Rice is considered as one of the most important food crops in the world. Rice plants infected by several plant pathogens. In Egypt, however important diseases of rice namely blast and brown spot are major limitation on rice production and becoming more sever on rice grown in silicon depleted soil. Disease that occurs to plant may reduce the ability of the plant to survive and in more severe cases could eventually lead to plant death.  Two field experiments were carried out to study the effect of different sources of biogenic silica nanoparticles on blast, brown spot diseases and yield component in rice at Rice Research and Training Center Experimental Farm, Sakha, Kafr El-Sheikh, Egypt. Theeffect of different sources of silica on the behavior and infection by rice blast on Sakha 101 rice variety had been studied in thefirst experiment. While the second experiment included the behaviorand infection bybrown spot of Egyptian Hybrid Rice One under silica nanoparticles biogenic treatments. The silica treatments were white rice husk, rice husk nanoparticles, white rice straw, rice straw nanoparticles, Mg₂O₈ Si_3, and K₂ SiO_2. Chemicalfungicides (Beam and Del-Cup) and tap water were used as control. Different biogenic and chemical silica led to decreasing blast disease infection in Sakha 101 compared with control (tap water). Most of the agronomic characters of Sakha 101 were affected significantly by different treatments. All treatment of different biogenic and chemical silica sources decreased the leaf infection percent and severity for brown spot disease on Egyptian Hybrid Rice One. Different treatments significantly affected panicle length, number of filled grains per panicle, number of unfilled spikelets per panicle, 1000-grain weight, and grain yield and harvest index of Egyptian Hybrid Rice One. The result of this study suggests that silica caused decrease the intensity of blast and brown spot diseases.