A field experiment was conducted to study the effects of weed management practices on cassava under irrigated conditions in Bhubaneswar (Odisha), India for consecutive three years (2010-11 to 2012-13). The results revealed that four rounds of manual weeding at 1, 2, 3 and 4 months after planting (MAP) and black polythene mulching resulted in taller plants, more number of nodes and leaves per plant, maximum number of storage roots per plant, maximum length and girth of storage roots as well as fresh storage roots yield per plant with lower weed biomass.  Mean fresh root yield due to black polythene mulching was at par with four rounds of manual weeding (at 1, 2, 3 and 4 MAP). Black polythene mulching resulted in higher dry matter partitioning efficiency and soil microbial population. The root yield decreased by 9.6%, due to pre-emergence  application of oxyfluorfen + two rounds of manual weeding (at 2 and 3 MAP) treatment and 10.1% in two rounds of manual weeding (at 1 and 2 MAP) + post-emergence application of glyphosate (at 3 MAP) compared to four rounds of manual weeding (at 1, 2, 3 and 4 MAP).