Effect of Thiobacillus and Superabsorbent on the Essential Oil Content and Some of Important Agronomic Characteristics in Thymus vulgaris L. and Thymus daenensis Celak.

Essential oil has a special position in world trade. Optimal nutrition without any environmental stresses has significant effect on the quantity and quality of it. This experiment was conducted in a completely randomized design with three replications under greenhouse conditions in the spring and summer of 2014. Treatments including the use of superabsorbent polymer in three levels (0, 0.5 and 1 g per kg of soil) and Thiobacillus (using and dont-using conditions) were applicated on two species of thyme (T. vulgaris and T. daenensis). Measured characteristics were: fresh and dry weight of aerial parts, fresh and dry weight of root, leaf area and essential oil content. The highest fresh and dry weight of plants (95.5 and 35.5 g, respectively) and leaf area (835.25 mm2) were obtained in the treatment of 1 g superabsorbent polymer per 1 kg of soil, but the highest essential oil content (2.3%) was measured in the treatment of Thiobacillus with 0.5 g of superabsorbent polymer per kg of soil. The effected Thiobacillus alone on agronomic traits and essential oil content was not significant, but interaction effect of Thiobacillus and superabsorbent on oil percentage was significat. T. daenensis showed the highest thymol content (51.18%) compared to T. vulgaris. It seems that superabsorbent polymer with Thiobacillus application can be used in T. vulgaris and T. daenensis production with the desired quality and quantity of the active ingredients.