The growth dynamics and Ca content of apple fruit were investigated over three growing seasons for the cultivar Spartan and two seasons for the cultivar McIntosh. Calcium content per fruit increased from fertilization to harvest, with some fluctuations during the season. The final Ca content ranged from 8 to 11 mg per fruit. Calcium concentration diminished markedly as a function of dilution during the first few weeks of growth after which it decreased less rapidly until reaching minimum values at 100 and 110 days after bloom for Mclntosh and Spartan respectively