Promoting flowering in sweet orange

Abstract

Two substances reported to stimulate flowering in citrus, Alar (N-dimethylamino-succinamic acid) at 3000 p.p.m. and Hyvar-X (5-bromo-6-n1ethyl-3-s-butyluracil) at 783 p.p.m., when applied twice to sweet orange plants under marginally flower-inducing conditions (24/19¦C day/night temperature) resulted in fewer flowers being formed than in the controls. These substances had no significant effect on the numbers of flowers formed by either fruit-bearing or non-fruiting plants under flower-inducing conditions (18/13¦C day/night temperature). In the field, Alar (3000 p.p.m.) applied twice or girdling of branches, about the time of flower formation, did not promote flowering on either fruit-bearing or non-fruiting branches.