APPLES: DCA STORAGE WITH REPEATED GAS STRESS - THE EXPERIENCE IN THE MANAGEMENT OF COMMERCIAL CELLS

Since 2006 in Trento province, fruit grower organizations (Melinda, La Trentina, Cio Serene, Valentina), have made a treasury of the experiments and research developed at the FEM-IASMA, applying the DCA management recommendations in commercial cold stores on superficial scald sensible apple cultivars. During the season 2011-2012 more than 50,000 t of apples were stored in 112 DCA cells, applying the experimental model of repeated gas stress based on the evaluation of the metabolites accumulation (i.e., ethanol, acetaldehyde). This technology consists in maintaining the apples for 15-20 days in anaerobic conditions (O₂: 0.5-0.7%, CO₂: <0.9%) favoring the accumulation of ethanol to threshold levels. This treatment should be repeated 2-3 times during storage.
The technique showed, on the involved cultivars ‘Granny Smith’, ‘Red Delicious’, ‘Morgenduft’, ‘Pink Lady’ and ‘Fuji’, an optimal control of superficial scald (<1%) even after 200 storage days + 15 days of shelf life, maintaining high qualitative standards (firmness and titratable acidity). The extension service program, advised during picking, loading and DCA management, is fundamental together with the application of adequate storage protocols. The multi-year management experiences, together with high qualified refrigeration and CA technologies, if well applied, have proven to be able to avoid postharvest chemical treatments.