effect of sowing date and seeding rate on essential oil content and composition of german chamomile (matricaria recutita l.) cv. presov

abstract in order to study the effect of sowing date and seeding rate on essential oil content and composition of chamomile (matricaria recutita l.) cv. presov, prepared from slovakia, an experiment was conducted. the experimental design was split-plot in the basic of randomized complete blocked design (rcbd) with three replications. main plots consisted of three sowing dates (6 nov, 5 mar, and 4 apr) and sub-plots included three seeding levels (0.2, 0.4 and 0.8 g/m2). evaluated traits were essential oil content and percent of -farnesene, -bisabolol oxide b, -bisabolol, chamazulene, -bisabolol oxide a. the results showed that spring sowing (mar and apr) produced chamomile with high level of essential oil content. on the basis of the results, the highest essential oil content (0.63 w/w percent) was obtained from the plots were sown on 5 of mar with 0.4 g/m2 but the highest -bisabolol and chamazulene content (75.99 and 17.31 percent respectively) were obtained from the plots were sown on 4 of apr with 0.2 and 0.4 g/m2. according to the results, because of high percent of essential oil and desirable content of -bisabolol and chamazulene, the most suitable sowing date and seeding level in mashhad condition is 5 of mar with 0.4 g/m2 seeds respectively.