Spores appear first as white, felt-like patches on the lower surface of the leaves of the apple. Secondary infections commonly appear first on the lower leaf surface, and may be detectable on the upper leaf surface as chlorotic spots. Leaves infected along the leaf margin may become curled, crinkled, or folded longitudinally. As the disease progresses, affected tissues develop the powdery, silver-gray appearance.
Where infestations are low, pruning of the infected terminal shoots is an effective control method. When the rate of infestation is high use foliar fungicides.
It begins as tiny purple flecks or specks on the front of the leaf. The purple flecks rapidly expand into irregularly shaped, often concentric, lesions. In severe infestation the leaves turn yellow and drop off.
Pruning of the affected shoots and planting resistant cultivars of apple.
Also spray effective fungicides e.g. copper based fungicides.
It appears as pale yellow or olive-green spots on the upper surface of leaves. Dark, velvety spots may appear on the lower surface. Severely infected leaves become twisted and puckered. The same symptoms on the leaves appear the same way on fruits
Plant resistant cultivars and proper timing of sprays is needed for fungicides to control disease.