Influence of plant growth promoter bacteria and plant density on yield components and seed yield of ajowan (carum copticum)

ABSTRACT: In order to study the effect of plant growth promoter bacteria and plant density on yield components and seed yield of ajowan (Carum copticum), an experiment was conducted as factorial experiment in the base of randomized complete blocks design with twelve treatments and three replications at research field of Agriculture Company of Ran in Firouzkuh of iran in 2011. The factors were plant growth promoter bacteria (Nitrogen fixing bacteria), mixture of Azotobacter chroococcum and Azospirillum lipoferum in four levels (non-inoculated, inoculated seeds, spray on the plant base at stem elongation stage and inoculated seeds + spray on the plant base at stem elongation stage) and plant density in three levels (12.5, 16.6 and 25 plants m-2). Results showed that plant growth promoter bacteria had significant effects on studied traits except plant height and weight of 1000 seeds. The highest, umbel number per plant, dry weight of plant and seed yield were obtained by using the plant growth promoter bacteria twice (inoculated seeds + spray on the plant base at stem elongation stage). plant density, also showed significant effects on mentioned traits except weight of 1000 seeds. The maximum umbel number per plant, and dry weight of plant were obtained with 12.5 plants m-2 and the highest plant height and seed yield were obtained with 25 plants m-2.