「海梨柑」與「無子桶柑」果實與枝梢生長比較

Comparison of Fruit and Shoot Growth between 'Hai-li' Tangor (Citrus tankan Hay. cv. Hai-li) and 'Seedless Tankan' Tangor (Citrus tankan Hay.)

海梨柑與無子桶柑為台灣重要的桶柑品種，前者雖為農曆年間之重要水果，但果汁率與果實品質均較低，而影饗其發展。本文即由兩者之果實與枝梢生長，探求造成此種差異之原因。兩者之果實均呈單S生長曲線，前者在花後40週即已成熟，種子數在6-18個之間：後者約遲4-8週，種子數在4個以下。果皮厚及全果實含水量的差異不大，但在峨眉地區海梨柑果皮含水蜇遠高於無子桶柑，顯示其果實水份散失較易。海梨柑果球的含水量與果汁率在果實發育20週之前仍較高，但22週之後即低於無子桶柑，兩品種之果貿水含量在花後20週，果汁率則在花後30週之後，增加速率即減少：即其水份的增加是隨著果實重暈的增加而增加；而花後20-30週（八～九月間）是決定果實水份與果汁率的重要季節。無子桶柑的徒長枝數、徒長枝長、徒長枝葉片數及橫向枝長均較海梨柑多。由此可見，海梨柑果汁率在果實發育中期之後，即開始偏低，其原因與營養生長關係不大，應與水份之分配與利用有關。

Hai-Ii'and 'Seedless Tankan' are two very famous groups of Tankan tangor in Taiwan. Although 'Hai-Ii'tangor harvest in New Year of lunar calendar (Chinese New Year), but the quality is more inferior toSeedless Tankan', especially its low juice content. This article discuses the differences of fruit and shoot growth and certain characteristics of fruit between these two citrus, and their relationship to fruit quality Fruit growth of both citrus shows a single S growth curve.'Hai-Ii'harvest 40 weeks after anthesis,'Seedless Tankan'harvest 4-8 weeks later. The former had 6-18 seeds per fruit, the latter had less thru1 4. Peel thickness, total water cotent were no different between two citrus. Although'Hai-li'had more water content in fruit and fruit segment before the first 20 weeks of fruit growth, after anthesis 22 weeks, it becomes significantly lower than'Seedless Tankan'. In matured fruit, water content of'Hai-li'peel was higher than'Seedless Tankan'. Shout growth vigor of·Seedless Tankan'was stronger than'Hai-li'. The results show that low water juice content of'Ha硨'fruit caused by water partition, usage and some other characteristics, but not growth .