Abstract
Five varieties including three types of summer vers. autumn growing habit (summer, intermediate and autumn types) and two types of twining habit (true twining and special non-twining types) were used. The effects of pinching the terminal bud retaining four compound leaves were examined and the following facts were found. 1. In most varieties, the pinching operation inhibited the growth of plants, but in some varieties it slightly increased the seed yield. 2. The effect of pinching showed some varietal differences as follows; a. The degree of inhibition of growth by pinching were large in the summer type, small in the autumn type and medium in the intermediate type, while the degree of increase of yield by pinching was quite reversed to the degree of inhibition above mentioned. b. In the two twining types the pinching severely inhibited the growth and decreased the seed yield. With the autumn type the effect of pinching expressed in the growth of top and root of plants was observed at the several periods of growth, and were found the following facts: 1. The pinching inhibited the growth of top and root expressed in both fresh and dry weight. 2. The above effect of pinching appeared in the growth were gradually recovered with the advance of growth.
