Comparison of essential oil content of sahendi savory (Satureja sahendica Bornm.) and its compounds under cultural conditions and natural habitats in Qazvin province

The Sahandi savory (Satureja sahendica Bornm.) is a native medicinal species of Iran, which is exposed to extinction. Organic farming of this species in low input systems has an important role to protect this valuable genetic reserve. To evaluate the essential oil content and components of the savory in natural habitat and field conditions, an experiment was conducted to investigate the plant growth responses to different fertilizer and redroot pigweed (Amaranthus retroflexus L.) density (0, 6, 12 and 18 plants/m2) in two planting patterns (rectangles, zigzag). The experiment was carried out in factorial based on RCBD with three replications at the Qazvin Agriculture and Natural Resources Research Center during 2010 to 2012. The nutrient treatments included NPK plus foliar application of micronutrients, four tons/ha vermicompost, two tons/ha vermicompost plus 40 liters/ha vermi-tea (liquid formulation of vermicompost). At the flowering stage, the essential oil content and compounds were measured in both samples of field and natural habitats. The effect of planting pattern was not significant. The highest content of essential oils in first harvest (28.38%) and in second harvest (46.04%) were obtained from organic fertilizer treatments, two tons vermicompost 40 liters vermin-tea and four tons vermicompost, respectively. These treatments were superior to the savory harvested from natural habitats. The essential oil content of savory under competition of redroot pigweed at all densities were higher than the natural habitats and the highest content in first and second harvest (30.41% and 51.80%) was obtained at 18 plants/m2 pigweed density. In all fertilizer treatments, the content of thymol in comparison to natural habitats (38.49%) was superior and the highest content (42.95%) was obtained with application of four tons vermicompost. In the absence of weed, the Sahandi savory produced the greatest content of thymol (45.18%) compared to the savory grown in natural habitats.