Influenced of post-harvest calcium chloride application on bitter pit and quality attributes of apple cv. ‘Red Delicious’ and ‘Golden Delicious’

An experiment was performed to develop a post-harvest practice for reduction of bitter pit disorder in apples. Physiologically mature apple fruits cv. ‘Red Delicious’ and ‘Golden Delicious’ were dipped in 0, 2, 4, 6 and 8% CaCl₂ solutions for 15 minutes and stored for 3 months at ambient temperature. Fruits were analyzed for incidence of bitter pit and various quality parameters viz., physiological loss in weight (PLW), fruit firmness, total soluble solids (TSS), titrable acidity and sugars. Concentrations of Ca, Mg and K were also determined in healthy and pitted fruits. The extent of disorder varied in both the cultivars with ‘Red Delicious’ showing less bitter pit incidence (7.5%) than ‘Golden Delicious’ (12.3%). Bitter pit-affected tissues had lower concentration of Ca but higher concentrations of K and Mg, which resulted in increase in K/Ca, Mg/Ca or (K+Mg)/Ca ratios in affected tissues. Apple fruit cv. ‘Red Delicious’ required 2% CaCl₂ treatment as against 4% in case of cv. ‘Golden Delicious’ to reduce bitter pit disorder to a minimum level.