High maize grain yields are related to a fast, complete and regular plant emergence. This experiment was carried out in Lages, SC, Brazil, with the objective of evaluating the effects of an uneven plant emergence on maize grain yield at different plant populations. A split plot design was used, with the main plots disposed in randomized complete blocks. Four plant populations, equivalent to 40,000, 60,000, 80,000 and 100,000 pl.ha-1 were tested in the main plots. Different levels of unevenness in plant emergence were analyzed in the split plots by varying the sowing dates of adjacent hills inside each as it follows: 1 - even emergence (0-0-0-0); 2 - unevenness of 12 days (0-12-0-12); 3 - unevenness of 19 days (0-19-0-19); 4 - unevenness of 12 and 19 days (0-12-19-0-12-19). The increase in plant population up to 76,500 pl.ha-1 enhanced grain yield to 12,900kg.ha-1. At this plant population, the difference in yield grain per hectare among treatments with even and uneven emergence was nearly 2,900kg. This indicates that under similar productivity levels replanting maize may be on economically viable option. Besides reducing grain yield, uneven emergence also limited maize response to the increment in plant population.
competition; unevenness of emergence; plant population; sowing
