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Peach Leaf Curl

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Disease name:  Peach Leaf Curl

Pathogen name: Taphrina deformans (fungus).

Hosts: Peach and nectarine (similar diseases from related fungi can affect cherry and plum.)

While Northern Illinois is not an area where peaches are grown commercially, there are many home gardeners who do grow peaches. Peach leaf curl is a fungal disease of peaches and nectarines and it has become more prominent in Northern Illinois in recent years. While primarily a leaf disease, it can impact fruit production and the overall health of the tree. The disease can be severe in years with a rainy spring. A wet spring can lead to defoliation in the early part of the season. This weakens the tree and can lead to infection by other diseases, winter injury, and a reduced crop in the following year.

Disease symptoms begin in spring on expanding leaves. The leaves will become thickened and often severely distorted along the midvein. The distorted areas are often noticeable because they will be brightly colored with pink, red, and purple colors. Later, as spores are produced, the leaf surfaces will turn gray or have a powdery appearance. The leaves will eventually turn yellow and fall off. Peach leaf curl can also infect flowers, developing fruit, and young shoots. Infected flowers and fruits often fall very quickly and may go unnoticed. Infected shoots will appear swollen.

Spores of Taphrina deformans, the fungus that causes peach leaf curl, overwinter on the buds and twigs of the host tree. Germination of the spores in spring is dependent on rainfall and temperature. Frequent periods of rain in spring, coupled with cooler temperatures (generally between 50 and 70 degree F), will lead to infection. If rain does not occur frequently or if temperatures are too warm, then little or no infection will occur. Infection generally does not occur later in the season, as only young plant tissues are susceptible. Infected leaves will produce new spores and these give the leaves a gray or powdery appearance. Spores produced on infected growth will be spread to twigs and buds by wind and rain. These spores will remain dormant until the following spring.

Cultural management: 

Keep trees vigorous and healthy. Avoid excessive fertilizer, as this can over-stimulate growth on the tree. Water trees in times of inadequate rainfall to minimize stress from drought. Avoid wetting foliage.

Resistant varieties:

There are a limited number of peach varieties that are resistant to this disease, many of which are not hardy in Northern Illinois. ‘Redhaven,’ which is hardy in Illinois, is considered tolerant of peach leaf curl.

Chemical management:

Fungicides are available to treat peach leaf curl. Timing is important in the application of a fungicide. A single application of a fungicide can be made in the dormant season, late fall or very early spring, before buds swell. Applications made after the buds open will not be effective. If the tree is being grown for edible fruit, the fungicide selected should be labeled for use on trees producing edible fruit.

For current pesticide recommendations, contact The Morton Arboretum Plant Clinic (630-719-2424 or