Taphrina deformans
Scientific Name:
Scientific Name:
Crops:
Crops:
Apricot
Biology
Control Method
Biology
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Definition
Peach leaf curl is a fungal disease that mainly affects the young shoots and leaves of stone fruit trees. It causes brittle deformities and blisters of a reddish, pale green or white hue, resulting in a loss of functional leaf area. Although flowers and fruits are rarely affected, the disease significantly weakens the plant and can affect production in the long term.
Development Lifecycle
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Overwintering : The fungus survives as a mycelium on the bud scales or in the infected tissues of the tree.
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Primary infection : In spring, when the buds emerge, the spores contaminate young leaves and shoots in active growth, especially in the event of rain and cool temperatures (10 to 20 °C).
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Development : The disease progresses rapidly in infected tissues, causing blisters and deformities.
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No secondary spread : once the leaves are full, they can no longer be infected during the season.
Symptoms
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Blisters and blisters on young leaves, green-white to red in colour.
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Deformations and thickening of the leaf blade.
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Leaves brittle, often falling prematurely.
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Deformed or curved shoots , stunted growth.
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In severe cases: gradual drying of the young twigs.
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Flowers and fruits are rarely affected.
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Contributing factors
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Spring temperatures between 10 and 20 °C.
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Frequent rainfall or prolonged humidity during bud break.
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Lack of preventive treatments.
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Poorly aerated trees or trees with excess vigour.
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Control Method
Preventive control
- Preventive spraying of copper-based fungicides (Bordeaux mixture):
- Application at the end of autumn (leaf fall).
- One or two applications in late winter/early spring before buds open.
- Removal of affected leaves if moderate attack.
- Avoid pruning that is too harsh which favours sensitive shoots.
- Maintain good aeration of the tree (well-balanced pruning).
Chemical control
- Treatment with specific fungicides: copper, dodine, ziram, etc.
- Important : treat before symptoms appear, as fungicides are only effective as a preventive measure.
Cultural control
- Use of partially resistant varieties if available.
- Keep the tree in good vegetative balance to limit sensitive tender shoots.
