SOURCE-SINK RELATIONS IN FRUITS .10. EFFECT OF NITROGEN ON FRUIT-GROWTH AND COMPOSITION IN SOUR CHERRY STEVNSBAER

Trees of sour cherry 'Stevnsbaer' growing in pots were watered with nu trient solutions implying six levels of nitrogen ranging from deficien cy to abundancy. With increasing nitrogen status, leaf nitrogen concen tration, leaf and shoot growth, and the concentration of titrateable a cids in fruits were augmented, while the concentrations of dry matter, 'sugars', and anthocyanins decreased noticeably along with their accu mulation towards ripening. Fruit size was not significantly affected o n a fresh weight basis, but dropped with increasing nitrogen on a dry weight basis. Fruits from base compared to top parts of trees attained lower concentration of dry matter and anthocyanins. The results are d iscussed on the basis of the effects on the water, carbohydrate, and n itrogen balances of the tree.