施用不同量鉀肥對椪柑葉片在不同季節含鉀量之研究

STUDIES ON THE SEASONAL POTASSIUM CONTENTS IN PONKAN LEAF UNDER THE USE OF DIFFERENT QUANTITY OF POTASSIUM ELEMENT

果樹為多年生作物，樹形高大，根群深廣且復有砧木與接穗之關係，故施入土中的肥料，對其樹體之營養如何，實需自各方面加以探究，葉片分析法為近代一般認為深測植物本身營養最適宜之方法，在柑桔方面，依據前人分析研究，鉀在柑桔葉片乾物量幅度為0.6~2.4%，且對柑桔果實大小，果皮厚薄，果實著色，以及可溶性固形物含量均有影響，今為瞭解在施用不同量鉀肥對椪柑葉片在不同季節含鉀量情形，乃作本試驗，並進行一年之調查，希望自分析中獲得結果以作當地施肥之參考。本文承蒙盛澄淵及朱長志兩位教授指導，以及臺灣化學肥料服務社資助，始克順利完成，特此致謝。

1.Leaf analysis is the better means to detect the nutrition of tree fruits. 2.To fix the amount of nitrogen and photophorus and change the amount of potassinm in thi experiment, it has been. going on three year since the beginning. This is the amount ofs potassium in the dry matter:Ko:0.7783-1.440O, Kl:0.9536-16364, KZ:0.9397-16667 The more the potassium in the field used, the more the potassium in the leaves we may get. 3.The highest potassium content is in the Spring cycle (April) and the lowest potassium content is in the development of fruits. 4.In such experiment, the range of potassium in dry matter of Ponkau leafis 1.0-1.7%. Then the grow th of trees, produotion and size of fruits may secure better effect.