Evaluation of Farmyard and Vermicompost Application and Spray of Ascorbic Acid and Humic Substances on Dragonhead Production (Dracocephalam moldavica L.)

In order to evaluate the effect of organic fertilizers, ascorbic acid and humic acid on dry matter yield, seed yield and essential oil production of dragonhead an experiment was conducted as a factorial based on completely randomized design with three replications at research farm of Faculty of Agriculture, University of Tabriz in 2017. Treatments were included as first factor, application of organic fertilizers (control, application of farmyard (30 t.ha-1) and application of vermicompost (15 t.ha-1) and the second factor was the spray of ascorbic acid and humic acid (control, ascorbic acid, humic acid and ascorbic acid + humic acid). Results showed that the highest amounts of morphological traits, plant dry weight, dry matter yield, grain yield and essential oil yield were obtained with vermicompost and combined application of ascorbic acid + humic acid treatments. The highest dry matter yield (2271 kg.ha-1), grain yield (645.9 kg.ha-1) and essential oil yield (12.3 kg.ha-1) were obtained with application of a combination of ascorbic acid + humic acid, which showed 36.5%, 18.1% and 72.8% increases as comparison to control, respectively. The highest 1000 grain weight was obtained with the application of humic acid and vermicompost (1.66g), combined application of humic acid + ascorbic acid and vermicompost (1.59 g) and combined application of humic acid + ascorbic acid and control (1.54 g), with 30.2%, 24.7% and 20.6% increases as comparison with non-application of organic fertilizers and without spray, respectively. The highest essential oil percentage (0.61%) was obtained with spray of humic acid + ascorbic acid and vermicompost application, which indicated 45.2% increases compared to control. Considering to positive response of the quantitative and qualitative performance of dragonhead to the use of the organic fertilizers, humic acid and ascorbic acid, it can be expected that application of farmyard and vermicomposte, humic acid and ascorbic acid increase the performance and essential oil of dragonhead.