摘要: 不同氮、磷、鉀施肥量及N、P、K組合對泰國拔番石榴結果數、產量、單果重及品 質之影響, 經兩年之試驗結果顯示,隨著氮肥( 0 至 400g )、磷肥( P O ㄐA0 至 200g )或鉀肥( K O,0 至 400g )施用量之增加,番石榴之結果數、產量、單果重及 品質亦隨著增加。惟氮肥之施用量超過 200g 時,則氮肥之增產之效果減緩,而磷肥及鉀肥 ,則施肥量分別達 200g 及 400g 時,產量仍明顯增加。但氮、磷、鉀三種肥料對番石榴結 果數、產量及單果重之促進效果,則以氮肥最大,鉀肥及磷肥其次。 以產量而言,施 400g N 較不施 N 肥者可顯著提高產量約 107%; 400g K O 較不施 K 肥者可顯著提高約 73% ;施 200g P O ㄧ 不施 P 肥者可顯著提高約 33%。 對果實品質而言,不施 N 肥、磷 肥或鉀肥,果實之果肉率、可溶性固形物含量及維生素 C 量最低。在不同 N、P、K 施肥量 之處理中,以施最高量之 N ( 400g N ),P 肥( 200g P O ㄐ^及鉀肥( 400g K O )之果肉率、可溶性固形物含量及維生素 C 含量最高。 在 10 個不同 N、P、K 組合中, 以 N、P、K 比例為 2:1:4 之結果數、產量、單果重及果 實之一般品質表現最佳,其施肥量為 200g N,100g P O ㄐA400g K O,可作為本省 番石榴栽培生產上肥培管理之依據。 Four-year-old guava trees (cv. Thai-Kou-Bar) growing in sandy loam soil in southern Taiwan, were received N:P O :K O at 0-400; 0-200; 0-400g/plant for two years. The fruit number, yield and fruit weight of guava increased with increasing rates of N, P and K fertilizer applied. However, the rate of yield increasing was reduced when the rate of N applied was higher than 200g/plant, while the yield were obviously increased by increases in the P and K application up to the highest rate at 200g and 400g, respectively. Among the N, P and K applied, the most beneficial responses to the fruit number, yield and fruit weight was obtained by N application, and secondly by P and K. The highest rate of N, P and K applied improved significantly the yield by about 107%, 73% and 33% respectively, compared to those of controls with no N, P and K applied. In the absence of N, P and K received, the fruits of guava were lower in flesh percentage, total soluble solid (TSS) and vitamin C content. Among different levels of N, P and K treatments, the fruit with the highest of flesh percentage, TSS and vitamin C content was obtained from those of trees received the highest rate of N, P and K, respectively. In total of ten NPK combinations, the performances of fruit number, yield and fruit weight and quality of guava were best when the trees received N:P O :K O=2:1:4 at rates of 200:100:400 per trees per year. Therefore, that NPK ratio and rates of fertilizers are recommended for guava fertilization in Taiwan. |