Answer: Your spray program would depend on which particular varieties you are growing and their susceptibility or resistance to the different diseases in your local area. What to use and when to use it depends on what you are trying to control. I would suggest you work with your local Cornell county extension to set up a regular spray program. They can also help you determine the right timing in your local area because it depends to some extent on the weather each year.
In the meantime, here is some information on peach leaf curl which is a fungal problem. Unfortunately, you have probably already missed the window of opportunity for the preventive spray for this year. You may need to cut and paste the complete url into your browser to make it work correctly.
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