Correlations among quality parameters of peach fruit

The correlations among quality parameters of peach fruit (Prunus persica L Batsch) were studied for eight different cultivar-shape-site-nitrogen-season combinations ('treatments'). Between 66 and 183 fruits were taken from each treatment and the quality parameters of skin colour, flesh firmness and taste were measured. Differences and similarities between treatments were analysed using a recent development in biplot multivariate analysis: the ACT method (Analyse Conjointe de Tableaux), which allows the study of several data tables in one unique analysis. Each treatment was characterised by a data table where records were the fruit and variables were quality parameters. A common pattern of correlation between quality parameters was found for all the treatments. Two main independent gradients were described. The first was a colour gradient and the second was a taste gradient. In the latter, the concentrations of sucrose and malic acid varied inversely with citric acid concentration. The firmness and the concentration of reducing sugars were independent of these gradients.