Incidence of bitter pit in relation to the calcium content of apples: Calcium distribution in the fruit

Abstract

AbstractThe distribution of calcium at harvest, its subsequent redistribution within the fruit during storage in air at 2.8°C and bitter pit development in samples of Cox's Orange Pippin apples picked at intervals during September and October were investigated. The distribution of calcium in the fruit changed on the tree and during storage. The percentages of pitted apples, assessed in January, were poorly related to calcium concentrations in the whole fruit or in any fruit zone at harvest. Redistribution of calcium from the mid and outer cortical tissues to the core zone was followed, at longer intervals over successive picks, by the appearance of bitter pit lesions. The earliest‐picked sample was less affected by bitter pit than samples picked later in September. The least bitter pit occurred in samples picked in October, after the climacteric rise in respiration, and these fruits were apparently less subject to fluctuations in calcium concentrations during storage.