Alteration in Essential Oil Yield and Compositions of Multi-Cut Dracocephalum polychaetum Grown under Different Fertilization Methods

Sustainable agriculture can increase the efficiency of resource utilization, provide longer productivity and create a balance in the environment. A field experiment was conducted to study the use of organic and chemical fertilizers on biomass, essential oil content and essential oil yield as well as chemical compositions of Dracocephalum polychaetum Burnm in the first and second cutting. The treatments were: broiler litter (1700 kg ha-1), cow manure (2500 kg ha-1), sheep manure (1700 kg ha-1), chemical fertilizer (110 kg ha-1) and control (no fertilizer) in three replications. The results showed that D. polychaetum was most responsive to application of broiler litter as compared with the other treatments. Gas chromatography–mass spectrometry analysis indicated that neral, geranial, geranyl acetate and α-pinene were the major chemical compounds of D. polychaetum in the both cuttings. In the first cutting the plants treated with sheep manure had the highest neral content (28.24%). The highest geranial content (26.85%) in the first cutting was recorded in plants amended with chemical fertilizer, without significant difference with broiler litter (26.36%). In the first cutting the greatest α-pinene (15.52%) content was observed in the control treatment without significant difference with broiler litter (15.09%). Unlike the first cutting, plant amended with cow manure had the maximum neral (23.89%) and geranial (29.27%) contents in the second cutting. The present study demonstrated that the application of organic manure improved essential oil content and quality and aroma profile of D. polychaetum.