1) The toughness and the percentage of silica of the leaf blades of rice wich had been cultured under, various combinations of silicic acid and. nitrogeous manure, were measured to find their relation to rice blast. And the result is as follows: 2) The application of silicic acid to the soil increases the resistance of rice to the blast disease. 3) The toughness of leaves measured by needle puncture method or by tearing method varies in inverse proportion to the quantity of nitrogenous manure. 4) In case the quantity of nitrogenous manure is equal, the percentage of silica of the rice leaves grown under the application of silicic acid is higher than that of those grown without it. 5) In case the qantity of nitrogenous manure is equal, the toughness of the rice leaf grown under the application of silicic acid is weaker than that of the rice leaf grown without it. 6) Measuring toughness of the leaf blade is a good method to see the grade of their resistance to rice blast, however, it is valuable only in the case of searching the mechanical weakness of the rice leaf grown under unfavorable condition such as surplus nitrogenous manure.
Mendeley出力
