Overwintering apple powdery mildew deforms the buds creating a feathered appearance (right) rather than a smooth round healthy bud (left).

Powdery mildew symptoms on apple foliage (right), notice upward curling of leaves and white appearance. Healthy foliage (left).

Powdery mildew affected fruit (left), healthy apple fruit (right). Fruit symptoms may differ in severity depending on age of fruit at time of infection and cultivar.

Primary powdery mildew infection of a blossom cluster and associated leaves (left), healthy blossom cluster (right).