Apple Scab
Risk near you, next 48h
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When it strikes
About
Apple scab (Venturia inaequalis) is the most important disease of apples and crabapples in temperate climates, infecting leaves and fruit during wet spring weather and disfiguring the crop.
Symptoms
Olive-green to brown velvety blotches on leaves that later turn black; corky, cracked scabby lesions on fruit; early leaf drop in severe cases.
Organic Treatment
Rake and destroy fallen leaves to break the cycle, apply sulfur or copper from bud break through wet spring weather, and prune for airflow.
Chemical Treatment
Myclobutanil, captan, or dodine applied on a protectant schedule during the primary infection period (green tip to petal fall).
Prevention
Plant scab-resistant cultivars, remove leaf litter in autumn, prune open canopies, and avoid wetting foliage.