Weed management in direct seeded rice: A review

Abstract

Direct seeding is done by sowing of pre-germinated rice seeds under puddled condition either manually or by drum seeding methods. Direct seeded rice (DSR) cultivation needs only 34 per cent of the total labour requirement and saves 29 per cent of the total cost of the transplanted rice. Weed infestation and competition are severe in direct wet seeded rice as compared to transplanted rice, because of the simultaneous growth of both crops and weeds. Uncontrolled weeds decreased the yield by 96 per cent in dry DSR and 61 per cent in wet DSR. The yield loss due to weeds varies from 40 to 100 per cent in direct seeded rice. Any delay in weeding will lead to increased weed biomass which has a negative correlation with yield. Though manual weeding is considered to be the best, undependable labour availability and escalating labour cost in many cases have given impetus to the development and use of new chemicals for weed control. In contrast to this, chemical weed control offers economic and efficient weed control if applied at proper dose and stage. The combination of chemical, manual and mechanical weed control is an efficient integrated weed management strategy for effective weed control in direct seeded rice.

Weed Dynamics and Productivity of Direct Wet Seeded Rice under Different Weed Management Practices

“…PE herbicide along with EPOE herbicide effectively reduced the weed biomass. This is in agreement with the findings of Bhagat Singh et al (2009) and Rathika and Ramesh (2019) who reported that weeds in DSR could be kept at lower level by herbicides.…”

“…Effective control of weeds in these treatments might be due to application of two herbicides in sequence could be more useful have resulted in decreased weed seed reserve in the soil. This is in line with the findings of Ajay Singh et al (2017) and Rathika and Ramesh (2019).…”

“…Among the BLW, Eclipta alba (L.) and Ammania baccifera (L.) were the dominant species in direct wet seeded rice ecosystem. Such broad spectrum of weeds in direct wet seeded rice ecosystem was also reported by Parameshwari et al, (2015), Raghavendra et al (2015), Goswami et al (2018) and Rathika and Ramesh (2019).…”

“…Uncontrolled weeds decreased the yield by 96 per cent in dry DSR and 61 per cent in wet DSR. The yield loss due to weeds varies from 40 to 100 per cent in direct seeded rice (Rathika et al, 2020). Any delay in weeding will lead to increased weed biomass which has a negative correlation with yield.…”

“…This warrants application of post emerg en ce h erbic id e th at w ill tak e care o f weed s emerging at a later stage. The use of herbicides either singly or in combination with manual or mechanical w eeding in p ud dled direct seed ed ric e h as b een highlighted by several workers (Hussain et al, 2008;Rathika and Ramesh, 2019). Use of alternative herbicides with wide spectrum control of the weeds in direct seeded puddled rice is the need of the present time (Nath et al, 2014).…”