摘要: 本試驗調查‘珍珠拔’果實生長發育期間果實與葉片礦物元素變化,果實中氮、磷、鈣、鎂、鐡、錳、銅、鋅濃度隨著果實肥大均呈下降趨勢;在葉片方面,隨著果實發育期之增加。葉片中氮、鉀濃度隨著果實肥大呈下降趨勢,而磷、鈣、鎂、鐡、錳、鋅濃度呈上升趨勢。冬果從開花至果實成熟約需有142天,夏果生長期較短,只需98天,生長曲線呈雙S型。 ‘珍珠拔’果實有易軟化之現象,而果實軟化似乎和果實中鈣含量有關,因此利用三種栽培技術以期改善果實礦物元素缺乏問題。不同葉果比處理之果實皆在達園藝成熟度時,果實中鈣濃度以留葉數8及16有較高濃度。不同葉果比處理,以果實留12-16葉有較高之果實品質。聚乙烯塑膠袋內襯白色舒果套及網袋二種處理,至果實達成熟採收時,果實大小二者並無明顯的差異,果實氮、磷、鉀、鐡、銅、鋅濃度,套袋處理間差異均不顯著,但鈣、鎂、錳濃度以網袋處理之果實較高。二種套袋處理之全可溶性糖含量無顯著差異,澱粉則以網袋處理較高。‘珍珠拔’番石榴嫁接4種不同實生苗砧木後,以‘大蒂’之根砧對於大量元素的吸收較好,接穗葉片之大量元素濃度較高。可溶性糖濃度以嫁接在‘珍珠拔’砧木最高,澱粉濃度以嫁接在‘水晶’砧木最高,其餘不同砧木品種間葉片可溶性糖及澱粉濃度差異不大。 果實中總可溶性固形物濃度與果實硬度和果實中鎂濃度成負相關。果實中鎂濃度和果實抗壞血酸成正相關。果實中鈣濃度和總可溶性糖成正相關。葉片磷、鈣濃度和總可溶性固形物濃度成負相關,葉片鈣濃度和抗壞血酸成正相關。 高品質果實氮濃度0.5-0.86%、磷濃度0.061-0.105%、鉀濃度1.04 -1.5%、鈣濃度0.024-0.068%、鎂濃度0.023-0.039%。葉片氮濃度1.45 -1.71%、磷濃度0.111-0.149%、鉀濃度0.69-1.21%、鈣濃度1.49-2.81%、鎂濃度0.15-0.33%,可作為田間肥培管理之參考。Mineral concentrations of fruits and leaves were investigated during the period of growth and development of guava “Jen-Ju Bar”. Results showed that N, P, Ca, Mg, Fe, Mn, Cu and Zn concentrations decreased with the growth of fruits. Leaf N and K concentrations also decreased, but P, Ca, Mg, Fe, Mn, Zn on the other hand increased with the increasing size of the fruits. From bloom to maturity, winter crops took about 142 days while summer crops needed relatively short period of about 98 days. Growth curve displayed a double sigmiodal pattern. “Jen-Ju Bar” tends to turn soft after harvest. This seems to be related to the Ca content in the fruits and three cultural techniques were employed to improve quality and to prevent Ca and other minerals deficiencies from happening. Regulation of leaf to fruit ratios was adopted to evaluate the Ca content and the results indicated that fruit Ca was higher in plants with 8 to 16 leaves per fruit at the time of maturation. Better fruit quality was obtained with 12 to 16 leaves per single fruit. Bagging with polyethylene in addition with white expandable polystyrene or net lining had no effect on fruit size at maturity. Neither did they affect N, P, K, Fe, Cu and Zn concentrations in fruit. By contrast, net lined bagging enhanced Ca, Mg, and Mn as well as starch content, but it contributed little to the total soluble sugar concentration. When “Jen-Ju Bar” guava scions were grafted onto 4 different stocks, mineral absorption by stock “Da-Ti” was most rapid and thus led to the accumulation of higher macro-element concentrations in leaves. Fruit soluble sugar concentration would reach the highest level whenever scion was grafted on “Jen-Ju Bar”. The starch content, however, was elevated to the highest level only when scions were grafted on “Shui-Jing” stock. No significant differences were found in leaf soluble sugar and starch in the graftage experiment. The firmness of fruit and the total soluble solids were negatively correlated with Mg whereas the ascorbic acid was positively correlated with Mg concentration. Fruit Ca and total soluble sugar had a similar trend. In leaf P and Ca concentrations were negatively correlated with total soluble solids, while Ca and ascorbic acid were found positively correlated. In the high quality”Jen-Ju Bar” fruits, N was found to be between 0.5 and 0.86%; P:0.061- 0.105%; K:1.04- 1.5 %; Ca:0.024-0.068%; Mg:0.023-0.039%. Leaf N concentration was 1.45-1.71%; P:0.111-0.149%; K:0.69-1.21%; Ca:1.49-2.81% and concentration of Mg ranged from 0.15 to 0.33 %. These figures could be used as a reference in the fertilization and management programs in producing good quality “Jen-Ju Bar” guava in the field. |