The fungus Podosphaera aphanis
The fungus can attack petioles, leaves, flower, calyxes, fruit stalks and fruit.
|How does in spread?|
The white mildew contains large numbers of spores, which may be carried long distances by the wind. Dry weather, high-humidity conditions, and temperatures between 15o C and 27o C favour disease development.
The disease may also be introduced through:
The fungus survives on diseased ratoon crops via overwintering fruiting bodies (cleistothecia).
There are several genera of fungi that causes powdery mildew diseases, e.g. Erysiphe, Leveillula, Oidium, Podosphaera, Sphaerotheca and Uncinula. These affect several horticultural crops, trees and woody ornamentals.
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