西印度櫻桃落花落果防治再試驗

FURTHER STUDIES ON THE CONTROL OF FLOWER AND FRUIT SHEDDING OF WEST INDIAN CHERRY

嘉義農業試驗分所于1953年由美國佛州引入西印度櫻桃種子四品種，養成苗木於1954年12月定植田間作觀察與裁培試驗。1957年開始開花，但甚少結果，1958年開花則甚繁盛，亦結果寥寥。曾應用2,4-D水溶液進行落花落果防治試驗，效果極為顯著，所得資料曾刊登「中國園藝」五卷一期。本年（1959）除少數植株之結果稍感滿意外，其他植株之落花落果情形仍極嚴重。似可判斷西印度櫻桃之結果習佳與個別植株（individuals）或品種有關，為解決結果不良植株之產量與噴藥技術等問題，本年（1959）仍繼續作噴藥試驗，以測定噴藥後之增產可靠性，與多次噴藥後對樹勢發育之影響。

1. Individuals of seedling strain of west lnclian cheny significantly showed variations in fruit production. Among 20. plants of west Indian creny of seedling strain, grown in the test area, E1, E2, B2, P3, E3 and C2 yielded 92.6kg ,50.9kg, 32.6 kg, 29.7 kg, 22.7 kg. and 18.1 kg. of fruits respectively throughout the year 1950. The other plants were very low in yielding and might be considered as shy Learers. 2. In regard to the yielding of west Indian cherry, it is possible to make use of clonal propagation of the plants of selected strain as wen as chemical spraying with 2, 4-D solution on the shy Learers during blossoming periods so to assure or increase the setting of the fruit. This Experiment was carried out only to increase the fruit setting of the shy bearers by means of chemical spraying. 3. Yielding of west Indian cherry seems to be determined by the setting ability of individual plant. The yleld'ng would usually be satisfactory, when the setting percentage was high. west Indian cherry has been usually found with abundant flowers, amounts of flowers seemed not to be an impo1iant factor influencit1g the yielding. Low yield appeared to be usually induced by the flower shedding. 4. water solution of 2,4-D in concentration of 12.5 ppm. was very effective in the prevention of flower shedding of west Indian cherry. In this experiment. Cs and Ds are shy bearers and yielded only 2.09 kg. and 2.13 kg. of fruits (estimated) respectivcly throughout the year 1959. when they were sprayed with 2,4-D solution for four times in the same year, their setting abilites were made highly improved, and their yields amounted to 77.7kg. and 57.lkg. or were 37.2 and 26.8 times of those respectively when not. sprayed. Adequate fertilization resulted in good growth of the plants, and satisfactory yields would be achieved after each spraying of 2, 4-D solution. when four times of spraying were made in 1959.