Peach scab is a fungal disease that causes small, greenish round spots to appear on the peach fruit, often more concentrated at the stem end. As spots age, they may become black and velvety, and heavily infected fruit may be deformed or cracked.
To manage peach scab:
Prune appropriately to promote air circulation
Fungicides may be used 10 to 12 days after the shuck split stage of bud development, for about six weeks.