產期調節對紅龍果產量及品質之影響

Abstract

中文摘要 本試驗於2001年12月至2002年12月，在中興大學農業試驗場(台中縣霧峰)進行田間試驗。探討紅龍果產期調節之方法，包括修剪時期、提升地溫和延長光照以及化學藥劑等處理，對紅龍果產量及品質之影響。試驗品種為紅皮白肉種。試驗包括(一)修剪時期處理：分成2001年12月上旬、2002年1月、2月及3月上旬修剪等四種處理。每一處理二十重複。(二)提升地溫(30℃)和延長光照(四小時)處理：分成提升地溫、延長光照、提升地溫加延長光照及對照等四種處理，每一處理十重複。處理期間為2001年12月至2002年3月。(三)化學藥劑處理：以氰胺、2-氯乙醇、電石水及益收倍等四種藥劑。於2002年1月份分四次在白天（9-10時）和夜間（22-23時）處理，分別塗抹藥劑於紅龍果芽刺及全枝條。採完全逢機設計(CRD)，以四個尚未結果之一年生枝條，及一個已結果之一年生枝條為一重複，計四重複。 本試驗分別調查紅龍果花芽數、結果數、結果枝數及產量。並分三次進行初期果、盛期果及晚期果食味品評試驗，同時進行市場價格及經濟效益分析。田間試驗結果顯示，紅龍果於2月上旬修剪處理，比提早或延後修剪，可獲得較高之花芽數、結果數、結果枝數及果實總產量。修剪時期對紅龍果產期無顯著差異。提升地溫加延長光照處理比對照處理，可增加平均果重及結果枝數，也可提早紅龍果花芽分化。四種化學藥劑處理則對紅龍果花芽分化之誘導沒有影響，無法提早紅龍果產期。 修剪時期對紅龍果2002年6月至11月，每月產量及比例有相當顯著影響。試驗結果顯示，2月上旬修剪處理，其初期果和晚期果之產量比例，均比提早及延後修剪處理較高。由於紅龍果生產初期及晚期市場價格遠高於盛產期，2月上旬修剪可以有比較高的利潤。 修剪時期對紅龍果品評試驗，初期果以2月上旬修剪處理，品評分數最高，3月上旬修剪處理最低。盛期果以1月上旬修剪處理，品評分數最高，3月上旬修剪處理最低。晚期果則以3月上旬修剪處理，品評分數最高，12月上旬修剪處理最低。在提升地溫和延長光照等處理對紅龍果品評試驗，以提升地溫加延長光照處理，對於初期果、盛期果及晚期果品評分數最高，品質較好。 根據迴歸分析推算，建議紅龍果栽培，修剪最適期為1月21日，可獲得最高產量。提升地溫加延長光照同時應用，對於提早產期最為有效，可提早紅龍果產期32天。

Yield and quality of pitaya (Hylocereus undatus Britt. &Rose) as affected by fruiting regulation Summary Teng-Wei Chang Field experiments were conducted from December of 2001 through December of 2002 to investigate the effects of pruning time, increasing ground temperature, extending light, and chemicals on fruiting regulation, fruit yield, and quality of pitaya. Field experiment was held at orchard in Agriculture Experimental Satation (AES; Wufeng, Taichung) of National Chung Hsing University (NCHU). The first part of experiment was four pruning time treatments (December 2001, January, February, and March 2002). Each treatment was conducted in the beginning of each month with 20 hill of pitaya plant as replications. The second experiment was modifying soil temperature and day length, which including increasing ground temperature (30℃), extending light (4hrs), increasing ground temperature with extending light, and control plot. Each treatment was conducted with 10 replications and were practiced from December 2001 to March 2002. The third experiment was chemicals, which including Hydrogen cyanamide, 2-Ethylene chlorohydrin, CaC2, and Ethrel. Chemicals were applied on areole and full cladodes four times at day (09:00-10:00AM) and night (22:00-23:00PM) respectively, in January 2002. Experimental design was conducted by completely randomized design (CRD) with 4 replications, each replication includes 4 unfruiting one-year old cladode and a young cladodes. The time flower buds emergence was investigated and recorded. Flower bud number, fruit number, fruiting cladodes and fruit yield were investigated. Sensory evaluation were also conducted to servey the quality of early-season, mid-season, and late-season fruits. Market prices and cost were also analyzed. The results of field experiments indicated that pitaya pruning at beginning of February had the highest flower buds, fruits, fruiting cladodes and fruit yield. Time of pruning had no significant effect on enhance earlier fruiting of pitaya, while increased ground temperature with extending light caused 32 days earlier fruiting, and also a higher averaged fruit weight and total fruit yield. Treatments of chemicals had no significant effects on inducing differentiation of flower bud. The production period were not affected. Pruning time significantly affected the proportions of fruit yield monthly from June to November. Experimental results indicated that pruning at beginning of February produced more early-season and late-season fruits with a higher market prices, and thus a higher profits than that pruning earlier or later. Results of sensory evaluation indicated that early-season fruits from pruning at beginning of February had the best quality, while pruning at beginning of March showed the poorest. Mid-season fruits had the best quality produced from treatment of pruning at beginning of January Late-season fruits produced from pruning at beginning of March showed the highest qualities, while that pruning at beginning of December showed the poorest. Increasing ground temperature with extending light treatment had the highest qualities pitaya fruits for all the season, thus improved income for farmers. According to the experimental results, it was suggested that it is the best time to prune the one year old cladodes of pitaya at beginning of February, which gained the best fruit yield and profit. Increasing ground temperature with extending light treatments enhanced pitaya fruiting 32 days earlier.