Effect of micronutrients foliar application and irrigation regimes on agronomic traits and yield of black cumin (Nigella sativa L.)

The application of micronutrients can improve the growth and yield of crops under stress conditions. In order to investigate the effect of micronutrient foliar application and irrigation regimes on black cumin, a field experiment carried out in Agricultural Research Center of Bojnord, Iran, in 2009. The experiment was conducted as split plots in a randomized complete block design with three replications. Irrigation intervals of7, 14 and 21 days were considered as main factors and five micronutrient foliar application steps including: control, B, Zn and Fe in 2, 3 and 4 PPT, respectively as well as a mixture of three above mentioned elements were considered as sub plots. Results showed that the irrigation regimes significantly affected plant height, subsidiary branches, capsule number per plant, number of seeds per plant and capsule, 1000 grain weight, grain and biological yield and harvest index, so that increasing the irrigation period decreased all of the above mentioned traits. The maximum grain yield obtained by seven-day irrigation regime. Moreover, foliar application of micronutrients significantly affected plant height, capsule number per plant, number of seeds per plant and capsule, grain and biological yield and harvest index. The differences amongst micronutrients spraying treatments and the control were significant for all above mentioned traits. Foliar application with the mixture of three micronutrients resulted in the greatest grain yield.