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Weed Ecology and Weed Management Strategies for Dry-Seeded Rice in Asia

Published online by Cambridge University Press:  20 January 2017

Bhagirath S. Chauhan
Bhagirath S. Chauhan*
Affiliation:
International Rice Research Institute, Los Baños, Philippines
*
Corresponding author's E-mail: b.chauhan@cgiar.org
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Abstract

Rice is a principal source of food for more than half of the world population, and more than 90% of rice worldwide is grown and consumed in Asia. A change in establishment method from manual transplanting of rice seedlings to dry-seeded rice (DSR) has occurred in some countries as growers respond to increased costs or decreased availability of labor or water. However, weeds are a major constraint to DSR production because of the absence of the size differential between the crop and the weeds and the suppressive effect of standing water on weed growth at crop establishment. Herbicides are used to control weeds in DSR, but because of concerns about the evolution of herbicide resistance and a scarcity of new and effective herbicides, there is a need to integrate other weed management strategies with herbicide use. In addition, because of the variability in the growth habit of weeds, any single method of weed control cannot provide effective and season-long control in DSR. Various weed management approaches need to be integrated to achieve effective, sustainable, and long-term weed control in DSR. These approaches may include tillage systems; the use of crop residue; the use of weed-competitive cultivars with high-yield potential; appropriate water depth and duration; appropriate agronomic practices, such as row spacing and seeding rates; manual or mechanical weeding; and appropriate herbicide timing, rotation, and combination. This article aims to provide a logical perspective of what can be done to improve weed management strategies in DSR.

El arroz es una de las principales fuentes de alimentación para más de la mitad de la población del mundo; a nivel global, más del 90% es cultivado y consumido en Asia. Un cambio en el método de establecimiento de trasplante manual de plántulas de arroz a siembra directa de la semilla (DSR), ha ocurrido en algunos países conforme los agricultores responden al incremento de costos o reducciones en la disponibilidad de mano de obra o agua. Sin embargo, la maleza constituye una importante limitante para la producción DSR, debido a la ausencia de tamaño diferencial entre el cultivo y la maleza, y al efecto restrictivo del agua encharcada en el crecimiento de la maleza durante el establecimiento del arroz. Herbicidas son usados para el control de la maleza en DSR, pero debido a la preocupación por la evolución de la resistencia a los mismos y a la escasez de herbicidas nuevos y eficaces, existe una necesidad de integrar otras estrategias de manejo de maleza con el uso de herbicidas. Además, debido a la variabilidad en los hábitos de crecimiento de la maleza, un solo método individual de control no puede proporcionar a lo largo de la estación un control eficaz en DSR. Varios enfoques de manejo de la maleza necesitan integrarse para lograr en DSR un control eficaz, sustentable y de larga duración. Estos enfoques podrían incluir sistemas de labranza, el uso de residuos de cultivo, el uso de cultivares competitivos con la maleza con alto potencial de rendimiento, apropiada profundidad y duración de agua, prácticas agronómicas adecuadas tales como espacio entre surcos y densidad de siembra, deshierbe manual o mecánico, tiempo apropiado de control, rotación y combinación. El objetivo de este documento es proporcionar una perspectiva lógica de lo que puede hacerse para mejorar las estrategias de manejo de maleza en DSR.

Keywords

RiceOryza sativa L.Stale seedbedseeding raterow spacingfloodingresiduetillage systemzero-tillherbicide
Type
Review
Information
Weed Technology , Volume 26 , Issue 1 , March 2012 , pp. 1 - 13
Copyright
Copyright © Weed Science Society of America 

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