I observed the habitude of plooming and maturing of red bean in the various sowing times and contemplated the relation between the yield of climatic elements and the above habitude. The results obtained are as follows. (1), The number of flower has the tendency to decrease as the sowing time delays. The flowering-date distribution in the case of early or proper sowing time shows the bi- or tri- modal curve, and in the delayed sowing shows mono-modal curve. The blooming period in the early or delayed sowing is shortet than the period in the proper sowing. (2), The blooming of every flower on a plant bigins from the middle node to the upper and lower nodes. On the branch, the flower of basal node blooms earlier than the top one. (3), The each period from 50 % blooming to maturing needs about 30 days. (4), The maturing-date distribution have the same tendency as the flowering one. (5), The seed number per pod seems to easily controlled by the environment, and have the tendency to decrease as the sowing time delays. When the sowing time delays and the maturing time prolongs, the seed becomes bigger. (6), The yield (seed weight) decreased as the sowing time delays in spite of the exaggerated vegetative growth. (7), It seems that the favourable air temperature on blooming are higher than 30°C maximum, 20°C minimum, 26°C average and the additional temperature from sowing to blooming needs more than about 1000°C.
