Effects of crop load on fruit water relations and fruit growth in peach

Abstract

SummaryMany studies have reported the effect of crop load on leaf water relations of fruit trees but none have dealt with the effect of crop load on water relations of the fruit and how such an effect might influence fruit growth. This is of interest because it could improve our understanding of the relationship between crop load and fruit size. In this study, we measured fruit water potential, fruit osmotic potential, fruit turgor potential and fruit growth, and leaf water potential and leaf conductance on nine-year-old ‘Yanco Queen’ peach ‘Prunus persica (L) Batsch’ trees carrying different levels of crop load. The trees were trained on Tatura trellis and had been either left unthinned (heavy crop load: 450 fruit per tree in 1986 and 560 fruit per tree in 1987) or were thinned (light crop load: 310 fruit per tree). Trees carrying the heavy crop load had lower fruit water potential and higher fruit osmotic potential, and consequently lower fruit turgor potential compared with trees carrying a light crop ...