Abstract
We examined a method of suppressing seedling blast in rice (Oryza sativa L.) by pouring potassium silicate solution into the ridging in a nursery box. The results were as follows: 1. Pouring 10 g (SiO_2 ingredient) of potassium silicate solution reagent per nursery box was effective for suppressing the symptoms of damping-off, and lesions on leaf blades caused by blast fungus. Though lesion suppression was high, when 250 g of silica gel fertilizer per nursing box was mixed in the bed soil, the suppression of damping-off was low. 2. For suppressing damping-off, 3 kinds of 5 g (SiO_2 ingredient) potassium silicate liquid fertilizer were almost as effective as the reagent. For suppressing lesions on leaf blades, the liquid fertilizer which showed the greatest effect over the reagent was selected, and the silicic acid content rate of this rice plant increased the most. 3. In a nursery box in which 5.0 g (SiO_2 ingredient) of selected liquid fertilizer (A) was poured, the damping-off seedling rate was suppressed to 7% to that of the untreated nursery box. 4. Right after sowing proved to be an appropriate time for pouring the potassium silicate solution, and 5 g (SiO_2 ingredient) per nursery box was an adequate rate of application. 5. From the above results, we concluded that the pouring of a potassium silicate solution reagent and fertilizer into the ridging in a nursery box are effective ways to suppress seedling blast, and are acceptable substitutes for fungicides like tricyclazole.
