@article{oai:soar-ir.repo.nii.ac.jp:00011112, author = {高馬, 進}, issue = {5}, journal = {信州大學農學部紀要}, month = {Mar}, note = {1.) In Japan, for the past twenty years or more, many a person has studied the grafting propagation of walnuts, trying to get a reliable grafting method as had been already successful in the foreign countries. But the attempt has been a failure, probably owing to the difference of the climatic condition. For instance, according to the Agricultural Experiment Station Report (1932) at Ohio in America, the union rate of the grafting of April, May and June is 92~100 %, and that of even February and March is 36~74 %, while in our country as the author's experiments show the grafting rate by the usual cut-grafting method were as follows; on the 11th of April, 1949 was only 41.9 %, on the 18th of April, 1950 was only 3.1 %, and on other days of March to June during 1949 to 1951 were all 0%, especially though in the same month, April, on the 5th and the 15th of April, 1950 and on the 15th of April, 1951 were all 0 %. 2.) Up to this time, so far as the grafting technics are perfect, the sprouting condition of the scion and the stock at the grafting time is regarded to be as one of the most important factors which influence the union rate of grafting of the various fruit trees. The fact will be this. When the scion buds of which have grown too large are grafted on the stocks, they will rapidly sprout and elongate before the junction tissue can fully develop 126 , No. 5 11% iffi between the scion and the stock after grafting, and the scion shoots are not sufficiently supplied with nutrition and water from the stock, so many of them die in the course of grafting, and their union rates are extremely low. Accordingly, the author used a simple electrical hot bed-soil temperature being about 25℃, soil moisture content, about 30%-for the performance of the grafting experiment of walnuts from January to April, promoting the root activity of the stock before the development of the buds of the scion, and found the union rates of all cases to be as good as 80~100 %. 3.) Even when the hot bed is used, the difference of growing degree of the scion buds at the grafting period caused by the difference of the cutting period and also of the storage method of scion shoots after cutting off from the mother tree, seems to affect the union percentage to a considerably high degree. Therefore far more detailed investigations were again made morphologically, nourishmentally, and physiologically in connection with these matters. As the resultes, the most convenient and ideal way of grafting, in practice, is to use the scion shoots gathered from December to January and stored in the cold place, grafting them in March or April in the simple electrical hot bed, and to transplant the grafted plants to the cold bed in the open air at a proper time of frost free to prevent their weak elongation. 4.) If the grafting period is deferred to May or June and the scion shoots till then stored in the cold place are used, their union rate will be 90~100 % in the electrical hot bed, and even if the electrical hot bed is not used, their rooting is easy and their union rate is also fairly good because the natural soil temperature is fairly high (22~23℃), but from the view of cultivation of grafted plants, this way of doing is not always appropriate because in this case the growth period of the grafted plants after junction becomes short. 5.) The tannin content in the shoots, the difficulty in the callus formation, the size of the vessels and the density of their distribution, which are said to have a close connection with the union rate of the graft-age, have been observed by the author to investigate the reason why the walnut grafting is very difficult in comparison with other fruit trees. It is true that the walnut shoots are sure to have comparatively much tannin like those of the persimmon and the chestnut, and this vessels are comparatively large too and the density of their distribution is rough, also that the formation of the callus at the wounded parts is difficult in comparison with other fruit trees. But there are too many contradictions and doubtful points to regard them as the principal factors of the difficulty in the walnut grafting. 6.) Since the seedlings of the Kashikurumi and the Onikurumi are easily got as the walnut stocks in our country, the Kashikurumi and the Karasu-kurumi (a variety of the Onikurumi) are grafted upon the two stocks above mentioned and their advantages and disadvantages are compared, Consequently, in spite of any variety of the scions, these grafted upon the stocks of the Onikurumi grow very vigorously at the undrained low moist region, while these grafted upon the stocks of the Kashikurumi grow surpassingly at the drained dry region. To know the relation between the growth and the nutrition of the tree, the leaf analysis of the three elements of the manure and the inquiry into the bearing of the carbohydrate to nitrogen ratio (C/N) in the new shoots, have been made with the grafted plants upon the two kinds of the stocks, but no constant tendency has been recognized in either case within the limits of the experimental results., Article, 信州大學農學部紀要 (5): 51-127(1956)}, pages = {51--127}, title = {胡桃の接木に関する研究}, year = {1956} }