Sample size of the characters in common bean cultivars

The aim of this research was to determine the sample size of characters in different common bean (Phaseolus Vulgaris) cultivars and to verify, its variability among cultivars and experiments. Fourteen Common beans cultivars were evaluated in ten experiments conducted in Santa Maria, Rio Grande do Sul State, Brazil (latitude 29 degrees 42' S, longitude 53 degrees 49' W altitude 95m), in agricultural years from 200012001 to 20051 2006. Randomized blocks design with three repetitions was installed to evaluated the following characters: height of first pod insertion, height of the final pod insertion, number of pods per plant, seeds per plant and seeds per pod in five plants sampled at random in each plot. It was found variability in the sample size among cultivars in relation to height of the final pod insertion, number of pods per plant and seeds per plant. When the ten experiments were compared, results also show variability of the sample size in relation to height of first pod insertion, height of the final pod insertion, number of pods per plant, seeds per plant and seeds per pod. To improve the experimental precision in the evaluation of characters in common beans plants it is recommended to increase the number of repetitions and use at least ten plants per plot.