Relationships between maturity and storage disorders in ‘Cox's Orange Pippin’ apples as influenced by preharvest calcium or ethephon sprays

Abstract

Abstract In a study over four growing seasons, changes in the starch pattern index, flesh firmness, and background colour were measured in ‘Cox's Orange Pippin’ apples harvested at 3–4-day intervals during fruit maturation, and related to quality and storage disorders of fruit stored at 3°C for 6 weeks. Trees were sprayed with ncsmal therapeutic sprays without Ca salts, or with Ca(NO3)2 at 2-week intarvals during the growing season. Calcium-sprayed fruit showed small but consistent delays in fruit maturity compared with unsprayed fruit, as determined by starch pattern indices and background colour, but not by flesh firmness. After storage, Ca-sprayed fruit were firmer than unsprayed fruit, but there was no effect on background colour. Unsprayed fruit that were harvested early had a high incidence of bitter pit which decreased as harvest date was delayed. Unsprayed fruit were more susceptible to senescent breakdown as harvest date was delayed in two out of the four years. Calcium sprays reduced both disord...