Q.Peach tree brown rot
I have some peach trees and grape vines that are 8 or 10 years old. They bud, bloom, leaf out, and fruit starts to grow but the peaches get to about golf ball size then they shrivel up, turn brown, and look like mummies. My neighbor says it is brown rot. How do I fix this?
I believe your neighbor is correct - it is brown rot. You can read more about brown rot and other peach tree diseases, along with recommended treatments, via the link below. Basically, in order to rectify brown rot, you will need to remove all mummies from the tree and the ground, prune out cankered or dead twigs, and apply a fungicide with thiophate methyl, captan or azoxystrobin just before fruits begin to ripen.
https://www.gardeningknowhow.com/edible/fruits/peach/common-peach-diseases.htm