Effect of Biofertilizers on Growth, Yield and Essential Oil Content of Thyme (Thymus vulgaris L.) and Sage (Salvia officinalis L.).

To study the effect of bio-fertilizers on growth, yield and essential oil constitutes of thyme (Thymus vulgaris L.) and Sage (Salvia officinalis L.) an experiment was conducted during two successive seasons of 2008-2009 and 2009-2010 at the research farm of Medicinal Plants and Drugs Research Institute of Shahid Beheshti University of Tehran, Iran. A randomized complete blocks design with three replications was used. The treatments consisted of commercial bio-fertilizers including N-fixer bacteria, phosphate solubilizing bacteria, mixed of these two bio-fertilizers and control (without fertilizer). Results of two years study showed that bio-fertilizers had no significant effect on growth, yield, essential oil percentage and chemical components of essential oil in both plants. The effect of plant age on all studied parameters was significant. The highest plant height, plant diameter, herb dry weight and essential oil yield were observed in two year old plants of both thyme and sage. The amounts of a-Thujone in sage and Thymol in thyme were considerably higher in two year old plants but the amount of Camphor in sage was not affected by age of plants. Results showed that three cuts in the second year of study can be achieved in both plants. The highest plant height, plant diameter and herb dry weight were achieved in spring cut but the highest essential oil content was obtained in summer cuts in both plants. Chemical constitutes of essential oils were not affected by cutting time in both plants. [ABSTRACT FROM AUTHOR]