Bio efficacy of pre and post-emergence herbicides on yield and economics of maize crop (Zea mays)

An AICRP- maize experiment was conducted at Crop Research Station, Bahraich, Uttar Pradesh, during kharif season of 2023 in randomized block design with three replications having twelve different treatments of weed management. Weed flora both broad- and grassy weeds were observed but dominance of broad-leaved weeds was more in entire field. Plant population was maximum in weedy free plots followed by pre emergence application of atrazine and hand weeding at 25-30 DAS than pyroxasulfone @ 127 g/ha fb halosulfuron methyl @ 67 g/ha at 25-30 DAS, similar trend was recorded in weed density and weed dry weight. The weed dry weight was less with Pyroxasulfone @ 127 g/ha fb halosulfuron methyl @ 67 g/ha at 25-30 DAS and pyroxasulfone @ 127 g/ha fb tembotrione @ 120 g/ha at 25-30 DAS. At maturity of crop maximum weeds were found in weedy plots followed by Atrazine 500 g/ha fb tembotrione @ 120 g/ha at 25-30 DAS treated plots. Among the treatments, maize grain yield was found significantly higher with the weed free plot (6967 kg/ha) followed by pre-emergence application of atrazine @ 500 g/ha + HW at 25-30 DAS (6798 kg/ha) while lower yield was obtained in weedy plot (4820 kg/ha). Pre emergence herbicides treated plots with pyroxasulfone fb post emergence yielded lesser due to poor plant population than Atrazine. Application of atrazine alone and with other post-emergence herbicide did not show any phytotoxic symptoms on crop except pyroxasulfone.