Eficácia de fluridone para o controle de Egeria spp. em caixas d'água e em represa de pequeno porte sem fluxo de água
Data
2001-02-14
Autores
Tanaka, Robson Hitoshi [UNESP]
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ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O presente projeto teve por objetivo avaliar a eficácia do herbicida fluridone para o controle das plantas aquáticas do gênero Egeria e seu efeito na qualidade da água em caixas d'água e em represa de pequeno porte, sem fluxo de água. No experimento em caixas d'água, foram avaliados os efeitos de doses crescentes de fluridone, nas formulações líquida e granulada, sobre as espécies Egeria densa Planchon e Egeria najas Planchon. Foram testadas as concentrações de 10, 20, 40, 80 e 150 ppb de fluridone na formulação líquida e 20, 40, 80 e 150 ppb na granulada. Utilizou-se 40 caixas d'água de fibra de vidro, com volume de 320 litros e cada uma constituiu uma parcela, com vinte plantas de cada espécie, cultivadas a partir de fragmentos apicais de 0,2 m de comprimento. O delineamento experimental utilizado foi o de blocos ao acaso, com dez tratamentos e quatro repetições. Realizou-se uma única aplicação, avaliando-se os sintomas de intoxicação das plantas aos 8, 15, 29, 35, 51 e 63 dias após a aplicação, realizada em junho de 1.998. Os resultados indicaram que o fluridone, nas concentrações de 80 e 150 ppb, em ambas as formulações, foi eficaz no controle das duas espécies. Nos tratamentos com concentrações de 10, 20 e 40 ppb na formulação líquida e de 20 e 40 ppb na formulação granulada, constatou-se a recuperação das plantas na última avaliação, realizada aos 63 dias após a aplicação do herbicida. Nestes tratamentos e nesta época, os resíduos de fluridone na água eram inferiores a 10 ppb. Nas condições do experimento, Egeria najas mostrou-se mais sensível que Egeria densa na primeira avaliação, porém o resultado final foi similar. No experimento em represa de pequeno porte sem fluxo de água, avaliou-se o efeito da manutenção das concentrações de fluridone no controle de Egeria najas... .
This project aimed to evaluate the efficacy of the herbicide fluridone to control aquatic plants from the genus Egeria and its effect on water quality in outdoor tanks and a small size pond. The experiment in tanks had the purpose to evaluate the effect of increasing rates of fluridone in two formulations, liquid and pellet, in the control of the species Egeria densa Planchon and Egeria najas Planchon. Concentrations of 10, 20, 40, 80 and 150 ppb of the liquid formulation and 20, 40, 80 and 150 ppb of the pellet were used. Forty fiberglass tanks with 320 liters of volume were used. In each tank, 20 plants of each species were planted using apical cuttings of 0,2 m. The experimental design used was randomized blocks, with 10 treatments and 4 replications. A single application of the herbicide was made in July 1998 and evaluations of symptoms were done at 8, 15, 29, 35, 51 and 63 days after the application. Results showed that fluridone, at 80 and 150 ppb of both liquid and pellet formulations, was efficient to control both species. Concentrations of 10, 20 and 40 ppb of the liquid formulation and 20 and 40 ppb of the pellet allowed the plants to regrowth at the last evaluation. In those treatments, fluridone residues in water, analyzed at 63 days after the herbicide application, were lower than 10 ppb. In the experimental condition of outdoor tanks, Egeria najas showed to be more sensitive to the herbicide in the former evaluation, but the final result was similar to that obtained for Egeria densa. In the experiment at the small size pond, the effect of keeping the fluridone concentration for an extended period of time on the control of Egeria najas was evaluated. One 1,980 square meter pond was treated seven times with fluridone, aiming to keep herbicide concentrations in water between 10 and 20 ppb... (Complete abstract, click electronic address below).
This project aimed to evaluate the efficacy of the herbicide fluridone to control aquatic plants from the genus Egeria and its effect on water quality in outdoor tanks and a small size pond. The experiment in tanks had the purpose to evaluate the effect of increasing rates of fluridone in two formulations, liquid and pellet, in the control of the species Egeria densa Planchon and Egeria najas Planchon. Concentrations of 10, 20, 40, 80 and 150 ppb of the liquid formulation and 20, 40, 80 and 150 ppb of the pellet were used. Forty fiberglass tanks with 320 liters of volume were used. In each tank, 20 plants of each species were planted using apical cuttings of 0,2 m. The experimental design used was randomized blocks, with 10 treatments and 4 replications. A single application of the herbicide was made in July 1998 and evaluations of symptoms were done at 8, 15, 29, 35, 51 and 63 days after the application. Results showed that fluridone, at 80 and 150 ppb of both liquid and pellet formulations, was efficient to control both species. Concentrations of 10, 20 and 40 ppb of the liquid formulation and 20 and 40 ppb of the pellet allowed the plants to regrowth at the last evaluation. In those treatments, fluridone residues in water, analyzed at 63 days after the herbicide application, were lower than 10 ppb. In the experimental condition of outdoor tanks, Egeria najas showed to be more sensitive to the herbicide in the former evaluation, but the final result was similar to that obtained for Egeria densa. In the experiment at the small size pond, the effect of keeping the fluridone concentration for an extended period of time on the control of Egeria najas was evaluated. One 1,980 square meter pond was treated seven times with fluridone, aiming to keep herbicide concentrations in water between 10 and 20 ppb... (Complete abstract, click electronic address below).
Descrição
Palavras-chave
Plantas aquaticas, Herbicidas, Defensivos vegetais, Aquatic botany, Herbicides
Como citar
TANAKA, Robson Hitoshi. Eficácia de fluridone para o controle de Egeria spp. em caixas d'água e em represa de pequeno porte sem fluxo de água. 2001. v, 51 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Ciências Agronômicas, 2001.