Chemical investigations on bitter pit of apples

Abstract

The skin of apples has been found to contain about 4 times as much calcium as the underlying flesh, on the dry-weight basis. The calcium-rich area consists of a layer of epidermal and underlying collenchyma cells.Healthy and pitted fruits from a number of orchards showed a consistent relation between pitting and low calcium level in the skin and flesh.

Bitter pit in Cox's Orange apples

“…using a method developed by Kidson et al (1963), show close relationship between calcium content and bitter pit incidence. The calcium figures in experiment 2 may seem rather high relative to the amount of bitter pit, but this is explained by the calcium sprays being too late to be absorbed throughout the apple flesh and thus failing to give good control of pit.…”