CHEMICAL CONTROL EVALUATION OF ALEXANDER GRASS (Brachiaria plantaginea) ON MAIZE (Zea mays) YIELD AVALIAÇÃO DO MÉTODO QUÍMICO DE CONTROLE DE PAPUÃ (Brachiaria plantaginea) SOBRE A PRODUTIVIDADE DO MILHO

• Main Authors: Evander Alves Ferreira, Siumar Pedro Tironi, Leandro Galon, Ignácio Aspiazu, Jesus Juares Oliveira Pinto
• Format: Article
• Language: English
• Published: Universidade Federal de Goiás 2010-10-01
• Series: Pesquisa Agropecuária Tropical
• Subjects: Controle químico; misturas herbicidas; planta daninha
• Online Access: http://www.revistas.ufg.br/index.php/pat/article/view/5170
• ISSN: 1983-4063

&lt;p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="pt-BR" align="JUSTIFY"&gt;&lt;span style="color: #000000;"&gt;&lt;span style="font-family: Times New Roman,serif;"&gt;&lt;span style="font-size: small;"&gt;The objective of this study was to evaluate the &lt;em&gt;Brachiaria plantaginea&lt;/em&gt; control with pre and post-emergence herbicides and their effects on the hybrid Pioneer 3063 maize yield. The trial was conducted by using a complete randomized blocks design, with four replications, under the conventional sowing system. The treatments consisted of the herbicide s-metolachlor (1,620 g ha&lt;sup&gt;-1&lt;/sup&gt;) and the mixture in tank of atrazine + nicosulfuron (1,250 + 28 g ha&lt;sup&gt;-1&lt;/sup&gt;), applied in pre and early post-emergence of the culture, respectively, plus one infested and one weed-free control. The plants of &lt;em&gt;B. plantaginea&lt;/em&gt; were obtained from the soil seed bank, with average population of 312 plants m&lt;sup&gt;-2&lt;/sup&gt;. The evaluated variables were control of &lt;em&gt;B. plantaginea&lt;/em&gt; by the herbicides and maize grain yield components, as well as grain yield. Among the herbicides, the one that provided better control of &lt;em&gt;B. plantaginea&lt;/em&gt; was the mixture atrazine plus nicosulfuron, applied in post-emergence of the crop, maintaining the field free of &lt;em&gt;B. plantaginea&lt;/em&gt;, from the beginning to the end of the cycle. The herbicide s-metolachlor showed to be an alternative for the initial control of weeds in maize, up to 20 days after emergence. The absence of &lt;em&gt;B. plantaginea&lt;/em&gt; control causes interference in all grain yield components of maize, being observed up to 98% of grain yield losses.&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt; &lt;p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="en-US" align="JUSTIFY"&gt;&lt;span style="color: #000000;"&gt;&lt;span style="font-family: Times New Roman,serif;"&gt;&lt;span style="font-size: small;"&gt;KEY-WORDS: Chemical control; herbicide mixtures; weed.&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;<br>&lt;p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="pt-BR" align="JUSTIFY"&gt;&lt;span style="color: #000000;"&gt;&lt;span style="font-family: Times New Roman,serif;"&gt;&lt;span style="font-size: small;"&gt;Objetivou-se, com o trabalho, avaliar o controle de &lt;em&gt;Brachiaria plantaginea&lt;/em&gt;, com herbicidas aplicados em pr&amp;eacute; e p&amp;oacute;s-emerg&amp;ecirc;ncia, e a influ&amp;ecirc;ncia destes na produtividade do milho h&amp;iacute;brido Pioneer 3063. Adotou-se o delineamento experimental de blocos casualizados, em sistema de cultivo convencional, com quatro repeti&amp;ccedil;&amp;otilde;es. Os tratamentos foram constitu&amp;iacute;dos pelo herbicida s-metolachlor (1.620 g ha&lt;sup&gt;-1&lt;/sup&gt;) e pela mistura em tanque de atrazine + nicosulfuron (1.250 + 28 g ha&lt;sup&gt;-1&lt;/sup&gt;), aplicados em pr&amp;eacute; e p&amp;oacute;s-emerg&amp;ecirc;ncia da cultura do milho, respectivamente, mais testemunha capinada e infestada. A popula&amp;ccedil;&amp;atilde;o &lt;em&gt;B. plantaginea&lt;/em&gt; originou-se do banco de sementes, com popula&amp;ccedil;&amp;atilde;o m&amp;eacute;dia de 312 plantas m&lt;sup&gt;-2&lt;/sup&gt;. As vari&amp;aacute;veis avaliadas foram o controle de &lt;em&gt;B. plantaginea&lt;/em&gt; e os componentes do rendimento, bem como a produtividade de gr&amp;atilde;os de milho. O tratamento herbicida que proporcionou melhor controle da planta daninha foi a mistura de atrazine + nicosulfuron, aplicada em p&amp;oacute;s-emerg&amp;ecirc;ncia da cultura, mantendo-se o controle do in&amp;iacute;cio ao fim do ciclo da cultura. O herbicida s-metolachlor mostrou efici&amp;ecirc;ncia no controle inicial de plantas daninhas, at&amp;eacute; os 20 dias ap&amp;oacute;s a emerg&amp;ecirc;ncia da cultura. O n&amp;atilde;o controle de &lt;em&gt;B. plantaginea&lt;/em&gt; causou interfer&amp;ecirc;ncia em todas as vari&amp;aacute;veis avaliadas, apresentando limita&amp;ccedil;&amp;atilde;o de produtividade de gr&amp;atilde;os de at&amp;eacute; 98%. &lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt; &lt;p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="pt-BR" align="JUSTIFY"&gt;&lt;span style="color: #000000;"&gt;&lt;span style="font-family: Times New Roman,serif;"&gt;&lt;span style="font-size: small;"&gt;PALAVRAS-CHAVE: Controle qu&amp;iacute;mico; misturas herbicidas; planta daninha.&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;