Fate of Tebuthiuron and Hexazinone in Green-Cane Harvesting System

Autor(es)

Pinheiro Tonieto, Thiago Antonio ^[1] ; de Pierri, Leticia ^[1] ; Tornisielo, Valdemar Luiz ^[2] ; Regitano, Jussara Borges ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo USP ESALQ, Dept Soil Sci, Ave Padua Dias 11, BR-13418260 Piracicaba, SP - Brazil

^[2] Univ Sao Paulo USP CENA, Lab Ecotoxicol, Ave Centenario 303, BR-13400970 Piracicaba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Agricultural and Food Chemistry; v. 64, n. 20, p. 3960-3966, MAY 25 2016.
• Citações Web of Science: 6

Resumo

In Brazil, fire prior to sugar cane harvesting has to be phased out by 2017, but it has already been phased out in up to 85-90% of the cropped area. The new system is called green cane and has entirely changed weed management practices. The main goal of this study was to evaluate the effects of the straw presence as well as humic acid (HA), formulation, soil type, and aging on the sorption and leaching of C-14-tebuthiuron and hexazinone. Both herbicides presented low sorption for all treatments (K-d,K-app <= 3.25 L kg(-1)), but it was higher for tebuthiuron in the clayer soil (LVd). Straw and aging only slightly enhanced sorption. The HA effects were not clear. Sorption was mostly affected by herbicide and soil type. Straw may promote physical trapping (similar to 40% of applied amount), which cannot be accessed by ``batch{''} sorption (similar to 15% of the applied amount is sorbed), attenuating leaching of highly mobile herbicides in green-cane systems. To properly assess leaching through straw residues under laboratory condition, rainfall distribution is very important. (AU)

• Processo FAPESP: 12/15843-0 - Sistemas de colheita (com e sem queimada palhada) na sorção e dessorção de herbicidas em cana-de-açúcar
• Beneficiário: Jussara Borges Regitano
• Modalidade de apoio: Auxílio à Pesquisa - Regular