Avoid excessive irrigation late in growing season. Minimize mechanical damage during harvest. Click to expand Potato skin looks bruised, tubers become soft and the skin moist. After infection, skin ruptures and tuber exudes liquid with slight pressure. A clear line can be drawn between healthy and diseased areas of infected tubers.
Infection usually occurs at harvest as tubers come into contact with spores in the soil.
Delay harvesting until tuber skins are mature. Avoid mechanical injury. Increase ventilation if rot occurs in storage area. Click to expand Leaves and stems develop brownish spots that spread rapidly under wet conditions. Skin turns purple and looks bruised.