Effect of planting dates and nitrogen rates on yield and yield components of black cumin (Nigella Sativa L.)

In order to study the effect of planting dates and nitrogen rates on yield and yield components of black cumin (Nigella sativa L.) a field experiment was conducted in spring 2006 in the Azad University of Birjand. The experiment was done as split plot based on compeletely randomized block design with 3 replications. Four planting dates (21 March, 4, 21 April, 5 May) were used as main plot and 3 levels of nitrogen (40, 80 and 120 kg/ha) were as sub plot. The results showed that the planting dates effect was significant on traits such as plant height, number of main branches, number of follicles per plant, biological yield and grain yield. As, maximum plant height, number of follicles per plant and biological yield were observed in first planting date and maximum number of main branches and grain yield were observed in first and second planting dates. Planting dates had no significant effects on number of follicles in main branches, number of seed per follicles, weight of 1000 seeds and harvest index. Nitrogen rates and interaction between planting dates and nitrogen rates had no significant effect on the traits. According to the results of this experiment 40 kg/ha nitrogen is enough for black cumin. Also, planting dates in 21 March and 4 April were recognised better because of high yield production.