Palha de sorgo associada ao herbicida imazamox no controle de plantas daninhas na cultura da soja em sucessão
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Data
2005-09-01
Autores
Correia, N.M. [UNESP]
Souza, I.F.
Klink, U.P.
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira da Ciência das Plantas Daninhas
Resumo
Os resíduos vegetais de uma cultura de cobertura de outono/inverno podem interferir na infestação das plantas daninhas das culturas de verão subseqüentes. Dessa forma, com o objetivo de avaliar o efeito da palha de híbridos de sorgo (Sorghum bicolor), associada ao uso do herbicida imazamox, no controle de plantas daninhas na cultura da soja (Glycine max), cv. 'Conquista', em sucessão, foi conduzido no ano agrícola 2000/2001 um experimento em Uberlândia-MG. Foram utilizados quatro tipos de cobertura: três provenientes de resíduos culturais de híbridos de sorgo (Sara, DKB 860 e Ambar) e uma sem restos vegetais (anteriormente sob pousio). Aos 24 dias após aplicação do herbicida, o controle das espécies Leonotis nepetifolia, Alternanthera tenella, Amaranthus hibridus, A. retroflexus, A. spinosus, Ipomoea grandifolia, Commelina benghalensis e Nicandra physaloides foi mais eficaz nas palhas dos híbridos Sara e Ambar, na ausência de imazamox, com porcentagens de controle de 40 e 41%, respectivamente. Quando associada a 15 g ha-1 de imazamox, a palha do Ambar resultou em melhor controle dessas espécies de plantas daninhas, com controle de 76%; e a 30 g ha-1 a palha do DKB 860 foi a mais eficaz, promovendo 85% de controle. Sem cobertura do solo, com 30 g ha-1 de imazamox obteve-se controle de 62,5%, e 47,5% com metade da dosagem. Os resultados indicaram variabilidade de controle em relação ao híbrido de sorgo estudado e a possibilidade de redução de dosagens do herbicida imazamox quando associado aos resíduos vegetais de sorgo.
Plant residues of a fall/winter coverage crop can influence weed infestation of the subsequent summer crops. This research was carried out to evaluate the effects of mulch from several sorghum (Sorghum bicolor) hybrids plus the herbicide imazamox on the control of the subsequent weed infestation of soybean crop (Glycine max cv. 'Conquista'). The experiment was carried out in the 2000/2001 crop year in Uberlândia, MG. Four types of mulch were used, three from sorghum hybrid residues (Sara, DKB 860 and Ambar) and one without residues (no previous winter crop). Twenty-four days after the application of imazamox, the control of the species Leonotis nepetifolia, Aternanthera tenella, Amaranthus hibridus, A. retroflexus, A. spinosus, Ipomoea grandifolia, Commelina benghalensis, and Nicandra physaloides was more effective with the use of Sara or Ambar mulch without the herbicide, with 40 and 41% of control, respectively. When associated to 15 g ha-1 of imazamox, Ambar mulch resulted in better efficiency, with 76% of control. DKB 860 combined with 30 g ha-1 of imazamox was the most efficient treatment, providing 85% of weed control. Without soil coverage, 62.5% of control was achieved with 30 g ha¹ of imazamox and 47.5% with 15 g ha-1. The results indicated wide control variability in relation to the sorghum hybrid used and possibility of imazamox dose reduction when associated to sorghum residues.
Plant residues of a fall/winter coverage crop can influence weed infestation of the subsequent summer crops. This research was carried out to evaluate the effects of mulch from several sorghum (Sorghum bicolor) hybrids plus the herbicide imazamox on the control of the subsequent weed infestation of soybean crop (Glycine max cv. 'Conquista'). The experiment was carried out in the 2000/2001 crop year in Uberlândia, MG. Four types of mulch were used, three from sorghum hybrid residues (Sara, DKB 860 and Ambar) and one without residues (no previous winter crop). Twenty-four days after the application of imazamox, the control of the species Leonotis nepetifolia, Aternanthera tenella, Amaranthus hibridus, A. retroflexus, A. spinosus, Ipomoea grandifolia, Commelina benghalensis, and Nicandra physaloides was more effective with the use of Sara or Ambar mulch without the herbicide, with 40 and 41% of control, respectively. When associated to 15 g ha-1 of imazamox, Ambar mulch resulted in better efficiency, with 76% of control. DKB 860 combined with 30 g ha-1 of imazamox was the most efficient treatment, providing 85% of weed control. Without soil coverage, 62.5% of control was achieved with 30 g ha¹ of imazamox and 47.5% with 15 g ha-1. The results indicated wide control variability in relation to the sorghum hybrid used and possibility of imazamox dose reduction when associated to sorghum residues.
Descrição
Palavras-chave
Sorghum bicolor, Glycine max, alelopatia, semeadura direta, Sorghum bicolor, Glycine max, allelopathy, no-till system
Como citar
Planta Daninha. Sociedade Brasileira da Ciência das Plantas Daninhas , v. 23, n. 3, p. 483-489, 2005.