Relationships among postharvest ripening attributes and storage disorders in ‘Honeycrisp’ apple

Introduction. The objective of this study was to examine the relationships among the ripening attributes of ‘Honeycrisp’ apples at harvest and after storage, and the direct and indirect contributions of these attributes to peel greasiness and the incidence of soft scald and soggy breakdown during storage using correlation and path-coefficient analyses. Materials and methods. Fruit were harvested from a commercial orchard at least five times throughout the commercial harvest period during four subsequent years (2008 to 2011). In two of the years, fruit were stored in air for 3 months at 3 °C and/or in a controlled atmosphere (1–2 kPa O2 + 1–2 kPa CO2) for 6 months at 3 °C. Fruit were analyzed at harvest and after storage. Results and discussion. Negative correlations were detected between internal ethylene concentration (IEC) and soluble solids concentration (SSC) or titratable acidity (TA) (the higher the IEC, the lower the SSC and TA) and a positive correlation between firmness and TA (the higher the firmness, the higher the TA). More peel greasiness and higher incidence of soggy breakdown during storage were associated with lower firmness, SSC and TA. Negative correlations were also detected between the incidence of soft scald and IEC or peel greasiness. The results of the path-coefficient analyses suggest that, in ‘Honeycrisp’, interrelationships among postharvest ripening indices and each individual disorder differ. Three possible path models for the interrelationships among ripening attributes (independent variables) and the incidence of peel greasiness, soft scald and soggy breakdown (dependent variables) are presented