The mango tree presents a high level of fruit abscission, which is increased in semiarid regions due to environmental stress. The use of biostimulants and phytoregulators has shown to be a promising strategy to improve fruit setting. Thus, the present study defined the best strategy for setting and development of the fruit, with the application of phytoregulators and biostimulants on the 'Keitt' mango tree, cultivated in the S & atilde;o Francisco Valley. Two experiments were performed. In experiment 1, a randomized block design was used, with four treatments T1: control, T2: gibberellic acid (AG(3) ) + 2,4-dichlorophenoxyacetic acid (2,4-D), T3: AG(3) + 2,4-D+Benzyladenine, T4: Biostimulant + CoMo (R) (sources of cobalt and molybdenum). In experiment 2, the factorial scheme (2 +3 + 1) distributed in randomized blocks was established, corresponding to two forms of potassium fertilization (recommended and adjusted), three gibberellin concentrations (0, 10 and 20 mg L-1 ) and additional treatment (control- recommended potassium fertilization and no setting strategy). The variables analyzed include the relative number of fruits, the number of fruits for domestic and foreign markets, productive potential, production, productivity, fruit volume, fruit mass, and the yield of peel, pulp and stone. The application of 10 mgL(-1) AG(3) + 10 mg L-1 2,4-D + 10 mgL(-1) Benzyladenine in full flowering of the 'Keitt' mango tree, increased the setting and the production of the fruit. Regardless of fertilization, sequential applications at 10 or 20 mg L-1 of AG(3) proved to be an effective strategy to produce 'Keitt' mango tree. Adjusted potassium fertilization and the application at 10 mg L-1 of AG(3) promotes the production of fruits with greater mass and volume.