Weed management in blackgram [Vigna mungo (L.) Hepper] under western undulating zone of Odisha

Field experiment was carried out at instructional farm-I, College of Agriculture, Odisha University of Agriculture and Technology, Bhawanipatna, under western undulating zone of Odish during kharif season of 2024 to study the weed control efficiency of different weed management practices including pre- and post-emergence herbicides in blackgram [Vigna mungo (L.) Hepper]. The blackgram variety “VBN-11” was sown in the trial. The experiment was fitted in a randomized block design (RBD) consisted of eight treatments and three replications viz, T₁: Oxyfluorfen 23.5 EC 50 g ha^-1 as PE (2 DAS), T₂: Quizalofop-p-ethyl 5EC 50 g ha^-1 as PoE (25DAS), T₃: Imazethapyr 10 SL 70 g ha^-1 as PoE (25DAS), T₄: Oxyfluorfen 23.5 EC 50 g ha^-1 as PE (2DAS) fb Imazethapyr 10 SL 70 g ha^-1 as PoE (25DAS), T₅: Oxyfluorfen 23.5 EC 50 g ha^-1as PE(2DAS) fb Quizalofop-p-ethyl 5EC 50 g ha^-1 as PoE (25DAS), T₆: Imazethapyr 10 SL 70 g ha^-1 + Quizalofop-p-ethyl 5EC 50 g ha^-1 as PoE (25 DAS), T₇: Two hand weeding (15 DAS and 30 DAS) and T₈: weedy check (control). The soil of the experimental field was sandy clay loam in texture, neutral in reaction (pH-7.04), medium in organic carbon (0.67%), low available nitrogen (182.0 Kg ha^-1) and medium in available phosphorus (15.01 Kg ha^-1) and medium in available potassium status (208.07 Kg ha^-1). In the experimental field amongst the grassy weeds, Cynodon dactylon, Digitaria ciliaris, and Echinochloa colonum were most dominant. The most abundant sedge was Cyperus rotundus. The most prevalent broad leaved weeds were Cleome viscosa, Commelina benghalensis, Parthenium hysterophorus, Ageratum conyzoides, Celosia argentea and Phyllanthus niruri. Two hand weedings at 15 DAS and 30 DAS remarkably reduced the monocot and dicot weed density (51.30 no. m^-2), weed biomass (26.10 gm ^‑2) and also increased WCE (82% at 40 DAS) and lowest weed index. It was followed by Oxyfluorfen 23.5 EC 50 g ha^-1 as PE (2DAS) fb Imazethapyr 10 SL 70 g ha^-1 as PoE (25DAS) treatment which remained at par with two hand weeding. Better plant characters at harvest such as plant height (78 cm), grain yield (885 kg ha^-1) and haulm yield (1865 kg ha^-1) were resulted from two hand weedings which remained at par with treatment Oxyfluorfen 23.5 EC 50 g ha^-1 as PE (2DAS) fb Imazethapyr 10 SL 70 g ha^-1 as PoE (25DAS). Though the highest gross return (Rs. 75,462 ha^-1) was obtained in case of two hand weedings but due to the high cost incurred for the manual weeding at different intervals the B:C ratio becomes 1.32. Moreover, highest net return (Rs. 27,579 ha^-1) and B:C ratio (1.59) was registered with the treatment Oxyfluorfen 23.5 EC 50 g ha^-1 as PE (2DAS) fb Imazethapyr 10 SL 70 g ha^-1 as PoE (25DAS). Hence, Oxyfluorfen 23.5 EC 50 g ha^-1 as pre-emergence and post emergence application of Imazethapyr 10 SL 70 g ha^-1 proved to be the best chemical treatment and practices can be advocated for growing kharif blackgram in western undulating zone of Odisha.