Eficiência de fluridone no controle de plantas aquáticas submersas e efeitos sobre algumas características ambientais
Carregando...
Data
2002-01-01
Autores
Marcondes, D.A.S.
Velini, Edivaldo Domingues [UNESP]
Martins, D. [UNESP]
Tanaka, R.H.
Carvalho, Fernando Tadeu de [UNESP]
Cavenaghi, A.L. [UNESP]
Bronhara, A.A.
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira da Ciência das Plantas Daninhas
Resumo
O objetivo deste estudo foi avaliar a eficiência do herbicida fluridone no controle de plantas aquáticas submersas (Egeria densa, Egeria najas e Ceratophyllum demersum), assim como seus efeitos sobre algumas características ambientais. A pesquisa foi conduzida no reservatório da Usina Hidrelétrica Eng. Souza Dias (Jupiá), região noroeste do Estado de São Paulo, em uma reentrância denominada lagoa Vírgula. A lagoa foi dividida em nove faixas e seis delas receberam uma aplicação inicial de fluridone para se obter uma concentração de 20 ppb. As aplicações subseqüentes foram dimensionadas para recompor esta concentração. Para o estudo do carreamento do herbicida pelo fluxo de água, foi efetuado o monitoramento das suas concentrações nas nove faixas da lagoa (com e sem aplicação) e em áreas a jusante e a montante. Foram analisados os efeitos do fluridone sobre características ambientais como: turbidez, temperatura da água, condutividade elétrica, concentração de oxigênio, pH e resíduos de fluridone. A eficácia do controle foi avaliada visualmente (pelos sintomas de fitointoxicação nas três espécies estudadas) e pela amostragem de biomassa. Observou-se que o fluridone controlou de forma satisfatória E. najas e E. densa. Quando cessou o efeito do fluridone, aconteceu a reinfestação de E. densa e E. najas. Não houve controle de C. demersum. O fluridone não produziu efeitos adversos sobre as características de qualidade ambiental estudadas.
This study aimed to evaluate the efficacy of the herbicide fluridone to control submersed aquatic weeds (Egeria densa, Egeria najas and Ceratophyllum demersum), as well as its effects on some environmental characteristics. The research was carried out in the reservoir of Eng. Souza Dias (Jupiá) Hydro-elecric plant power, Station in northwestern São Paulo, Brazil, in Lagoa Vírgula bay. The bay was divided in nine zones and six of them received an initial application of fluridone to achieve the concentration of 20 ppb. The amounts of fluridone used in all other applications were calculated to restore the 20 ppb concentration. In order to study the herbicide loss due to water flow, fluridone concentrations were monitored in all treated and non-treated zones of the bay and in upstream and downstream areas. Fluridone effects on some environmental characteristics, such as turbidity, water temperature, electric conductivity, oxigen concentration, pH and fluridone residues were evaluated. Visual evaluation of phytotoxicity symptoms on the three species studied and biomass evaluations were also carried out. Fluridone controlled the submersed aquatic plants E. najas and E. densa. E. densa and E. najas regrew as the effect of fluridone ended while C. demersum was not controlled. Fluridone did not produce any negative effect on the environmental quality characteristics studied in the treated areas.
This study aimed to evaluate the efficacy of the herbicide fluridone to control submersed aquatic weeds (Egeria densa, Egeria najas and Ceratophyllum demersum), as well as its effects on some environmental characteristics. The research was carried out in the reservoir of Eng. Souza Dias (Jupiá) Hydro-elecric plant power, Station in northwestern São Paulo, Brazil, in Lagoa Vírgula bay. The bay was divided in nine zones and six of them received an initial application of fluridone to achieve the concentration of 20 ppb. The amounts of fluridone used in all other applications were calculated to restore the 20 ppb concentration. In order to study the herbicide loss due to water flow, fluridone concentrations were monitored in all treated and non-treated zones of the bay and in upstream and downstream areas. Fluridone effects on some environmental characteristics, such as turbidity, water temperature, electric conductivity, oxigen concentration, pH and fluridone residues were evaluated. Visual evaluation of phytotoxicity symptoms on the three species studied and biomass evaluations were also carried out. Fluridone controlled the submersed aquatic plants E. najas and E. densa. E. densa and E. najas regrew as the effect of fluridone ended while C. demersum was not controlled. Fluridone did not produce any negative effect on the environmental quality characteristics studied in the treated areas.
Descrição
Palavras-chave
fluridone, macrófita aquática, Egeria densa, Egeria najas, Ceratophyllum demersum, fluridone, aquatic macrophyte, Egeria densa, Egeria najas, Ceratophyllum demersum
Como citar
Planta Daninha. Sociedade Brasileira da Ciência das Plantas Daninhas , v. 20, n. spe, p. 63-71, 2002.