Grain yield data were used from 101 cultivar competition trials of corn (Zea mays L.), carried out in Rio Grande do Sul State, Brazil, in the agricultural years 2002/2003, 2003/2004 and 2004/2005, with the aim at evaluating statistics for classification of the experimental precision. The experimental coefficient of variation and significant minimum difference among cultivars by Tukey's test, expressed in percentage of the mean, are associated to the mean and the residual variance, being statistics appropriated for the classification of experiments with similar means. The highest values of the statistics herdability, coefficient of determination, test F value for cultivars, and Fasoulas index of differentiation are associated to greatest genetic variabilities and minor residual variances, and are independent from the mean trials; these statistics are appropriated for classification of the experimental precision.
Zea mays; indication; coefficient of variation
