Morphological Characteristics and Essential Oil Production of Sweet Basil (Ocimum basilicum L.) under Application of Nitrogen and Iron

Sweet basil (Ocimum basilicum L.) is one of the most important medicinal plants that its essential oil utilized in different medicinal industries. In order to investigate the effect of nitrogen and iron nutrients on morphological characteristics and essential oil content and yield of Sweet Basil, this research was performed in agricultural research farm of the University of Zanjan. The experiment conducted based on randomized complete block design in factorial arrangements with three replications. Factors include four levels of nitrogen (0, 60, 120 and 180 kg.ha-1) as urea and iron in three levels (0, 2 and 4 g.L-1) as nano iron chelate. Results showed that nitrogen and iron applications significantly influenced on number of lateral branches, number of nodes, plant height, fresh and dry weight, essential oil content and total essential oil production. The highest content of essential oil (i.e. 0.84%) was recorded in 2 g.L-1 iron followed by the combination of 2 g.L-1 iron plus 180 kg.ha-1 nitrogen (i.e. 0.79%) compared to 0.51% essential oil in control treatment. The highest fresh and dry weight, and total essential oil production was recorded in 2 g.L-1 iron in combination with 180 kg.ha-1 nitrogen. In this treatment the total essential oil production (13.6 kg.ha-1) was reached to almost twice of the control (7.1 kg.ha-1). Collectively the results showed that the best treatment for highest vegetative growth leading to high fresh and dry weight and essential oil production achieved in 2 g.L-1 iron in combination with 180 kg.ha-1 nitrogen.