Control of broadleaf weeds with post-emergence herbicides in four barley (Hordeum spp.) cultivars

Limited information is available on control of broadleaf weeds in barley and response of barley cultivars to herbicides. Field experiments were conducted from 2007 to 2009 to evaluate, post-emergence herbicides for control of broadleaf weeds in four barley cultivars. Herbicide treatments included 2,4-D sodium salt at 500 g ai ha(-1), carfentrazone-ethyl at three rates (15, 20 and 25 g ai ha(-1)), and metsulfuron-methyl at 4 and 5 g ai ha(-1). The results suggested that density of broadleaf weeds was not affected by barley cultivars in 2007 and 2008, but it was influenced in 2009. Application of carfentrazbne-ethyl or metsulfuron-methyl at all the rates was effective to reduce density and biomass of broadleaf weeds in all the years. A variable response was observed for yield attributes among barley cultivars. Barley grain yield was similar in all barley cultivars in 2007; however, higher yield was recorded in 'DWRUB 52' in 2008 and 2009 compared to other cultivars. All herbicide treatments Were usually effective to secure higher barley yields in all the years and there was a significant interaction between barley cultivars and weed management treatments. Hand hoeing was not as effective as herbicide treatments to reduce density and biomass of broadleaf weeds; however, barley yield was usually comparable with herbicide treatments. Results also revealed that there was no significant herbicide injury on any barley, cultivar during three year experiments. It is concluded that carfentrazone-ethyl and metsulfuron-methyl are additional tools for broadleaf weed control in barley. However, more research is required-to evaluate efficacy of these herbicides as a tank mix partner that may increase weed control spectrum in barley. (C) 2012 Elsevier Ltd. All rights reserved.