Roy, D. K.Bhargaw, Piyush Kumar2018-10-242018-10-242018http://krishikosh.egranth.ac.in/handle/1/5810082002A field experiment was conducted during kharif season of 2017 at the research farm of Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar to study the“Integrated Weed Management in Dry Direct Seeded Rice (Oryza sativa L.)”. The experiment was conducted in Randomized Block Design having 10 treatments. T1 -Pendimethalin @ 1 kg/ha at 0-2 DAS fb Bispyribac-Na @ 25 g/ha at 20 DAS, T2 - Pendimethalin @ 1 kg/ha at 0-2 DAS fb two hand weedings at 20 & 40 DAS, T3 - Stale seedbed using Glyphosate @ 1 kg/ha at 10 DBS fb Bispyribac-Na @ 25 g/ha at 20 DAS, T4 - Stale seedbed using Glyphosate @ 1 kg/ha at 10 DBS fb Pendimethalin @ 1 kg/ha at 0-2 DAS fb Bispyribac Na @ 25 g/ha at 20 DAS, T5 - Mulch @ 5 t/ha (By wheat straw) fb Bispyribac-Na @ 25 g/ha at 20 DAS fb one hand weeding at 40 DAS, T6 - Stale seedbed using Glyphosate @ 1 kg/ha at 10 DBS fb Mulch @ 5 t/ha (By wheat straw) fb Bispyribac-Na @ 25 g/ha at 20 DAS, T7 - Pendimethalin @ 1 kg/ha at 0-2 DAS &Sesbania co-culture fb 2,4-D Na salt @ 0.5 kg/ha at 20 DAS fb one hand weeding at 40 DAS, T8 - Pendimethalin @ 1 kg/ha at 0-2 DAS fb 2,4-D Na salt @ 0.5 kg/ha at 20 DAS fb one hand weeding at 40 DAS, T9 - Weed free (By hand weedings at 20, 40 & 60 DAS) and T10 - Weedy check with three replications. The rice variety used was Rajendra Bhagwati. All the weed management practices both hand weeding or herbicidal treatments had reflective effect on growth and yield attributes as well as the ultimate yield as reflected in their superiority over the weedy check. Hand weedings at 20, 40 and 60 DAS was found significantly superior over all the integrated weed management practices. Amongst herbicidal treatments Pendimethalin @ 1 kg/ha at 0-2 DAS fb two hand weedings at 20 and 40 DAS was superior to rest of herbicidal treatments which wasstatistically at par with treatment Stale seedbed using Glyphosate @ 1 kg/ha at 10 DBS fb Pendimethalin @ 1 kg/ha at 0-2 DAS fb Bispyribac Na @ 25 g/ha at 20 DAS,Mulch @ 5 t/ha (By wheat straw) fb Bispyribac-Na @ 25 g/ha at 20 DAS fb one hand weeding at 40 DAS and Pendimethalin @ 1 kg/ha at 0-2 DAS fb 2,4-D Na salt @ 0.5 kg/ha at 20 DAS fb one hand weeding at 40 DAS, recorded top advert in almost all the crop growth stages and yield attributing characters and also in the yield of grain. The results affecting to weed population, weed dry weight and nutrient uptake by crop and weeds separately were a close consideration of growth and yield pattern whereas hand weeding which was significantly superior to all the treatments. Amongst herbicidal treatments, Pendimethalin @ 1 kg/ha at 0-2 DAS fb two hand weedings at 20 & 40 DAS was superior to rest of all herbicidal treatments. The highest weed control efficiency (76.26%) and the lowest weed index (3.71%) was found significantly superior in treatment Pendimethalin @ 1 kg/ha at 0-2 DAS fb two hand weedings at 20 & 40 DAS. Protein content in grain was similar in all the treatments except the weedy check in which it was significantly lower. The most evident part of the results rested in its economic studies, where in all the herbicidal treatments either pre-emergence applications or combination of pre and post emergence applications got higher net return and scored better B:C ratio. Pendimethalin @ 1 kg/ha at 0-2 DAS fb 2,4-D Na salt @ 0.5 kg/ha at 20 DAS fb one hand weeding at 40 DAS (`32,244/ha) retained the highest net return which was statistically at par with Pendimethalin @ 1 kg/ha at 0-2 DAS fb two hand weedings at 20 and 40 DAS (`31,997/ha), Weed free (`31,080/ha), Stale seedbed using Glyphosate @ 1 kg/ha at 10 DBS fb Pendimethalin @ 1 kg/ha at 0-2 DAS fb Bispyribac Na @ 25 g/ha at 20 DAS (`30,482/ha) and Pendimethalin @ 1 kg/ha at 0-2 DAS fb Bispyribac-Na @ 25 g/ha at 20 DAS (`30,229/ha). As against these treatments, the net return realized by weedy check was lowest (`12,777/ha). The B:C ratio further broadened the gap between manual weeding and herbicidal applications. The highest B:C ratio of 1.0 was recorded from pre-emergence application of Pendimethalin @ 1 kg/ha at 0-2 DAS fb Bispyribac-Na @ 25 g/ha at 20 DAS which was statistically at par with Pendimethalin @ 1 kg/ha at 0-2 DAS fb 2,4-D Na salt @ 0.5 kg/ha at 20 DAS fb one hand weeding at 40 DAS (0.97), Stale seedbed using Glyphosate @ 1 kg/ha at 10 DBS fb Pendimethalin @ 1 kg/ha at 0-2 DAS fb Bispyribac Na @ 25 g/ha at 20 DAS (0.94) and stale seedbed using Glyphosate @ 1 kg/ha at 10 DBS fb Bispyribac-Na @ 25 g/ha at 20 DAS (0.90).ennullThesis