Evaluation of Broadleaf Weeds Control with Selectivity of Post-Emergence Herbicides in Sugar Beet (<i>Beta vulgaris</i> L.)

• Main Authors: Ali Asghar CHITBAND, Reza GHORBANI, Mohammad Hassan RASHED MOHASSEL, Majid ABBASPOOR, Rahmat ABBASI
• Format: Article
• Language: English
• Published: University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca 2014-12-01
• Series: Notulae Scientia Biologicae
• Online Access: http://notulaebiologicae.ro/index.php/nsb/article/view/9457

<span style='font-size:10.0pt;font-family:"Times New Roman"; mso-fareast-font-family:SimSun;letter-spacing:-.2pt;mso-ansi-language:EN-US; mso-fareast-language:ZH-CN;mso-bidi-language:AR-SA'>The reduction of herbicide applications is a main research priority in recent years. In order to study the effect of individual post-emergence application of sugar beet broad-leaf herbicides at four to six true-leaf stage of weeds</span></a>, experiments were conducted during 2013. Treatments included untreated control and several rates of desmedipham + phenmedipham + ethofumesate, chloridazon and clopyralid on </span></a><i>Portulaca oleracea</i>,<i> Solanum nigrum</i>, <i>Amaranthus retroflexus</i> and<i> Chenopodium album</i>. A completely randomized layout with three replications was used for each herbicide. Three weeks after spraying (WAS), plants were harvested and measured their dry weight. These herbicides were more effective to control <i>Portulaca oleracea</i> than other weeds, thereupon minimum dose required for a satisfactory efficacy of 90% reduction of Portulaca oleracea</span></i><span style='mso-bookmark:OLE_LINK16'> aboveground dry matter </span></a>(ED₉₀) were 299.22, 1138.31 and 129.44 g</span></span></span></st1:metricconverter><span style='mso-bookmark:OLE_LINK17'><span style='mso-bookmark:OLE_LINK18'><span style='font-size:10.0pt;font-family:"Times New Roman";mso-fareast-font-family: SimSun;letter-spacing:-.2pt;mso-ansi-language:EN-US;mso-fareast-language:ZH-CN; mso-bidi-language:AR-SA'> a.i ha^-1 </span></span></span><span style='font-size:10.0pt;font-family:"Times New Roman";mso-fareast-font-family: SimSun;letter-spacing:-.2pt;mso-ansi-language:EN-US;mso-fareast-language:ZH-CN; mso-bidi-language:AR-SA'>of desmedipham + phenmedipham + ethofumesate, chloridazon and clopyralid, respectively. <i>Solanum nigrum</i> was more affected by clopyralid application (</span><st1:metricconverter ProductID="132.40 g"><span style='font-size:10.0pt;font-family:"Times New Roman"; mso-fareast-font-family:SimSun;letter-spacing:-.2pt;mso-ansi-language:EN-US; mso-fareast-language:ZH-CN;mso-bidi-language:AR-SA'>132.40 g</span></st1:metricconverter><span style='font-size:10.0pt;font-family:"Times New Roman";mso-fareast-font-family: SimSun;letter-spacing:-.2pt;mso-ansi-language:EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:AR-SA'> a.i ha^-1), and did not make significant difference in <i>Portulaca oleracea</i>. Chloridazon had lower effect for control of <i>Chenopodium album</i> due to existence of powdery covering on abaxial side of the leaves. Biomass <span style='mso-bidi-font style:italic'>ED₅₀ or ED₉₀</span>, based on log-logistic dose–response curves, for <i>Chenopodium album</i> was considerably higher than other species. These results showed that tank mixtures with other herbicides may be required for satisfactory weed control and reduction in applied herbicides doses.</span>