In order to study the effect of tri (n-butyl) tin 2,4-dichloro-phenoxy acetate on seed germination and seedling growth of Medicago sativa L. and Sorghum sudanense, Hydroponics method was used in this experiment with different concentrations of tri ( n-butyl ) tin 2,4 -dichloro - phenoxy acetate (0,50,100,150 mg/L)for cultivating seeds of alfalfa and Sudan grass and, germination index, germination potential, germination rate, peroxidase aetivity and chlorophyll content of seedlings were determined. The results showed that the inhibiting ef...