Weed Dynamics in Maize (Zea mays L.) as Influenced by Pre and Post-emergence Herbicides under Temperate Conditions of Western Himalayan Region

Field experiments were conducted in 2017-18 during main cropping seasons of the year 2017 and 2018 at Dryland (Karewa) Agriculture Research Station, SKUAST-K to determine the effect of different post and pre emergence herbicides application on weed dynamics in maize (Zea mays L.). The experiment was laid out in randomized block design with four replications and variety used was Bio-605. Five treatments Five treatments viz, Atrazine 50% WP @ 1.0 kg ha-1 as pre-emergence and Paraquat dichloride 24% SL @ 0.5 kg ha-1, 2,4-D sodium salt 58% WSC @ 1.0 kg ha-1 as post-emergence herbicides (application at 2-3 leaf stage of weeds), hand weeding as standard check and weedy check as control were used. Effect of different herbicides on weed density was found significant. in plots managed with hand weeding, no weed was recorded. The Atrazine treated plots @ 1.0 kg ai ha-1 as pre-emergence had the weed population of 5.51, 5.4, 3.73, 5.12, 4.28 and 41.4m-2 , respectively in Echinochloa spp., Eleusine indica, Digitaria sanguinalis, Amaranthus viridis, Sorghum halepense and Cyperus spp. However, the maximum population of weeds was recorded in weedy check with 21.54 m-2, 20.87 m-2, 19.16 m-2, 21.5 m-2, 16.7 m-2 and 60.7 m-2. No significant difference was observed between Paraquat dichloride 24% SL @ 0.5 kg ai ha-1 and 2,4- D Sodium salt 58% WSC @ 1.0 kg ai ha-1 except for Cyperus spp. with density of 51.37 m-2 and 43.04 m-2 respectively. The potential of the atrazine in controlling weeds thereby enhancing yield of maize was found in this study.