Peach Leaf Curl
This fungal disease is rare in Utah as it requires a long wet spring for development. Symptoms appear as puckered red lesions on new foliage that soon turn green to tan. These leaves eventually turn brown and drop. New growth is usually healthy.
The fungus overwinters on leaf debris from infections during the prior year. New infections only occur on rainy days in spring, when temperatures are below 79°F. Wind-driven rain splashes fungal spores onto leaves. Once the temperatures rise, further infections of leaves end.
- Puckered red lesions on new foliage
- Foliage turning pink, then yellow-green, then brown
- Distortion and discoloration of foliage
Once infections are visible, fungicides will not work. So the purpose of monitoring will be to know whether to treat in the fall. Monitor in spring by looking for tiny puckered areas. Infections will show up within a few weeks after a cool rain event.
Once you see the disease, there is nothing you can do. Wait until leaf-drop in the fall, and apply copper or lime-sulfur. If a tree is infested, maintain tree vigor by thinning more fruit than normal, reducing drought stress with irrigation, and apply extra nitrogen fertilizer.