From the ArcaMax Publishing, Gardening Newsletter:
http://www.arcamax.com/news/gardening/s-2535-869937
As peaches mature look for brown, rotten areas. The fungus starts on immature fruit as a small circular brown spot, later enlarging, and ultimately rotting the fruit. Remove and destroy infected fruits and spray a fungicide such as sulfur.
This news arrived on: 06/21/2009