In no-tillage systems, burndown is one of the most important steps to achieve maximum initial crop growth and minimize weed interference during early stages of the crop cycle. The purpose of this work was to evaluate the effect of different burndown systems before no-tillage sowing of soybean. A field experiment was carried out in Iguaraçu, Paraná State, during the 2004/2005 growth season. Under field conditions, five burndown dates (10, 7, 5, 3 and 0 days before sowing) combined with three herbicide treatments (glyphosate 1080 g, glyphosate + flumioxazin 1080 + 25 g ha-1 and glyphosate + flumioxazin 1080 + 40 g ha-1) were compared in regards to desiccation speed, initial weed emergence, development and yield of soybean. Compared to the use of glyphosate alone, this association showed positive aspects such as faster desiccation speed and a soil residual effect over the first cycle of weed emergence after crop sowing. With a faster decrease in soil cover, it is possible to begin soybean sowing shortly after desiccation.
herbicide association; burndown; soybean; no-tillage