抄録
In this paper the writer has compared the ash figures of leaves of the rice plant grown under a combination-practice of several effective measures for the control of blast disease with those of the same plant cultivated under conventional methods. Regardless of the method of cultivation, the upper portion of leaves surpasses their lower portion in the number of the silicated epidermal cells, and the degree of silicification of the bulliform cells is higher than that of the long and short cells. The number of the silicated epidermal cells per unit area of the leaf, especially of the bulliform cells, is larger in plants grown under such combination-practice than in those cultivated under conventional methods.
Several workers have already pointed out that the blast fungus (Piricularia Oryzae BR. et CAV.) is capable of penetrating the bulliform cells more easily than the long and short cells. There fore, it seems to be very interesting that the number of the silicated bulliform cells varies in accordance with such different practices of cultivation.
The size of the silicated epidermal cells shows no recognizable difference in the plants cultivated under such different practices. However, it is generally recognized that the cells of the upper portion of leaves are wider transversely than those of their lower portion and the cells of the latter elongate longitudinally.
