Integration of Agronomic Practices with Herbicides for Sustainable Weed Management in Aerobic Rice

Abstract

Till now, herbicide seems to be a cost effective tool from an agronomic view point to control weeds. But long term efficacy and sustainability issues are the driving forces behind the reconsideration of herbicide dependent weed management strategy in rice. This demands reappearance of physical and cultural management options combined with judicious herbicide application in a more comprehensive and integrated way. Keeping those in mind, some agronomic tools along with different manual weeding and herbicides combinations were evaluated for their weed control efficacy in rice under aerobic soil conditions. Combination of competitive variety, higher seeding rate, and seed priming resulted in more competitive cropping system in favor of rice, which was reflected in lower weed pressure, higher weed control efficiency, and better yield. Most of the herbicides exhibited excellent weed control efficiency. Treatments comprising only herbicides required less cost involvement but produced higher net benefit. On the contrary, treatments comprising both herbicide and manual weeding required high cost involvement and thus produced lower net benefit. Therefore, adoption of competitive rice variety, higher seed rate, and seed priming along with spraying different early-postemergence herbicides in rotation at 10 days after seeding (DAS) followed by a manual weeding at 30 DAS may be recommended from sustainability view point.

E Efficacy and Economics of Herbicidal Weed Management in Monsoon Rice of Bangladesh

“…Due the higher weed suppressive ability, hybrid rice yielded 15-25% more over inbred cultivars (Walker et al, 2008;Dass et al, 2017). Therefore, through selection of weed competitive cultivars, the weed emergence and its subsequent growth can be suppressed and at the same time reduce the cost of weed management Gibson et al, 2002;2003;Zhao et al, 2006;Rao et al, 2007;Mahajan and Chauhan, 2011;Anwar et al, 2013;Dass et al, 2017). Whereas, Lemerle et al (1996) and reported a higher weed control in combination system of herbicides with crop species or genotypes of superior competitiveness.…”

Integrated weed management approach to improve weed control efficiencies for sustainable rice production in dry-seeded systems

“…In another study, the application of pretilachlor þ safener fb propanil/thiobencarb reduced weed density by 60% compared with the weedy treatment. This reduction was further increased to 75% with the application of pretilachlor þ safener fb propanil/thiobencarb fb bentazon/MCPA (Anwar et al, 2013).…”

“…Depending on the season, location, and management practices used, DSR systems can save total labour requirements by 11e66% and irrigation water need by 35e57% (Bhushan et al, 2007;Jat et al, 2009) compared with puddled transplanted rice. However, one factor that hampers the sustainability and profitability of DSR systems is the prevalence and infestation of weeds, thus, efforts are being made to develop effective and sustainable weed management strategies for these systems (Singh et al, 2006;Anwar et al, 2013).…”

“…For instance, compared with season-long weedy plots, the application of a PRE herbicide followed by a POST herbicide increased rice grain yield by 48e56% in Malaysia (Suria et al, 2011), by 60e82% in Bangladesh , by 76e84% in the Philippines (Chauhan and Opeña, 2013), and by 80e86% in India (Singh et al, 2006). Therefore, in some situations, a PRE herbicide followed by a POST herbicide followed by one handweeding is considered the best weed management option in DSR systems (Mahajan and Timsina, 2011;Anwar et al, 2013;Chauhan and Abugho, 2013).…”

Competitiveness of Winter Rice Varieties against Weed under Dry Direct Seeded Conditions

“…The potentiality of using weed competitive variety in integrated weed management has been documented in many crops including rice [44]- [49]. The deployment of weed competitive variety is not only ecofriendly [50] [51] but also a very cost effective [52] [53]. No work has so far been done to assess the ability of the huge pool of Bangladeshi rice germplasms to wrestle weeds under aerobic soil conditions.…”