Seletividade e eficiência agronômica de herbicidas no controle de capim-colchão na cultura da melancia
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Data
2002-09-01
Autores
Maciel, Cleber D.G. [UNESP]
Constantin, Jamil
Goto, Rumy [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Associação Brasileira de Horticultura
Resumo
Foi avaliada a seletividade e a eficiência agronômica dos herbicidas clethodim e sethoxydim, no controle de Digitaria horizontalis (capim-colchão) na cultura da melancia (cv. Crimson Sweet). O experimento foi conduzido em campo, no município de Floresta, PR, em 1995/96, em delineamento de blocos ao acaso, com quatro repetições. Os tratamentos avaliados foram clethodim nas doses de 84; 96 e 108 g i.a./ha adicionado de 1,0 L/ha de óleo mineral (Dytrol), sethoxydim na dose de 230 g i.a./ha adicionado de 1,0 L/ha de óleo mineral (Assist) e testemunhas com e sem capina. Os herbicidas foram aplicados em pós-emergência, quando a melancia apresentava ramas com 1,4 m e a D. horizontalis em estádio de três folhas a três perfilhos e densidade de 240 plantas/m². Para a aplicação dos herbicidas utilizou-se pulverizador costal de pressão mantida por injeção de CO2, equipado com pontas de jato plano XR110.02 e volume de calda de 200 L/ha. As avaliações de seletividade (Escala E.W.R.C.) e controle das plantas daninhas (0 - 100%) foram efetuadas aos 7; 15 e 30 dias após aplicação dos tratamentos. Os resultados indicaram que o herbicida clethodim, a partir de 96 g i.a./ha, controlou eficientemente a D. horizontalis, sendo estatisticamente superior ao herbicida sethoxydim e à testemunha sem capina. Nenhum dos tratamentos químicos causou fitotoxicidade que afetasse o desenvolvimento e a produção da melancia. A D. horizontalis interferiu no desenvolvimento da cultura, causando redução média de 36,0% da produção da melancia.
The selectivity and agronomic efficiency of clethodim and sethoxydim herbicides on D. horizontalis control in watermelon crop was evaluated. The experiment was carried out at Floresta, Paraná State, Brazil, in 1995/96. The watermelon cultivar used was Crimson Sweet and the experimental design was a randomized block with four replicates. The treatments evaluated were clethodim (240 g/L) in the dosage of 84; 96, 108 g i.a./ha with 1.0 L/ha of mineral oil (Dytrol); sethoxydim (184 g/L) in the dosage of 230 g i.a./ha with 1.0 L/ha of mineral oil (Assist); free of weeds and weedy. The herbicides were applied in post-emergency, when the watermelon had branches up to 1.4 m long and the D. horizontalis presented three leaves and three tillers, and density of 240 plants/m². The injury evaluations (E.W.R.C.), control (0-100%) and weed control. were performed at 7. 15 and 30 days after application of treatments. The clethodim herbicide, in the dosage of 96 g i.a./ha or higher, controlled efficiently the D. horizontalis (100), being more efficient than sethoxydim in controlling weeds. None of chemical treatments affected the watermelon development and production. Weedy plots with D. horizontalis interfered in the culture development, resulting in a 36% reduction on watermelon production.
The selectivity and agronomic efficiency of clethodim and sethoxydim herbicides on D. horizontalis control in watermelon crop was evaluated. The experiment was carried out at Floresta, Paraná State, Brazil, in 1995/96. The watermelon cultivar used was Crimson Sweet and the experimental design was a randomized block with four replicates. The treatments evaluated were clethodim (240 g/L) in the dosage of 84; 96, 108 g i.a./ha with 1.0 L/ha of mineral oil (Dytrol); sethoxydim (184 g/L) in the dosage of 230 g i.a./ha with 1.0 L/ha of mineral oil (Assist); free of weeds and weedy. The herbicides were applied in post-emergency, when the watermelon had branches up to 1.4 m long and the D. horizontalis presented three leaves and three tillers, and density of 240 plants/m². The injury evaluations (E.W.R.C.), control (0-100%) and weed control. were performed at 7. 15 and 30 days after application of treatments. The clethodim herbicide, in the dosage of 96 g i.a./ha or higher, controlled efficiently the D. horizontalis (100), being more efficient than sethoxydim in controlling weeds. None of chemical treatments affected the watermelon development and production. Weedy plots with D. horizontalis interfered in the culture development, resulting in a 36% reduction on watermelon production.
Descrição
Palavras-chave
Citrullus lanatus, Digitaria horizontalis, clethodim, sethoxydim, Digitaria horizontalis, watermelon, clethodim, sethoxydim
Como citar
Horticultura Brasileira. Associação Brasileira de Horticultura, v. 20, n. 3, p. 474-476, 2002.