Weed Technology 2015 29:56–62 Broadleaf Weed Control in Winter-Sown Lentil (Lens culinaris) Hassan Karimmojeni, Ali Reza Yousefi, Per Kudsk, and Amir Hossein Bazrafshan* Winter sowing of lentil results in higher yields than a spring-sown crop. However, when lentil is winter-sown, the critical period of weed control is extended and might require sequential herbicide management strategies to obtain maximum yields. The efficacy of POST alone or soil applied followed by (fb) POST herbicides or hand weeding were evaluated in 2002 and 2003. Trifluralin (PPI) or pendimethalin (PRE) were applied at planting, and pyridate or oxyfluorfen were applied POST at the three- to four-leaf stage of lentil. The lowest level of weed biomass was recorded with all treatments, except pyridate alone in both years, pendimethalin PRE fb pyridate in 2002, and oxyfluorfen in 2003. Application of pyridate or oxyfluorfen POST alone resulted in lower yields. In 2002, trifluralin PPI or pendimethalin PRE fb one hand weeding or pendimethalin fb pyridate resulted in yields similar to the weed-free treatment. In 2003, yields were similar to the weed-free treatment, except pyridate or oxyfluorfen alone and trifluralin PPI fb oxyfluorfen. Weed species observed in the present study required sequential management to achieve both effective control and maximum lentil yield. Nomenclature: Oxyfluorfen; pendimethalin; pyridate; trifluralin; lentil, Lens culinaris Medik. ‘Ziba’. Key words: Amaranthus blitoides, black nightshade, common cocklebur, common lambsquarters, chemical weed control, Chenopodium album, hand weeding, POST herbicides, prostrate pigweed, Solanum nigrum, Xanthium strumarium. La siembra en invierno de lenteja resulta en mayores rendimientos que la siembra en la primavera. Sin embargo, cuando se produce lenteja en el invierno, el per´ıodo cr´ıtico para el control de malezas es ma´s largo y puede requerir estrategias de manejo con aplicaciones secuenciales de herbicidas para obtener rendimientos ma´ximos. En 2002 y 2003, se evalu´ o la eficacia de herbicidas POST aplicados solos, de herbicidas aplicados al suelo seguidos (fb) de herbicidas POST, y de deshierba manual. Trifluralin (PPI) o pendimethalin (PRE) fueron aplicados a la siembra, y pyridate u oxyfluorfen fueron aplicados POST en los estadios de desarrollo de tres a cuatro hojas de la lenteja. La menor biomasa de malezas se registr´ o con todos los tratamientos, excepto pyridate solo, en ambos a˜ nos, pendimethalin PRE fb pyridate en 2002, y oxyfluorfen en 2003. La aplicaci´ on POST de pyridate u oxyfluorfen solos result´ o en rendimientos ma´s bajos. En 2002, trifluralin PPI o pendimethalin PRE fb deshierba manual o pendimethalin fb pyridate result´ o en rendimientos similares al testigo libre de malezas. En 2003, los rendimientos fueron similares al testigo libre de malezas, excepto por pyridate u oxyfluorfen solos y trifluralin PPI fb oxyfluorfen. Las especies de malezas que se observaron en el presente estudio requirieron un manejo secuencial para alcanzar un control efectivo y un rendimiento ma´ximo de la lenteja. Lentil is an important legume crop in both rainfed and irrigated cropping systems in several regions around the world (Mohamed et al. 1997). In 2010, the world’s total harvested area of lentil was 4.2 million ha, with a total production of 4.6 million tons. The average lentil yield in Iran is 489 kg ha 1 , and it is low compared to the global average of 1,094 kg ha 1 (FAOSTAT 2010). Many factors, such as lack of certified seed and poor crop management, contribute to the low yields (Kayan and Adak 2006), but weeds are also a major constraint to achieving higher yields in lentil. Lentils are poor competitors with weeds because of their short stature, slow establishment, and limited vegetative growth (Ball et al. 1997; Elkola et al. 2004; Tepe et al. 2004). The low competitive ability of lentil is compounded under low temper- ature and dry conditions; thus, weed management in lentil is crucial for maximum yield and quality DOI: 10.1614/WT-D-13-00184.1 * First and fourth author: Assistant Professor and Graduate Student, Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan, Iran; second author: Associate Professor, Department of Agronomy and Plant Breeding, University of Zanjan, Zanjan, Iran; third author: Professor, Department of Agroecology, Aarhus University, Flakkebjerg, DK-4200 Slagelse, Denmark. Corresponding author’s E-mail: yousefi. alireza@znu.ac.ir 56  Weed Technology 29, January–March 2015