Girdling Effects on Orange Fruit Set and Young Fruit Abscission1

Abstract

Abstract A previous report that girdling at the beginning of bloom increases yield of orange trees by increasing fruit number but not fruit size has been confirmed. Girdling caused the abortion of some flowers which were in the early differentiation stages at girdling time, and decreased the drop of ovaries during the first portion of the shedding season. Thus fewer flowers produced more fruits. Since it has been shown that girdling increases gibberellin activity in the aerial parts, the dual effect of gibberellin on flower formation and fruit setting may explain these influences of girdling.