Studies on the Development of 'Chun-Choi' Carambola (Averrhoa carambola L.) Fruit

Abstract

The objectives of this study were to clarify the changes in ‘Chun-Choi' carambola (Averrhoa carambola L.) fruit characteristics during development and to provide farmers some information on proper harvest time and orchard management. The growth curve of carambola fruit showed a single sigmoid curve. The fruit length, fruit circumference, rib thickness and rib depth began to increase rapidly 1 week after bloom. However, the fruit fresh weight and fruit volume started to increase rapidly 3 weeks later, and total soluble solids started to increase 7 weeks after bloom. The period of fruit growth and development (from bloom to ripeness) were 10 weeks and 12 weeks for summer and winter fruits, respectively. Total soluble solids (TSS) increased with fruit development, whereas titratable acidity (TA) decreased during the same period. Summer fruit had higher TSS and lower TA than winter fruit. Fruit firmness declined with fruit growth. Fruit color changed gradually from dark green (6 to 7 weeks after bloom) to fully-yellow at ripeness (12 to 13 weeks after bloom). The fruit growth period, from anthesis to ripeness, in winter was 2 to 3weeks longer than in summer.本研究主要探討'秤錘'楊桃(Averrhoa carambola L.)在不同發育季節果實的形態與成分變化。由調查結果顯示，楊桃果實的生長曲呈單S型，以夏果而言，果長、周長、稜厚及稜寬在花後1週即開始快速增加；鮮重及體積隨後於花後4週開始快速上升；而可溶性固形物直到花後7週才開始迅速累積；果實到達成熟期所需日數因季節而有所不同，夏、冬果分別於花後10週、12週進入生理成熟期。果實可溶性固形物隨果實發育而加，且夏果高於冬果；果實硬度、可滴定酸則隨果實發育而降低；夏果果實顏色由發育中期(花後6~7週)的深綠色逐漸轉為完熟期(花後12~13週)的黃色