Pesquisa Agropecuária Tropical (Oct 2010)

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

  • Evander Alves Ferreira,
  • Siumar Pedro Tironi,
  • Leandro Galon,
  • Ignácio Aspiazu,
  • Jesus Juares Oliveira Pinto

DOI
https://doi.org/10.5216/pat.v40i4.5170
Journal volume & issue
Vol. 40, no. 4

Abstract

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

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