Studies on the growth habit of so-called summer vers, autumn soy beans. : (2) On the relationships between the said habit and other cyaracteristics

The relationships between the growth habit of so-called summer vers. autumn soy beans (reported by T.Nagata in 1948) and other characteristics, which were investigated parallel, found as follows ; (1) The interrelation between the growth habit of summer vers. autumn soybeans and the earliness of flowering of the tested varieties was so closer that correlation coefficient showed as in r=0.85. Therefore, the summer type found as the earier, the autumn types the later, the intermediate types the medium late varieties. (2) 4 types were observed in the changes of flowering days (from germination to flowering) according to the differrent periods of seeding. These types were called as "the Ecological types of flowering". (fig 1) The autumn types belonged to the type I and type III, namely their flowering days were remarkably shortened when they were sown in both July and August. The type II and type IV, namely those not remarkably shortened even when they were sown in July and thereafter, were recognized mostly in the summer types. In the intermediate types, there were found all these 4 types existed. (3) It was found that the first flower was born at the heigher nodes in the autumn types and at the lower in summer typer. And the correlation coefficient calculated between these characteristics was r=+0.86. The changes in order according to the different seeding times was found as same as in that of flowering days. (4) The closer relationships between the growth habit of summer vers. autumn types and the stem length, number of blanches, grain weight per plant, and the weight of a plant were observed. Therefore, the autumn types produced comparatively more yields than the summer types. The pseudo summer types (SIp) was long as in stem length, but it had a small number of branches. (5) There was found no closer relationships between the growth habit of summer vers. autumn soy beans and the morphological characteristics, namely the forms and colour in various parts of the plant. Therefore, differences. in summer vers. autumn types were defined purely as physiological and ecological.