Abstract
The economic importance of the leaf-roll disease of potatoes has been recognised for a number of years owing to the fact that its incidence leads to a heavy reduction in marketable ware. The annual loss to potato growers in England and on the Continent from leaf-roll amounts to a high figure, but the disease is not of such prime importance to the Scottish cultivator as certain other diseases of the virus class to which the potato is prone, namely, mosaic and crinkle.