This study was conducted during two successive seasons (2018 and 2019) in a private farm located at Tokh district, Qaluobiya Governorate; to investigate the application yeast, amino acids and salicylic acid (SA) on leaf area, tree nutritional status, productivity and fruit quality attributes of Balady Mandarin Trees. Yeast  application was added either soil addition at 2.5, 5 and 10g/tree or foliar spraying at 0.25, 0.50 and 1% were carried out either in the solely or in combined with spraying  of amino acids (tryptophan, methionine and cysteine) at 5% and salicylic acid at 50 ppm. All treatments were done four times at growth start (1st week of March), just after fruit setting (mid of April) and at two months intervals. The results showed that the application of yeast, amino acids and salicylic acid either alone or in combination among them had the best results compared to untreated plants in the tested seasons. Triple application of yeast at concentration of 10 g/tree plus foliar spraying of amino acids at 0.5% and salicylic acid at 50 ppm resulted in significantly the heviest yield, improved fruit quality attributes in terms of increasing fruit weight, total soluble solids%(ssc), total sugars %, and decreasing total acidity %, as well as stimulated  leaf area(cm²) and  leaf content of total chlorophylls, nitrogen, phosphorus, potassium and zinc of Balady mandarin trees.