‘愛文’檬果著果與果實品質研究

Abstract

本試驗探討臺南玉井之‘愛文’檬果果實屬性與著生在果穗上的分布和落果習性，及疏果時每果穗留果數及留果位置與果實品質的影響，並調查疏花序和兩性花重量的關係，以探討果穗上果實分布的原因；最後，探討果實經不同套袋材質、套袋時期和地面反光等對果實品質的影響，冀供疏果和套袋之參考，以改進果實品質。 幼果階段，‘愛文’檬果均可著生有子果、胚夭折果和無子果，以有子果果實較長；果實分布均以靠近果穗基部少，中段及末端較多；以果穗第一級分支而言，有子果分布靠近花序軸處，胚夭折果分布於各處，無子果則有遠離花序軸端的趨勢。落果於盛花日後50天後趨於平緩，落果初期以無子果比例高，後期才出現胚夭折果和有子果；盛花日後64天累積落果率達96.0%，其中，無子果為88.4%，胚夭折果和有子果分別為7.0%和0.6%。兩性花限制授粉，並無法獲得胚夭折果和有子果。果實後熟時，種子正常發育的有子果最大，胚夭折果次之，無子果最小；‘愛文’檬果疏果後，每穗留一顆或二顆有子果，果熟時皆以著生在果穗末端第一級分支的果實較重。 盛花日僅留花穗各第一級分支遠軸端部分小花，仍僅著生無子果。花穗抽出10cm長時，僅留花穗末端分支。此分支可繼續伸長，花期由32天增加至46天，小花節位數、總花數、兩性花數及其比率皆可提高，縱使著果，分支上果實的分布，有子果偏向近軸處，無子果仍趨向遠軸處。以兩性花重量而言，第一級花較重，且以分佈在花穗末端近軸處的第一級花較重。 ‘愛文’檬果盛花日後90天，果實套白色紙袋的果色較佳，雙層牛皮紙袋次之，鋁箔袋最差，果重以鋁箔袋處理者最重，但總可溶性固形物低。果熟前，將鋁箔紙和雙層牛皮紙袋套袋更換為白色紙袋，目視果皮紅色面積和花青素含量雖有增加的趨勢，但仍不如白色紙套袋者。分別在果長3、6和9cm套上雙層牛皮紙袋，果色皆不如果長9cm套白色紙袋者。果實套白色紙袋後，於樹冠下地面覆蓋鋁箔板和Tyvek®防潮蓆作為反光材料，總可溶性固形物、目視果皮紅色面積和花青素含量皆有顯著差異，Tyvek®防潮蓆使果重減少約12.0%。

The objective of this study was to bases on attribute of seed, the habit of fruitlet distribution on fruit cluster and fruit drop, and after fruit thinning the effect of fruit number and position on each cluster on fruit quality. Moreover, by the inflorescence thinning and investigated the weight of hermaphrodite flower on rachis, to discussed the reason of the fruit distribution. Finally, effects of bagging materials, bagging stage and enhancement of light reflection from the ground on fruit quality of ‘Irwin’ mango in commercial orchard at Yu-Jing, Tainan. In young fruit stage, seeded, embryo-aborted and seedless fruit on each cluster. Most of the abscised fruits of mango were seedless and dropped in their early developmental stages. Embryo-aborted fruits were also abscised in the later stages. However, some of the seedless and embryo-aborted fruits retained on the trees until mature stage and these fruits are born on the middle and distal parts of peduncles. The size of embryo-aborted fruits varied significantly. After fruit thinning, one or two seeded fruitlets on each cluster, both the fruit on primary (I°) branch of rachis is heavier. Retain the flowers on distal to rachis of I° branch, still got the seedless fruit. Then, the rachis was 10 cm length, retained the terminal I° branch. The branch continued to elongate, the flowering season from 32 days increased to 46 days, the flower order, total flower number, number and percentage of the hermaphordite flower all increased. But seeded fruitlets were more frequently found on the branch proximal to the rachis, seedless fruitlets were distal. For the weight of hermaphordite flower, the first order of flower was heavier, especially in proximal of terminal I° branch of rachis. Fruits were bagged in white-paper were of higher anthocyanin and total soluble solids than in black or aluminum-foil bags although those in aluminum foil had the largest fruit size. Before the fruit was ripened, change the aluminum-foil bags or the black paper bag to the white-paper bags, the red-color and anthocyanin content although has increased, but still was inferior to a white-paper set of bag. The black paper bag was put on the fruit length were 3, 6 and 9 cm individually, those color of fruit were inferior to the white paper bag was put on the 9 cm fruit length. Fruits were bagged with transparent paper and aluminum foil or moisture-proof Tyvek® sheet (DuPont) was covered above the ground but under the crown of ‘Irwin’ mango trees at ninety days after anthesis. The moisture-proof treatment also increased red-color percentage and anthocyanin content and total soluble solid content significantly but their fruit size decreased 12 % significantly.