:Two field experiments were carried out during the two successive summerseasons of 2019 and 2020 in the private Farm at Keshek Village, Abou- Hamad district, Shahrkia Governorate, to study the effect ofpotassiumrates(45, 60, 75 and 90 kg K₂O/fad.) assoil applicationsand differentsources ofpotassium, i.e.potassium citrate (K_₃C_₆H_₅O_₇) at 1 ml/l,potassium humate (C₉H₈K₂O₄) at 3 g/l,potassium thiosulfate (K₂S₂O₃) at1ml/l andpotassium silicate (K_₂SiO_₃)at 3 ml/l, besidesprayed with water (control treatment)asfoliar application on dry weight, mineral uptake andyieldand its componentsofeggplant (cv. long black).The interaction between K₂O at 90 kg/fad. and foliar spray with K_₃C_₆H_₅O_₇at 1 ml/lsignificantly increaseddry weight ofbranches, leaves and shoots/plant, N, P and K uptakeby shoots, average fruit weight, yield/plant,andtotal yieldwith no significant differences with K₂O at 75 kg /fad., and spraying with K_₃C_₆H_₅O_₇at 1 ml/l, followed by theinteraction between90 kg K₂O/fad., and spraying withpotassiumhumateat 3g/linboth seasons.In the same time, total yield /fad. (14.649 and 14.768 ton/fad.)produced from75 kgK₂O and spraying with K_₃C_₆H_₅O_₇at 1 ml/l treatmentwere more than total yield/fad. (12.320 and 12.290 ton/fad.)produced from90 kg K₂O and unsprayed (spraying with water)in the 1^st and 2^nd seasons, respectively.As forpotassium use efficiency(KUE), the highest values of KUE wererecorded withthe interaction between 45 kg K₂O/fad. and K_₃C_₆H_₅O_₇at 1 ml/lfoliar spray (245.3 and 247.2 kgfruit/kgK₂O) in the 1^st and 2^nd seasons, respectively