PEOPAGATION AND CULTIVATION OF FRUIT TREES IN JAPAN. 101 



Besides the customary use of night soil and stable manures, wood and 

 straw ashes, rape-seed cake, soy-bean cake, and fish-oil cake are used 

 more or less. Fish manures can now be obtained at a cheap rate, and 

 have also been imported from America in recent years. Bone manures 

 are seldom used in our farms and orchards, since cattle rearing is 

 hardly developed in this country. 



Generally speaking, the majority of our farmers and growers are still 

 ignorant of the use of manures for fruit raising, and no serious attention 

 is paid to it, as is done in the case of rice cultivation. 



Some experts have, however, made experiments on the relative value 

 of different commercial fertilizers on orchard and other crops. 



Particular kinds of manures, the nature of which is kept secret, are 

 also used by some. For citrous fruits, for example, an expert grower in 

 the Province of Kii is said to use common salt to enhance the keeping 

 quality of oranges and mandarins. The first results were strikingly 

 good, and since that time he has continued its use, and it is an 

 established fact that the application of potash in reasonable quantities 

 improves citrous fruits in many respects. Oranges and mandarins 

 treated in this way improve in flavour, appearance and keeping quality. 

 They also become much sweeter and more agreeable to the taste ; the 

 rind becomes of a deeper colour, thinner, smoother, and better attached 

 to the pulp. The improved keeping quality is, however, the most impor- 

 tant point. I have heard also from the communications in this Jour- 

 nal that lemons improve in quality when soap-water is applied as 

 manure. From these facts it probably follows that the application of 

 alkali in reasonable quantities would markedly improve the quality of 

 citrous fruits. 



The above results have been verified in the Experiment Station at 

 Okitsu, and similar results have also been arrived at by others. This 

 fact is well known to our growers in citrous centres, who use ashes 

 and other potash manures. 



Besides, our farmers are accustomed to use salt to date plums as a 

 remedy against the premature dropping of the fruit. They bury empty 

 salt packages, made of straw, near the roots, or tie the packages on the 

 stems. Saline water is said to be often poured around the trees. 



Though accurate experiments have never been made to prove it, 

 I am convinced that the dropping is caused by the rapid growth of the 

 shoots and roots as well as by the want of some nutriment. According 

 to Dr. Yamada, chemist to the Fukui Experiment Station, Kaki trees 

 in off years are markedly poor in phosphoric acid and magnesia, and 

 also deficient in soluble carbohydrates, proteids, and amides. Particu- 

 larly, the amides and magnesia show remarkably low percentages in off 

 ^ years. From this fact the importance of magnesia salts for the bear- 

 i ing of date plums is clear. Thus, it is necessary to give such salts 

 ; to exhausted trees in off years to improve the fruiting in the following 

 !,, year. Our custom of burying salt packages near the roots is justifiable 

 ji from this point of view, because a mixture of sodium and magnesium 

 * Eeport of the Station No. 1, 1903. 



