Shoot growth, crop load, and fruit quality within vase-shaped canopies of ‘Fairtime’ peach trees

Abstract

Position within the canopy and shoot type can affect final fruit quality in peach (Prunus persica (L.) Batsch). In this study we examined the variation of vegetative growth, crop load, and fruit quality within vase-shaped peach canopies. In four adult 'Fairtime' peach trees trained to vase, each shoot was labeled and numbered from the top to the bottom of each branch and consequently also in a centripetal direction with respect to the main axis. The length and diameter of each 1-year-old shoot was measured, and the number of sprouts and fruits was recorded. Fruit weight and soluble solid content (SSC) were measured at commercial harvest to determine fruit quality. Total shoot length, yield, total number of fruits, average shoot length, and number of fruits per shoot decreased from top/outside to bottom/inside of the canopy according to a cubic model with a lag phase in the middle part of each branch. Yield per shoot declined linearly from top/outside to bottom/inside of the canopy, whereas SSC decreased exponentially. Shoot diameter, number of sprouts, and number of fruits per shoot were proportional to shoot length, whereas SSC was directly correlated to shoot length and diameter and number of fruits and sprouts.