Abstract
Attention to phytotherapy has caused cultural extension, managements and programming of drug plants. Black cumin is one of the most important pharmaceutical plants that have characteristics like increasing mother's milk, antibacterial and antivirus and ant epilepsy. In order to effects of plant density and nitrogen on yield and yield components of Black cumin (Nigella sativa L.), an experiment in the form of factorial RCB design with 4 replications has been conducted at Ferdowsi University of Mashhad, Iran. Studied factors were plant density with 4 levels (60, 120, 180 and 240 plants per m(2)) and nitrogen with for levels (0, 50, 100 and 150 kg/ha). Studying traits were plant height, LAI (leaf area index), TDM (total dried matter), CGR (crop growth rate), biomass, seed weight, seed No. in follicle, yield and harvest index. Results showed that LAI, TDM and CGR increased by increasing plant density and nitrogen levels. LAI and CGR were highest in reproduction stage. Relative growth rate (RGR) was not affected by plant density and nitrogen and had a diminishing procedure during growing season. Number of flowering branches and follicles per plant were decreased by increasing plant density. However, plant density had no significant effect on plant height, 1000 seeds weight, number of seed per follicle, seed yield, biological yield and harvest index. Seed yields were 779, 804, 809 and 502 kg/ha in plant density treatments, respectively. There were significant differences between nitrogen application treatments and without nitrogen application. Nitrogen increased plant height, no. of flowering branches, no. of follicle per plant, biological yield and seed yield. Seed yield was 590 kg/ha in no. nitrogen treatment. Application of 50, 100 and 150 kg/ha of nitrogen resulted in 815, 895 and 896 kg/ha seed yield, respectively. But, there were no significant differences among 50, 100 and 150 kg/ha nitrogen levels for above parameters. Number of seed per follicle was minimum at 0 and 150 kg/ha nitrogen levels and was maximum at 50 kg/ha nitrogen. Nitrogen had no significant effect on 1000 seeds weight. There was negative correlation between nitrogen level and harvest index.