Peach (Plum) – Brown Rot
Q: What is the problem with my peaches? Is it brown rot?
A: Why do you need me to diagnose your problem when you’ve done such a good job figuring out the problem yourself?
It is most definitely brown rot.
The disease is sometimes caused by sucking insects like stinkbugs or curculio weevils visiting a diseased fruit and then sticking their snout into a ripe one.
The disease is disheartening because it typically appears just before the fruit is ready to pick. It affects both peaches and plums. Its control requires planning, since it can also start in spring when the trees are blooming.
During warm weather, infected twigs from last year disperse fungal spores onto open flowers. Spores can also come from diseased fruit on the ground under the tree and from insects . As the fruit grows, the fungus slowly increases. When the fruit is full of sugar the fungus grows rapidly, making a brown, rotted peach.
After flowering, regular pesticide sprays are required to control insects.
I do not know of organic programs that give acceptable results in Georgia. You can help the process by picking up and destroying all fruit and twigs under the trees.
The best cure is to implement a good disease and insect control spray program each spring from now on.
Remember to spray insecticides only AFTER blooms are gone, in order to protect bees.