Leaves are distorted and veins turn pale yellow. Control Aphids and Leafhoppers , that spread this disease. Remove and destroy infected plants. Plants are covered with a white, ash-gray powder. Dust plant with Rose Dust .
Plant plants farther apart to increase air-circulation.
There is no foliage or it is turning yellow and wilts. Discard roots that show decay. Lower leaves turn yellow and wilt. Only one side of the plant may be affected. When the stem is sliced open dark streaks may be visible.