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Sample size for estimating the within plot variance in experiments designed to evaluate common bean progenies

Elaine Aparecida de Souza; Daniel Furtado Ferreira; Magno Antonio Patto Ramalho

Departamento de Biologia, Escola Superior de Agricultura de Lavras, Caixa Postal 37, 37200-000 Lavras, MG, Brasil. Send correspondence to M.A.P.R.

ABSTRACT

Ninety-three segregant progenies, of the F₃, F₄ and F₅ generations, from the cross between common bean cultivars Jalo and Small White, were assessed during the dry season of 1991. The purpose was to calculate the within plot variability and to determine the minimum plot sample size necessary to quantify this variation. For these experiments five plants from each plot were harvested individually and the mean and variance of yield, number of pods and number of seeds per plant were calculated. Different sample sizes were simulated, varying from 5% to 50% of the number of plots. Ten samples of the same size were used for each simulation. By comparing the estimates obtained per sample with those of the whole population, it was shown that the samples were representative of the population for all characteristics and generations even when the smallest size, 5% of the plots, was used.

Keywords: sample size; estimating; within plot variance; common bean progenies.

REFERENCES

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