Peach tree curl cure
For managing peach leaf curl in backyard situations look for products with chlorothalonil in it. The following are on my list as having this active ingredient: Ortho Multi Purpose Fungicide, Dragon Daconil 2787, Ferti-lome Liquid Fungicide, Security Fungi-Gard, Pennington Multi-Purpose Fungicide, Ortho Garden Disease Control. Check to see if peach trees (fruit trees) are listed on the label. Copper compounds are fairly effective as well.
You are past the window for effective treatment. This needs to be put on before the peach buds begin to swell (April) or after approximately 50% of the leaves have fallen. It is hard to say if you will get some benefit from the chlorothalonil treatment at this late date.
The pathogen does its infections in the first few weeks after the buds start to open in the spring when the air temperature is 46 to 53 F & leaves are wet for most of the day. Some years we do not get these precise conditions and we escape the disease. Unfortunately we have had 3 or 4 wetting events in that temperature range this spring so I suspect that you will see at least some symptoms.