the effect of application of organic and biological fertilizers on quantity and quality essential oil of foeniculum vulgare mill. (fennel)

abstract in order to evaluate the effects of different organic and biological fertilizers on quantity and quality of essential oil of fennel an experiment was conducted in a completely randomized block design with three replications. the experimental treatments were two organic (compost and vermicompost) and two biological (pseudomonas putida and azotobacter chroococcum ) fertilizers, their all twin combinations (ps. putida + a. chroococcum, ps. putida + compost, ps. putida + vermicompost, a. chroococcum + compost, a. chroococcum + vermicompost and compost + vermicompost) and control (without any fertilizer). there were significant differences between different treatments in terms of seed essential oil percentage, essential oil yield; anethole, fenchone, limonene and estragole content in seed essential oil. results showed that the highest and lowest percentage of essential oil contents were obtained in control (% 2.9) and a. chroococcum + vermicompost (% 2.2) treatments, receptivity. the highest essential oil yield (29.9 l/ha) and anethole content of essential oil (69.7%) and the lowest fenchone (6.14%), limonene (4.84%) and estragole (2.78%) contents of essential oil were obtained in compost + vermicompost treatment. essential oil yield and percentage of anethole content in essential oil were significantly higher in all organic and biological treatments compare with control. the highest of fenchone, limonene and estragole essential oil content were obtained in control treatment.