The purpose of this study was to check the effect of different potassium nitrate sprays on flowering induction of ‘Carabao’ mango shoots in the Philippines. Newly-emerging shoots on the trees were tagged, to get shoots of 4,5 to 8,5 months old. In August and at monthly interval thereafter up to December, randomly designated shoots were sprayed with 0, 10, 20 or 40 g/l KNO3. The control shoots were sprayed with tap water. All potassium nitrate treatments at 10 to 40 g/l induced the flowering of 4,5 to 8,5 old ‘Carabao’ mango shoots. The oldest shoots of 8,5 months required only 10 g/l KNO3 to produce the best flowering response. The best results were obtained with the younger shoots (4,5 to 7,5 months) and sprays of 20 g/l KNO3. The high concentration treatment (40 g/l KNO3) reduced percentage of flowering, panicle length and number of flowers at all stages of maturity for mango shoots. All control shoots did not flower.
