Biennial bearing in apple and pear: A literature survey

Abstract

Fruit growers do not want biennial bearing which is an old problem in fruit growing. Although the problem is less urgent with modern cultivars and cultural techniques, it is still there. In particular, some cultivars of high fruit quality, which have a biennial bearing habit, are a challenge to modern growers. The formation of fruit buds is the central problem, which may be influenced by a number of factors such as, e.g., fruit set and fruit growth, type of branch, rootstock, pruning and growth regulators. By deflowering halves of trees, it is possible to have at least halves of a crop each year and this seems a practical solution for home gardens, although one does not obtain a full crop. The best prospects are for the use of growth regulators which can promote fruit bud formation in an “on-year” and reduce it in an “off-year”. These might be used after thinning of an excess of fruits or even when no thinning has taken place.