Effect of Plant Spacing and Nitrogen Levels on Growth, Yield and Essential Oil Content of Rosemary (Salvia rosmarinus Spenn) under Marginal Land Conditions

Salvia rosmarinus has the ability of environmental restoration as it prevents desertification and rapid soil erosion, this species has been assessed on marginal lands of Kashmir valley which was devoid of vegetation and in order to achieve maximum herbage and oil yield of rosemary, the optimization of plant spacing and nitrogen levels were very important factors that determine the physiology of the plants in the field. Four levels of spacing viz. 30x20 cm, 30x30 cm, 45x40 cm and 60x50 cm along with nitrogen viz. control, 175 kg N/ha, 225 kg N/ha and 275 kg N/ha were used to assess their effect on growth, yield and essential oil content of rosemary. The experiment consists of 16 treatment combinations which were replicated three times in a factorial randomized block design. Considering the results, rosemary plants transplanted at the widest spacing of 60x50 cm exhibited maximum growth, yield and quality attributes per plant except plant height. On a hectare basis, the growth, yield and quality attributes were found maximum at the closer spacing of 30x20 cm. Among nitrogen levels, rosemary plants nourished with a moderate amount of nitrogen (225 kg N/ha) attained maximum growth, yield and quality attributes. However dry leaf to stem ratio and essential oil content was not significantly influenced by plant spacing and nitrogen levels.