The present study aimed to use silica nanoparticles for bakanae disease management after appearance of symptoms. Preparation of silica nanoparticles from milled and/or acid leaching rice husk prior to calcination were estimated to determine optimal methods. Characterisation using XRD, TEM and DLS showed amorphous SiNPs with high purity, sphere particles with diameter of 15 nm and stability of SiNPs, respectivelly. At laboratory, SiNPs led to significant reductions in sporulation of Fusarium fujikuroi. In contrast, mycelial growth and colony-forming units (CFU) were increased. At greenhouse, Disease Severity Index (DSI) decreased with application of different SiNPs concentrations as seed treatment. SiNPs at 50 mg/L improved rice plants silica content, electrolyte leakage and peroxidase activity. At field, foliar application of SiNPs after disease symptoms appearance significantly reduced the disease incidence and increased grain yield. The current results suggested that controlling F. fujikuroi once appearing of bakanae disease symptoms considered a new effective management practices.