EFFICACY OF DIFFERENT ESTABLISHMENT METHODS AND WEED MANAGEMENT PRACTICES ON WEED DENSITY, WEED DRY MATTER, WEED CONTROL EFFICIENCY AND YIELD UNDER RAINFED LOWLAND RICE

Abstract

A field experiment was conducted during the kharif season of 2011-12 at Agronomy Research Farm, Central Research Station, Orissa University of Agriculture and Technology, Bhubaneswar. The experiment was laid out in split-plot design to find out the effect of various establishment methods and weed management practices on different weed parameters such as weed density (Grasses, Sedges and Broadleaf weeds), weed dry matter, weed control efficiency and grain yield under rainfed lowland rice. Experiment resulted that Weed parameters like total weed density (8.0 no. m-2), weed dry matter (6.4g.m-2) and weed index were lowest in system of rice intensification (SRI) at 30 days after transplanting/sowing (DAT/S). With respect to weed management practices total weed density (7.53 no.m-2),weed dry matter (2.3 g m-2) was recorded lowest in pyrazosulfuron-ethyl @20 g.ha- and highest weed control efficiency 97.04 percent were recorded in conoweeder. Grain yield of 5.02 t ha-1 and 4.76 t ha-1 were recorded in SRI and conoweeder respectively. While highest straw yields were recorded in SRI (5.8 t ha-1) and conoweder (5.5 t ha-1). Severe infestation of weeds reduced the yield by 32, 38, 39 and 52 percent in transplanted, SRI, drum seeded and direct seeded rice