Response of Seed Yield and Essential oil of Black Cumin (Nigella sativa L.) Affected as Foliar Spraying of Nano-fertilizers

In order to investigate the effect of micronutrients foliar application on seed yield and essential oil of black cumin, a field experiment was conducted based on Randomized Complete Block Design (RCBD) with three replications at the farm located in Naqadeh city, West Azerbaijan province, Iran, during 2015-2016 growing season. Treatments were separate application of Nano-Iron, Nano-Zinc and Nano-Manganese and double and triple combined treatment of them (Fe+Mn, Fe+Zn, Zn+Mn, Fe+Zn+Mn) and control. Treatments were applied at 2 g/L twice at stem elongation and early flowering stages. Different traits such as plant height, number of follicle per plant, number seed per follicle, 1000- seed weight, biological yield, seed yield, essential oil percentage and yield were measured. The results showed that foliar application of micronutrients had a significant effect on all studied traits and improved yield components and essential oil yield as compared to control. Yield components, seed yield, essential oil percentage and essential oil yield were enhanced by foliar application compared with control. Therefore, combined usage of micronutrients (Nano-Fe+ Nano-Zn+ Nano-Mn) showed the greatest increase in studied traits than their individual usage. The highest seed yield (706.67 kg.ha^-1) and essential oil yield (8.66%) were obtained from Fe+Zn+Mn treatment. In general, the results of the present study revealed that the foliar spraying of Nanomicronutrients plays a remarkable role in improving the quantitative and qualitative yield of black cumin as a medicinal plant.