Abstract
The growth of water cultured rice plants supplied vs. not supplied with silica, both plots being grown under limited vs. natural sun light respectively, were compared. Materials and methods were similar as those in the previous experiments by the same author2). The results obtained were as follows: The plant height was heigher both in the Si and Non-Si plots with limited sun light than those with natural light respectively, and the difference between the two formers was larger than that of the two letters. Dry matter weights of leaf blade, leaf sheath, culm, panicle and root, and of the whole plant in the Non-Si plots were smaller under the shaded condition than under natural sun light through the whole growth stage. And the almost same tendency was observed too in the SiO2 contents. The translocation of N, P, K in the plants of the Non-Si plot under shading was not better than that in the plant of Non-Si plot under natural light. It was the most remarkable difference that the plants of the Si plots ripened normally, but in the Non-Si plots, number of ripened grains per ear was 5 in the natural light condition, and was 0 in the Shaded one. From the results obtained, it was recognized that in the plant of the Non-Si plot, the amounts of absorped or translocated SiO2, N, P2O5 and K2O and the weight of dry matter decreased respectively, and ripening was retarded. And such a tendency was found stronger in the shaded plot than in the control. And silica application would remove the injury.
