In this research, the effects of bio-organic fertilizers and zeolite on seed yield ,essential oil content and composition of Pimpinella anisum L., as, aromatic and medicinal plant, was investigated. Field experiment was conducted in the Agriculture Research Station at Sanandaj, Iran, in 2008. Experimental Factors were three levels of vermicompost (0, 5 and 10 t.ha-1), two amount of zeolite (0 and 4.5 t.ha1) and mixture of Azotobacter, Azospirillum and Pseudomonas (inoculation and not-inoculation). The results showed that vermicompost levels highly increased the quantitative characters including plant height, umbel no/plant and seed yield. The application of 10 t.ha-1 vermicompost gave the highest value of those characters. These values were 18.3%, 29.9% and 43.1% higher than the first level of Vermicompost, for plant height, umbel no/plant and seed yield, respectively. Quantitative characters were also significantly increased by PGPR inoculation and zeolite application. Applying the third level of vermicompost caused the highest value of essential oil and anethol percentage. Zeolite application had a significant effect on essential oil content, but no significant effect on anethol percentage. Generally the most favorable interaction treatment for umbel no/plant and seed yield was the PGPR inoculation combined with the highest level of vermicompost.
