Fruit drop and quality are the most important factors in Washington navel orange production and
exporting potential. This study was done at a private farm located in Sadat district, throughout the two seasons
of 2020 and 2021 on Washington navel orange trees 20 years old was planted in sand soil. Three different
concentrations (0.0, 5.0, 15.0 and 25.0 ppm) of Gibberellic acid (GA3) were applied as foliar spray at full bloom
stage of orange cultivars. To determine the association of GA3 with fruit set and fruit drop. The obtained results
showed that GA3 sprays at 25 ppm were more effective compared with other treatments and control in term of
fruit set, retention, and yield as number or weight (Kg) /tree, improved the yield as well as the physical and
chemical fruit characteristics, decreased drop. It might be recommended that foliar spraying with 25 ppm GA3
gave the best values of yield (kg) /tree, fruit physical and chemical properties.