In Ethiopia the effects of foliar applied potassium nitrate alone and in combination with urea at different concentrations were evaluated on flowering, fruit set and fruit quality of Tommy Atkins´ mango. The sprays were conducted initially on the immature postharvest flushes and then repeated after the maturation of the flushes for dark green leaves. There were no significant differences found for the quality parameters. But for most of the flowering and yield parameters potassium nitrate in combination with urea (5 liter solution of 4% KNO3+ 0,5 g urea tree−1 and 5 liters of 4% KNO3+1 g urea tree−1) produced better results.