One year old Leptochloa chinensis seeds' germination ranged from 25 to 29% at temperatures ranging from 25° to 45°C. The fresh and two years' old seeds did not germinate irrespective of the temperature. Submergence periods ranging from 1 to 5 weeks were equally effective in preventing the seedling emergence during the period of submergence. However, at 15 days after the termination of each submergence, the seedling emergence was significantly less under more than two week submergence treatments than one week submergence. No seedling emerged beyond the submergence depth of 2.5 cm, whereas at 2.5 cm, 4.7% s~dlings emerged from the soil but failed to emerge out of the water surface. r"