The results revealed that foliar sprays of both zinc and boron, alone or in combination increased significantly the concentration of N, K, Mn, Zn and boron in the mandarin leaves of spring flush compared with control. Significant increase in the yield of applied trees was obtained. The highest yield was achieved in response to zinc or boron alone, especially in the second season. Moreover, foliar sprays of such elements appeared to balance the biennial bearing of mandarin trees. The values of fruit size, fruit weight, juice, peel and pulp percentages per fruit showed a significant increase. Similar trends were observed with the chemical parameters values of mandarin fruit juice at the maturation stage. The physical characters of fruits treated with zinc and boron either alone or in combination decreased significantly with increasing storage period. On the other hand, TSS, total acidity and vitamin C content declined gradually after the cold storage period. Similar results were also detected for the changes in TSS / acid ratio of fruit juice. Thus, storability of fruits treated with zinc and boron in cold storage either alone or in combination was found to be better, as it minimized the magnitude of fruit weight loss, decayed fruit, juice, TSS percentages and vitamin C content and extended the storage life of mandarin fruits. Generally, foliar application of Zn or B on mandarin trees not only increased their yield but also appeared to improve the quality and storability of their fruits.