EFFECTS OF PRUNING ON CARBOHYDRATE DISTRIBUTION IN THE TRUNK OF SWEET CHERRY (PRUNUS-AVIUM L)

During the annual carbohydrate cycle, starch and soluble sugar concentrations were quite similar in the lower and upper parts of the trunk of sweet cherry. The seasonal variations were characterized by a maximum carbohydrate content between summer and mid-November and at the end of winter. Bloom and fruit development were distinguished by carbohydrate depletion. The effects of the removal of low branches on the level of the carbohydrates were related to the time of pruning. After summer pruning, the middle and upper parts of the trunk contained the highest concentrations of starch and soluble sugars. The following year, starch had completely disappeared in the upper and lower parts of the trunk. The autumn pruning induced an increase in starch and soluble sugar levels in the upper part. The winter pruning mainly induced a rapid accumulation of soluble sugars in the upper part only.