Evaluation of three pomegranate cultivars: leaf mineral concentration, yield and fruit quality

The study was carried out in the experimental orchard at the Agricultural University of Athens (Greece) in 2016 with the aim of comparing the nutritional status, fruit set, yield, fruit and juice characteristics of two well-known pomegranate cultivars ('Wonderful', 'Acco') and a Greek genotype ('Persefoni'). The experimental trees of 'Wonderful' and 'Acco' were 6 years old and those of 'Persefoni' 5 years old. The experimental design was completely randomized with three replications. All the trees received the same horticultural management practices. Expanded leaves from the exterior of each tree were collected on 11th July and analysis of nutrients (N, P, K, Na, Mg, Ca, Zn, Mn, Cu, Fe and B) was carried out. Fruit weight and dimensions (fruit length with and without calyx, and diameter), external fruit color, total soluble solids (TSS), pH, titratable acidity (TA), TSS:TA ratio and percentage of juice were measured. The results showed that TSS did not significantly differ among the three genotypes. 'Wonderful' had significantly higher fruit weight and fruit dimensions than the other two. The external fruit color differed significantly. The percentage of juice (% juice fruit(-1) weight) was lower in 'Persefoni' than in the other two. 'Wonderful' had lower pH and higher TA than 'Acco' and 'Persefoni'. The TSS:TA ratio was significantly lower in 'Wonderful' than the other genotypes. 'Persefoni' had the lowest fruit set compared with 'Wonderful' and 'Acco'. 'Acco' had the greatest number of fruit tree(-1) among the three. However, 'Wonderful' had the highest yield (total fruit weight tree(-1)), which was twice that of 'Acco' and three times higher than that of 'Persefoni'. From the nutrients measured in leaves, only the concentrations of Ca, Mn and Fe were significantly different among the three. In conclusion, 'Persefoni' was found to be the sweetest and ' Wonderful' the most sour. 'Wonderful' was the most productive of the three.