Weed Diversity in Rice Ecosystems: Taxonomy, Ecology, Identification, and Integrated Management Strategies

Abstract

Rice production systems worldwide are challenged by diverse weed communities that compete aggressively for nutrients, water, light, and space, causing substantial yield losses and increasing production costs. Weed interference remains one of the most important biological constraints to rice productivity, particularly in direct-seeded rice systems where crop–weed competition begins immediately after emergence. This review synthesizes current knowledge on the taxonomy, morphology, ecology, economic significance, and management of major weed species occurring in rice ecosystems. Particular emphasis is given to dominant grass weeds including Echinochloa crus-galli, Echinochloa colona, and Leptochloa chinensis; sedges such as Cyperus rotundus, Cyperus difformis, and Fimbristylis miliacea; and broadleaved weeds including Eclipta prostrata, Ammannia baccifera, and Acalypha indica. Diagnostic morphological traits useful for field identification are discussed alongside ecological adaptations that contribute to weed persistence and competitiveness. The review further evaluates integrated weed management strategies encompassing cultural, mechanical, biological, and chemical approaches. Special attention is given to herbicide resistance evolution, precision weed management technologies, artificial intelligence-assisted weed recognition systems, and emerging bioherbicide-based solutions. Sustainable rice production will increasingly depend on integrated and knowledge-intensive weed management programs that combine accurate species identification, diversified control tactics, and advanced decision-support technologies.

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