The study was conducted to investigate the influence of seaweed extract, chelated manganese, and two other chemical substances that are known as Agro promotor1(substance No.48) and Agro promotor2 (substance No.50) on the growth, yield, and quality of cauliflower. Results revealed that yield and its components increased with using each seaweed extract(3ml/l), chelated manganese (12%) at a concentration of 0.25g/l, and Agro promotor1 (substance No.48) at a concentration of 3 ml/l compared with control (untreated) treatment. Using both seaweed and chelated manganese treatments exceeded other foliar spraying treatments and caused a significant increase in fresh weight of the whole plant, leaves fresh weight,leaves dry weight percent, yield, TSS and vitamin C. The increase in total yield ranged from 12.8-48.2% by using the previous treatments as compared with control. Also, foliar sprays of seaweed extracts led to the earliness in cauliflower production as compared with the control. This study recommends using seaweed extract at a concentration of 3ml/l or chelated manganese (12%) at a concentration of (0.25g/l) for cauliflower production. Agro promotor1 (substance No.48) at a concentration of 3 ml/l can be applied in case of unavailability of seaweed extract or chelated manganese (12%).