Experts and BHG readers answer.
My peaches get brown gooey spots every year, ruining about half of each fruit. What can I do?
The problem that you describe sounds most like brown rot, a serious disease problem on peaches and other stone fruits. It usually takes several steps to keep brown rot under control. First, remove any overwintering mummies (dried up fruits clinging to the tree.) Also, prune trees to maintain good airflow. And spray with a preventative fungicide; don't wait until you see spots developing. By that time infection has already occurred, and the fungicide won't stop its spread.
For more detailed instructions check out the excellent Extension guide sheet from Virginia Tech University.