Green synthesis of copper nanoparticles using mosquito repellent plant leaves for the management of pulse beetles

The biogenic CuNPs from Ocimum tenuiflorum and Vitex negundo were subjected for antimicrobial activity against 3 human pathogens Escherichia coli, Bacillus subtilis and Staphylococcus aureus along suitable controls for comparison. Among CuNPs biosynthesized using V. negundo and O. tenuiflorum, V. negundo showed high inhibition zones than O. tenuiflorum. Nanoparticles treated seeds showed low incidence of seed mycoflora in which the incidence of Aspergillus niger and Curvularia lunata was reduced to 4%. Aspergillus flavus was depleted by 8% over control. Interestingly, the incidence of common field fungi in sorghum was reduced by 8% over control. In general the incidence of all the fungi remained low in CuNPs treated samples compared to control set. It indicated the antifungal effect of biogenic CuNps to some fungi which are commonly affecting the foliages in the sorghum fields during growth. Its occurrence was reduced in biosynthesized CuNPs through Ocimum tenuiflorum and Vitex negundo leaf extract. Insecticidal activity of the above biosynthesized CuNPs against Callosobrushus chinensis was assessed by treating the green gram seeds treated with 20mg/ml of CuNPs. The activity and mortality rate of C. chinensis was found decreased compared to control, thus, proving the insecticidal activity of the biosynthesized CuNPs from Vitex negundo and Ocimum tenuiflorum. Thus, it is proved the possibilities of biosynthesized nanoparticles as an ecofriendly approach to manage the field fungi and storage pests in pulses.