Green synthesis of ZnO nanoparticles using Lantana camara leaf extract for the enhancement of plant growth

Zinc is an important micronutrient for plants, involved in numerous physiological processes as well as numerous enzymatic and metabolic events. Zinc deficiency results in slowed plant development, higher chlorosis rates, smaller leaves, and fewer tillers, which lengthen the crop maturity period and lowers crop quality. In the present study, zinc oxide nanoparticles (ZnONPs) were synthesized through co-precipitation approach by using Lantana camara plant leaf extract. The synthesized ZnONPs were hexagonal in shape with mean size of around 60 nm. The bactericidal activity of ZnONPs was assessed against three phytopathogenic bacterial strains namely Ralstonia solanacearum, Xanthomonas campestris and Erwinia carotovora through broth dilution method. The MIC50 of ZnONPs was 248.33 μg ml⁻¹, 320 .27 μg ml⁻¹ and 320.95 μg ml⁻¹ against R. solanacearum, X. campestris and E. carotovora respectively. The fungiciadal activity of ZnONPs against three phytopathogenic fungal strains was studied by poison food technique. It was observed that 500 ppm ZnONPs could inhbit 86%, 85% and 55% growth of Alterneria solani, Fusarium oxysporum and Athelia rolfsii respectively. The efficacy of ZnONPs as nano fertilizer was evaluated in Solanum lycopersicum Linn. by foliar spray under laboratory condition and it was observed that in comparison with micron sized ZnO, ZnONP treatment could significantly boost up fresh and dry weight, root and shoot length, chlorophyll, lipid and carbohydrate content of the plants.