fruitfulness, viticultural term describing the number of bunches of grapes on each shoot. It can also be used to describe the potential productivity of buds. A shoot of low fruitfulness will have zero or one bunch only, while a fruitful one may have two or three or, very rarely, four. Some varieties are known to be very fruitful, an example being the so-called french hybrids, no doubt due to their part-American parentage. At the other end of the fruitfulness spectrum is sultana, which has notoriously low fertility of buds at the base of canes. Most of the commercially important wine grape varieties fall between these two extremes and two bunches per shoot is most common. Where fruitfulness is low, the vine-grower must prune to canes as opposed to spurs, as shoots which arise from short spurs will typically be of lower fruitfulness, arising as they do from basal buds.