A field experiment was conducted during 2022 and 2023 aimed to declare the response of ‘Solo’ papaya trees productivity and fruit quality to inoculation with Azospirillum and Azotobacter as a diazotrophic bacteria. It is clay from the obtained results that, under clay loam soil under El-Minia Governorate conditions that inoculated ‘Solo’ papaya trees with diazotrophic bacteria (Azospirillum and Azotobacter spp.) significantly improved yield and its components as well as fruit physicochemical properties. However, Azospirillum inoculation shows more effective rather than Azotobacter inoculation, on all studied properties. Furthermore, increasing the doses from 50 to 150 ml significantly improved all studied parameters. In addition, the companied inoculation with both examined micro-organisms at higher dose (150 ml) produced the best yield, fruit number/tree, fruit weight (g) as well as all physical and chemical properties.