Impact of silver nanoparticles against stored product pest Sitophilus oryzae (L.) and effect on agromorphological characteristics of Zea mays (maize seeds)

Abstract

The present study, comparative entomotoxic efficacy of silver nanoparticles obtained through the chemical and biological route against Sitophilus oryzae L. Physicochemical characterization results revealed that silver nanoparticles (Ag NPs) were spherical morphology with an average size of 20–51 nm having excellent stability. XRD diffraction peaks showed major peaks at (2 theta) 38.19º, 44.37º, 64.56º, and 77.47º confirming their crystalline nature. UV–vis spectra inferred strong absorbance between 410 and 450 nm. Bioassay studies exhibited the LD50 values as 40.16 mg/100 g for c-Ag NPs and 24.69 mg/100 g for b-Ag NPs. The mortality brought by b-Ag NPs at the dose of 130 mg after 6 days of exposure was 100% whereas only 80% of mortality was observed for c-Ag NPs at the same dose. These c-Ag NPs also enhanced seedling characteristics i.e., germination (96%), seedling length (45.33 cm), vigor index (4351.68), and dry matter production (4.20 g). The experiment results shows that the b-Ag NPs are an alternative to insecticides against S. oryzae and improving agromorphological characteristics of maize.