Abstract
This paper reports the varietal differences of common buckwheat in shoot growth and flower development during two cropping seasons. The stem elongated vigorously at about the start of anthesis in all cultivars. The start of anthesis was earlier in summer-type cultivars (ST) than in autumn-type cultivars (AT), and during autunm cropping (AC) as compared to summer cropping (SC). But their differences were small. Anthesis started at the same node on the main stem for all cultivars and croppings, except for Miyazakizairai during SC (two nodes higher than the others). On the other hand, the differences in shoot growth and flower development after the start of anthesis were very large between ST and AT. The ST finished shoot growth and flower development about two weeks after the start of anthesis during both cropping seasons. The AT during AC also showed the same process as the ST. But the AT during SC continued stem elongation and new leaf emergence for a longer period. As a result, the AT during SC had a very long stem and many leaves. Additionally, the AT during SC showed a syncronous rate of new leaf energence and flower cluster anthesis at the rate of one leaf and one flower cluster per two days. In the others, however, the rate of new leaf emergence was the same, but the rate of new flower cluster anthesis was faster (one per one day).
