Leaves may be distorted, stunted and fall prematurely. This fungus overwinters on bud scales. When buds expand, infection of new leaves occurs. Spores produced on leaves are disseminated by wind. Yellowish-green to purple blisters appear on leaves.
Blistered leaves remain on the tree.
Small round to angular spots, variable in size and color appear on leaves. Defoliation may occur in extreme cases. These physiological conditions are soil related. Soil condition, such as pH, may make nutrients unavailable to plants, or the soil may be exhausted of some nutrients. Some leaf fall may occur.