Authors: Suzan ALTINOK, Ahmet ERAÇ, Ralph C. MARTIN
Abstract: This research, was conducted in the experimental fiels of Agronomy Department, Faculty of Agriculture, Ankara University, Turkey in 1989 and 1992 and in the greenhouse of Plant Science Department, Nova Scotia Agricultural College, Canada in 1991. The experiment was arranged in a split-plot design with four replications. Three annual medic species (Medicago polymorpha L. var. brevispina (Benth.) Heyn, Medicago scutellata (L.) Mill. and Medicago ciliaris (L.) Willd.) were the main plot units and cutting stages (a) beginning of flowering, b) %50 flowering, and c) end of flowering) were the sub-plot units. The highest stem development, root development and forage yields were taken from M. scutellata, however, M. polymorpha var. brevispina had the lowest values in both field and greenhouse experiments. The effects of cutting at different phenological stages and stem and root development and forage yields of annual medics were numerically higher in the greenhouse experiments than the field experiments. According to the progressive cutting stages, stem and root development and forage yields of annual medics were increased in the greenhouse experiment. Nodulation was occured in the field experiments, indicating the presence of native rhizobia. In the second greenhouse trial, seeds were inoculated commercial strain of Rhizobium meliloti for nodulation. But, only the nodules of M. scutellata were active for fixing nitrogen which was found by acetylene reduction assay.