Effect of gibberellic acid and zinc sulfate spraying on fruit cracking and quantitative ‎and qualitative characteristics of pomegranate cv. ‘Malase Saveh’‎

In the current study, for reducing of fruit cracking and improvement of quantity and quality of pomegranate fruit cv. ‘Malase Saveh’, gibberellic acid (0, 30 and 60 mg/l) and zinc sulfate (0, 1500 and 3000 mg/l) treatments were utilized as a factorial experiment based on randomized complete block design with three replications. Gibberellic acid and zinc sulfate was sprayed in three stages of fruit developmet in the late of spring and midsummer. The fruit and leaf samples were harvested randomly from various parts of the pomegranate trees at fruit ripening and some morpho-physiological characteristics of fruit and leaf were measured. The results showed that the spraying of gibberellic acid alone or in combination with zinc element significantly reduced the fruit cracking percentage compared to the control. The lowest level of fruit cracking was related to gibberellic acid treatments with levels of 60 and 30 mg/l and 3000 mg/l zinc element with mean values of 7.73 and 7.80%, respectively. The highest amount of fruit cracking was observed in control samples (30 %). The fruit weight, length and diameter, moisture percentage and thickness of fruit peel, TSS, zinc element and ascorbic acid concentrations significantly were increased with application of 60 and 30 mg/l gibberellic acid, and 3000 mg/l zinc sulfate compared with the control samples. In general, the results showed that spraying of pomegranate trees with gibberellic acid and zinc sulfate can improved some morpho-physiological characteristics of the fruit, which are effective in controlling of fruit cracking and increasing the qualitative and quantitative characteristics of pomegranate fruit.