Manejo químico de plantas adultas de Digitaria insularis com glyphosate isolado e em mistura com chlorimuronethyl ou quizalofop-p-tefuril em área de plantio direto
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Data
2009-09-01
Autores
Correia, Núbia Maria [UNESP]
Durigan, Julio Cezar [UNESP]
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ISSN da Revista
Título de Volume
Editor
Instituto Agronômico de Campinas
Resumo
O objetivo deste trabalho foi avaliar a eficácia do herbicida glyphosate, isolado e em mistura com chlorimuron-ethyl ou quizalofop-p-tefuril, e o efeito da adição de óleo mineral à calda de glyphosate e chlorimuron-ethy no controle de plantas adultas de Digitaria insularis, em área sob sistema de plantio direto. Foram desenvolvidos dois experimentos, em condições de campo, um de novembro de 2005 a fevereiro de 2006 e outro de novembro de 2006 a janeiro de 2007, em Jaboticabal (SP). O delineamento experimental foi o de blocos ao acaso, em esquema fatorial, com quatro repetições. No primeiro experimento, foram avaliadas oito combinações (Fator A) entre o glyphosate (0,72; 1,44; 2,16 e 2,88 kg ha-1) e o chlorimuron-ethyl (0 e 10 g ha-1), três doses (Fator B) de óleo mineral (0; 0,5 e 1,0 L ha-1) e uma testemunha mantida infestada sem a aplicação de herbicida. No segundo, foram estudadas seis associações (Fator A) entre o glyphosate (1,44; 2,16 e 2,88 kg ha-1) e o quizalofop-p-tefuril (0 e 120 g ha-1) e um tratamento de quizalofop-p-tefuril (120 g ha-1) isolado, combinados com aplicações sequenciais (Fator B) de glyphosate (0; 0,72 e 1,44 kg ha-1), pulverizado 15 dias após a primeira a aplicação, além de uma testemunha infestada sem a aplicação de herbicida. Nas avaliações iniciais, no experimento de 2005/ 2006, em plantas pulverizadas com as maiores doses de glyphosate, isolado ou em mistura ao chlorimuron, havia injúrias visuais severas, com classificação do controle de bom (71% a 80%) a muito bom (81% a 90%). Com o decorrer do tempo, as plantas rebrotaram revelando seu potencial de recuperação e a ineficácia dos herbicidas no controle definitivo desta espécie. A adição de óleo mineral à calda de glyphosate e chlorimuron não contribuiu para o controle de D. insularis. No outro experimento, o quizalofop isolado e a sua associação ao glyphosate, combinados à aplicação sequencial de 1,44 kg ha-1 de glyphosate, resultaram em melhor controle da planta daninha.
The objective of this work was to evaluate the efficiency of the herbicide glyphosate used alone, in combination with chlorimuron-ethyl and quizalofop-p-tefuril as well as the effect of the addition of mineral oil to control adult Digitaria insularis plants in a no-tillage field. Two experiments were conducted under field conditions from November 2005 to February 2006 and from November 2006 to January 2007, at Jaboticabal, São Paulo State, Brazil. Experiments were set in randomized blocks with four replications. In the first experiment (2005/06) it were tested eight combinations among glyphosate (0.72; 1.44; 2.16 and 2.88 kg ha-1), chlorimuron-ethyl (0 and 10 g ha-1) mineral oil (0; 0.5 and 1.0 L ha-1) and an infested, untreated control. In the second experiment (2006/07) it were tested six associations among glyphosate (1.44; 2.16 and 2.88 kg ha-1), quizalofop-p-tefuril (0 and 120 g ha-1), quizalofop-p-tefuril (120 g ha-1) alone and combined to three (0; 0.72 and 1.44 kg ha-1) glyphosate doses, sprayed 15 days after the first application, besides an infested and untreated control. In 2005/06, plants sprayed with higher glyphosate doses, alone or combined with chlorimuron, showed severe injuries, with a control classification ranging from good (71 to 80%) to very good (81 to 90%). Over time plants tillered and showed their recovery potential and the inefficiency of the herbicides to control this weed species. The addition of mineral oil to glyphosate and chlorimuron solution did not entrance its efficiency. In the other experiment, the quizalofop alone or associated with glyphosate, combined to sequential application of glyphosate 1.44 kg ha-1, resulted in the best weed control.
The objective of this work was to evaluate the efficiency of the herbicide glyphosate used alone, in combination with chlorimuron-ethyl and quizalofop-p-tefuril as well as the effect of the addition of mineral oil to control adult Digitaria insularis plants in a no-tillage field. Two experiments were conducted under field conditions from November 2005 to February 2006 and from November 2006 to January 2007, at Jaboticabal, São Paulo State, Brazil. Experiments were set in randomized blocks with four replications. In the first experiment (2005/06) it were tested eight combinations among glyphosate (0.72; 1.44; 2.16 and 2.88 kg ha-1), chlorimuron-ethyl (0 and 10 g ha-1) mineral oil (0; 0.5 and 1.0 L ha-1) and an infested, untreated control. In the second experiment (2006/07) it were tested six associations among glyphosate (1.44; 2.16 and 2.88 kg ha-1), quizalofop-p-tefuril (0 and 120 g ha-1), quizalofop-p-tefuril (120 g ha-1) alone and combined to three (0; 0.72 and 1.44 kg ha-1) glyphosate doses, sprayed 15 days after the first application, besides an infested and untreated control. In 2005/06, plants sprayed with higher glyphosate doses, alone or combined with chlorimuron, showed severe injuries, with a control classification ranging from good (71 to 80%) to very good (81 to 90%). Over time plants tillered and showed their recovery potential and the inefficiency of the herbicides to control this weed species. The addition of mineral oil to glyphosate and chlorimuron solution did not entrance its efficiency. In the other experiment, the quizalofop alone or associated with glyphosate, combined to sequential application of glyphosate 1.44 kg ha-1, resulted in the best weed control.
Descrição
Palavras-chave
sourgrass, Brazilian cerrado, desiccation, Chemical control, capim amargoso, Cerrado, dessecação, Controle químico
Como citar
Bragantia. Instituto Agronômico de Campinas, v. 68, n. 3, p. 689-697, 2009.