Doses e horário de aplicação do diquat no controle de Eichhornia crassipes
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Data
2011-06-01
Autores
Pitelli, R.A. [UNESP]
Bisigatto, A.T. [UNESP]
Kawaguchi, I.
Pitelli, R.L.C.M.
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira da Ciência das Plantas Daninhas
Resumo
O aguapé (Eichhornia crassipes) é uma das mais importantes macrófitas aquáticas que colonizam reservatórios e corpos hídricos nas regiões tropicais e subtropicais do mundo, causando uma série de interferências no uso múltiplo da água e do corpo hídrico e no controle de vetores de doenças humanas. Para evitar prejuízos econômicos, sociais, estéticos e ao meio ambiente, essas plantas são controladas por vários métodos, incluindo o controle químico com o uso de herbicidas. Com o objetivo de avaliar a eficácia do herbicida diquat no controle dessa macrófita aquática, foram instalados dois ensaios em casa de vegetação. No primeiro, foram comparadas duas formulações (Reward® e Reglone®) aplicadas em dois horários (diurno e noturno) e em quatro doses (0,1, 0,2, 0,3 e 0,4 kg ha-1), num esquema fatorial 2 x 2 x 4, com seis repetições. Os resultados mostraram que a formulação Reward® foi mais eficiente no controle dessa macrófita, agindo mais rapidamente, sobretudo em menores doses, e que as aplicações realizadas no período noturno apresentavam melhor desempenho no controle em relação às realizadas no período diurno. Assim, um segundo ensaio foi realizado utilizando apenas a formulação Reward®, comparando a aplicação no período noturno e no diurno e as doses de 0,1, 0,2, 0,3 e 0,4 kg ha-1, obedecendo a um esquema fatorial 2 x 4. As plantas de aguapé foram cultivadas em caixas-d'água, e o delineamento experimental adotado foi em blocos ao acaso com quatro repetições, considerando a posição das caixas dentro da casa de vegetação. Os resultados confirmaram que o diquat é eficiente no controle do aguapé, principalmente nas doses de 0,3 e 0,4 kg ha¹ em aplicações noturnas. Doses baixas e aplicações diurnas não impediram intensas rebrotas das plantas afetadas.
Water hyacinth (Eichhornia crassipes) is a major weed in several water bodies in the tropical and sub-tropical regions of the world, causing different types of negative interference in the multiple use of water and water bodies and in the prevention of human diseases. The control of this macrophyte is required under these conditions. Aiming to evaluate the efficacy of the herbicide diquat in the control of water hyacinth, two trials were carried out under greenhouse conditions. In the first assay, a factorial design 2 x 2 x 4 was used comparing two diquat formulations (Reward® and Reglone®), two spraying times (day and night time) and four herbicide doses (0.1; 0.2; 0.3 and 0.4 kg ha-1). The plants were grown in 1L pots and the plots were arranged in a completely randomized experimental design with six replications. The Reward® formulation was more efficient than Reglone® in the control of water hyacinth, acting faster, especially at smaller doses. The night application promoted better control than the day spraying. In a second assay, only Reward® was evaluated in a factorial design experiment comparing two spraying times (day and night time) and four doses (0.1; 0.2; 0.3 and 0.4 kg ha-1). The plants were grown in 40 L square pots, arranged in a completely randomized block design, with four replications. The results confirmed that night application promoted better control of water hyacinth. The doses of 0.3 and 0.4 kg ha-1 provided the best control at two months after spraying, preventing intense re-growth of water hyacinth shoots.
Water hyacinth (Eichhornia crassipes) is a major weed in several water bodies in the tropical and sub-tropical regions of the world, causing different types of negative interference in the multiple use of water and water bodies and in the prevention of human diseases. The control of this macrophyte is required under these conditions. Aiming to evaluate the efficacy of the herbicide diquat in the control of water hyacinth, two trials were carried out under greenhouse conditions. In the first assay, a factorial design 2 x 2 x 4 was used comparing two diquat formulations (Reward® and Reglone®), two spraying times (day and night time) and four herbicide doses (0.1; 0.2; 0.3 and 0.4 kg ha-1). The plants were grown in 1L pots and the plots were arranged in a completely randomized experimental design with six replications. The Reward® formulation was more efficient than Reglone® in the control of water hyacinth, acting faster, especially at smaller doses. The night application promoted better control than the day spraying. In a second assay, only Reward® was evaluated in a factorial design experiment comparing two spraying times (day and night time) and four doses (0.1; 0.2; 0.3 and 0.4 kg ha-1). The plants were grown in 40 L square pots, arranged in a completely randomized block design, with four replications. The results confirmed that night application promoted better control of water hyacinth. The doses of 0.3 and 0.4 kg ha-1 provided the best control at two months after spraying, preventing intense re-growth of water hyacinth shoots.
Descrição
Palavras-chave
aquatic weeds, Chemical control, water hyacinth, formulation, Macrófitas aquáticas, Controle químico, aguapé, formulação
Como citar
Planta Daninha. Sociedade Brasileira da Ciência das Plantas Daninhas , v. 29, n. 2, p. 269-277, 2011.