Effect of Treatment with Tryptophan and Yeast on soil microbial activities, growth and productivity of Thymus vulgaris L. under Middle Sinal Conditions

Two Successive field experiments were carried out at EI-Maghara Research Station, (DRC), during 2004-2005 and 2005-2006 seasons, to study the effect of biofertilization with yeast (Saccharomyces cerevisiae) and amino acid tryptophan, applied as soil drench, and/or foliar spraying methods on the growth, yield and essential oil constituents of Thymus vulgaris, L. plants, grown in sandy soil using drip irrigation system. Microbial activities and antimicrobial effects of this treatment were also investigated. The obtained data revealed that the best yield and the essential oil were obtained by using combinations of both tryptophan and yeast applied as soil drench plus foliar spraying methods. Also, stimulated microbial activities, exhibited powerful antagonistic effects of thyme essential oil against some pathogenic microorganisms.