In the National Research Center in Nubaria, Egypt, a field study was carried out in 2023, and 2024 two growing seasons. The purpose of the experiment was to determine how potato cv. Spunta's vegetative development, yield, and chemical composition were affected by varying rates of mineral fertilization (100, 80, and 60% NPK) and foliar spraying of Blue green algal (BGA) extract (1, 2, and 3 cm/ L). In a split plot system, a randomized complete block design was applied. In this investigation, plant growth and yield characteristics were improved by mineral fertilizers (NPK) applied at 100% as opposed to 80% or 60% NPK. Furthermore, the ratio of N, P, and K minerals in potato leaves, and tuber were highest at 100 or 80% NPK, compared to 60% NPK in both years. The results for potatoes' computed levels of starches, nitrates, carbs, and total sugars showed the same outcomes. When the amount of foliar spraying was raised from 1 to 3 cm/L, the usage of algal extract rose in vegetative characteristics, yield, composition, and chemical analysis. The best vegetative parameters were observed at 100% NPK and the highest concentration of algae extract (3 cm/ L), according to the results of the interaction between mineral fertilizer and algae extract application. However, using 80 or 100% NPK along with a high concentration of algal extract (3 cm/L) improved the yield and it's chemical in both seasons.