Determination of nutritional status, some fruit quality parameters and antioxidant activity of pomegranate orchards (Punica granatum L.) in Antalya region

In this study, that aims to investigate the nutritional status of pomegranate orchards, soil samples from two different depths, 0-30 and 30-60 cm, and leaf and fruit samples were taken from 60 different pomegranate orchards. Soil analysis was performed for each depth for the following parameters; texture, CaCO3, organic matter, EC, pH, total N, plant available P, exchangeable K, Ca, Mg and Na, plant available Fe, Mn, Zn and Cu; in leaf samples, N, P, K, Ca, Mg, Na, Fe, Mn, Zn and Cu were determined. Moreover, fruit samples were representatively taken from each orchards and fruit weight, fruit diameter, fruit height, rind thickness, rind color, and; total soluble solids (TSS), vitamin C and antioxidant activity were also determined in fruit juice.Most of the soils had texture of loam, slightly alkaline and alkaline and high level of CaCO3 that possibly affects plant growth negatively, and low in organic matter; while no salinity problem was recorded. Soil N and K status were generally adequate in two depths (0-30 and 30-60 cm); however, plant available P, exchangeable Ca and Mg status were found to be highly good enough. Moreover, exchangeable Na was fixed to be low. For micro nutrients; while plant available Fe, Mn and Cu were sufficient, Zn status ranged from low to marginal. Macro nutrient concentrations (N, P, K, Ca and Mg) of leaf samples were generally sufficient, whereas micro nutrient status showed some deficiencies especially in Fe, Mn, Zn and Cu.Fruit weight varied among 304.73-815.97 g, fruit diameter among 84.07-115.86 mm, fruit height among 75.45-105.43 mm, rind thickness among 3.66-9.07 mm; and ring color was measured at the range of 39.39-61.64 for chroma and of 20.38-46.49 for hue values. In fruit juice, TSS ranged from 14.0-18.2 %, vitamin C from 13.2-48.7 mg L-1 and antioxidant activity in term of EC50 from 0.00704?0.01790 ml. In addition, the correlation between the soil and plant analysis results and each other was also carried out and statistical differences were found.As a result, particularly high soil pH and CaCO3 were the most striking problems on the one hand, low organic matter and low to marginal plant available Zn status of soils on the other. In the leaf samples; Fe, Zn, Mn and Cu deficiencies were identified; however, there were not fruit quality problems at the end.KEY WORDS: Antalya, pomegranate, nutritional status, fruit quality parameters, antioxidant.