Empirical Study on Effect of Silicon Application on Rice Blast Disease and Plant Morphology in Indonesia

Si fertilizer was never used in rice cultivation by farmers in Indonesia. To evaluate the effect of Si application on blast disease, plant morphologies, and stomata formation on rice plant, a field experiment was conducted in West Java, Indonesia. Two treatments, Si+ (with 1000 kg ha-1 of silica gel) and Si- (without Si application) were set in a randomized complete block design. The results showed that Si application in soil with high available Si 426 mg SiO2 kg-1 significantly reduce leaf (p < 0.01) and neck (p < 0.05) blast disease infection and increased stomata density (p < 0.01). Si- had severer leaf blast infection than Si+ which could reach up to score 4 and 5. Si deposited on the tissue surface acts as a physical barrier by thickening the Si layer in cuticle which could decrease the number of blast lessions on leaf blades by limiting hypa penetration and invasion. Recently there was no report to prove whether Si deposition improves or changes the stomata density. The results confirmed that Si application have the potential of improving rice growth and yield through the increase of resistance to blast infection and increment in stomata density although they did not result in the yield increment in the present study.