Erysiphe tortilis

Powdery mildew on dogwood

Description

Erysiphe tortilis is a powdery mildew on dogwoods, chiefly Cornus sanguinea and C. mas (also other Cornus spp.). It forms superficial mycelium and conidia on leaves through the growing season; late in summer it produces chasmothecia. The fungus overwinters mainly in fallen leaves and serves as a source of new infections in spring. It is widespread in Europe. Intensity of infestation is usually not strong, yet heavy, repeated infections can reduce leaf assimilation area and may worsen the overall vitality and ornamental appearance of shrubs and young trees.

Symptom

White powdery patches on dogwood leaves (often upper surface); later small dark chasmothecia appear and patches may merge into larger irregular areas.

Tree Species: Dogwoods

Part of a plant- attacked: Leaf / Needle, Branch

Pest significance: Less harmful

Pest Category: Fungi

Invasive Species: No

Present in EU: Yes