scion in viticulture, is the piece of the fruiting vine that is grafted on to the quite separate rootstock. When grown, such a plant will have the leaves and desired fruit of one vine variety (Cabernet Sauvignon, for example), but the roots of the other, rootstock, variety (110 Richter, for example). grafting is very widely used in viticulture since rootstocks are needed to combat soil-borne pests or diseases, such as phylloxera and nematodes.
© Jancis Robinson and Oxford University Press 1994, 1999, 2006, 2015