Repeatability reveals to be a useful method to evaluate the quality of an experiment with common beans

Abstract

Field experiment should be carried out with high accuracy since the discarding of a trial involves waste of time and resources, and can mislead breeders in selecting inferior genotypes. The simulation of a large number of experiments with great variability of traits is the main strategy to assist breeders on how to perform the experiment. Therefore, the objective of this study was to evaluate two criteria to infer the experimental quality: Coefficient of Variation (CV) and repeatability coefficient. Experimental data from evaluations of common bean lines carried out in 104 experiments were used in this study. The simulation of the scenarios used the following parameters: number of cultivars, number of blocks, genetic variance, mean yield, and coefficient of variation. Two thousand replications for each scenario were simulated. Genotypes means were arranged in an order, and the Spearman correlation was obtained between the estimated genotypes mean and the true genotypic values. Results revealed that CV is not a reliable parameter to evaluate the quality of experiment in the field. In conclusion, repeatability coefficient is the parameter that defines the discarding criteria of evaluation experiments and the recommendation of cultivars, as long as the values for each response variable are established.