Modeling Peach Fruit Growth and Carbohydrate Requirements: Reevaluation of the Double-sigmoid Growth Pattern

Abstract

Abstract Seasonal patterns of fruit growth were measured on early and late-maturing peach ( Prunus persica L. Batsch) cultivars (‘June Lady’ and ‘O’Henry’, respectively). Seasonal relative growth rates of fruit dry matter accumulation were calculated. The relationships between fruit relative growth rates and respiration were used to develop a quantitative carbon budget model of peach fruit growth and sink activity. The resulting model indicates that the double-sigmoid growth pattern of peach fruits involves only two physiologically distinct phases of sink activity instead of the three stages that are traditionally recognized. The traditional stage II of fruit growth is apparently a function of the timing of the shift between these two physiological phases of sink activity.