採收期與疏花對金柑(Fortunella spp.)開花與果實生育之影響

Effect of Harvest Date and Flower Thinning on Flowering and Fruit Growth of Kumquats (Fortunella spp.)

葉侑橋(You-Chiao Yeh)

指導教授 ： 陳右人

國立臺灣大學/生物資源暨農學院/園藝學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.01427

摘要

本試驗先探討採收時間與長實金柑(Fortunella margarita Swingle)、長壽金柑(Fortunella obovata Tanaka)與金彈(Fortunella crassifolia Swingle)果實品質之關係，再探討疏花處理對長實金柑花期、結果期之影響，以討論疏花能否調整金柑產期。
金柑在夏季時可連續開花，故採收期長可達數月。金柑果農採收標準為果皮轉色與否。依此標準，自2013年11月3日起，每15天自宜蘭礁溪果園採集果實，調查果實之糖度、有機酸含量等性狀，以了解三種金柑之採收適期。長實金柑，果實自11月3日到12月18日共採收四次，12月3日採收之果實，糖酸比為12.37顯著高於其他三次採收，而11月3日採收果實之有機酸含量為1.63 %顯著高於其他三次採收，果重及體積以12月3日採收果實較高於其他三次採收，分別為16.49 g與17.73 cm3，主要採收適期從12月開始。長壽金柑果實自11月3日至翌年2月1日共採收七次，重量與體積以11月18日到12月18日連續三次採收之果實較其餘四次採收之果實為重且大，平均有37.85 g與41.63 cm3；12月3日採收果實之總可溶性固形物為9.24 °Brix，顯著高於其他六次採收之果實，故長壽金柑採收適期為11月至12月；金彈自12月3日至翌年1月2日共採收三次，糖酸比由33.89降至18.12，故金彈採收適期由12月開始。長實金柑適採期較長壽金柑晚一個月，且在採收適期前一個月果實品質差，易造成多餘人力消耗，而若減少非採收適期果實數目與增加適採期的產量，有助於增加農民收益。
在2014年6月至9月，對宜蘭礁溪果園共32棵長實金柑植株，進行8個疏花處理。長實金柑每年可開花四至五期，花期集中於第一期花，平均每枝條有7朵花，結2個果實為結果之主要貢獻者。若將第一期花疏除，將減少該枝條產量。然僅疏除第一期花者，第二期花數與結果數顯著高於未處理者之第二期花。將三期花全疏除，會使花期及結果期延後近2個月，且平均每枝條少於1朵花，產量低下。疏花處理後，花期及結果期延後，越晚疏花延後越久。雖疏花處理使平均結果數下降，然第一期花多，著果率相較為低。夏季金柑兩周開花一次，經疏花處理後隔次花期需兩周，可藉疏第一期花來促使第二期花發生。疏去一期花即可使長實金柑結果期延遲一個月，可達成增加採收適期果實數之目標。

關鍵字

採收適期 ； 糖酸比 ； 結果率 ； 可溶性固形物含量 ； 有機酸含量

並列摘要

In this research, we discussed the possible effects of harvest timing on fruit quality of Fortunella margarita Swingle, Fortunella obovata Tanaka, and Fortunella crassifolia Swingle. We also discussed the effects of flower thinning to flowering time, fruit set timing, and fruit quality of F. margarita Swingle. These allow us to know the possibility of forcing through flower thinning in kumquat production.
Kumquat flowers continuesouly during summer, therefore, the time for harvest lasts several months. Whether to harvest or not depends on fruit coloration. According to the criteria for harvest from local cultivators, we harvested fruits from orchards located in Jiaoxi, Ilan, every 15 days starting from Nov. 3rd, 2013. The measurement of total soluble solids and organic acid contents were made to better understand the appropriate time to harvest. Fruits of F. margarita were collected four times from Nov. 3rd to Dec. 18th. The fruits harvested on Dec. 3rd have higher ratio of total soluble solids to organic acid contents, which was 12.37, compared with the rest. The fruits harvested on Nov. 3rd have higher organic acid contents, which was 1.63%. The fruits harvested on Dec. 3rd have higher fruit weights and volume, which were 16.49 g and 17.73 cm3, when comparing to other time of harvest. The appropriate time for harvest starts from December for F. margarita. As for F. obovata, a total of seven times of harvest was done from Nov. 3rd to Feb. 1st next year. The fruits harvested from Nov. 18th to Dec. 18th have an average weight and volume of 37.85 g and 41.63 cm3, which was greater than fruit from other time for harvest. In the fruits harvested on Dec. 3rd, total soluble solid reached 9.24 °Brix, which is the highest in the entire harvest season. The appropriate harvest season for F. obovata is found from Nov. to Dec. As for F. crassifolia, a total of three times of harvest was done from Dec. 3rd to Jan. 2nd next year. The ratio of total soluble solid to organic acid contents decreased from 33.89 to 18.12 if the time for harvest delayed. In short, the appropriate harvest time for premium quality of F. margarita was later than that of F. obovata, with a month of poor fruit quality before the appropriate harvest time, which waste labour cost. If an increment in the number of fruit set can be imposed into the appropriate harvest time, it’s possible to raise grower’s income.
From Jun. to Sep., 2014, eight flower thinning treatments were made to thirty-two F. margarita trees in the orchard in Jiaoxi, Ilan. F. margarita flowers four to five times a year, while the time for most flowers anthesis of F. margarita is mainly in first flowering time, an average of seven flowers and two fruits per shoot was observed, which contributed mainly to the total number of fruit set. Flower thinning was done on Jun. 30th, this caused a decrement in total fruit set. However, only flowers were thinned in the first flowering time, the amount of flower anthesis and fruit set in the second flowering time were significantly more than the second flowering time when untreated. If flowers were thinned for three flowering times, the next flowering time and main fruit set timing will be postponed to about two months, with an average number of flowers less than one flower per shoot and lower yield. After thinning, a delay was found in timing of both flowering and fruit set. The later thinning was done, the longer these periods postponed. Although, thinning gave a decrement in total number of fruit set. Relatively low rate of fruit set and drastic yield variation due to weather condition can be assumed, since large amount of flowers anthesis in the first flowering time. In summer, after the first flowering time, the second flowering time appeared for about two weeks later. Flower thinning in the first flowerinng time can asure a delay in the time for the second flowering time with certain amount of flowers and fruit set. In sum, flowering thinning in the 1st flowering time can postpone the time of fruit set for a month, reaching the goal of raising the number of fruit set in the appropriate harvest time for Fortunella margarita Swingle.

並列關鍵字

appropriate harvest time ； the ratio of total soluble solid to organic acid contents ； fruit set ； total soluble solid ； organic acid content

參考文獻

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