Curley leaf, or Taphrina deformans, is a common unattractive fungal disease that affects peaches and nectarines. The spores overwinter in the bark of trees and infect the fresh growth. With the change in temperature, spores are produced and then blown around the tree. When your trees break bud and the new leaves appear, you may see this trademark deformity in all its glory.
The leaves will become distorted, discolored, and sometimes form gnarly growths. In severe cases, the leaves may eventually fall off. Fruit may also be affected and drop early. If left untreated the problem will get worse every year and will reduce the trees’ ability to produce lots of fruit.
Planting your trees where there is good airflow will minimize fungal problems. A healthy tree is able to combat issues much better than an unhealthy tree, so manage splits and deadwood, and keep them well-fed and watered ensuring your trees are in the best position to fight off pests and diseases.
Once the leaves have the disease, you cannot get rid of it. Prevent the spread by removing the affected leaves if reasonable, and don’t put the leaves in the compost.
Spraying with a fungicide before bud burst during late /early spring will prevent curly-leaf from establishing and it’s a good idea to do this every year until you have no visible signs on the tree.