effect of training system and calcium chloride foliar application on improving fruit colour and mineral nutrient composition of apple cvs. gala and delbarestival

training systems and calcium foliar application can improve apple fruits pigmentation by changing mineral compositions. in this study, effect of foliar application of calcium chloride with different concentrations (0, 0.75, 1.5 and 3 g l-1) over 2, 4 and 6 weeks before harvest time on fruit mineral nutrient composition and colour values of apple cvs. gala and delbarestival which trained in three different systems (v shape, hightech and cordon) was investigated. the results showed that training systems and calcium foliar application had a significant effect on apple fruit mineral nutrient composition and colour values. apple fruit cv. gala which treated v- shape and hightech showed suitable pigmentation as compare to cordon, but the favorite fruits pigmentation was found in delbarestival, when trained in high tech. furthermore, the highest calcium concentration was found at v- shape and hightech for gala fruits and hightech for delbarestival. calcium foliar application could increase significantly fruit peel a* value that means anthocyanin pigment synthesis and red colour production. phosphorous and potassium contentin ‘delbarestival’ fruits were sprayed to 1.5 g l-1 calcium increased but their content decreased in higher concentration of calcium application. overall, the results showed that color improvement of ‘gala’ apple fruits in hightech and v shape systems and ‘delbarestival’ fruits in hightech system which spray 1.5 g l-1 calcium at three times could be due to increasing calcium concentration in fruits.