effects of irrigation intervals and nitrogen fertilizer levels on vegetative and reproductive yields of basil (ocimum basilicum l.) under birjand conditions

in order to study the effect of irrigation and nitrogen fertilizer levels on yield of basil, an experiment was conducted as split plot based on randomized complete block design with three replications in birjand (moud region) in 2010. main plot factor was two irrigation levels (7 and 14 days interval) and nitrogen fertilizer (as urea) was considered as sub plot factor in four levels (0, 50, 100 and 150 kg.ha-1). results indicated that treatments affected on majority studied traits of basil. seed yield was increased in 7 days irrigation interval by 18.4% in compared to 14 days irrigation interval. the highest seed yield was achieved in 100 and 150 kg.ha-1 nitrogen fertilizers that were higher than control by 29.4 and 36.1%. total biomass was 153.3 g.m-2 in 7 days irrigation interval in compared to 133.8 g.m-2 in 14 days irrigation treatment. the greatest total biomass was show in 150 kg.ha-1 nitrogen fertilizer and the lowest was resulted from 0 and 50 kg ha-1 nitrogen fertilizer levels. ear number per plant was significantly affected by nitrogen fertilizer levels, but irrigation and fertilizer treatments had no significant effects on seed weight of basil. increasing of irrigation intervals decreased the leaf yield of basil by 21.3%. increasing of nitrogen application increased leaf and vegetative yields on basil.