Effect of weed management practices on weed density, weed control efficiency, weed dry weight and yield of direct seeded rice under puddled condition

The present investigation was conducted at Instructional Farm of Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.) India during the kharif season (June-October) 2006. The experiment was laid out in randomized block design comprised of eight treatments of various combinations of different herbicides viz. T1:PIH 2023 10% SC 15 g a.i/ha at 18 DAS; T2: PIH 2023 10% SC 20 g a.i/ha at 18 DAS; T3: PIH 2023 10% SC 25 g a.i/ha at 18 DAS; T4: PIH 2023 10% SC 30 g a.i/ha at18 DAS; T5: PIH 202310% SC 60 g a.i/ha at 18 DAS T6: Almix 20% WP 4 g a.i/ha 18 DAS; T7 :Control (unweeded check) and T8: Hand weeding at 30 DAS with three replications. Rice cultivar “IR-64” was grown as a test crop. The weed dry matter accumulation was significantly highest in unweeded check. Application of PIH 2023 10% SC 25 g a.i/ha attributed to their effective weed killing capacity during the crop growth period and minimum dry matter production in this stage. Grain yeild and stalk yield was maximum under PIH 2023 10% SC 60 g a.i/ha-1. Maximum weed index were noticed under unweeded control whereas minimum weed index were registered under PIH 2023 10% SC 30 g a.i/ha. The maximum weed control efficiency was recorded under PIH 2023 10% SC 25 g a.i/ha-1.Maximum grain yield and straw yield was under PIH 2023 10% SC 60 g a.i/ha Echinochloa colona, Cyperus spp., F. miliaceae, L. hyssopifolia were the pre-dominant weeds in experimental plot. Minimum weed density was noted under post emergence application of Almix 4 g ha-1 and PIH 2023 25 g ha-1 at 20, 40, 70 and 90 DAS. Whereas, at harvest lower dry matter of weeds and highest weed control efficiency was recorded under Almix 4 g ha-1 (T6), PIH 2023 25 g ha-1 and PIH 2023 60 g ha-1, respectively. It was found effective to control broad spectrum of weeds viz., grasses, sedges and forbs.