초록
춘기발아전에 지조를 각각 선단벌채, 조장의 1/3, $\frac{1}{2}$, 2/3 벌채하여 발아 생장하는 신아의 발육상황을 조사하였다. (1) 지조를 벌채하면 불발아비율이 대체적으로 감소하여 무처리구의 반이하로 되는 것인데 1/3 벌채구가 가장 그 비율이 적어진다. 그리고 또 지조를 벌채하면 불발아는 지조의 하반부에 집중한다. (2) 지조를 벌채하여도 발아를 촉진시키는 일은 없고 도리어 약간 늦어지는 경향이 있는 것 같지마는 발아후의 개엽속도는 매우 빨라져서 탈순에서부터 제 5개엽기까지의 소요일수는 무처리구의 16일에 비하여 벌채 각구는 7~9일이며 그 중 가장 빠른 것은 2/3벌채구의 7일이다. (3) 지조를 벌채하면 신아의 발육을 촉진시켜서 5월 5일부터 6월 10일까지 45일간의 생장량이 무처리구의 34cm에 비하여 벌채각구는 그 1.6~2.5배나 생장하여 가장 생장량이 큰 것이 2/3벌채구의 83cm이다. 그리고 벌채각구는 생장속도도 무처리구에 비하여 빠르다. (4) 엽수의 증가비율은 무처리구에 비하여 벌채각구가 약간 많기는 하지만 그 차는 그리 크지 않다. (5) 신아의 총생장량은 무처리구에 비하여 벌채각구가 현저하게 많으며 2/3벌채구는 생장계적아수가 벌채각구중에서 가장 적지만은 1아의 평균아장이 가장 길다. (6) 신소삽목의 삽수를 되도록 빨리 채취하기 위해서는 조장의 2/3정도를 벌채하는 것이 적당할 것 같다.
The aim of this work was to investigate how the mulberry shoots grew well when the mulberry branches were cut down, in hight, 1/3, $\frac{1}{2}$ and 2/3 of them, respectively, just before the Spring budding. The results obtained are as follows: 1. The rate of un-sprouted buds decreased sharply down as much as half of the control if the mulberry branches were cut off. The treatment, 1/3, was best one of various cut down sizes and the un-sprouted buds concentrated on the lower parts of the branches. 2. Even though the branches were cut down, at first it seemed flat to accelerate the sprouting of buds, but rather to have a tendency to become late. The speed of leaf growth, however, became faster after the sprouting. It took 7~9 days from the beginning of buddings to the 5th full grown leaf, and.7 days for the shortest one in the treatment, 2/3, when compared with 16 days of the control. 3. If the branches were cut down, the growth of the new sprouts was accelerated. For 45 days (on 5th of May to on 10th of June), therefore. the shoots had grown up to 1.6～2.5 times of the control, 34cm long. The shoots of which the branches were cut down at 2/3 of them were longest (83cm). Furthermore. the speed of shoot growth of cut-down branches was faster than that of the control. 4. In the increased rate of the number of the mulberry leaves, there was not significant difference between the control and the treatments. 5. The total amount of shoot growth showed considerably much more in the treatments than in the control. The successing growing shoots of treatment, 2/3 were little in a number but longest per one shoot in mean shoot length. 6. It seems to be much available that we may cut down branches at 2/3 of them in order to get the scions for the cutting as soon as possible.