仙人掌果（Hylocereus undatus Britt. & Rose）之開花及果實生長

Flowering and Fruit Growth of Pitaya (Hylocereus undatus Britt. & Rose)

調查越南種仙人掌果紅龍之花芽分化，由可見花芽至開花平均需17天，花長度達31.2cm，於夜晚綻放花朵，至凌晨1:00花徑達最大（23.4cm），2:00開始逐漸萎凋，至陽光照射後完全凋謝。果實生長呈單一S型，自開花後至果實呈紅色可採收平均需33天，此時果重達339g，果心可溶性固形物達最大之19.5°Brix，至花後50天果實仍緩慢生長，果重可達487g，但甜度變化不顯著。

Flowering and fruit growth of pitaya (Hylocereus undatus Britt. & Rose) are studied. Growth period of flower bud from visible to an thesis (31 .2cm in length) is 17 days. An thesis occurrs from sunset to sunrise the next day and flower attains maximum (23.4cm in diameter) around 1:00 am. Fruit growth shows single sigmoid pattern. The red fruit (average weight 339g) can be harvested 33 days after an thesis and total soluble solids attain maximum (19.5 Brix in center of flesh). Fruit weight can reach 487g when harvested 50 days after anthesis. However, the changes of total soluble solids are not significant from 33 to 50 days after an thesis.