Desiccation Periods of Urochloa brizantha ‘Piatã’ Before Sunflower Sowing

In no-till farming, which integrates crops and livestock, the crop that is sown is often noted for reduced productivity. The aim of this experiment was to study the influence of a desiccation period of Urochloa brizantha ‘Piatã’ on sunflower ‘Aguará 4’ development and productivity. The desiccation was carried out using glyphosate herbicide at a dose of 1.92 kg·ha-1. The treatments consisted of seven periods of U. brizantha desiccation (27, 22, 17, 10, 5, 3 and 0 days) prior to sunflower sowing (2010/11). The experimental design established randomized blocks with five replicates. The reduced period between cover desiccation and crop sowing impaired sunflower development (capitulum diameter, plant height, leaf area, and leaf and stem dry masses) over the course of the evaluations, especially for periods less than or equal to 10 days. Thus, our data suggest that sunflower producers should carry out the desiccation at least ten days prior to sowing.