Original Articles: 2016 Vol: 8 Issue: 6
Effect of nitrogen and phosphorus application on herb and essential oil composition of Satureja montana L. �carvacrol� chemotype
Abstract
A field experiment was carried out during two successive seasons to study the effects of nitrogen fertilizer (0, 50 and 100 kg N/fed.) and phosphorus fertilizer (0, 15.5 and 30 kg P/fed.) as well as 1st and 2nd cuts on dry matter, essential oil percentage and composition of Satureja montana under Egyptian conditions. In the two seasons, herb dry weight/plant, essential oil % and oil yield in two cuts were significantly increased with the rise in nitrogen and/or phosphorus fertilizers. 2nd cut gave higher values for herb dry weight/plant, essential oil % and oil yield than 1st cut. The maximum herb dry weight/plant and oil yield was obtained from plants fertilized (50 kgN+30 kg p/fed.) and harvested at 2nd in both seasons, while maximum essential oil percentage was obtained from plants harvested in the 1st cut with fertilized at (100 kgN /fed.) and from plants harvested in the 2nd cut with fertilized at (30 kg p/fed.) in the first and second seasons, respectively. Carvacrol was the major marker compound in Satureja montana. Other important compounds were p-cymene (7.78 to 9.95% and 4.10 to 6.44%), γ-terpinene (3.45 to 6.43% and 2.03 to 4.02%), linalool (0.56 to 1.70% and 0.81 to 2.60%), thymol (1.78 to 2.58% and 1.28 to 3.93%) and β-caryophyllene (1.88 to 2.34% and 2.32 to 3.20%) considered as minors in the first and second cuts, respectively. The highest carvacrol percentage was recorded from Satureja montana harvested at 2nd cut and fertilized by (50 kgN+30 kg p/fed.). This study showed that the accumulation of essential oil constituents is influenced by the nitrogen and phosphorus fertilizers as well as 1st and 2nd cuts.