Response of Satureja sahendica Bormn. to nitrogen and plant density

Satureja sahendica Bormn., which is native to Iran, is a medicinal species from Lamiaceae family and its habitat is west of Iran. In a split plot experiment, the effects of nitrogen fertilizer at levels of 0 (control), 40 and 80 kg/ ha (as main plots), and the sowing density of 8, 10 and 12 plants /m2 (as sub plots) were studied on height, number of branches per plant, yield and the essential oil yield of aerial parts of S. sahendica. The experiment was carried out in agricultural research farm of Takestan, Islamic Azad University of Iran, during 2009-2011.There was no significant difference in terms of height, number of branches per plant, the yield of flowering shoots and oil content between using 40 and 80 kg/ha nitrogen treatments. However, higher values were recorded for both treatments compared to control. The highest essential oil content and oil yield was obtained by application of 40 kg nitrogen per hectare and using more nitrogen reduced the oil yield. A sowing density of 10 plants per square meter increased aerial part yield and oil yield. The highest yield of flowering shoot, and essential oil yield were obtained by application of 40 kg nitrogen/ha and a sowing density of 12/m2 (2096 kg/ha, 2.1 percent and 44.1 kg /ha, respectively) that showed no significant differences by application of 40 kg nitrogen per hectare and the sowing density of 10 plants /m2.