Characterization of Synthesized Zinc Oxide Nanoparticles and Their Effect on Growth, Productivity and Zinc Use Efficiency of Wheat And Field Pea in the Indian Himalayan Foothills

Nanofertilizers have emerged as an effective alternative to traditional fertilizers. They contribute to increased agricultural production by increasing input efficiency and reducing relevant losses. The present study was carried out at the G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India, during 2016–17 to study the effect of synthesized zinc oxide nanoparticles (ZnO NPs) on the growth and productivity of wheat and field pea crops. The results of the study revealed that significantly greater wheat and field pea plant height was recorded with 10, 20 and 50 ppm concentration of ZnO NPs, which decreased at 100 ppm concentration. A significantly higher yield of wheat was recorded at 50 ppm ZnO NPs concentration (3.28 ± 0.51 g plant^–1), followed by 20 ppm (3.05 ± 0.43 g plant^–1), which was at par with 100 ppm (3.02 ± 0.45 g plant^–1), and the minimum at 10 ppm concentration (2.70 ± 0.34 g plant^–1) over control. A similar trend in yield was observed for field pea. With respect to the mode of application, a higher yield of wheat was observed in the seed-soaking method (3.05 ± 0.43 g plant^–1); however, in the case of field pea, a higher yield was observed using foliar spray (6.21 ± 0.52 g plant^–1) method of ZnO application. Higher Zn content was observed in 50 ppm concentration for wheat (42.39 mg g^–1) and field pea (26.00 mg g^–1). The higher Zn use efficiency in terms of physiological efficiency was recorded at 20 ppm concentration (1.46) for wheat and 10 ppm (5.51) for field pea. Hence, it can be concluded that the applied ZnO NPs have stimulating effects on wheat and field pea crop growth and yield through increased zinc content in plants, zinc uptake and zinc use efficiency.