The study was carried out in 2015 in the experimental orchard of the Agropodrinje apple introduction centre in the Gorazde area. The impact of different methods of calcium fertilizer application on fruit quality and calcium content in the ‘Idared’ fruit of an 8-year-old apple tree were studied. Fruit mineral composition and quality parameters were estimated after harvest. Calcium fertilizers used in this research were Folifertil- Ca, calcium-ammonium nitrate (CAN), and calcium oxide (CaO). Folifertil-Ca was applied through leaves, and CaO and CAN were applied through soil. The method of application where CAN was applied in combination with Folifertil-Ca significantly increased the accumulation of Ca in apple leaves and fruits. Also, this method of calcium fertilizer application had the greatest impact on apple fruit firmness increase. In the present study sugar content and acidity of apple fruit did not differ significantly, regardless of the application method of calcium fertilizers.
The results of this study support the fact that the Ca uptake by plant roots and its transport to leaves and fruits are directly affected by a plant’s transpiration rate. This fact suggests that in apple cultivation is better if calcium fertilizers applied through soil or in combination with foliage treatment.