The symptoms depend on the virus strain, potato variety, growing conditions, and source of infection. Infection from seed tubers results in more severe symptoms than current-season infection. Plants may be stunted and leaves show yellowing or other discoloration in a mosaic pattern. Leaves may be crinkled or rolled from the edges, and become stiff and rattle, when shaken. In potato leaf roll, severely infected tubers show net necrosis (streaks of darkened dead tissue).
High levels of virus infestation in crops cause substantial yield losses. The tuber symptoms of leaf roll can result in rejection of potatoes for processing.
