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Microsphaera alphitoides

Oak powdery mildew

Description

The fungus was introduced in to Europe sometime in 1907, possibly from the USA. Disease begins with a white floury coating that very often occur on both sides of the leaf. Severely damaged leaves curl up and die, sprouts can be deformed as well. Young leaves under 3 weeks, mainly on early summer sprouts are predisposed to the infection. At the end of summer, speckled yellow, reddish and finally black cleistothecia are formed on leaves. Disease progress is supported by low air humidity and direct high-level solar radiation. Growth and development of the fungus can be suppressed by air polluted with SO2.

Symptom

White floury coating that very often occur on both sides of the leaf.

Tree Species: Oak

Part of a plant- attacked: Leaf / Needle

Pest significance: Harmful

Pest Category: Fungi

Invasive Species: Yes

Present in EU: Yes

Seasonal frequency of occurrence

Seasonal frequency of occurrence