The objective of this research was to compare two methods of estimating the optimum plot size (Xo) to assess 12 characters of corn hybrids single, triple and double and verify the variability of the Xo among characters and hybrids. It was measured morphological (height plant and cob) and productive (ear weight, number of rows per ear, length and diameter of ear, weight and diameter of cob, weight of hundred grains, number of grain per ear and length and grain yield) characters, in basic experimental units of a meter, in 48 uniformity assays. The Xo was determined using the methods of the maximum curvature modified and the maximum curvature of the model coefficient of variation for each character. The optimum plot size obtained by maximum curvature modified method is concordant, but higher than obtained by maximum curvature of the model coefficient of variation. The optimum plot size of productive characters is greater the morphological. The optimum plot size among the hybrids is 5.04 basic experimental units for the simple hybrid (4.03m²), 5.24 for the triple hybrid (4.19m²) and 5.53 for the double hybrid (4.42m²).
Zea mays L.; maximum curvature modified; maximum curvature of the model coefficient of variation; first order autocorrelation; experiment planning
