Field experiment was conducted during Rabi 2022-23 at Wetland farm of S.V. Agricultural College, Tirupati, Andhra Pradesh, India in a randomized block design. The objective was to evaluate and identify effective and economic herbicide treatment to manage weeds and improve productivity of blackgram (Vigna mungo L.). Nine weed management treatments were evaluated in RBD with three replications. Among the tested weed management treatments, lower weed density and biomass with higher weed control efficiency was recorded with pre-emergence application (PE) of diclosulam 20 g/ha followed by (fb)1 hand weeding (HW) at 15 days after seeding (DAS), and it was on par with HW twice at 15 and 30 DAS and the later was on par with post-emergence application (PoE) of fluazifop-p-butyl + fomesafen 222 g/ha and sodium-acifluorfen + clodinafop-propargyl 245 g/ha PoE. Significantly higher values growth parameters, yield attributes and yield of blackgram were recorded with HW twice at 15 and 30 DAS, which was however, on par with fluazifop-p-butyl + fomesafen 222 g/ha as PoE at 20 DAS and sodium-acifluorfen + clodinafop-propargyl 245 g/ha PoE at 20 DAS, while the later two treatments resulted in higher net returns and benefit-cost ratio. It was concluded that fluazifop-p-butyl + fomesafen 222 g/ha PoE or sodium-acifluorfen + clodinafop-propargyl 245 g/ha PoE at 20 DAS provide the most effective and economical weed management in blackgram.