採穗時期與低溫冷藏時間對臺灣新興梨穗品質的影響

The Effects of Harvest Stage and Cold Storage Duration on Fruit Bud Quality of 'Shinko' Pear Scion in Taiwan

蔡世宗(Shih-Tsung Tsai)

指導教授 ： 陳右人

共同指導教授 ： 張祖亮

國立臺灣大學/生物資源暨農學院/園藝學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.02420

摘要

九十六年十月十九日起，每兩星期採取梨山地區海拔2000公尺之‘新興’梨梨樹枝條，進行梨山地區‘新興’梨花芽發育與枝梢內容物之變化及採穗時期對梨山‘新興’梨接穗冷藏需求與梨穗品質之影響兩項試驗。
梨山生產之梨穗在充分冷藏後，萌芽率大致上可接近或超過90％，與日本進口之梨穗差異不顯著；開花、花朵數及著果率大致上隨採穗時間之延後而變佳，但至元月二十五日採穗時，反而得到較差之結果；其中，十二月中旬以後所採梨穗高接後的表現，與日本梨穗之表現差異不顯著，元月上、中旬採收之梨穗，開花著果表現甚至優於日本進口者。分析所採之枝條與葉片中碳水化合物與全氮含量，結果顯示在採樣期間內，梨樹枝梢碳水化合物以80％乙醇可溶性醣為主，澱粉為輔。枝條內80％乙醇可溶性醣隨著取樣時間的行進，由十月十九日採樣時的114.33 mg/g DW，明顯上升至十一月三十日的168.73 mg/g DW，其後雖會下降，但大致會維持在約130 mg/g DW以上之水準，至元月二十五日回降至十月十九日之水準。由於澱粉含量較低，大致在20 mg/g DW左右，且變動不大，導致總碳水化合物之變動，大致上與可溶性醣含量之變動趨勢相近。枝條中之全氮9.3 mg/g DW，逐步上升至12.0 mg/g DW的水準，隨後略微下降至11至10 mg/g DW之間。梨山地區之梨樹葉片在十二月初完全脫落，因此分析前四次採穗之葉片樣品，結果顯示十月十九日採樣之葉片，總碳水化合物含量有57.71 mg/g DW，但兩星期後下降至43.9 mg/g DW，並維持此一水準至落葉，氮含量在前三次取樣時，約維持在18 mg/g DW之水準，十一月三十日取樣者，下降至14 mg/g DW以下，顯示其已開始分解並準備落葉。梨穗碳水化合物含量，可能是造成結果表現差異之主因。從萌芽、開花、結果之表現及植體營養狀況上看，梨山地區新興梨穗之採收時間，應在十二月至元月上中旬間。
由萌芽、開花及結果之表現上看，梨山之梨穗採收後立即高接，萌芽率與萌芽整齊度，會隨採收時間之延後而提升。以5℃冷藏後，可明顯改善萌芽率與萌芽整齊度。經適度冷藏後，接穗高接後之開花與著果率亦隨之提升。由萌芽率、萌芽整齊度、開花率、開花數及著果率綜合考量，梨山之新興梨穗在十一月採收者需至少以5℃冷藏四星期以上，十二月採穗者，至少應以5℃冷藏三星期，元月上旬採收者應以5℃冷藏二星期，元月下旬採收者應5℃冷藏一星期。但似乎過度冷藏，接穗嫁接後之表現，有轉劣之傾向。
綜合以上結果，臺灣高海拔地區生產之梨穗，隨著採收時期的延後，接穗冷藏的時間可逐漸縮短。較適宜之採收期應在十二月至元月中旬，冷藏是必要之工作，愈早採收者，冷藏時間需更長。而在適時採收集適度冷藏下，國產梨穗之品質與日本進口梨穗差異不大。

