Weeds of direct-seeded rice in Asia: problems and opportunities

Matloob, Amar, Khaliq, Abdul and Chauhan, Bhagirath Singh (2015) Weeds of direct-seeded rice in Asia: problems and opportunities. Advances in Agronomy, 130 291-336. doi:10.1016/bs.agron.2014.10.003

Author Matloob, Amar
Khaliq, Abdul
Chauhan, Bhagirath Singh
Title Weeds of direct-seeded rice in Asia: problems and opportunities
Journal name Advances in Agronomy   Check publisher's open access policy
ISSN 0065-2113
Publication date 2015
Year available 2015
Sub-type Article (original research)
DOI 10.1016/bs.agron.2014.10.003
Open Access Status
Volume 130
Start page 291
End page 336
Total pages 46
Place of publication Maryland Heights, MO, United States
Publisher Academic Press
Collection year 2016
Language eng
Formatted abstract
Rice production symbolizes the single largest land use for food production on the Earth. The significance of this cereal as a source of energy and income seems overwhelming for millions of people in Asia, representing 90% of global rice production and consumption. Estimates indicate that the burgeoning population will need 25% more rice by 2025 than today's consumption. As the demand for rice is increasing, its production in Asia is threatened by a dwindling natural resource base, socioeconomic limitations, and uncertainty of climatic optima. Transplanting in puddled soil with continuous flooding is a common method of rice crop establishment in Asia. There is a dire need to look for rice production technologies that not only cope with existing limitations of transplanted rice but also are viable, economical, and secure for future food demand.

Direct seeding of rice has evolved as a potential alternative to the current detrimental practice of puddling and nursery transplanting. The associated benefits include higher water productivity, less labor and energy inputs, less methane emissions, elimination of time and edaphic conflicts in the rice–wheat cropping system, and early crop maturity. Realization of the yield potential and sustainability of this resource-conserving rice production technique lies primarily in sustainable weed management, since weeds have been recognized as the single largest biological constraint in direct-seeded rice (DSR). Weed competition can reduce DSR yield by 30–80% and even complete crop failure can occur under specific conditions. Understanding the dynamics and outcomes of weed–crop competition in DSR requires sound knowledge of weed ecology, besides production factors that influence both rice and weeds, as well as their association. Successful adoption of direct seeding at the farmers' level in Asia will largely depend on whether farmers can control weeds and prevent shifts in weed populations from intractable weeds to more difficult-to-control weeds as a consequence of direct seeding. Sustainable weed management in DSR comprises all the factors that give DSR a competitive edge over weeds regarding acquisition and use of growth resources. This warrants the need to integrate various cultural practices with weed control measures in order to broaden the spectrum of activity against weed flora. A weed control program focusing entirely on herbicides is no longer ecologically sound, economically feasible, and effective against diverse weed flora and may result in the evolution of herbicide-resistant weed biotypes. Rotation of herbicides with contrasting modes of action in conjunction with cultural measures such as the use of weed-competitive rice cultivars, sowing time, stale seedbed technique, seeding rate, crop row spacing, fertilizer and water inputs and their application method/timing, and manual and mechanical hoeing can prove more effective and need to be optimized keeping in view the type and intensity of weed infestation. This chapter tries to unravel the dynamics of weed–crop competition in DSR. Technological issues, limitations associated with DSR, and opportunities to combat the weed menace are also discussed as a pragmatic approach for sustainable DSR production. A realistic approach to secure yield targets against weed competition will combine the abovementioned strategies and tactics in a coordinated manner. This chapter further suggests the need of multifaceted and interdisciplinary research into ecologically based weed management, as DSR seems inevitable in the near future.
Keyword Cultural strategies
Dry-seeded rice
Integrated weed management
Weed ecology
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Queensland Alliance for Agriculture and Food Innovation
Official 2016 Collection
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Citation counts: Scopus Citation Count Cited 5 times in Scopus Article | Citations
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Created: Tue, 24 Feb 2015, 00:52:43 EST by System User on behalf of Qld Alliance for Agriculture and Food Innovation