Some experiments were carried out in 1949 and 1951 to study the effects of light intensity on the reproduction of the bean, using the dwarf variety “Masterpiece” The results obtained are summarized as follows.
(1) The reduction of light intensity lowered the assimilation ability of bean plants. Severe restriction of light (less than 30% of natural light intensity in the field) checked remarkably the plant growth.
(2) As the light intensity was reduced, the latent flower buds increased and the number of
flowers decreased. Furthermore, the shading brought the increase of flower-dropping and the decrease of pod-setting.
(3) Severe restriction of light resulted in the increase of flower bud dropping and the reduction of flower number as well as of pod number by half compared with the control plot.
(4) The reduction of light intensity had almost no effects on the functions of pollen, i.e. germination of pollen grains, elongation of pollen-tube, amount of starch, etc.