Studies on the interactive effects of water regimes, weed control treatments and nitrogen levels in direct-seeded rice

Abstract

Field and green house experiments were conducted in the Division of Agronomy, Indian Agricultural Research Institute, New Delhi, during 1982 and 1983 to study the interaction of nitrogen x weed control x water regimes, on the growth, productivity and nutrient use pattern of direct seeded rice. The treatments in the field trails consisted of 4 levels of nitrogen (0, 50, 100 and 150 kg N ha-1). 3 weed control treatments (weedy check, butachlor, bentazone in 1982 and bentazone plus propanil in 1983) and 2 water regimes (continuously and intermittently flooded). The experiment was laid out in a split plot design, replicated thrice. The variables in the green house experiment were 2 rice cultivars (Pusa 33, drought susceptible and Pusa 312, drought tolerant), 3 nitrogen levels (0,100 and 200 mg N kg soil-1) and 5 soil moisture regimes (submergence to saturation, 0-0.025 MPa, 0-0.05 MPa, 0-0.075 MPa 0-0.10 MPa soil moisture tension).