荔枝樹枝晚花現象之觀察

Some Investigations on the Delayed Flower Shoots of Litchi Tree

荔枝樹同一株上間常有開花結果較晚之枝發生，為瞭解其果實在形態、產量、品質等各方面之差異及此種晚花現象發生之原因，乃於1965〜1967年間在臺中縣太平、豐原等鄉鎮就農家栽培最多之黑葉荔枝從事調查觀察，包括著果落果之檢查，形態及產量品質之比較，晚花原因之探討。根據調查分析結果，獲知晚生花穗較正常而早生之花穗花數及著果數遙多，雖落果率相差無幾，然結果率則超過早生者一倍以上，晚生果穗粗短果實較大而密生，果殼薄可食部百分率及糖度均較高，但果實著色較差，酸分較高。晚花原因經檢查係因枝條曾經壓條繁殖行環狀剝皮或受其他傷損所造成，此種現象似可利用以增進荔枝之產量品質，惟如何實施為適猶待試驗。

Delayed flower shoots sometimes were found on the same Litchi tree that bearing normal flower shoots. In order to understand the differences in yield, quality and appearance of fruits between these two kinds of flower shoots, and also the causes of delayed flower shoot formation, observations and investigations were made during 1965一1967 in Taichung. The variety Hak Ip were used. Items investigated includes flower set, flower drop, outer appearance and quality of fruits as well. Results obtained were as follows: Delayed flower shoot bore more flowers and set more fruits than normal flower shoo t. As the number of drop fruit of these two kinds of shoots were both high (8096 and above), delayed flower shoots still had more fruits than normal flower shoo t. The delayed flower shoot resulted in short, thicken and compact fruit bunch with larger fruit. Fruits were with thinner fruit peel, higher per cent of edible portion, fruit juice. and sugar content. Color was inferior and acid slightly higher. The causes of delayed flower shoots happening seems to be related to airlayered branches or SOme other kind of injuries done to branches. It seems probably that mechanical injuries may be used to promote delayed flower shoots for the purpose of increase the yield and quality of Litchi fruit, but how to carry out into field practices waits for further research.