Endogenous hormone causes flower and fruit drop of wax apple (Syzygium samarangense cv. Citra)

Abstract

The aim of this study was to obtain information about the content of endogenous hormones that causes flowers and fruit drop of wax apple. The variables observed in the six stages of flower and fruit development that drop easily and retention of indole-­3-­acetic acid (IAA), cytokinin (zeatin and kinetin), gibberellins (GA₃), 1­-amino cyclopropane­-1-­carboxylic acid (ACC), total sugar, and starch. Six stages of development of wax apple fruit: (1) Bud Development (initial flowering) 0­-3 days before anthesis. (2) Anthesis (perfect blooming flowers), 0­-7 days after anthesis. (3) Fruit set, 7­-14 days after anthesis. (4) Fruit development, 14-­28 days after anthesis. (5) Fruit Maturation, 28­-35 days after anthesis. (6) Fruit ripening, 35­-50 days after anthesis. The results showed that the content of IAA, zeatin, GA₃, and total sugar of flowers and fruit of wax apple at 6 stages that would fall smaller than those of retention and ACC content and starch was higher in flower and fruits that drop easily than retention. The kinetin content in the flower development that drop easily is smaller than the retention but in the fruit development the kinetin content is not significantly different between those that drop easily and retention.