Preparation and characterization of silica nanoparticles (sol–gel & river sand): A comparative toxicity studies against seed weevil (Sitophilus oryzae L). and effect on agro-morphological characteristics of maize seeds

Abstract

The present study aimed to compare the entomotoxic efficacy of silica nanoparticles obtained through sol–gel and river sand against Sitophilus oryzae L. by keeping insecticidal dust (malathion 5D) as a control. Physicochemical characterization results revealed that silica nanoparticles (SiO2 NPs) were spherical in shape. Bioassay studies exhibited the LD50 values as 0.44 mg/100 g for sol–gel synthesized SiO2 NPs and 0.92 mg/100 g for river sand based SiO2 NPs. Cent percent mortality was brought about by sol–gel synthesized SiO2 NPs at the dose of 3 mg after 4 days of exposure whereas only 73.33 ± 1.57 per cent mortality was observed for river sand based SiO2 NPs at the dose of 9 mg after 4 days. Further, sol–gel synthesized SiO2 NPs [LD90 (6.64 mg/100 g maize seed)] enhanced the seedling characteristics i.e., (%) germination (98 ± 1.72), seedling length (49.71 ± 0.13 cm), vigour index (4871.58) and dry matter production (4.00 ± 0.01 g) compared to river sand based SiO2 NPs.