effects of different manure and vermicompost rates on yield and essential oil contents of dragonhead (dracocephalum moldavica l.)

application of organic fertilizers increases quality and yields in the sustainable crop production and considerably replaces or reduces chemical fertilizers. in order to study the effects of different manure and vermicompost rates on yield and essential oil contents of dragonhead, an experiment was conducted as a randomized complete blocks design with eight treatments and three replications in the field of pakdasht city in 2012. the treatments were 10 and 20 t/ha manure, 5 and 10 t/ha vermicompost, 5 t/ha manure + 2.5 t/ha vermicompost, 10 t/ha manure + 5 t/ha vermicompost, chemical fertilizer (70 kg/ha nitrogen) and control (without fertilizer). the results showed that the highest herbage yield, essential oil contents and yield, geranyl acetate percentage and geraniol percentage in essential oil were obtained by using 10 t/ha manure, 5 t/ha vermicompost and integrated application of 10 t/ha manure and 5 t/ha vermicompost, respectively. the highest geranial percentage, neral percentage and neryl acetate percentage in essential oil were obtained by using 10 t/ha vermicompost application. generally, the highest herbage and essential oil yields were obtained by using 10 t/ha manure application and the highest essential oil contents with vermicompost application.