Unlike cherries, peaches have to be thinned. Otherwise, they produce more fruit than they can support, both physically and energetically. Several heavy peach fruits will cause a branch to bend and possibly to break. The peach tree cannot collect enough energy to produce large, high quality fruit if there are too many. If you want large fruit, you have to have fewer of them.
I should have thinned the fruits on my peach tree some time ago, when they were just beginning to form. The fruits that I removed on Sunday (June 16th) represent wasted energy.
The goal is to have no more than one fruit every four to six inches (10 to 15 cm) on a branch. I had to remove more than half the peach fruit to achieve this. I used my fingers to break the fruit off where the stem joins the branch.
I wrote about pruning the peach tree on April 12th.