Experiment was carried out under heavy black clay soil (vertisol) at the Experimental Farm,  N.M. College of Agriculture, Navsari Agricultural University, Navsari during two successive seasons of 2007-08  and 2008-09 to study the effect of varying plant population and weed management practices on weed flora and productivity of sweet corn (Zea mays L. Saccharata). Weed density and biomass was significantly lower with crop population of 1,11,111 plants/ha. Significantly higher green cob (9.5 t/ha) and green fodder (14.9 t/ha) yield with net return ( 75,779/ha) and benefit: cost ratio (5.36) was produced with plant population of 1,11,111 plants/ha and was at par with crop population of 83,333 plant/ha.  Significantly lowest weed biomass was recorded in weed free check which recorded highest yield of green cob (10.7 t/ha) and fodder (17.1 t/ha). Application of atrazine 1 kg/ha + hand weeding at 40 days after sowing was remunerative  with higher net return ( 88,873/ha) and benefit: cost ratio (6.72).