The current investigation aimed to maximize the productivity of “Washington Navel" orange by reducing fruit splitting %, increase fruit weight and size, quality, in addition to improve marketability. So, in the 2016/2017 and 2017/2018 seasons a field experiment was carried out on a private orchard in Kafr El-Sheik governorate, Egypt. Trees were treated with Benzyladenin (BA) at 50ppm, Sytofix (CPPU) at 10ppm, GA3 at 50ppm, and GA3 combined with BA or CPPU. Plant growth regulators (PGRs) were applied three times after the full bloom stage by 15, 30 and 45 days as foliar application. Results revealed that PGRs increased quality parameters, productivity, and chlorophyll content, as well as reduced fruit splitting % and carotene content. GA3 plus CPPU gave the highest fruit fresh weight, fruit length, fruit yield, and SSC%. However, GA3+BA registered the greatest fruit diameter, chlorophyll content, TA%, vitamin C, as well as decreased fruit splitting % and carotene content. Regarding the marketing period, GA3 plus BA obtained the highest reduction % in weight loss, decayed fruit percentage, however, recorded the greatest vitamin C and chlorophyll contents. ABA results clarified that application of PGRs tended to decrease significantly its content in peel fruit, in particular, GA3 alone or combined with BA showed the lowest content of ABA in both seasons. These results will not only help researchers to understand the roles of PGRs in navel orange fruit growth, development, and productivity but can also be applied to large-scale fruit production and prolong the marketing period.