Two field experiments were carried out at an organic farm during 2005- 2006 and 2006-2007 seasons. The aim of this research is studying the response of damssisa to biofertilization and compost amendment in presence of Pseudomonas fluorescens. Obtained data showed significant increase of nitrogenase and phosphatase activity with dual of biofertilization and organic manuring rather than each one individually. Moreover, ammoniacal, nitrate nitrogen and available phosphorus were the highest records with dual application of biofertilizers and compost. Generally, compost amendment gave higher records of growth characteristics and herb yield compared with biofertilizers inoculation. Significant increase was observed in studied growth characteristics and herb yield of damssisa under dual application of biofertilizers and compost in presence of Ps. fluorescens.

Key words: Damssisa, biofertilization, organic manuring, Ps. fluorescens, nitrogenase, phosphatase activity and damssisa herb yield.