Impact of Pre and Post-emergence Herbicide Mixtures in Direct Seeded Rice (Oryza sativa L.)

Rice (Oryza sativa L.) is a major source of food for more than half of the world population especially in South and Southeast Asia and Latin America. A field experiment was conducted at Krishi Vigyan Kendra, Yamunanagar district, Haryana during Kharif season of 2022 to study the effect of pre and post-emergence herbicides combinations herbicides in direct-seeded rice under irrigated condition. The experiment was laid out in a Randomized block design with three replications. The weed management treatments were T1: Pendimethalin + pyrazosulfuron T2:Pendimethalin + pyroxasulfone, T3:Pretilachlor + pyrazosulfuron, T4: Fenoxaprop-p-ethyl with safener + ethoxysulfuron,T5: Cyhalofop-butyl + penoxsulam and metsulfuron-methyl + chlorimuron-ethyl, T6.:Triafamone + ethoxysulfuron, T7: Pendimethalin + pyrazosulfuron fb bispyribac-sodium, T8: Pendimethalin + pyroxasulfone fb bispyribac-sodium, T9:Pretilachlor + pyrazosulfuron fb bispyribac-sodium, T10:Pendimethalin fb fenoxaprop-p-ethyl + ethoxysulfuron T11: Weed free, T12:Weedy check. Among herbicides, application T10 (pendimethalin fb fenoxaprop-p-ethyl + ethoxysulfuron) and T5 (cyhalofop-butyl+ penoxsulam and metsulfuron methyl + chlorimuron ethy (pre-mix) was superior over other treatment. Application of pendimethalin fenoxaprop-p-ethyl + ethoxysulfuron reduced 58.89% grassy weed and 50 % BLWs compared to weedy check plot at 60 DAS. Assessment at 60 DAS and at harvest showed that bispyribac-sodium was effective in controlling E. colona and E. crus-galli. However, bispyribac-sodium did not control D. aegyptium and L. chinensis. Fenoxaprop significantly reduced the densities of Dactyloctenium aegyptium, L. chinensis, and Digitaria sanguinalis. Fenoxaprop tank-mix with ethoxysulfuron appeared to be synergistic for the control of E. crusgalli and E. colona, and Cyperus sp. as this tank mixture. Integration of pendimethalin fb fenoxaprop-p-ethyl+ ethoxysulfuron provided control of all type of weeds with highest grain yield (6.1 t ha-1) among different treatments which was statistically at par with weed free (6.3 t ha-1). In economics points of views, the highest B-C ratio (3.03) was obtained in cyhalofop-butyl + penoxsulam + metsulfuron methyl + chlorimuron ethy followed by pendimethalin fb fenoxaprop-p-ethyl + ethoxysulfuron (2.98).