Peach: Leaf curl

Biology

Peach leaf curl is a fungal disease affecting primarily the leaves and shoots. Fruit is occasionally attacked. Young leaves develop yellow to reddish discoloration and become thickened, crisp, and crinkled. Affected leaves are curled and deformed. A white powdery coating of the fungus later develops on infected leaves. Infected leaves either turn yellow and drop or remain on the tree, turning dark brown as the season progresses. Infected green shoots become thickened and distorted. Fruits may show swollen, reddish areas on the surface. These areas lack the normal peach fuzz. The fungus overwinters on twigs and buds. This disease is a major problem of peaches in western Washington. Severe leaf drop affects fruit production, reduces vigor of trees, and increases susceptibility to winter injury.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

• Plant disease-tolerant or resistant varieties. ‘Krummel’, ‘Muir’, and ‘Redhaven’ are reported to be tolerant. ‘Rosy Dawn’ is somewhat resistant. ‘Frost’ is disease-resistant and is recommended for planting in western Washington. However, it has no juvenile resistance and must be protected during the first 2 to 3 years.
• Remove infected leaves when they first appear prior to sporulation of the fungus. Destroy infected material.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

• Apply a fungicide during the first week of January.
• Make 2 to 3 additional applications at 3- to 4-week intervals.
• If weather is cool and wet, apply fungicides at 3-week intervals.
• If the weather is warm and dry, apply fungicides at 4-week intervals.
• Homeowners should not make foliar applications to trees over 10 ft tall.
• Consult a commercial pesticide applicator for treatment of trees and shrubs over 10 ft. tall.

Approved Pesticides

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.

• Bonide Fung-onil Multi-Purpose Fungicide Concentrate
  Active ingredient: chlorothalonil [EPA registration number: 60063-9-4]
• GardenTech Daconil Fungicide Concentrate
  Active ingredient: chlorothalonil [EPA registration number: 67572-82-71004]
• Monterey Liqui-Cop Copper Fungicidal Garden Spray
  Active ingredient: copper-ammonia complex [EPA registration number: 54705-7]
• This list may not include all products registered for this use.

Additional Images