Maize is considered one of the most imperative cereal crops worldwide. In this work, high throughput silica nanoparticles (SiO2-NPs) were prepared via the sol-gel technique. SiO2-NPs were attained in a powder form followed by full analysis using the advanced tools (UV-vis, HR-TEM, SEM, XRD and zeta potential). To this end, SiO2-NPs were applied as both nanofertilizer and pesticide against four common pests that infect the stored maize and cause severe damage to crops. As for nanofertilizers, the response of maize hybrid to mineral NPK, "Nitrogen (N), Phosphorus (P), and Potassium (K)" (0% = untreated, 50% of recommended dose and 100%), with different combinations of SiO2-NPs; (0, 2.5, 5, 10 g/kg soil) was evaluated. Afterward, post-harvest, grains were stored and fumigated with different concentrations of SiO2-NPs (0.0031, 0.0063. 0.25, 0.5, 1.0, 2.0, 2.5, 5, 10 g/kg) in order to identify LC50 and mortality % of four common insects, namely Sitophilus oryzae, Rhizopertha dominica, Tribolium castaneum, and Orizaephilus surinamenisis. The results revealed that, using the recommended dose of 100%, mineral NPK showed the greatest mean values of plant height, chlorophyll content, yield, its components, and protein (%). By feeding the soil with SiO2-NPs up to 10 g/kg, the best growth and yield enhancement of maize crop is noticed. Mineral NPK interacted with SiO2-NPs, whereas the application of mineral NPK at the rate of 50% with 10 g/kg SiO2-NPs, increased the highest mean values of agronomic characters. Therefore, SiO2-NPs can be applied as a growth promoter, and in the meantime, as strong unconventional pesticides for crops during storage, with a very small and safe dose.
Keywords: LC50; NPK; SiO2-NPs; fertilizer; maize; mineral; productivity; toxicity; weevils.