Comparative analysis of the insecticidal activity against Sitophilus oryzae (L.) and agro-morphological characteristics of maize using non-biogenic and biogenic ZnO nanoparticles

Abstract

Utilizing environmentally friendly nanomaterials to address insect pests and promote plant growth is imperative. The present study was conducted to find an alternative to chemical insecticides by comparing the entomotoxic efficacy of non-biogenic and biogenic zinc oxide nanoparticles against Sitophilus oryzae L. (Curculionidae; Coleoptera) in maize (Zea mays L.). Entomotoxic studies against S. oryzae exhibited LD₅₀ values of 22.33, 46.01, and 4.73 mg/100 g of maize seeds for non-biogenic ZnO NPs, biogenic ZnO NPs, and malathion 5D, respectively. SEM studies of non-biogenic and biogenic zinc oxide nanoparticles attached on the surface of the maize seeds, act as physical poison, adhering to the surface of the insect and causing desiccation, dehydration and ultimately death to S. oryzae. A higher seed germination percentage (99%) and dry matter production (4.8 g) were seen in non-biogenic zinc oxide nanoparticle treated seeds. In conclusion, zinc oxide nanoparticles prepared through a non-biogenic (sol–gel) approach exhibited a dual role by acting as an insecticide against S. oryzae and a growth promoter in maize seeds.