Observations on the relationships among seed number, fruit calcium, and senescent breakdown in apples

In a population of 'Delicious' apples (Malus domestica Borkh.) with varying seed number at harvest, fruit size and Ca concentration in fruit increased with seed number. Neither K nor Mg concentration in fruit was related to seed number. In another population of 'McIntosh' apples from 50 commercial orchard blocks, the per- centage of fruit that developed senescent breakdown, a Ca-deficiency disorder, de- creased linearly as seed number per fruit increased. Low seed number is probably a factor contributing to Ca deficiency in apple fruit.