Abstract This investigation was conducted during the two successive seasons i.e. 2019 and 2020 on Zaghloul date palm grown at the experimental orchard, Faculty of Agriculture, South Valley University, Qena, Egypt. This work conducted to study the effect of different sources of potassium fertilizers on fruiting of Zaghloul date palm under Qena condition. Potassium fertilization via nano-technology, vinasse and potassin were used. The experiment was arranged in a complete randomized design with three replications. It is evident from the obtained results that using nano-potassium, either soil dressing or foliar spray, as well as foliar spray of vinasse or potassin significantly increased the fruit retention, bunch weight and yield/palm compared to fertilize by potassium sulphate (check treatment). Also, these treatments significantly improved dates quality in terms of increasing fruit weight, flesh percentage, TSS, sugar percentages and anthocyanin contents moreover, decreasing total acidity and total tannins compared to fertilize with the recommended potassium doses via potassium sulphate. From the results, it could be concluded that fertilized Zaghloul date palm with potassium fertilization via foliar spray of either nano-potassium, vinasse or potassium to improve the fertilization efficiency and get high yield with best dates quality. In addition, hasten advance the fruit ripening and overcome potassium fertilization problems.