The fungus overwinters on fallen leaves on the ground. Trees are infected in the spring as they begin to bud. New spores develop in wet, warm weather and cause additional infections during the growing season. The pathogen can thus spread very fast.
Cherry leaf spot [Blumeriella jaapii]
Cherry leaf spot - image 1
Pattern of damage
Small, reddish-purple spots appear on the upper sides of the leaves (Picture 1). Whitish spore masses can be found on the undersides of the leaves. Severe infection leads to shedding of leaves.