Efficacy of herbicides applied alone and in tank mixture with isoproturon against wild oat (Avena ludoviciana) and broad-leaf weeds in wheat (Triticum aestivum)

An investigation was conducted during winter seasons of 1996–97 and 1997–98 at Gurdaspur, Punjab, on fields heavily infested with broad-leaf of weeds. An application of metribuzin (0.175 kg/ha) or pendimethalin (0.7 kg/ha) alone or tank mixture of isoproturon + metribuzin (0.75 + 0.131 kg/ha), isoproturon + atrazine (0.75 + 0.094 kg/ha) or isoproturon + 2, 4-D (0.94 + 05 kg/ha) provided effective control of broad-leaf weeds in wheat (Triticum aestivum L. emend. Fiori & Paol.) Application of 2, 4-D or diclofopmethyl/tralkoxydim alone was not effective against broad-leaf weeds, especially Medicago denticulata Willd., Lathyrus aphaca L. and Vicia sativa L. However, diclofopmethyl or tralkoxydim alone in tank mixture with isoproturon effectively controlled wild oat. Isoproturon + atrazine and isoproturon + 2, 4-D recorded the lowest dry matter of weeds in the first and second year respectively. The maximum weed density and dry matter of weeds were recorded in weedy check. Application of metribuzin (0.175 kg/ha) resulted in the maximum grain yield which was at par with tank mix application of isoproturon + metribuzin, isoproturon + atrazine, isoproturon + 2,4-D, isoproturon and pendimethalin, whereas weedy check resulted in the minimum grain yield. The maximum net returns were obtained with metribuzin (0.175 kg/ha) application, followed by isoproturon + metribuzin. However, maximum benefit: cost ratio was registered with atrazine applied @ 0.094 kg/ha. Diclofopmethyl resulted in the lowest net returns and benefit: cost ratio.