This field experiment was conducted at Research Station B, Department of Horticulture and Landscape Engineering, College of Agricultural Engineering Sciences, University of Baghdad, Jadiriyah during the fall season of 2019-2020 to evaluate the effect of cultivation dates and soil fertilization source on the growth, yield and quality of broccoli. A split plot design within the RCBD design with three replicates was applied as the Max F1 hybrid broccoli seedlings were transferred to the field at two dates 25, Sep. 2019 and 15, Oct. 2019, which were symbolized as A and B, respectively, and occupied at the main plot. After two weeks of cultivation, the soil fertilizers were applied three times during the season in 20 days between each application including Biohealth fertilizer at a rate of 1 and 2 kg per donum, symbolized as T1 , T2 and NPK nano fertilizer at a rate of 250 and 500 ml donum, symbolized as T3 and T4 , as well as the control treatment that was fertilized according to the fertilizer recommendation and symbolized as T0 . This factor was considered the most important (sub plot) and the number of plants per experimental unit reached 15 plants. The results revealed a significant effect under the combination of first cultivation date and the soil application of Biohealth fertilizer at a concentration of 1 kg dunum (AT1) on the leaves content of N and k, leaves number, leaves area, the diameter and weight of the main disc, the total yield, the total soluble solids percent (TSS) and the heads content of beta-carotene, which were recorded 3.96, 2.99%, 41.0 Leaf-1 plant, 227.44 dm2 Plant-1, 74.0 cm, 896.40 gm Plant1 , 37.35 Tons Ha-1, 11.00%, 6.95 mlg 100 gm wet weight-1, respectively, which did not significantly differ from the combination of the first cultivation date and the application of nano-NPK fertilizer at a concentration of 500 ml dunum (AT4) on leaves area, the weight of the main head, and the total yield, which were recorded 212.39 dm2 plant-1 and 884.55 gm plant-1 and 36.85 tons ha- 1, respectively compared to the second date of cultivation and the application of fertilizer recommendation (BT0), which gave 2.33, 1.68%, 34.0 leaves, 139.99 dm2 plant-1, 51.0 cm, 689.23 gm plant-1 and 28.71 tons ha-1, 8.17% and 4.57 mlg 100 gm wet weight-1, respectively.
