effect of plant density and time of nitrogen application on morphological, phenological characteristics, yield and yield components of black cumin (nigella sativa l.)

abstract in order to study the effect of density and time of nitrogen application on morphological, phenological characteristics, yield and yield components of black cumin (nigella sativa l) a field experiment was conducted at chenaran in khorasan razavi province in 2005 growing season. three nitrogen fertilizer (urea) application times (1- control 2- at 4-6 leaves stage 3-preblooming 4-complete flowering) and three plant densities (150, 250, 350 plant m-²) were compared in a split plot based on complete randomized block design with three replications. studied components were stem branch, capsule weight, seed weight/capsule weight, ratio number of capsules per plant, number of seeds in each part of capsule and phenological characteristics. results showed that nitrogen fertilizer application times had significant effects on number of capsules per plant, capsule weight, stem branch, number of seeds in each part of capsule. densities had significant effects on capsule weight, seed yield and distance of the first branch from soil surface. results showed that 250 plant m-² and nitrogen application at 4-6 leaves stage had the highest seed yield (588 kg/ha) in this region.