The objectives of this study were to evaluate the variability of the emission of seed radicle of corn (Zea mays L.) and to establish indexes of primary root emission to test the vigor of commercial seed lots. Samples of corn seeds not treated with fungicides, were taken from ten lots of the same cultivar. Two hundred seeds from each lot were distributed on wetted paper towels and also within paper rolles at 25 °C. Each 12 hours, seeds with primary root emission were counted and removed. Indexes of primary root emission were calculated and compared to conventional laboratory tests (first count; accelerated aging; cold test) and field emergence. It was concluded that the primary root emission test, in rolled paper towels can be of great value for evaluating the vigor of corn seeds.
seed; corn; vigor