This investigation was conducted in greenhouses protected, Al-Haram, Ministry of Agriculture and Land Reclamation, Giza, Egypt during the two seasons 2019/20 and 2020/21 to evaluate some biological control agents i.e. Trichoderma harzianum, T. viride, Bacillus subtilis and Pseudomonas fluorescens, as well as the biofungicide -Blight Stop and micronic sulfur treatments to control Leveillula taurica, the main causal of powdery mildew disease in sweet pepper plants cv. Godeon Hybrid F1. All previous treatments proved efficacy in reducing disease incidence and severity of L. taurica in vitro and greenhouses, as well as recorded an increase in productivity, fruit quality, chemical constituents and enzymatic activity of sweet pepper cv. Godeon Hybrid F1, compared to untreated plants. The treatment of pepper plants with Blight stop at the rate of 1 L:50 L water recorded the highest percentage of decrease in disease incidence and severity of pepper plants, and also recorded the highest increase in vegetative growth, yield, fruit quality such as "total soluble solids and ascorbic acid"; biochemical analysis such as total chlorophyll; total phenol content, peroxidase and polyphenoloxidase activities during the two growing seasons, followed by T. harzianum isolate in effectiveness. On the contrary, micronic sulfur treatment showed less effect compared to other treatments except untreated plants. The study was recommended the use of biocide Blight stop at a concentration of 1 L: 50 Lwater for sweet pepper cultivation to obtain the best growth, highest productivity and quality of pepper fruits with the lowest percentage of powdery mildew infection under greenhouse condition.