Fruiting effects on diurnal changes in sorbitol and starch contents in peach leaves

Using potted peach (Prunus persica Batsch.) trees at the fruit maturation s tage, fruiting effects on sorbitol and starch contents in leaves from day t o night as well as before and after fruit removal were examined. Sorbitol c ontent per unit fresh weight in leaves before fruit removal increased signi ficantly during the day; it decreased at night. Within one day after fruit removal, sorbitol increased to a level greater than that before fruit remov al, whereas the decrease at night did not differ significantly between befo re and after fruit removal. The diurnal changes in starch content of the le aves exhibited a similar pattern to those of sorbitol before fruit removal. Likewise, within one day after fruit removal, starch content increased dur ing the day to a higher level but the decrease at night was smaller compare d to the level before fruit removal.