TOLERANCE OF A VERY LATE SEASON PEACH CULTIVAR TO TEMPERATURE AND ATMOSPHERE COMPOSITION

Jesca is a very late season peach clone with fruits that are very firm, non-melting and pale yellow in colour. Extending the commercial life of Jesca peaches would be very advantageous to reduce competition with other cultivars. However, cold storage of peaches is usually limited by the occurrence of physiological disorders, known as chilling injury (CI), which appear at temperatures below 8°C (Bramlage, 1982). Susceptibility to CI varies according to genetic background, maturity grade and orchard, with late-season varieties being the most sensitive (Von Mollendorf, 1987). Controlled atmospheres can reduce CI and hence maintain quality and minimize postharvest losses. Storage recommendations for peaches are 0-5°C with 3-5% CO₂ and 1-2% O₂, (Kader, 1980) but tolerance depends on cultivar. The aim of this work was to establish the behaviour of Jesca peaches stored at a low temperature and their tolerance to CO₂ and O₂ concentrations at the limits of the recommended ranges for peaches.