修剪時期與夏季遮陰對番石榴開花、結實與果實品質之影響

Accessing the effects of pruning time and summer shade on flowering, fruiting and fruit quality in guava (Psidium guajava L.)

李忠孝(Chung-Hsiao Li)

指導教授 ： 陳幼光 博士

國立屏東科技大學/農學院/農園生產系所/碩士(2011年)

https://doi.org/10.6346/NPUST.2011.00144

摘要

番石榴為台灣重要果樹產業之一， ‘帝王拔’及‘珍珠拔’分別為國內目前新興及主要之栽培品種，然前者其相關生育及生理資料尚闕如，而後者夏果品質不佳之問題仍待解決。為瞭解不同時期（春、夏）修剪對‘帝王拔’生產夏果與冬果枝梢之開花、結實與果實生育習性，以及遮陰對‘珍珠拔’夏果品質之影響，首先於2009年3月、6月在高雄縣大社鄉5年生‘帝王拔’果園進行慣行修剪，並調查對其後續營養生長與生殖生長之表現；次於2010年6月假岡山鎮5年生‘珍珠拔’果園，在盛花後2週、6週由植株樹冠上方搭設20、35、50%之遮光網，以不遮陰為對照組，繼而比較果實生長速率與品質。
‘帝王拔’於3月修剪者之開花枝（生產夏果）比例（62%）高於6月者（生產冬果）（42%），惟二者均以第三節之開花比率為最高（分別為76%、100%），停梢時之長度分別為21.9 cm（6.9節與13.8枚葉片）及40.5 cm（8.2節與16.4枚葉片）。夏果及冬果之生長俱為雙S曲線（double sigmoid curve），其生育日數分別為112天及91天，惟前者之鮮重雖高於後者（424.2g vs 366.3g），但絕對生長速率、果肉糖度及乾重均較後者為低於（0.81g/d.DW vs 0.69g/d.DW；8.8°Brix vs 11.7°Brix；45.6g vs 51.6g）。
遮陰不影響‘珍珠拔’ 夏果之品質（糖度、比重、酸度與硬度），惟其生育日數及果實鮮重隨遮陰程度(0-35%)之增加而增加，最多達10-14天(為對照組的115%)、292.9g-363.6g（為對照組的124%），而果徑之絕對生長速率隨之降低，最大差距達0.01 cm/d（為對照組的87%）。
結果顯示， 3月修剪之‘帝王拔’，所萌之開花枝比例高於6月修剪者，而果實品質較差，夏果於樹冠之留果數遠較冬果者高或為前者品質不佳之原因。遮陰不影響‘珍珠拔’ 夏果之品質，但會增加果實鮮重與延後成熟期，未來進一步探討其對植株生育之影響或有必要。

關鍵字

番石榴 ； 修剪 ； 遮陰 ； 開花 ； 果實 ； 品質

並列摘要

Guava (Psidium guajava L.) has become an economically important fruit crop with two dominant cultivars in Taiwan. ‘Diwang Ba’ is a promising cultivar that was released recently, whereas ‘Jen-Ju Ba’ is currently the most widely planted cultivar for fresh consumption and export. Poor fruit quality in the summer season has been reported as the major production constraint in the guava industry; however, the mechanism causing this is unclear and a practical trial for improving this problem is still unavailable.
The objectives of this study were to document 1) effect of pruning time (March and June of 2009, respectively) on vegetative and generative growth on 5-year-old field-grown ‘Di Wan Ba’ trees; and 2) effect of summer overhead shade (20-50%) on fruit growth pattern and quality during fruit growing period of 5-year-old field-grown ‘Jen-Ju Ba’ trees cultivated in the Kaohsiung area.
Flowering shoots of ‘Di Wan Ba’ emerging after March pruning account for 62.0% of total flushes and it reached an average of 21.9 cm with 13.8 leaves by quiescence, while those emerging after June pruning were 42%, 8.2cm and 16.4 leaves, respectively. Flower mainly arise from axillary bud 3 (76% and 100%, respectively) and comprised of cyme, single or bicorpus. Fruit growth shows a double sigmoid curve based on dry weight, and it needed 16 weeks for summer season and 13 weeks for winter season to complete a growing cycle. At harvest, fruit maturing in summer had a greater fresh weight than that of winter （424.2g vs 366.3g）, while an inferior absolute growth rate of dry weight, total soluble solids and dry weight were recorded（0.81g/d.DW vs 0.69g/d.DW；8.8°Brix vs 11.7°Brix；45.6g vs 51.6g）.
At harvest, no difference of fruit quality, including firmness, sugar content, specific gravity and acid concentration was exhibited in all of the shade treatments of ‘Jen-Ju Ba’. However, fruit growth duration was extended 10-14 days (115% of control) and fruit weight increased 292.9g to 363.6g (112% of control) with increasing shading (0-35%), whereas a decreasing absolute growth rate of diameter occurred, up to 0.01 cm/d (87% of control).
It is indicated that ‘Di Wan Ba’ trees pruned in March received a far higher fruiting shoot proportion than those pruned in June, and consequently produced inferior and higher fruit quality in summer and winter, respectively. On the other hand, poor summer fruit quality may be induced by a much heavier crop loading compared with those bearing in winter. Shade does not affect fruit quality in summer season but enhance fruit fresh weight and postpones maturation in ‘Jen-Ju Ba’. Further work to evaluate the effect of shade on whole plant physiology is needed.

並列關鍵字

guava ； pruning ； shade ； flowering ； fruit ； quality

參考文獻

王武彰 (1987) 加工番石榴整枝方法。中華農業研究36(2)：190-1950。

王武彰 (1992) 番石榴採收時期對果實品質影響之研究。中華農業研究 41(3)：261-270。

王茗慧、林慧玲 (2009) 低溫貯藏及蒸熱處理對‘帝王’番石榴果實品質之影響。台灣園藝 55：113-126。

許仁宏、廖秀真、林慧玲、李國權 (1998) 蓮霧果實生長期間果實外部型態與內部有機成分的變化。中國園藝 44：491-501。

張哲嘉、林宗賢 (1998) 台灣番石榴生產之現況與改進。中國園藝 44(2)：116-124。