Abstract
The present paper deals with the results of experiments on the silicate absorption and a change in resistance to Helminthosporium blight in rice plants. Sodium silicate was used as a silicate source. The susceptible variety, Magatama, showed the increase in resistance with the amount of silicate given. The resistant variety, Kameji, however, did not show a definite inclination to the disease occurrence with the supply of silicate.
The toughness, silicification of leaves and total amount of silicic acid deposited in the plant body increased in Magatama, when the increased amount of silicate was given. On the contrary, Kameji showed no correlation between the silicate deposition and the application of silica. Therefore, it seems that they do not absorb silicate more than the control, though the increased amount of silicate was given. Expressed juice of plants which were supplied with silicate did not give a change on the germination of conidia compairing with that of the control. Osmotic pressure of cell may have no correlation to the disease occurrence.
Catalase activity in leaves becomes increased in both varieties with the grading supply of sodium silicate. In Kameji it is more active than in Magatama. However, it may have no correlation with the disease susceptibility.
