Tests were conducted in 1982 and 1983 to determine the effect of time of application of KCl fertilizer on yield, value and chloride concentration on burley tobacco. Recent interest in source of K for Burley tobacco results from the greater cost of K2SO4 than KCl and because high concentrations of Cl in leaves reduces quality and burn rate. There were sixteen treatments; two application dates (November and May), four rates of potassium per hectare (112, 224, 336, 448 kg); and two sources of potassium fertilizer (KCl and K2SO4). These treatments were replicated three times each at six locations. Results indicate that source of K in the leaf had little effect on yield and concentration of Cl when applied in November but both were increased when applied in May.