Growth regulators in fruit production reviewed from ISHS symposia at St. Paul and Long Ashton, 1972

Abstract

The papers of two ISHS symposia, held in 1972, are reviewed. Regarding growth regulators in fruit production, the output of papers on scientific research far exceeds the number of publications on their use in horticultural practice. Only limited information is still available about their mode of action. Hormonal control of fruit growth is best understood in the grape. Gibberellins are widely used to prevent seed formation in grape and to promote fruit set in pears and citrus. One of the most promising chemicals is (2-chloroethyl)phosphonic acid (ethephon) (CEPA). On the other hand, the practical use of abscisic acid (ABA) is nil. A mixture of an auxin, a gibberellin and a cytokinin is used to induce parthenocarpy on apple. Several growth regulators are applied in succesion in a superintensive system of apple growing in Great Britain: the ‘meadow orchard’, a possible breakthrough towards a more mechanised way of fruit growing.