[en] Sprinkler irrigation can reduce the irrigation water needed to grow rice. However, most available information on weed control with herbicides is related to flood irrigated rice because this is the main growing method. Field experiments were conducted at Zaragoza (Spain) during two years to study weed control and tolerance of sprinkler irrigated rice to several herbicides. The main weeds were Atriplex prostrata Bouchér ex DC., Cyperus rotundus L., Echinochloa crus-galli (L.) Beauv. and Sonchus oleraceus L. Rice cv Guadiamar was tolerant to preemergence (PRE) application of clomazone at 0.36 kg ha-1 and oxadiazon at 0.5 kg ha–1. PRE application of pendimethalin at 1.32 kg ha–1 combined with clomazone at 0.36 kg ha-1 decreased rice yield. Postemergence (POST) application of bentazon at 1.6 kg ha–1 + MCPA at 0.25 kg ha–1 did not injure rice but POST application of azimsulfuron at 0.025 kg ha–1 produced visual crop injury. Only treatments that controlled grassy weeds since rice was planted and by more than 80% at harvest time lead to acceptable rice yield (&gt; 5,000 kg ha–1). Clomazone applied PRE at 0.36 kg ha–1 provided good control of grassy weeds (&gt; 80%) and the highest rice yield, so it is recommended as a selective and efficacious PRE treatment for weed control of annual weeds in sprinkler irrigated rice. The perennial purple nutsedge was difficult to control at high plant densities (&gt; 150 plants m–2) and the recommended herbicide is azimsulfuron applied at POST at 0.02 kg ha–1.

[es] El riego por aspersion puede reducir el riego necesario en arroz. Sin embargo, casi toda la informaci&oacute;n sobre control de malas hierbas con herbicidas se refiere a arroz inundado por ser la forma principal de cultivo. Se realizaronensayos de campo durante dos a&ntilde;os para estudiar el control de malas hierbas y la selectividad de diversos herbicidas en arroz regado por aspersi&oacute;n. Las principales malas hierbas fueron Atriplex prostrata Bouch&eacute;r ex DC., Cyperus rotundus L., Echinochloa crus-galli (L.) Beauv. y Sonchus oleraceus L. El arroz cv Guadiamar toler&oacute; las aplicaciones en preemergencia (PRE) de clomazona a 0,36 kg ha&ndash;1 y de oxadiaz&oacute;n a 0,5 kg ha&ndash;1. La aplicaci&oacute;n en PRE de pendimetalina a 1,32 kg ha&ndash;1 combinada con clomazona a 0,36 kg ha&ndash;1 disminuy&oacute; el rendimiento del arroz. La aplicaci&oacute;n en postemergencia (POST) de bentazona a 1,6 kg ha&ndash;1 + MCPA a 0,25 kg ha&ndash;1 no afect&oacute; al arroz, pero la aplicaci&oacute;n en POST de azimsulfur&oacute;n a 0,025 kg ha&ndash;1 produjo fototoxicidad visual. Solamente los tratamientos que controlaron m&aacute;s de un 80% las gram&iacute;neas desde la siembra del arroz hasta la cosecha obtuvieron rendimientos aceptables de arroz (&gt; 5.000 kg ha&ndash;1). La aplicaci&oacute;n de clomazona en PRE a 0,36 kg ha&ndash;1 control&oacute; de forma eficaz las gram&iacute;neas (&gt; 80%) y produjo los mayores rendimientos de arroz, recomend&aacute;ndose para el control de malas hierbas anuales en arroz regado por aspersi&oacute;n. La junquilla fue dif&iacute;cil de controlar a densidades altas (&gt; 150 plantas m&ndash;2), siendo el herbicida recomendado el azimsulfur&oacute;n a 0,02 kg ha&ndash;1.