The tensile strength does not show significant differences in the plastics containing bean starch (Fig. 2), while it decreases as the irradiation dose increases in the case of cassava starch, reaching a reduction of about 11% at the dose of 50 kGy. A large decline in the elongation is observed till 10 kGy (Fig. 3) for both plastic materials with no further variation with the increasing dose. Elongation fell by 57% and 47% in materials containing bean and cassava starch, respectively.