N and K nutrition levels affect growth and essential oil content of costmary (Tanacetum balsamita L.).

摘要

Vegetative growth and essential oil content of costmary (Tanacetum balsamita L.) were evaluated in response to N and K. Experimental treatments included different concentrations of N (100, 200, 300 and 400 mg L-1) and K (100 and 200 mg L-1) based on the modified Hoagland's nutrient solution. Results showed that fresh and dry weight of plants increased by increasing N concentration up to 200 mg L-1 in the nutrient solution. The highest leaf number was observed in 200 mg L-1 N. Chlorophyll content of leaves increased significantly by adding nitrogen concentration in the nutrient solution up to 400 mg L-1. However, K concentration had no effect on the chlorophyll content. N and K treatment combinations in the solution affected growth characteristics and essential oil content of costmary, so that the highest essential oil content (0.54%) and yield (11 ml m-2) were obtained in N₂₀₀K₂₀₀ treatment. Essential oil content in N₂₀₀K₂₀₀ treatment was 8% higher than that of N₄₀₀K₁₀₀ treatment. Moreover, essential oil yield in N₂₀₀K₂₀₀ treatment was 35% higher than that of N₁₀₀K₁₀₀ treatment. N and K treatment combinations influenced fresh and dry weight of leaves (medicinal material), and the greatest amount was recorded in N₂₀₀K₂₀₀, which had the highest leaf area as well. The total net photosynthesis was affected by treatments, and the highest data was recorded in N₂₀₀K₁₀₀ treatment. Different concentrations of N and K influenced height of the plants, the greatest height being observed in N₂₀₀K₂₀₀ treatment. It can be concluded that different concentrations of N and K have remarkable effects on the growth and essential oil content of costmary.