Eficácia de imazethapyr e chlorimuron-ethyl em aplicações de pré-semeadura da cultura da soja
Carregando...
Data
2006-09-01
Autores
Procópio, S. O.
Menezes, C. C. E.
Pires, F. R.
Barroso, A. L. L.
Cargnelutti Filho, A. [UNESP]
Rudovalho, M. C.
Morais, R. V.
Silva, M. V. V.
Caetano, J. O.
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira da Ciência das Plantas Daninhas
Resumo
O trabalho teve como objetivo avaliar a ação dos herbicidas imazethapyr e chlorimuron-ethyl em aplicações de pré-semeadura da cultura da soja, visando o controle das plantas daninhas presentes antes da semeadura e a redução na emergência de plantas daninhas durante o ciclo da cultura. O experimento foi conduzido a campo, em área de produção de soja em sistema de plantio direto. O delineamento experimental utilizado foi o de blocos casualizados, com quatro repetições, em esquema fatorial (4 x 4 + 1), sendo quatro tratamentos herbicidas [glyphosate (1,62 kg ha-1); glyphosate (1,62 kg ha-1) + imazethapyr (100 g ha-1); glyphosate (1,62 kg ha-1) + chlorimuron-ethyl (10 g ha-1); glyphosate (1,62 kg ha-1) + chlorimuron-ethyl (20 g ha-1)] e quatro intervalos entre a aplicação dos herbicidas e a semeadura da soja (0, 1, 3 e 7 dias), mais uma testemunha não-dessecada. A adição dos herbicidas imazethapyr (100 g ha¹) e chlorimuron-ethyl (10 ou 20 g ha-1) junto ao glyphosate não melhorou o controle e também não diminuiu a rebrota posterior das plantas daninhas Digitaria insularis, Tridax procumbens e Leptochloa filiformis. Três dias antes da semeadura da soja foi o intervalo mínimo para que o controle dessas três espécies de plantas daninhas não fosse prejudicado pela operação de semeadura mecânica. Constatou-se que os tratamentos herbicidas não afetaram o número de plantas emergidas das espécies Sida santaremnensis, Digitaria insularis, Eleusine indica, Chamaesyce hirta, Bidens pilosa e Senna obtusifolia. Apenas para a espécie Althernantela tenella foi verificado que a adição de imazethapyr ou de chlorimuron-ethyl junto ao glyphosate reduziu a emergência dessa planta daninha na área, mostrando eficiência em pré-emergência. Todos os tratamentos herbicidas aplicados em pré-semeadura proporcionaram maior produtividade da cultura da soja em relação à testemunha não-dessecada, mas o incremento dos herbicidas imazethapyr e chlorimuron-ethyl ao glyphosate não resultou em aumento de produtividade da soja.
This work was carried out to evaluate the efficacy of the herbicides imazethapyr and chlorimuron-ethyl under pre-sowing conditions in soybean crop. Weed control before sowing and emergence reduction during the crop season were evaluated. The experiment was established in the field soybean had been cultivated, under no tillage, arranged in a randomized block design in a factorial design (4 x 4) + 1. Four herbicide treatments [glyphosate (1.62 kg ha-1); glyphosate (1.62 kg ha-1 ) + imazethapyr (100 g ha-1 ); glyphosate (1.62 kg ha-1 ) + chlorimuron-ethyl (10 g ha¹ ); glyphosate (1.62 kg ha-1 ) + chlorimuron-ethyl (20 g ha-1 )] were combined with four application intervals between herbicide application and sowing time (0, 1, 3 and 7 days). The variety MG/BR 46 (Conquista), with rows spaced 0.50 m was also used as control, with no herbicide application. The addition of the herbicides [imazethapyr (100 g ha-1 ) and chlorimuron-ethyl (10 ou 20 g ha-1)] to glyphosate did not improve weed control nor decreased late re-growth of the following species: Digitaria insularis, Tridax procumbens and Leptochloa filiformis. Three days was the minimum interval in which the three species were not injured by the mechanical sowing process. The herbicide treatments did not affect the number of emerged plants of the following species: Sida santaremnensis, Digitaria insularis, Eleusine indica, Chamaesyce hirta, Bidens pilosa e Senna obtusifolia. Only Althernantela tenella had its emergence rate decreased by herbicide addition to glyphosate, showing pre-sowing efficiency. All the herbicide treatments during pre-sowing increased soybean yield, compared to the control. Herbicide addition to glyphosate did not result in increasing yield.
This work was carried out to evaluate the efficacy of the herbicides imazethapyr and chlorimuron-ethyl under pre-sowing conditions in soybean crop. Weed control before sowing and emergence reduction during the crop season were evaluated. The experiment was established in the field soybean had been cultivated, under no tillage, arranged in a randomized block design in a factorial design (4 x 4) + 1. Four herbicide treatments [glyphosate (1.62 kg ha-1); glyphosate (1.62 kg ha-1 ) + imazethapyr (100 g ha-1 ); glyphosate (1.62 kg ha-1 ) + chlorimuron-ethyl (10 g ha¹ ); glyphosate (1.62 kg ha-1 ) + chlorimuron-ethyl (20 g ha-1 )] were combined with four application intervals between herbicide application and sowing time (0, 1, 3 and 7 days). The variety MG/BR 46 (Conquista), with rows spaced 0.50 m was also used as control, with no herbicide application. The addition of the herbicides [imazethapyr (100 g ha-1 ) and chlorimuron-ethyl (10 ou 20 g ha-1)] to glyphosate did not improve weed control nor decreased late re-growth of the following species: Digitaria insularis, Tridax procumbens and Leptochloa filiformis. Three days was the minimum interval in which the three species were not injured by the mechanical sowing process. The herbicide treatments did not affect the number of emerged plants of the following species: Sida santaremnensis, Digitaria insularis, Eleusine indica, Chamaesyce hirta, Bidens pilosa e Senna obtusifolia. Only Althernantela tenella had its emergence rate decreased by herbicide addition to glyphosate, showing pre-sowing efficiency. All the herbicide treatments during pre-sowing increased soybean yield, compared to the control. Herbicide addition to glyphosate did not result in increasing yield.
Descrição
Palavras-chave
herbicida, planta daninha, Glycine max, glyphosate, herbicide, weed, Glycine max, glyphosate
Como citar
Planta Daninha. Sociedade Brasileira da Ciência das Plantas Daninhas , v. 24, n. 3, p. 467-473, 2006.