Title : Sowing dates, phosphorus resources and plant density effects on black cumin (Nigella sativa L.) characteristics
To investigate the sowing dates, phosphorus resources and plant density in Black cumin (Nigella sativa L.) during 2015 and 2016 at Qazvin, Iran this experiment was laid out in completely randomized complete block design with split-split arrangement at three replications. Sowing dates were in 28 October, 11 November and 25 November. Phosphorus resource was control, 50% recommended chemical Phosphorus + biological Phosphorus and biological Phosphorus alone) and Plant density also were 20, 30 and 40 plants/m2. The results demonstrated that maximum number of carpels per capsule, number of grain per plant, grain weight per plant, grain yield were obtained at November 11 sowing date. The highest number of grain per capsule and number of grain per carpels were obtained in biological phosphorus application. Also, the maximum number of grain per plant (2952) and grain weight per plant (6.6g) were obtained in 20 plants/m2 plant density while minimum number of grain per plant (1522) and grain weight per plant (3.4g) were obtained in 40 plant/m2 densities. Results indicated that 1000 grain weight and harvest index had no significant effect, in the black cumin treatments.