The objective of this research was to determine how many evaluations (experiments) were necessary to predict the performance of common bean (Phaseolus vulgaris) cultivars. Fourteen common beans cultivars were evaluated in nine experiments conducted in Santa Maria, in Rio Grande do Sul State, Brazil (latitude 29°42'S, longitude 53°49'W, altitude 95m) in agricultural years from 2000/2001 to 2004/2005. The evaluations were constituted by grain yield, number of pods per plant, number of seeds per pod, weight of 100 grains, final population of plants, number of days of the emergency to flowering, number of days of the emergency to harvest, height of first pod insertion, height of the final pod insertion, degree of the down and colour of grain tegument. Repeatability estimations were obtained through three methods variance, structural, and principal component analysis. In conclusion, seven evaluations are sufficient to identify superior genotypes for productive, phenologic and morphologic characteristics of the common beans, with 85% accuracy of the real value.
Phaseolus vulgaris L.; repeatability; selection; experimental precision
