抄録
During late July and early August in 1950, leaf samples of Jonathan and Rall's Janet, the two lea-ding varieties in the Nagano Prefecure, were collected from commercial orchards, and their chemical com-position was determined in order to obtain some informations about the nutritional condition of the trees from which the samples were collected.
The contents of nitrogen, phosphorus, and potassium in the leaves of the two varieties were as follows:
Jonathan (121 samples) Rall's Janed (102 samples) Lowest Highest Mean Lowest Highest Mean N 1.91% 2.79 2.34 2.30 2.98 2.59 P 0.12% 0.23 0.164 0.12 0.24 0.181 K 0.69% 2.14 1.35 0.76 2.33 1.37
Comparison of chemical composition in twenty pairs of the two varieties in which the ages of the trees, cultural practices and other conditions seemed to be corresponding, revealed that N, P and K contents of Rall's Janet were significantly higher than the ones of Jonathan. (Table 2)
The age of trees affected slightly the N and P content in Jonathan and P content in Rall's, the trees the older, the contents in the leaves the less.
Potassium content in the leaves was low in Kamitakai county, and was decidedly high in Nagano city and Ina district. Twelve out of 223 samples were less than 1.0% in potassium content, most of which were found in the Kamitakai county. Phosphorus content was low in northern part of Kamitakai county, and was generally high in Higashi-Chikuma county and Nagano city
There was no correlation between the content of natritional elements in the apple leaves and the amount of the elements applied in the year as fertilizers.
There was no ceifference between the leaf composition of apples grafted on Malus Sieboldii (Mitsuba-kaido) stock and the ones grafted on M. prunifolia (Maruba-kaido) stock. Positive correlation was found between nitrogen and phosphorus content in the apple leaves in both, varieties.
