Data/hora: 04/06/2024 09:06:33

Provedor de dados: 	87	
País: 	Brazil	
Título: 	Differential susceptibility of biotypes of conyza sumatrensis to Chlorimuron-ethyl herbicide	
Autores: 	Santos,F.M.; Vargas,L.; Christoffoleti,P.J.; Agostinetto,D.; Mariani,F.; Dal Magro,T.	
Data: 	2014-06-01	
Ano: 	2014	
Palavras-chave: 	Chemical control; Horseweed; Low level resistance; ALS.	
Resumo: 	Horseweed (Conyza spp.) is an annual weed, infesting soybean crops in southern Brazil, with chlorimuron-ethyl being one of the most commonly used herbicides for its control. However, in recent soybean harvests, an unsatisfactory control of this weed using this herbicide was observed, generating suspicion regarding the selection of resistant biotypes. The objective of this study was to evaluate the susceptibility of horseweed biotypes to the herbicide chlorimuron-ethyl. Two experiments were conducted in a greenhouse; in the first one, the biotypes were selected selected, and the second experiment was arranged in a 5 x 5 factorial in a completely randomized design with four replications. The treatments used in the preparation of the dose response curves were doses of the herbicide chlorimuron-ethyl (0.0, 1.56, 3.13, 6.25, 12.5, and 25 g ha-1), applied on the five horseweed biotypes at the 3-4 leaf growth stage. The variables evaluated were visual control percentage and shoot dry weight, compared to the control without herbicide application, and plant acetolactate accumulation. It was concluded that there is a differential susceptibility among the biotypes at doses of less than 20 g ha-1 (dose response curves), which indicates low-level resistance. The practical consequences are the indications of chlorimuron-ethyl application at the maximum doses recomended and that the practice of rotating mechanisms of action must be used in the chemical weed management of these areas.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582014000200021	
Editor: 	Sociedade Brasileira da Ciência das Plantas Daninhas	
Relação: 	10.1590/S0100-83582014000200021	
Formato: 	text/html	
Fonte: 	Planta Daninha  v.32 n.2 2014	
Fonte: 	info:eu-repo/semantics/openAccess