Potato leafroll—Potato leafroll virus
Plants with leafroll infections typically are stunted and may appear erect. Leaves roll upward at the margins, have a stiff leathery texture, may be chlorotic, and die prematurely. Potato leafroll virus can also cause necrotic netting in the tuber vascular tissue of some varieties.
Potato leafroll virus can be introduced to a potato field by infected seed tubers or by aphids that have fed on infected potato plants. The most efficient vector of the virus is the green peach aphid. Several minutes to hours are required for the aphid vector to acquire the virus, but once the virus has been acquired, the aphid carries it for life. Winged aphids carried in air currents spread the virus over long distance, and wingless aphids are important in spreading it from plant to plant. Aphid feeding introduces potato leafroll virus into the food-conducting tissue of a plant vascular system, where the virus multiplies, spreads, and initiates disease. Potato leafroll virus is not transmitted mechanically.
Although leafroll is transmitted by aphids, control of aphids once present will not prevent disease. Use of reflective mulches to repel aphids may help. Use certified seed pieces. Avoid saving seed potatoes from gardens. Use resistant potato varieties. Remove and destroy any infected plants to help control virus spread. Brown areas in tubers can be cut away before eating, if desired.
Rolling of leaf infected with potato leafroll
Necrotic netting in tuber vascular tissue