Secondary stage-Diseased leaves appear whitish gray; dusty; or have a powdery white appearance. Petioles; cluster stems; and green shoots often look distorted or stunted. Berries can be infected until their sugar content reaches about 8% If infected when young; the epidermis of the berry can split and the berries dry up or rot. When older berries are infected; a netlike pattern often develops on the surface of the berry.