Effects of growth regulators on fruit set and June drop of pears and apples.

Abstract

To increase yields of pear and apple trees the growth regulators kinetin, gibberellin (A3 and a mixture of A4 and A7), Alar and CCC were applied by spraying on blossoms or fruitlets and by injection into the trunk. Kinetin and particularly gibberellins were effective in stimulating fruit set in pears. Doyenne du Cornice pear set more fruits with a mixture of gibberellin A4 and A7 than with gibberellin A3. Although the majority of stimulated fruits abscised during the June drop period, the crop was markedly increased. The growth retard-ants Alar and CCC were inactive in increasing fruit set, but prevented excessive drop of fruits when applied after a gibberellin application.-Lab. TuinbPl, Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)