Data/hora: 03/06/2024 15:26:00

Biblioteca(s): | Embrapa Meio Ambiente.
Data corrente: | 08/02/2018
Data da última atualização: | 08/02/2018
Autoria: | VAZ, L. R. L.; BARIZON, R. R. M.; QUEIROZ, S. C. do N. de; REGITANO, J. B.
Afiliação: | L. R. L. VAZ; ROBSON ROLLAND MONTICELLI BARIZON, CNPMA; SONIA CLAUDIA DO N DE QUEIROZ, CNPMA; J. B. REGITANO.
Título: | Hexazinone and diuron runoff in green cane systems.
Ano de publicação: | 2017
Fonte/Imprenta: | IN: SETAC LATIN AMERICA, 12., 2017, Santos. Biennial Meeting. Santos: Sociedade Brasileira de Ecotoxicologia, 2017. Ref. SP042. p. 66.
Idioma: | Inglês
Conteúdo: | Sugarcane is a major crop in Brazil and of great importance to the world. Higher yields implicate in higher use of pesticides, such as diuron and hexazinone. The adoption of green cane system, in which the straw is kept in the soil surface after mechanical harvesting, has changed the environmental behavior of theses herbicides. Therefore, the goal of this research was to evaluate runoff losses of diuron and hexazinone in green cane systems. The 3x2x2 (12 treatments) factorial experiment was performed in a randomized block with 4 replicates. The factors were i) 3 levels of sugarcane straw (0, 50% and 100%, based on a dose of 14 t ha-1); ii) 2 levels of initial soil moisture (10 and 18% VWC), and iii) 2 rainfall periods (0 and 3 d after herbicides application). A rainfall simulator was adjusted to simulate an 80 mm h-1 rainfall event for one and a half hour (120 mm) over plots of 1 m2. A commercial product containing diuron and hexazinone was used at rate of 3 kg ha-1 dissolved in 700 L ha-1, according to label recommendations. The amounts of water and sediments were registered and herbicides concentrations analyzed by UPLC. Herbicides attached to the sediments were estimated according to sorption data from the literature. The results were evaluated by ANOVA and means compared by Tukey test (p< 0.05). Sugarcane straw decreased water, sediments, and diuron losses by runoff, but did not affect hexazinone losses. In other words, crop residues cannot prevent losses of highly soluble molecules, such as hexazinone. Greater herbicides losses were observed in the aqueous phase, even for the control treatment (without straw), since straw reduces the amounts of detached sediments. However, no difference was observed between the two levels of straw (50 and 100%), meaning that 7 t ha-1 is sufficient for mitigating water, sediments, and diuron losses by runoff. Higher soil moisture (18 versus 10%) resulted in higher herbicides runoff. Yet, rainfall period did not affect herbicide losses, indicating that 3 days were not long enough for enhancing these herbicides dissipation or sorption.
Thesaurus Nal: | Diuron; Hexazinone.
Categoria do assunto: | W Química e Física
Registro original: | Embrapa Meio Ambiente (CNPMA)
Exemplares: | CNPMA - (16019-1) - UPC - SP - DD -  -  - Barizon - DIS