The aim of this research was to determine the sample size needed to evaluate peach fruit characters at harvest and after cold storage. Fruits were collected from a commercial orchard. In the laboratory, split randomly, two samples of 120 fruits each, one sample assessed at harvest and one stored at -0.5°C for 30 days, and then for five additional days at 20°C. Eleven characters were measured on each fruit at harvest and twelve after cold storage, being the central tendency measures and dispersion calculated and normality checked. After, it was compared the average and the homogeneity of variance at harvest and after cold storage and calculated the sample size for each character. In peach, 169 fruits are needed to estimate the pulp firmness, 34 fruits to estimate the weight, acidity and ratio, 11 fruits to assess fruit juiciness and six fruits to estimate the others characters at harvest and after cold storage, with an estimation error of 5% on average.
Prunus persica; sample dimensioning; experimental planning
