Seasonal development
and life cycle—Powdery mildew
All powdery mildew fungi require living plant tissue to grow. Most powdery mildew fungi grow as thin
layers of mycelium on the surface of the affected plant part. Spores, which are the primary means of dispersal,
make up the bulk of the powdery growth and are produced in chains that can be seen with a hand lens. Spores
are carried by the wind to new hosts. All powdery mildew species can germinate and infect in the absence
of water. Moderate temperatures and shady conditions are generally the most favorable for powdery mildew
development. Spores are sensitive to extreme heat and direct sunlight.
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Spores
of powdery mildew on pea leaf
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