Influence of supplementary hoe weeding on the efficacy of ButaForce for lowland rice (Oryza sativa L.) weed management

Field experiments to determine the influence of supplementary hoe weeding on the efficacy of ButaForce (N-(butoxymethyl)-2-chloro-N-2,6-dimethyl acetanilide) for low land rice (Oryza sativa L.) weed management was conducted at the Faculty of Agriculture Teaching and Research Farm of the University of Port Harcourt during the early cropping seasons of 2018 and 2019. Seven treatments were used for the experiment namely:  ButaForce at 1.5 L/ha + SHW (21 DAS), ButaForce  at 2.0 L/ha + SHW (21 DAS), ButaForce at 2.5 L/ha + SHW (21DAS), ButaForce at 3.0 L/ha (recommended rate), weed-free (weekly weeding), hoe weeded twice at 21 and 42 DAS and weedy check. The treatments were laid out in a Randomized Complete Block Design (RCBD) with three replicates. Results from the study showed that weed-free check (weekly weeding) was more effective in weed control in lowland rice. It also gave the highest growth and yield attributes over all other treatments. Weed suppression and rice performance was better in plots treated with ButaForce at 2.5 L/ha + SHW (21 DAS) than in other supplementary hoe weeding. The economic analysis showed  that although hoe weeded plots had higher yields, the profit obtained from them were lower when compared with the supplementary hoe weeding and ButaForce at 3.0 L/ha. Among all the weed control treatment, plots treated with ButaForce at 2.5 L/ha with supplementary hoe weeding gave the highest profit. Since the highest profit was recorded in plots treated with ButaForce at 2.5 L/ha with supplementary hoe weeding, it is therefore recommended to rice farmers in the study area. Key words:  Hoe weeding, lowland rice, supplementary, weed management, economic analysis.