Almost half of all fruits produced worldwide are produced from grapes, making them the most frequently planted fruit crop worldwide. For two seasons in a row, 2023 and 2024, experiments were carried out on the Thompson seedless grape cultivar. Treatments used by foliar spraying were 50 ppm potassium citrate, 100 ppm potassium citrate, 200 ppm tyrosine, 200 ppm lysine, 200 ppm methionine, 200 ppm glycine, 30 ppm B6, 30 ppm B12, 70 ppm ZnO, 70 ppm ZnSo₄, and control with three replicates/ treatment. Tyrosine at 200 ppm exceeded all the other treatments as it recorded 8.57 and 7.43 kg/vine in the two seasons of study. Furthermore, it produced the highest leaf area (110.67 and 109.07 cm²) during the two seasons of study in addition to the highest cluster weight (429.14 and 513.95 g). Glycine at 200 ppm registered the highest values of TSS/ acid (199.83 and 111.30) during the two seasons of study, respectively. Glycine at 200 ppm and ZnSO₄ at 70 ppm registered the highest reducing sugar values (22.43 and 24.75 %) during the two seasons of study, respectively.