Compatibility and efficacy of post-emergence herbicides tank mixed with zinc sulphate and urea for weed management in wheat

A study was conducted to evaluate the compatibility and efficacy of post-emergence herbicides with zinc sulphate and urea (tank-mixed) in wheat during the year 2018–19, 2019–20 and 2020–21 at the research farm of CCSHAU Regional Research Station, Bawal, Haryana, India. The experiment was designed in a factorial randomized block design with three replications. The first factor included two treatments: with foliar spray of zinc sulphate plus urea and without the foliar spray of zinc sulphate plus urea, while the second factor comprised of seven weed control treatments: metsulfuron 4 g/ha, carfentrazone 20 g/ha, 2,4-D sodium salt 500 g/ha, 2,4-D ester salt 500 g/ha, metsulfuron + carfentrazone (RM) 24 g/ha, unweeded check, and weed-free. The herbicides tested were found compatible with zinc sulphate (0.5%) + urea (2.5%) when tank-mixed, as no phytotoxicity was observed on the crop at any stage. The application of zinc sulphate (0.5%) + urea (2.5%) was found to be compatible with different herbicides recommended for the post-emergence management of broad-leaved weeds and increased wheat grain yield by 4%. Among different herbicides, metsulfuron + carfentrazone (RM) 24 g/ha recorded the highest grain yield (6.06 t/ha) and achieved the maximum net returns (₹ 85,907/ha) with a benefit-cost (B:C) ratio of 2.78 over three seasons. The highest weed control efficiency was also observed with metsulfuron + carfentrazone (RM) 24 g/ha tank-mixed with zinc sulphate and urea. The various herbicides when tank mixed with zinc sulphate plus urea provided higher weed control efficiency than the herbicides used alone.