Uniformidade de distribuição de plantas e estande de milho (Zea mays L.) em função do mecanismo dosador de sementes

The aim of this work was to evaluate the spacing of corn plants ( Zea mays L. ) in three speeds of two precision planters in no-tillage systems (one with vacuum-disk metering and another with horizontal seed plate) and their influence on initial and final stand of plants. It was observed that plant spacing in the sowed areas was not uniform in more than half of the measured spacing, both for vacuum-disk and horizontal plate mechanism, in the three studied speeds (3.0; 4.5 and 7.0 km h -1 ). However, the spacing percentage among plants considered normal was better in the vacuum-disk, mainly when the speed was equal to or lower than 4.5 km h -1 . The machines, in the three speeds, did not alter stand formation.