Seletividade de herbicidas: III - aplicação de herbicidas em pós emergência inicial e tardia da cana-de-açúcar na época da estiagem
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Data
2006-09-01
Autores
Azania, C.A.M.
Rolim, J.C.
Casagrande, Ailto Antonio [UNESP]
Lavorenti, N.A.
Azania, A.A.P.M. [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira da Ciência das Plantas Daninhas
Resumo
Este trabalho objetivou avaliar a seletividade dos herbicidas diuron+hexazinone, azafenidin+hexazinone, metribuzin e isoxaflutole aplicados em pós-emergência inicial e tardia das plantas de cana-de-açúcar, variedade RB835089, na época da estiagem, em soqueira de quarto corte, após colheita com queima prévia do canavial, em Araras, SP. O delineamento experimental foi o de blocos casualizados com testemunhas pareadas, com cinco tratamentos e quatro repetições, existindo uma testemunha capinada para cada tratamento químico dentro de cada bloco. Os tratamentos foram: diuron+hexazinone (1.170+330 g ha-1), azafenidin+ hexazinone (192,5+247,5 g ha-1), metribuzin (1.920 g ha-1), isoxaflutole (127,5 g ha¹) e testemunha capinada. Concluiu-se que os herbicidas foram mais fitotóxicos quando aplicados na pós-emergência tardia. em pós-emergência inicial, as plantas recuperaram-se totalmente dos efeitos fitotóxicos dos herbicidas. Na pós-emergência tardia, azafenidin+hexazinone, isoxaflutole e diuron+hexazinone prejudicaram o índice de fluorescência e a produtividade agrícola.
This research aimed to evaluate selectivity of azafenidin+hexazinone, diuron+hexazinone, metribuzin and isoxaflutole on sugarcane, applied early and during late postemergence in dry season. The study was conducted over 4-yr sugarcane ratoons (cv. RB 835089), in Araras, SP. The experimental design was a randomized block (four replications) with five treatments, plus one weed control to each chemical treatment. The treatments were: diuron+hexazinone (1,170+330 g ha-1), azafenidin+hexazinone (192,5+247,5 g ha-1), metribuzin (1,92 L ha-1 ) and isoxaflutole (127,5 g ha-1 ) and weed control. Height, stand, chlorophyll, fluorescence index, production and technological characteristics were analyzed by the F test and the t test, for average comparison. The herbicides caused more damage to the sugarcane in later postemergence. At initial postemergence, the herbicides did not cause any damage to the sugarcane. At later postemergence, azafenidin+hexazinone, isoxaflutole and diuron+hexazinone damaged fluorescence index and sugarcane production.
This research aimed to evaluate selectivity of azafenidin+hexazinone, diuron+hexazinone, metribuzin and isoxaflutole on sugarcane, applied early and during late postemergence in dry season. The study was conducted over 4-yr sugarcane ratoons (cv. RB 835089), in Araras, SP. The experimental design was a randomized block (four replications) with five treatments, plus one weed control to each chemical treatment. The treatments were: diuron+hexazinone (1,170+330 g ha-1), azafenidin+hexazinone (192,5+247,5 g ha-1), metribuzin (1,92 L ha-1 ) and isoxaflutole (127,5 g ha-1 ) and weed control. Height, stand, chlorophyll, fluorescence index, production and technological characteristics were analyzed by the F test and the t test, for average comparison. The herbicides caused more damage to the sugarcane in later postemergence. At initial postemergence, the herbicides did not cause any damage to the sugarcane. At later postemergence, azafenidin+hexazinone, isoxaflutole and diuron+hexazinone damaged fluorescence index and sugarcane production.
Descrição
Palavras-chave
phytointoxication, Saccharum spp., Fitointoxicação, Saccharum spp.
Como citar
Planta Daninha. Sociedade Brasileira da Ciência das Plantas Daninhas , v. 24, n. 3, p. 489-495, 2006.