關鍵字

梨穗 ； 高接

並列摘要

‘Hsinko’ pear scions were collected from Lishan (2000 m in altitude) every two week since Oct. 19th, 2007 for two experiments, the first was flower development and variation of nutrient content in ‘Hsinko’ pear branches from Lishan and the second were the effect of harvest date on cold storage duration and quality of Hsinko’ pear scions from Lishan.
Bud burst rate were near or over 90% after sufficient cold storage, which is not significantly different from those imported from Japan. Blooming date was advanced, number of flowers and rate of fruit set was promoted as delayed action of harvest date, but scions harvested on Jan. 25th, 2008 did not perform as expected. Scions harvested later than mid Dec. performed as well as those imported from Japan, and scions harvested at early and mid Jan. performed better than Japanese scions.
Carbohydrates of pear branches were majorly composed of 80% ethanol soluble solid and with starch as minor during sampling period. 80% ethanol soluble solid raised from 114.33 mg/g DW of branches harvested on Oct. 19, 2007 to 168.73 mg/g DW of branches harvested on Nov. 30, 2007, it decreased later on but with a level over 130 mg/g DW, and branches harvested on Jan. 25th, 2008 performed as those harvested on Oct. 19th, 2007. Content of starch kept low without big fluctuation at about 20 mg/g DW, therefore, fluctuation tendency of total carbohydrates mainly followed tendency of 80% ethanol soluble solid. Nitrogen was raised from 9.3 mg/g DW to 12.0 mg/g DW and decreased slightly to 10-11 mg/g DW in branches.
Pear leaves in Lishan fall off completely during early Dec. Total carbohydrates of leaves sampled on Oct. 19, 2007 was 57.71 mg/g DW, but decreased to 43.9 mg/g DW two weeks later and kept at this level until defoliation. Nitrogen content was about 18 mg/g DW for the first three sampling of leaves and decreased to 14 mg/g DW on Nov. 30, 2007, which indicated degradation of nitrogen and preparation of defoliation. Carbohydrate content of pear scions might be the major reason for variation of the results. Harvest date of ‘Hsinko’ pear scions should be between Dec. to mid Jan. according to performance of bud burst, blooming, fruit set and plant nutrient analysis.
The rate and uniformity of bud burst of ‘Hsinko’ pear scions from Lishan were enhanced as delayed action of harvest. After cold storage in 5℃, rate and uniformity of bud burst were greatly improved, so were the number of flowers and rate of fruit set after grafting. Based on the performance of rate and uniformity of bud burst, rate of flowering, number of flowers and rate of fruit set, ‘Hsinko’ pear scions from Lishan harvested on Nov. should be cold stored in 5℃ for over 4 weeks, those harvested on Dec. should be cold stored for 3 weeks, those harvested on early Jan. should be cold stored for 2 weeks, and those harvested on late Jan. should be cold stored for 1 week. Excess cold storage, however, would deteriorate performance of scions after grafting.
On account of the above results, cold storage period of pear scions produced from high elevation areas in Taiwan could be shortened as delay action of harvest date. Appropriate harvest date should be between Dec. to mid Jan. Cold storage was of necessity, as the earlier the date of harvest, the longer the period of cold storage. Domestic pear scions perform as well as those imported from Japan if harvested at suitable time and cold stored for an optimal period.

並列關鍵字

pear scion ； top-grafting

參考文獻

阮素芬、陳右人. 2005. 促進高接梨著果技術之探討. 台中區農業改良場特刊. 梨栽培管理之研討會專輯. 75:223-241.

盧柏松. 2005. 高接梨嫁接適期之研究. 台中區農業改良場特刊. 梨栽培管理之研討會專輯. 75:175-190.

廖萬正. 2005. 梨台中1號與台中2號品種之育成. 台中區農業改良場特刊. 梨栽培管理之研討會專輯. 75:112-136.

劉方梅. 2005. 梨產業現況與發展策略. 台中區農業改良場特刊. 梨栽培管理之研討會專輯. 75:1-11.

林嘉興. 1997. 梨天然災害預防及復育. 果樹天然災害預防復育手冊台中區農業改良場特刊39:p.145-155.