Mildew - Downy

Is a fungal disease which forms on the undersides of infected leaves and spreads rapidly in cool, humid conditions on plants with wet leaves.

Shows as angular markings, usually yellow, brown or purple on the upper surface of the leaf, flowed by distorted growth and premature leaf fall. On the undersides of the leaf a downy or felt-like growth, ranging in colour from white or grey to purple, the plant gradually declines in vigour.