Assessment of seed rate and weed management practice on weed control, crop productivity and profitability of dry direct-seeded rice

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Dry direct-seeded rice (DDSR) is gaining attention as a sustainable alternative to traditional transplanted rice, addressing critical issues like water scarcity, labour shortage, and high production costs. However, heavy weed infestation poses a major limitation, significantly reducing yields. To evaluate optimal weed management and seeding rates, a field study was conducted during 2021 and 2022 at ICAR-Directorate of Weed Research, Jabalpur, India. The experiment tested four seed rates (30, 40, 50, and 100 kg ha -1 ) and four weed management practices {pendimethalin 38.7% CS at 678 g a.i. ha -1 [2 days after sowing (DAS) as pre-emergence (PE)] followed by ( fb ) bispyribac-sodium 10% SC at 25 g a.i. ha -1 [20 DAS, as post-emergence (PoE)], pretilachlor 30% + pyrazosulfuron-ethyl 0.75% WG 615 g a.i. ha -1 (PE) fb cyhalofop-butyl 5.1% + penoxsulam 1.02% OD 135 g a.i. ha -1 (PoE), pretilachlor 30% + pyrazosulfuron-ethyl 0.75% WG 615 g a.i. ha -1 (PE) fb hand weeding at 30 DAS and weedy check} on weed control, crop productivity and profitability. Results revealed that a seed rate of 100 kg ha -1 significantly suppressed weeds by 27.3–33.2% due to higher plant density. Interestingly, the lowest seed rate (30 kg ha -1 ) led to better crop growth parameters, such as biomass, leaf area, and grain characteristics. Despite this, the highest grain yield (4641–5691 kg ha -1 ) and profitability (693–882 USD ha -1 ) were achieved at a moderate seed rate of 40 kg ha -1 . Among weed management practices, the combination of pretilachlor + pyrazosulfuron-ethyl fb cyhalofop-butyl + penoxsulam proved most effective, with 90.8–96.7% weed control efficiency, enhanced crop growth and grain yield (4612–5494 kg ha -1 ), and returns of 829–1089 USD ha -1 . In conclusion, seeding at 40 kg ha -1 coupled with integrated herbicide application is the most effective strategy for maximizing weed suppression, crop productivity, and economic returns in DDSR systems.