Crop Establishment and Weed Control Options for Sustaining Dry Direct Seeded Rice Production in Eastern India

Abstract

Dry direct seeded rice (DSR) has emerged as an economically viable alternative to puddled transplanted rice to address emerging constraints of labor and water scarcity and the rising cost of cultivation. However, wide adoption of DSR is seriously constrained by weed management trade-off. Therefore, the availability of effective weed control options is critical for the success and wide-scale adoption of DSR. A field study was conducted at ICAR-National Rice Research Institute, Cuttack, India, in the dry seasons of 2015 and 2016 to evaluate the performance of three crop establishment methods and five weed control practices on weed management, productivity, profitability and energetics of dry DSR. The results demonstrated that weed density and weed dry weight was lower in drill seeding than broadcast seeding by 26–36% and manual line-seeding by 16–24%, respectively, at 30 and 60 days after crop emergence (DAE). Among herbicides, post-emergence application (17 DAE) of azimsulfuron was most effective in controlling weeds compared to early post application of bispyribac-sodium and bensulfuron-methyl+pretilachlor. Weed competition in the weedy check treatment resulted 58% reduction in rice yield. Among establishment methods, drill-seeding was most profitable with US $ 685 ha−1 higher net income than broadcast seeding primarily due to higher yield. Among weed control treatments, azimsulfuron was most profitable resulting in US $ 160 and 736 ha−1 higher net income than weed free and weedy check, respectively. The specific energy was lowest for drill seeding among establishment method and azimsulfuron among weed control practices, suggesting lowest energy consumed in producing per unit of grain yield.

Weed-Free Durations and Fertilization Regimes Boost Nutrient Uptake and Paddy Yield of Direct-Seeded Fine Rice (Oryza sativa L.)

“…In Asia, it is cultivated with irrigation systems, while in Pakistan, rice is ranked the third most prominent crop, covering 10% of the cultivated area and contributing 17% to the total cereal production [6][7][8]. However, rice cultivation through nursery transplanting in a puddled field is cumbersome, time-consuming and is a prodigal water use method [9]. Under the changing climate, looming water crises and the uncertainty of climatic optima have endangered the sustainability of transplanted rice's production systems, which no longer seems a feasible technique, especially in South Asian countries, such as Pakistan, China, India and Bangladesh.…”

Efficacy of pre- and post-emergence herbicide combinations on weed control in no-till mechanically transplanted rice

“…The post-emergence herbicide fenoxaprop + ethoxysulfuron failed to control sedges; however, this herbicide was reasonably effective at controlling broadleaf weeds. compound, halosulfuron, was very effective at controlling all sedge weeds, including rhizomepropagated plants: consequently, the treatment fenoxaprop fb halosulfuron resulted in a significant reduction in sedge density which has been previously observed in South Asia (Saha et al, 2021).…”

“…Our results demonstrate that either pre-emergence or post-emergence herbicides alone was not able to control weed flora effectively: weed control efficiency was less than 60% in these treatments relative to combinations of pre-and post-emergence herbicides (Table 3). The effectiveness of sequential application of herbicides in managing weed flora under mechanized rice establishment in both no-till and tilled experiments was reported by various studies (Jat et al, 2021;Kaur & Singh, 2015;Kumar & Ladha, 2011;Mahajan & Chauhan, 2015;Rao et al, 2007;Saha et al, 2021;M. Singh et al, 2015;V.…”

“…No pre-emergence herbicide alone was effective at preventing the establishment of weeds at later sampling dates due to the relatively short-lived persistence of pre-emergence herbicides under hot and moist conditions (Saha et al, 2021). Post-emergence herbicides were also able to reduce weed density: in particular, the bispyribac alone or bispyribac + pyrazosulfuron treatments not only controlled both grassy and broadleaf weeds well but also effectively controlled sedges, particularly Cyperus iria which is a major sedge weed in the region (Jat et al, 2021;Saha et al, 2021). In our experiment, bispyribac + pyrazosulfuron and bispyribac alone reduced the grass weed density by 66-67%; while the broadleaf weed density was reduced by 79 and 66% during 35 and 55 DAT, respectively.…”

“…In our experiment, bispyribac + pyrazosulfuron and bispyribac alone reduced the grass weed density by 66-67%; while the broadleaf weed density was reduced by 79 and 66% during 35 and 55 DAT, respectively. This ability of bispyribac-based treatments to suppress many different weed types is attributed to the wide spectrum range of weed flora targeted: bispyribac alone controls grass weeds well, and also to some extent sedges and broadleaf weeds; when combined with a sulfonylurea compound such as pyrazosulfuron it also effectively control sedges and broadleaf weeds in their early growth stages (Gill et al, 2013;Saha et al, 2021;V. Singh et al, 2016).…”