Abstract
Many varieties, 136 in total, conected from Japan, Korea. China and U. S. A . were used. Seeds were sown at 6 suceeeding periods from April to September. Dates of germiuation, beginning and end of flowering, and maturity were recorded. With these data, the fouowing 3 duration were calculated ; A. Flowering days from germination to beginning of flowering, B. Flowering duration-from beginning to end of flowering, C. Growing duration-from germination to maturity By using the above 3 items (A, B, C), the classification of summer vers. autumn types of varieties were tried in respect to the following 3 ecological characteristics ; (I) The rate of shortening of the flowering days due to the delay of seeding periods calculated by assuming the mode of change of the flowering days according to the seeding periods to be 1 linear. (II) Relative length of flowering duration to flowering days, B/A. (III) Relative length of growing days to flowering days, C/A. As shown by the following table we can distinguish firstly 3 types of Summer, Intermediate and Autumn, secondarily 3 classes in Summer type (SI, SIp, SII), 2 classes in Intermediate type (MIII, MIV), and 3 classes in Autumn type (AV, AVI, AVII). [Table]
