The samples were collected on the day of the application (day zero) and 2, 4, 8, 16, 32 and 64 days thereafter (DAP).
For the application in the tanks, we have used carbon dioxide (CO2) precision equipment, providing a flow rate of 200 L The recommended dose, according to the manufacturer, was 7.0 L The experiment was designed in two treatments with four repetitions, the first being colonized by water hyacinths and the second without the presence of the macrophyte. Eight fiber-cement tanks with the storage capacity of 250 liters were used under the conditions without water flow and without replacement of water. The present study had the purpose to assess the behavior of the herbicide glyphosate in the control of water hyacinths, in a water environment through half-life, in a controlled and closed experimental field, in order to contribute to the analysis of the risk of the environmental impact of the use of this product.
