Redistribution of minerals in apple fruit during storage: Effects of storage temperature,varietal differences and orchard management

Transverse calcium redistribution from the cores to the outer zones of the fruit was interrupted for a short period when calcium was imported by the cores of both Cox and Spartan apples, especially at 3.5°C. Bitter pit lesions developed in mid and outer cortical tissues of Cox fruit stored at 3.5°C 2 to 4 weeks after calcium concentrations in these zones were reduced. Redistribution of magnesium from the outer zones to the cores of Spartan apples occurred during storage at 3.5°C but was inhibited at 0°C. Redistribution of magnesium in Cox's Orange Pippin apples was mainly from inner cortex to the core and outer zones at 3.5°C and from central to outer zones at 0°C, but immediately low temperature breakdown become evident at 0°C, magnesium was transferred from the peel and core to the affected zones. The redistribution of phosphorus to the cores, which occurred in Spartan apples (resistant to low temperature breakdown) stored at either 3.5°C or 0°C was barely evident in Cox fruit (susceptible to low temperature breakdown) stored at 3.5°C and did not occur at 0°C. Irrigated grass compared with overall herbicide soil management increased the proportion of calcium in the core zones of both Cox and Spartan apples and the proportion of magnesium in the core zone of Spartan apples at harvest. Irrigated grass management also increased the rate of calcium redistribution in Cox and Spartan fruit during storage and altered magnesium redistribution in Spartan apples stored at 0°C.