Seletividade do oxyfluorfen para a cultura do pinhão-manso
Data
2009-12-01
Autores
Gonçalves, K.S [UNESP]
São José, A.R
Velini, Edivaldo Domingues [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira da Ciência das Plantas Daninhas
Resumo
Realizou-se um experimento para avaliar a seletividade do oxyfluorfen para a cultura do pinhão-manso. Foi utilizado o delineamento experimental inteiramente casualizado, com cinco repetições, em esquema fatorial 2 x 2 + 1, sendo duas doses do herbicida (600 e 1.200 g ha-1 do ingrediente ativo), dois modos de aplicação (sobre a planta e sobre o solo) e uma testemunha sem aplicação do herbicida. Após o transplante das mudas para vasos plásticos com 10 litros de solo, os tratamentos foram aplicados com o auxílio de um balde. O oxyfluorfen, quando aplicado sobre as plantas, mostrou-se tóxico nas duas doses testadas, sendo observados sintomas mais intensos nos primeiros dias após a aplicação dos tratamentos. Após esse período, as mudas recuperaram o vigor e surgiram novas brotações que não apresentavam sintomas de toxicidade. Esses sintomas consistiram de manchas esbranquiçadas nas folhas, que evoluíram para necrose. Nas mudas em que o herbicida foi aplicado no solo, não foram observados sintomas visuais de toxicidade. Observou-se redução na massa fresca e seca das folhas quando 600 g ha-1 do herbicida foram aplicados sobre a planta ou 1.200 g ha-1 sobre o solo. Contudo, a área foliar e o número de folhas não diferiram significativamente entre as doses utilizadas e os modos de aplicação. Das quatro espécies daninhas semeadas (Brachiaria decumbens, Brachiaria plantaginea, Sida rhombifolia e Bidens pilosa), apenas Bidens pilosa não foi controlada pelo oxyfluorfen aplicado em pré-emergência.
An experiment was carried out to evaluate the selectivity of oxyfluorfen for physic nut culture. The experiment was arranged in a completely randomized design with five replications in a factorial 2 x 2 + 1, two herbicide doses (600 and 1,200 g ha-1 of active ingredient), two modes of application (on the plant and soil) and a control without herbicide application.. After transplanting the seedlings into plastic pots with 10 liters of soil, the treatments were applied using a bucket. When applied on the plants, oxyfluorfen was shown to be toxic in the doses tested, with more intense symptoms in the first days after treatment. After this period, the seedlings recovered strength and new shoots came out showing no symptoms of toxicity. These symptoms consisted of whitish spots on the leaves progressing to necrosis. In plants where the herbicide was applied in the soil, no visual symptoms of toxicity were observed. There was a reduction in fresh and dry weight of the leaves when 600 g ha-1 of the herbicide was applied on the plant or 1,200 g ha-1 was applied on the soil. However, leaf area and number of leaves did not differ significantly between the doses used and modes of application. of the four weeds sown (Brachiaria decumbens, Brachiaria plantaginea, Sida rhombifolia and Bidens pilosa) only Bidens pilosa was not controlled by oxyfluorfen applied in pre-emergence.
An experiment was carried out to evaluate the selectivity of oxyfluorfen for physic nut culture. The experiment was arranged in a completely randomized design with five replications in a factorial 2 x 2 + 1, two herbicide doses (600 and 1,200 g ha-1 of active ingredient), two modes of application (on the plant and soil) and a control without herbicide application.. After transplanting the seedlings into plastic pots with 10 liters of soil, the treatments were applied using a bucket. When applied on the plants, oxyfluorfen was shown to be toxic in the doses tested, with more intense symptoms in the first days after treatment. After this period, the seedlings recovered strength and new shoots came out showing no symptoms of toxicity. These symptoms consisted of whitish spots on the leaves progressing to necrosis. In plants where the herbicide was applied in the soil, no visual symptoms of toxicity were observed. There was a reduction in fresh and dry weight of the leaves when 600 g ha-1 of the herbicide was applied on the plant or 1,200 g ha-1 was applied on the soil. However, leaf area and number of leaves did not differ significantly between the doses used and modes of application. of the four weeds sown (Brachiaria decumbens, Brachiaria plantaginea, Sida rhombifolia and Bidens pilosa) only Bidens pilosa was not controlled by oxyfluorfen applied in pre-emergence.
Descrição
Palavras-chave
controle químico, herbicida, Jatropha curcas, toxicidade, chemical control, herbicide, Jatropha curcas, toxicity
Como citar
Planta Daninha. Sociedade Brasileira da Ciência das Plantas Daninhas , v. 27, n. spe, p. 1111-1116, 2009.