Agricultural Use of Porous Hydrated Calcium Silicate : Effect of porous hydrated calcium silicate on resistance of rice plant (Oryza sativa L.) to rice blast (Pyricularia olyzae)

摘要

The effect of porous hydrated calcium silicate (PS) application on the resistance of rice plants (Oryza sativa L.) to rice blast (Pyricularia olyzae) was evaluated. Experiments were conducted in Andisol at the experimental farm of Tohoku University from 1993 to 1995. The blast infection in the PS plot was much less than that in the control plot. On the other hand, slag (commercial slag silicate fertilizer) used in our experiment had no effect on blast infectioln. The number of silicified bulliform cells, the main invasion site for rice blast, was increased 320-980% by PS application, but only 80% by commercial slag. These results imply that PS application is effective in preventing fungal infection through silicification of bulliform cells. The number of silicified bulliform and trichome cells increased exponentially with increasing content of the silicon in the leaf blade, whereas the number of silicified short cells, which are smaller than bulliform cells and tichomes, had no relation to the silicon content in the rice leaf blade. We may conclude that the application of porous hydrated calcium silicate for rice plants is effective in incrasing rice blast resistance because PS incrase the number of silicified bulliform cells.