. Gunadi, N. 2009. Potassium Sulphate and Potassium Chloride as Sources of Potassium Fertilizeron Shallots. An experiment to determine the effect of 2 sources of potassium fertilizer i.e. potassium sulphate (K2SO4)and potassium chloride (KCl) and the rate of potassium fertilizer on the growth and yield of shallots was conductedat farmer's field in Ciledug Village (12 m asl.), Cirebon, West Jawa from June until August 2003. Two sources ofpotassium fertilizers i.e. potassium sulphate and potassium chloride were assigned as main plots and the rates ofpotassium fertilizers i.e. 50, 100, 150, 200, and 250 kg/ha were assigned as subplots. The experiment was arrangedin a split plot design with 3 replications. The results indicated that the effect of source of potassium fertilizer was notsignificantly affect the growth parameters such as plant height, shoot number, leaf number, and dry weight of plant.While at harvest, however, the effect was significant. The application of potassium sulphate gave higher dry yieldper plant, fresh yield per plot, and dry yield per plot (15 m2) compared to potassium chloride. The use of potassiumsulphate did not significantly increase the quality of shallot bulb at harvest compared to the use of potassium chloride.The effect of potassium fertilizer rate was not pronounced on some growth parameters and yield of shallots such asplant height, shoot number per plant, and leaf number per plant, total plant dry matter, fresh and dry yield either perplant or per plot (15 m2).