Stone fruit are turning mouldy on a healthy tree?
I have two peach trees, and they have flowered well with good fruit set, but as the fruit has matured several of the peaches have become shriveled and moldy.
I recommend dormant spraying with a horticulural oil and copper fungicide. And then during fruit set start preventive treatments with a biological fungicide like this:
Good soil fertility and water management will help the trees and fruit resist diseases and pests.