Main effects of tillage system (T) and weed management regime (W) were significant for seed yield, while the T × W interaction was not significant (Table II). Regardless of weed management regime, the greatest grain yields were recorded for NTRCS (3838 kg ha-1) and NTSD (3574 kg ha-1), while the lowest amounts were recorded for TDHDP (3137 kg ha-1) and TCPDP (3080 kg ha-1) (Table III). This result is in accordance with the findings of Di Ciocco et al. (2008), who reported higher soybean seed yield for no tillage system compared with conventional tillage system