Persistence of biological activity of imazaquin and imazethapyr sprayed in two seasons of the year

• Autor(a) principal: Inoue, Miriam Hiroko
• Data de Publicação: 2008
• Outros Autores: Oliveira Junior, Rubem Silvério de, Constantin, Jamil, Oliveira, Maurilio Fernandes de
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Acta Scientiarum. Agronomy (Online)
• Texto Completo: http://www.periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/2851
• topic: bioensaio; imidazolinonas; persistência no solo; 5.00.00.00-4 Ciências Agrárias

With the aim of estimating the persistence of imazaquin and imazethapyr soil biological activity in a dark red latosol in Maringá, PR, Brazil, experiments were carried out in two different seasons of the year (winter/spring - from July to October, 1999, and spring/summer - from December 1999, to March, 2000). The herbicides were applied at 150 and 600 g/ha, and soil samples from 0-2 cm depth were collected from herbicide-treated plots an no-herbicide check up to 91 days after application (DAA). In greenhouse, bioassays using cucumber and sorghum as test-species were carried out, sowing these two species in soil samples collected from the experimental field. Results obtained allowed to conclude that imazaquin displayed a longer soil residual effect, and that higher rates (600 g/ha) of both herbicides provided longer periods of persistence, despite the season of application. The inhibition percentage of biomass production in samples from spring/summer herbicide-treated soil decreased faster, when compared with winter/spring application. Cucumber was more sensitive than sorghum as bioindicator of imazaquin and imazethapyr soil biological activity