leaf / Needle

Pest significance: Very harmful

Pest Category: Fungi

Invasive Species: No

Present in EU: Yes