This experiment was carried out during two successive summer seasons of 2021 and 2022 at the private Farm in Basandela Village, Belqas, Dakahlia Governorate, Egypt (31° 20' 326.7" N and 31° 45' 286.0" E) to study the effect of planting date (planting on 15^th April and planting in 15^th May) and potassium fertilization sources (five potassium treatments, i.e., 100 % K₂O of the recommended rate (RD) equal 72 kg K₂O /fad. only as soil application (SA), 75 % K₂O RD (equal 54 kg K₂O /fad). and spraying with potassium humate (KH) at 3ml/l, 75 % K₂O RD and spraying with potassium citrate (KCit) at 1 ml /l, 75 % K₂O RD and spraying with potassium silicate (KSil) at 3 ml/l, and 75 % K₂O RD and spraying with thiosulpahte potassium (KTS) at 1 ml /l on plant growth as well as   tuber yield and its quality of Jerusalem artichoke Feusa cultivar. Planting date  on 15^th May condition  and fertilization Jerusalem artichoke plants  with 75 %   K₂O  of the recommended  rate  (equal 54 kg K₂O/faddan) and   spraying with  KCit at1 ml/l or KSil at3 ml/l  significantly increased  number of main  shoots/ plant, shoot dry weight , total chlorophyll concentration  in leaf tissues, K contents and its uptake by shoots,   total yield, potassium use efficiency, yield of inilne, P and K contents  in tuber, total carbohydrates and  dry matter contents, whereas  planting  date  on 15^th April  and treating plants with the same fertilizers  recorded the highest plant height and shoot fresh weight. Planting on 15^th May and fertilization Jerusalem artichoke plants with 75 %  K₂O of the recommended rate   and   spraying with KCit at 1 ml /l or KSil at 3 ml/l  were the best treatments to increasing the productivity and improving the tuber quality characters, and these treatments recorded increases in total yield about 38.09 and 36.29 % as average two seasons than planting on 15^th April and fertilizing with 100% K₂O only.