西印度櫻挑落花落果防治試驗

STUDIES ON THE CONTROL OF THE FRUIT DROP OF WEST INDIAN CHEBRY

西印度櫻桃在台灣栽培尚屬適宜，但幼齡期落花現象甚激烈，本試驗在天氣乾燥期中．用人工授粉可增加其結果率，可使收獲成熟果樹達開花數之31.5%。又用2,4-D噴液處理開花者，結果率更可增加，12.5ppm.之濃度，可使收穫成熟果數達開花數之52.0%。又在雨季時期（六月六日）經12.5ppm.之2,4-D噴液處理之植株，果實產量均大量增加，在噴液處理期間每月平均產量相當于其他最高月份產量為149.5%-571.4%（果實個數），或51.3%-304.5%（果實重量），處理西印度櫻桃最適當之2.4-D噴液濃度似為12.5ppm.，濃度愈高，嫩稍與嫩葉發生捲縮之現象亦較烈，濃度低于1Oppm.時，對防止落花落果效用不顯著。

This experiment was carried out at Chia-yi Agricultural Experimeut Station. in 1958. 7 out of 20 plants of west Indian cherry 4 years of age grown in the field were used under treatment and observation. The plan,s have grown well in the field, and profusely bloomed from mid-march through November of this year. unfortunately most of the flowers droped without, setting after opening. Causes of flower-droping may be pari ly due to lack of pollination and physiological disturbance. Jn this experiment. artificial pollination made during march 14 to April 3 of this year resulted in increasing the number of fruits matured to 31.5 percent of the flowers pollinated, while the, flowers not artificially pollinated did not set any fruit. 2,4-D spraying also effect ively helped the f1 uit setting. on April 5, 1958, 2,4-D spraying in concentration of 12. 5 ppm. resulted in increasing the number of fruits matured to 52.O percent of the flowers observed, another spraying with the same concentration was made on June 6, 1958, product:on of the west indian cherry was considerably increased, too, and the next cropping was delayed to the mid-August so that expense for harvesting might be largely saved.