Effects of Irrigation Interval and Nitrogen Amount on Different Clary Sage (Salvia sclarea L.) Characters in Karaj

Salvia sclarea L, is an important medicinal plant that its oil has been evaluated for antioxidant, antibacterial, antifungal, anti-inflammatory, antimalarial, anticholinesterase and antiviral. Yield of plants are influenced by environmental and agricultural management factors such as drought stress and nutrition. Plant nutrition is one of the most important factors that positively influence plant production. Nitrogen, an essential plant nutrient is the most recognized in plants for its presence in the structure of the protein molecule. This experiment was conducted in 2011 in Alborz Research Station, Research Institute of Forests and Rangelands, Karaj, Iran. In order to evaluate the effect of drought stress and nitrogen on traits of Clary Sage, The experiment was conducted in split plot based on a randomized complete block design with three replications. The main factor was irrigation period (every 3, 6 and 9 days) and the sub factor was nitrogen application (0,100 and 200 and 400 kg/ha). Results indicated that irrigation interval significantly affected all the measured traits except for petiole yield, chlorophyll b and RWC. Nitrogen significantly affected all the measured traits except for leaf yield, chlorophyll b and RWC. The interaction of irrigation×nitrogen had also a significant effect on all the measured traits. Shoot yield was the highest in the interaction of 3 days×200 kg/ha (3680kg/ha). Oil percentage was the highest in the interaction of 9 days×0 kg/ha (0.05%). This experiment briefly indicated that clary sage can be cultivated in areas with low water supply, and it can produce the highest essential oil yield about 1400 kg/ ha when irrigated every 9 days without fertilizer.