著者

渋川 潤一 相馬 盛雄 泉谷 文足 宇野 登喜

出版者

一般社団法人 園芸学会

雑誌

園芸學會雜誌 (ISSN:00137626)

巻号頁・発行日

vol.27, no.2, pp.81-88_1, 1958

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Studies on the nutrient deficiencies of N, P, K, Ca and Mg in one-year old apple trees (varieties: Jonathan, Ralls and Indo) and in apple seedlings (seedlings of Jonathan and Indo) were carried out using sand culture method in 1954.<br> Nutrient deficiency symptoms and the contents of nutrient elements in the leaves showing symptoms were summarized as follows.<br> 1. Deficiency symptoms Nitrogen deficiency: Lack of nitrogen in the cultural solution resulted in the smaller leaves and the slower terminal growth of the apple trees very quickly. Leaves showed pale yellowish green color, but were neither scorched nor burned. Reddish coloring started on the older leaves and proceeded toward the younger ones, and finally terminal leaves turned to reddish brown.<br> Phosphorus deficiency: Phosphorus deficiency expressed itself in abnormally smaller size of the eaves and slenderness of the new growth. Foliage color was dark green, and later in the season it turned to bronze with purple or brown spottings, or to dull dark purple.<br> Potassium deficiency: Deficiency symptom of potassium appeared on the basal leaves of the current growth at first, and proceeded upwards as the time advanced. Terminal leaves, however, remain-ed normal. Slight marginal chlorosis of grayish yellow green color was followed by marginal scorching. The scorched area of grayish brown color extended into the body of the leaf in some cases.<br> Calcium deficiency: Visible symptom of direct calcium deficiency was not so easily distinguishable as in the cases of other elements. Margin of basal leaves was discolored and burned, its color changing to medium or dark brown.<br> Magnesium deficiency: Symptom appeared on the basal leaves of the current growth at first, and proceeded to younger ones. Prominent feature was yellowing of leaf margin and interveinal portions. Then those portions showed necrosis, and turned to brown. Many of the dead tissues were colapsed finally, as their size grew larger. Basal leaves were defoliated prematurely.<br> 2. The nutrient contents in the leaves which showed the visible deficiency symptoms were as follows:<br> Nitrogen 1.5_??_2.0%, Phosphorus 0.09_??_0.13%, Potassium 0.6_??_1.0%, Calcium 0.6%, Magnesium 0.20_??_0.29%, respectively.