摘要 : The aim of this research was to contribute to increasing fruit set, given the importance it has in determining yield. The effects of phytohormones (auxins, gibberellins and cytokinins) were evaluated in the mooring on 'Washington ... 展开 The aim of this research was to contribute to increasing fruit set, given the importance it has in determining yield. The effects of phytohormones (auxins, gibberellins and cytokinins) were evaluated in the mooring on 'Washington Navel' and 'Thomson' (<i>Citrus sinensis</i> (L) Osb.) orange fruit set. The experimental design was a split plot in a randomized complete block with five treatments and four replications. Flowering tissue samples were stored in liquid N until the extraction of gibberellins and the identification and quantification of GA₃. The results show statistically significant differences (P<=0.05) between treatments in the number of fruits retained 129 d after flowering and percentage of final set. GA₃ content ranged from 1.66 mg g^-1 in the control to 20.79 mg g^-1 dry weight in the high dose treatment. The mean rate (32.2 mg L^-1 auxins, 32.2 mg L^-1 gibberellins and 83.2 mg L^-1 cytokinins) caused the largest increase in fruit set. 收起