Changes in secondary metabolite and biologically active compounds of Ajowan (Trachyspermum ammi L.) upon organic and conventional production systems

Abstract

Ajowan is one of the most important medicinal species of the family Apiaceae, which has pharmacological properties for future research in drug development. The essential oil composition of this species in response to different sources of nitrogen and organic fertilizers has not been investigated yet, though the issue is of interest. The factorial combination of four nitrogen sources levels including control (no nitrogen source), urea (U), sulfur-coated urea (SCU), half of the sulfur-coated urea (1/2 SCU) + Alkazot Plus biological fertilizer) and organic fertilizers at four levels such as control (no organic sources), humic acid, vermicompost, half of vermicompost + humic acid) were laid out in a randomized completed block design (RCBD) in a field experiment. Results showed that the interaction between different sources of nitrogen and organic fertilizers on Ajowan essential oil percent and yield were significant (P < 0.01). The highest essential oil percent (5.5%) and essential oil yield (85.4 kg/ha) were obtained at control and Urea + vermicompost treatments. The results of essential oil analysis showed that seven compounds were identified in the ajowan oil, which are based on the highest amount included: Thymol, Gamma-terpinen, O-cymene, Alpha-terpineol propionat, Beta- pinene, Para-cymene, and Alpha pinene.