Hello Thomas,

If leaves are puckered and reddish, I believe you are referring to peach leaf curl

Pest and disease control - Peach leaf curl is an intermittent disease that is easy to control with one spray, but timing is important. Apply a material labeled for the disease (Carbamate (ferbam), Bordeaux mixture*, fixed copper* (various products) at 75% or more leaf drop in the fall or before 1st bud swell (no later). A very few varieties are available that have natural peach leaf curl resistance, but these varieties are generally grown in the Pacific Northwest region where the disease is particularly severe. From: Growing Peaches in the Backyard - Bill Shane, Michigan State University Extension.

More information at Stone Fruit IPM - Chapter 12 - Peach leaf curl (more for commercial growers) at this link: https://www.canr.msu.edu/ipm/uploads/files/StoneFruitIPM_Peachleafcurl12.pdf

Please read this article: Before or during bud swell is the time to treat peach leaf curl, a fungal disease that deforms leaves and then defoliates peach trees. At this link: https://www.canr.msu.edu/news/treat_peach_leaf_curl_now

Please read the information on Peach leaf curl from the Midwest Home Fruit Production Guide - Ohio State University (Pages 103 & 104) at this link: https://plantpathology.ca.uky.edu/files/mw_home_fruit_productn_b591.pdf

Hope this helps!!

You are welcome and have a great day!!