Abstract
Photosynthesis and dry-matter-production were investigated with the rice plants grown on the field under heavy manured and dense planted conditions, and the following results were obtained: 1) The experimental formulae which the authors postulated (1957) on the composition of the field photosynthetic ability of rice plants and on the light curves of their field photosynthesis, can also be applied to those plants grown under the above-mentioned conditions. 2) While the rates of dry-matter-production in dense planted, heavy manured plots are higher than the normal spaced, normal manured control plot, under abundant solar radiation, the relation is reversed when the solar radiation is scarce. This was explained from the balance between photosynthesis and respiration by introducing an idea of 'limiting intensity of solar radiation' for dry-matter-production. 3) The rate of dry-matter-accumulation in ears under scanty solar radiation is mainly deter-mined by the two factors ; the amount of total dry matter accumulated by the heading stage, and the rate of respiration, of the community.
