Seletividade de herbicidas pré-emergentes para gramíneas forrageiras tropicais
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Data
2002-12-01
Autores
Alves, E. [UNESP]
Martins, D. [UNESP]
Souza, F.H.D.
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira da Ciência das Plantas Daninhas
Resumo
Este trabalho constou de quatro estudos que foram realizados em casa de vegetação, nos quais se avaliou a seletividade de diferentes herbicidas, aplicados em pré-emergência, sobre algumas gramíneas forrageiras tropicais: Brachiaria decumbens, Brachiaria brizantha cv. Marandu e Panicum maximum cultivares Tanzânia e Mombaça. Os herbicidas e as doses utilizadas, em g ha-1, para cada estudo foram: alachlor - 1.680 e 3.360, metolachlor - 1.200 e 2.400, diuron - 800 e 1.600, imazaquin - 75 e 150, imazapyr - 250 e 500, imazethapyr - 50 e 100, clomazone - 450 e 900, flumetsulam - 70 e 140, ametryn - 625 e 1.250, metribuzin - 525 e 1.050 e trifluralin - 900 e 1.800, além de uma testemunha sem aplicação de herbicidas. Utilizou-se o delineamento experimental inteiramente casualizado, com seis repetições. O consumo de calda de aplicação foi de 180 L ha-1,e a barra de aplicação continha quatro bicos de jato plano tipo 'Teejet' 110.02, espaçados de 0,50 m. Avaliou-se visualmente a intoxicação das plantas através de uma escala percentual de notas e, no final dos estudos, a altura e o peso de matéria seca de plantas. Para P. maximum cv. Mombaça, apenas os herbicidas imazaquin (75 g ha-1), imazethapyr e flumetsulam, em ambas as doses testadas, foram seletivos. Para P. maximum cv. Tanzânia, nenhum dos herbicidas testados foi totalmente seletivo. em relação a B. decumbens, os herbicidas imazaquin e imazethapyr, em ambas as doses, e ametryn (625 g ha¹) foram seletivos. No caso de B. brizantha, os herbicidas diuron (800 g ha¹), ametryn, imazaquin, imazethapyr e flumetsulam, em ambas as doses, apresentaram-se seletivos.
This research comprised four experiments carried out under greenhouse conditions to evaluate the selectivity of herbicides, applied in pre-emergence conditions, on the following tropical grass forages: Brachiaria decumbens, Brachiaria brizantha cv. Marandu, Panicum maximum cv. Tanzânia and Mombaça. The herbicides and rates (g ha-1) applied for each experiment were alachlor (1.680 and 3,360), metolachlor (1,200 and 2,400), diuron (800 and 1,600), imazaquin (75 and 150), imazapyr (250 and 500), imazethapyr (50 and 100), clomazone (450 and 900), flumetsulam (70 and 140), ametryn (625 and 1,250), metribuzin (525 and 1,050), trifluralin (900 and 1,800), and a control plot, without herbicide aplication. The experimental design was completely randomized, with six replications. The spray volume was 180 L ha-1 by four flat fan spray (TEEJET 110.02). Plant intoxication was evaluated by visual grading . At the end of the study plant height and dry matter weight were evaluated. For P. maximum cv. Mombaça, only imazaquin (75 g ha-1), imazethapyr and flumetsulam at both rates tested were selective. For P. maximum cv. Tanzânia, none of the tested herbicides were selective. Regardeless of the rate, imazaquin, imazethapyr and ametryn (625 g ha-1) were selective to Brachiaria decumbens. For Brachiaria brizantha, the herbicides diuron (800 g ha-1), ametryn, imazaquin, imazethapyr and flumetsulam at both tested rates were selective.
This research comprised four experiments carried out under greenhouse conditions to evaluate the selectivity of herbicides, applied in pre-emergence conditions, on the following tropical grass forages: Brachiaria decumbens, Brachiaria brizantha cv. Marandu, Panicum maximum cv. Tanzânia and Mombaça. The herbicides and rates (g ha-1) applied for each experiment were alachlor (1.680 and 3,360), metolachlor (1,200 and 2,400), diuron (800 and 1,600), imazaquin (75 and 150), imazapyr (250 and 500), imazethapyr (50 and 100), clomazone (450 and 900), flumetsulam (70 and 140), ametryn (625 and 1,250), metribuzin (525 and 1,050), trifluralin (900 and 1,800), and a control plot, without herbicide aplication. The experimental design was completely randomized, with six replications. The spray volume was 180 L ha-1 by four flat fan spray (TEEJET 110.02). Plant intoxication was evaluated by visual grading . At the end of the study plant height and dry matter weight were evaluated. For P. maximum cv. Mombaça, only imazaquin (75 g ha-1), imazethapyr and flumetsulam at both rates tested were selective. For P. maximum cv. Tanzânia, none of the tested herbicides were selective. Regardeless of the rate, imazaquin, imazethapyr and ametryn (625 g ha-1) were selective to Brachiaria decumbens. For Brachiaria brizantha, the herbicides diuron (800 g ha-1), ametryn, imazaquin, imazethapyr and flumetsulam at both tested rates were selective.
Descrição
Palavras-chave
Brachiaria decumbens, Brachiaria brizantha, Panicum maximum cv. Tanzânia, Panicum maximum cv. Mombaça, Brachiaria decumbens, Brachiaria brizantha, Panicum maximum cv. Tanzânia, Panicum maximum cv. Mombaça
Como citar
Planta Daninha. Sociedade Brasileira da Ciência das Plantas Daninhas , v. 20, n. 3, p. 457-464, 2002.