Producing new transformants phosphate bio-stimulate (PBS) bacterial inoculates in addition to study their potential effect on growth, yield and quality of kohlrabi plants at two successive seasons 2017/2018 and 2018/2019 were studied in this present work. The obtained results revealed that using the three tested phosphate bio-stimulate inoculates (PBS1, PBS2 and PBS3) alone or combined with different doses of phosphate mineral fertilizer PMF (calcium superphosphate) increase considerably growth, yield and quality of kohlrabi plants as compared to control. Among all tested PBS inoculates treatments, plants treated with PBS2 was superior and gave the best results in all studied traits when used alone or in combination with PMF doses at both seasons. Applying PBS (1,2 and 3) inoculates alone or combined with PMF doses improved the quality of kohlrabi knobs by increasing the values of total soluble solid TSS%, carbohydrates% and L-ascorbic acid% content in the same time, it decreased significantly the fiber% and nitrate content in knob as compared to the control in both seasons. So it could be recommended that to reduce the actual hazard of mineral fertilizer on soil and human health and to produce safe and healthy vegetable for local market and exportation it should be used PBS inoculates alone or combined with low PMF doses.