Effects of foliar application of calcium, boron and gibberellic acid on seasonal change of mineral nutrition and fruit quality of pomegranate ( Punica granatum L.)

This study was conducted to determine the effects of calcium, boron and giberellic acid on seasonal changes of mineral nutrients, yield and quality. The experiment was set up according to randomized plot design with three replicates. Two different doses of calcium nitrate, boric acid and giberellic acid were applied to the leaves during full bloom and one month after full bloom. The trees of the experiment were determined according to phenological observations, yield, number of A type and B type flowers, fruit set rate, number of fruit per tree, cracked fruit ratio, sunburn ratio), the physical and chemical quality characteristics of fruits ( fruit weight, fruit diameter, fruith length, fruit peel ratio, fruit arils number, 100 aril weight, aril efficiency, fruit juice efficiency, fruit juice color, aril water content, peel water content, total soluble solids content, pH, fruit peel phenolic contents, fruit juice total phenolic content, fruit juice total monomeric anthocyanin amount, fruit juice ascorbic acid content, titratable acid content). Mineral nutritions (nitrogen, phosphorus, potassium, calcium, magnesium, copper, manganese, iron, zinc and boron) were determined according to seasonal changes in the leaf, aril and fruit peel samples.The yield was increased by applications of calcium and boron. The rate of fruit quality was reduced by application of giberellic acid. Sunburn rate was reduced by application of calcium. Fruit juice efficiency was increased by applications of giberellic acid and calcium nitrate. Calcium nitrate has increased the water content of the fruit peel. All applications have increased the amount of total soluble solids. The amount of ascorbic acid was increased by application of giberellic acid. Application of calcium has increased the uptake of mineral nutrients. Nutrient concentrations declined throughout the growing season in the arils and fruit peel. Mineral nutrient concentrations in the leaf samples remained stable for one month, i.e. 15 August-15 September. As a result, of this study on Hicaznar variety the yield was increased by calcium and boron applications and fruit quality was increased by giberellic acid application. Additionaly, it was determined that the most appropriate time for leaf collection is the period between 15 August-15 September.