Hi- this is a sour cherry tree, about 8 years old. It has a white fungal growth that started out like a black wet patch.

Can you tell me what it is?

What should I expect to happen if I do nothing?

Can I treat it or should I cut the tree down?

What would be a good sour cherry tree/shrub replacement (disease resistant). I live in a norther suburb of St. Paul (zone 4a). The soil is clay with some sand and is fairly moist in the area of concern.

Thanks