|Title:||利用葉分析診斷柑桔營養狀態之研究||Other Titles:||Study on Leaf Analysis as a Means of Diagnosing Nutritional Status of Citrus Plants||Authors:||邱再發
|Issue Date:||4-Jun-1961||Publisher:||農業試驗所||Journal Volume:||10||Journal Issue:||2||Start page/Pages:||25-33||Source:||農業研究||Abstract:||
3.柑葉 N. P. K含量隨季節之不同其變化甚大。五月各養分之濃度為最高，此為春天展開之新葉，以後各養分漸漸減低至翌年三月為最低，蓋三月所採者均為前年留下之老葉。
5. P 含量在無磷區為0.131%～0.140%而對照區為0.138%～0.142%，其差異不大，但無氮區之P含量比對照區者顯著的增高，其差異達到統計的顯著標準。
1. Leaf analysis was conducted as a means of diagnosing nutritional status using Citrus Ponkan trees on the fertilizer experiment orchards as materials. The fertilizer experiments have been started since January, 1958 at one lacality in Yuanlin and two localities in Hsinpu, with five treatments layout, i. e. a) No N plot (PK), b) No P plot (NK), c) No K plot (NP), d) NPK plot (Check), e) Trace Elements plot (NPK+Mg, Mn, Zn).
2. Leaf samples were collected at each experimental plot in March, May, July, September and November 1959 respectively, then N, P, and K were analyzed in order to investigate the effect of fertilization and time of sampling on leaf compositions.
3. All these citrus trees had generally the highest leaf contonts of N, P and K in
May which is at the early stage of foliation and these contents decreased gradually thereafter. In March next year, it became the lowest contents which is attributed to old age of leaves.
4. N contents in citrus leaves at each locality were 2.76%-3.03% on average in the no N plot, while there were 3.02%-3.21% in the check plot. The critical percent-tage of nitrogen in Citrus Ponkan leaves was considered at about 3.0%.
5. P contents in the no P plot were 0.131%-0.140% and there were 0.138%-0.142% in the check Plot. The differerence of P contents between these two plots was so small but it increased greatly at the no N plot. P contents in the no N plot was significantly higher than that in the check plot.
6. K contents in the no K plot were 0.86%-1.19% and there were 0.98%-1.31% in the check plot. K contents in the no N plot also showed apparently higher, so that nitrogen deficiency would be considered to promote the accumulation of P and K in citrus leaves. It was also found that the difference of K contents in leaves among those three orchards was quite large, but it was small in the case of N and P.
7. The position of leaves at citrus twigs and number of leaves sampled in this experiment was seemed to be little influennce on leaf compositions.
|Appears in Collections:||1.台灣農業研究(1950～迄今)|
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