Influence of nano zinc on growth, yield and economics of Rabi sorghum (Sorghum bicolor L.)

A field experiment was conducted during rabi2019–20 to study the effect of various sources of zinc nano particles in sorghum under rainfed condition. The results revealed that foliar spray of both green and chemical zinc oxide nanoparticles (ZnO NPs) was superior to conventional zinc sulphate heptahydrate (ZnSO₄.7H₂O) sources. Foliar spray of green ZnO NPs @ 1000 ppm recorded significantly higher grain yield (2664.26 kg ha⁻¹), stover yield (12102.93 kg ha⁻¹) and the results were on par with the treatment receiving foliar spray of chemical ZnO NPs @ 1000 ppm (2567.89 kg ha⁻¹) and (11817.80 kg ha⁻¹). The higher net returns and B:C was obtained with treatment receiving foliar spray of green ZnO NPs at 1000 ppm (? 56,876.64) and (3.26) and also inhibitory effect was observed in nano ZnO concentration >1000 ppm reveals the toxicity and hence need for judicious usage of nano particles in foliar applications.