The effect of time of application (10 and 30 Days after sowing) and doses of common salt viz.,50, 100 and 150 kg ha^-1 and 2,4-D Na salt @1.5 kg ha^-1 application on weed growth and yield of direct seeded upland rice was evaluated during wet seasons of 2003 and 2004. Application of 2, 4-D @1.5 kg ha^-1 applied at 10 and 30 days after sowing significantly reduced weed population and dry matter accumulation, and was at par with common salt @150 kg ha^-1 applied at 10 and 30 DAS. 2,4-D Na salt @1.5 kg ha^-1 applied at 10 and 30 DAS recorded better growth ,yield attributes and yield viz., plant height ,number of tillers hill^-1, dry matter accumulation, number of panicles m^-2 number of effective grains panicle^-1 and grain yield in comparison to common salt @50 kg ha^-1 applied at 10 and 30 DAS. The highest benefit cost ratio was recorded with 2, 4-D Na salt @1.5 kg ha^-1 applied at 10 days after sowing (2.47) followed by common salt @150 kg ha^-1 applied at 10 days after sowing. Early application of common salt and 2, 4-D (10 days after sowing) recorded more grain yield and benefit cost ratio in comparison of latter application (30 DAS) of these treatments. Common salt application was not economical in comparison to 2, 4-D application.