This study was carried out at private farm, Dakahlia Governorate, Egypt, to investigate the response of deficit irrigation water under both traditional and drip irrigation systems combined with soil amendments, on the growth and chemical constituents of pepper plants (Capsicum annum L. "California Wonder"). The experiment tested 30 treatments arranged in strip split plot design. The horizontal-plots were allocated to the irrigation systems (surface and drip irrigation), whereas the vertical-plots were devoted to the irrigation regimes of 40, 60 and 80% from the irrigation water requirement (IWR), while the subplots were includedfive soil amendments (without, 250, 500 kg.fed^-1 potassium silicate ore, and 35 and 70 kg.fed^-1 potassium humate). The results of both seasons indicated that, drip irrigation system produced significantly higher values of vegetative growth characteristics and chemical constituents than surface irrigation system. The irrigation regime treatment at 80% following irrigation at 60 from IWR were recorded significantly highest values. The results also showed that, the higher average values were obtained from soil amendments at 70 kg/fed from potassium humate following with 500 kg/fed from potassium silicate. In addition, the results indicated that the higher average values of vegetative growth and chemical constituents were obtained from soil amendments at 70 kg/fed. from potassium humate following with 500 kg/fed. from potassium silicate under drip irrigation system at 80% from IWR following irrigation at 60% from IWR. Therefore, we recommend this treatment because it saves irrigation water and obtains the best vegetative growth and chemical constituents traits of sweet pepper plants.