Effects of Humic Acid, Vermicompost and Zinc Foliar Spray on Some Quantitative and Qualitative Characteristics of Pomegranate (Khazar Bardaskan cv.)

Considering the high cultivation area of pomegranate in Iran, it is necessary to pay attention to this plant nutrition in order to increase quantitative and qualitative of pomegranate fruit. Nutrition management is one of the most important factors for determining the yield and quality of fruit that there are a few studies to reach the optimal management of nutrition in pomegranate. Therefore, the present study was conducted to investigate the effect of different levels of organic component and chemical fertilizers on quantity and quality characteristics of Punica granatum fruit cv. KhazarBardaskanas a factorial design based on randomized complete blocks design with three replications. Treatments include vermicompost in three levels of 0, 12.5 and 18.75 (V1, V2, V3) kg tree-1 and humic acid in two levels of 0 and 5 g tree-1 (H1, H2) as the soil application and zinc chelate in the two levels of 0 and 0.005 (Zn1, Zn2) as foliar spray. The measured factors were yield, length and diameter of fruit and some qualitative characteristics of fruit juice such as total phenol, antioxidant activity, titratable acidity (TA), total soluble solids (TSS). Also, the concentration of nitrogen, phosphorus, potassium and zinc were determined in leaves. The results of present study showed that the effects of treatments were significant for more measured parameters. The maximum amount of yield 29.09 kg tree-1, antioxidant activity (39.79 %) and total phenol (863.12 mg GAE 100g-1) were observed in V2H2Zn2 treatment of 12.5 kg tree-1 vermicompost, 5 g tree-1 humic acid and 0.005 foliar sprayof zinc. Also, the level of nitrogen, potassium and zinc in the leaves were obtained from the above mentioned treatment (V2H2Zn2), which compared with the control treatment can be recommended as the superior treatment.