On the varietal difference of the mode of change of stem length due to the seeding periods in soy beans.

[摘要] 1) Soy bean varieties were grouped into the following three types according to the mode of change of stem length due to the seeding periods; Type I; the stem is the longest in April seeding, medium in May seeding and the shortest in June seeding. Type II; the stem is the longest in May seeding, medium in April seeding, and the shortest in June seeding. Type III; the stem is the longest in May seeding, but medium in June seeding, and the shortest in April seeding. 2) Type I and II contains respectively all types of summer-autumn growing habit, or early-late flowering habit. Summer types or early flowered varieties, however, mostly belong to Type II, and autumn types or late flowered varieties mostly belong to Type I. In type III, all varieties are summer types or early flowered varieties. 3) All varieties of "true twining type" and most varieties of "special non-twining type" belong to type III with few exception which belongs, to Type II. 4) Among those varieties used, some relationships were found between these types and geographical distributions. Moreover, summer types grown in northern regions (Manchuria, Hokkaido) are Type II and III, while those grown in southern region (Kyusyu) are Type I and II.

[学科分类] 农业科学（综合）