Magnesium (Mg) and potassium (K) are the most crucial elemental constituents of chlorophyll molecules that regulate photosynthesis processes and affect grape production and quality. The production response of ‘Flame Seedless’ grapes was assessed under varying amounts of magnesium (0.05, 0.1, and 0.2%) and potassium citrate (250, 500, and 1000 ppm) via foliar application during 2023 and 2024 in Minia Governorate conditions. In a complete randomized block design with three replicates, findings indicated that during both seasons, foliar application of potassium citrate was more effective than magnesium, particularly at 1000 ppm, followed by 500 ppm, with no significant variation observed between the two concentrations. The foliar spraying with the highest combined concentration yielded the greatest mean values for yield, cluster parameters, and berry physicochemical features; the two subsequent highest concentrations exhibited no significant variance. These findings indicated that the application of foliar 0.1% Mg+ 500 ppm potassium citrate was the most economically treatment for best yield and fruit quality.