The capabilities of foliar application by copper sulfate, zinc sulfate, magnesium sulfate and ferrous sulfate as micronutrients, hydrogen peroxides, ascorbic acid and salicylic acid as inducers, potassium silicate and sodium silicate as silicon salts and different combination of NPK, on controlling sugar beet powdery mildew casued by Erysiphe beta were studied. Also, yield and sugar purity and changes in oxidative enzymes, comparable with non-treated plants and Eminent (EW12.5% I m/L) fungicide were estimated. In greenhouse under artificial infection all treatments significantly decrease disease severity compared with control. Eminent fungicide was the most effective treatment in reducing disease severity,followed by higher concentration of copper sulfate, zinc sulfate, hydrogen peroxide then salicylic acid and potassium silicate. The lowest treatments were NPK combination levels N2P1K1, N1P1K1, N2P2K1, ferrous sulfate 10 ppm and sodium silicate at concentration 4 ppm. Under field condition, all tested treatments significantly reduced disease severity, while yield and sugar purity were increased in both seasons. Eminent, copper sulfate 20 ppm, ascorbic acid 100 ppm, zinc sulfate 20 ppm and Hydrogen peroxide followed by salicylic acid 50 ppm, potassium silicate 15 cm3/L were significantly higher in decreasing disease severity and increasing root weight, sucrose and purity percentage compared with control treatment. Whereas, the lowest treatments in decreasing severity and yield parameters were magnesium sulfate 30 ppm followed by ferrous sulfate then N1P2K2. All tested chemicals significantly increased activity of phenylalanine ammonia lyase (PAL), Polyphenol oxidase (PPO) and Peroxidase (PO) activities in sugar beet leaves compared with control. PAL and PPO activity exhibited the highest value with treatments of hydrogen peroxide 1.5%, ascorbic acid 100 ppm, salicylic acid 50 ppm, potassium silicate 15 cm3/L and copper sulfate 20 ppm followed by zinc sulfate 20 ppm. Meanwhile, PO activity was higher in treatments of hydrogen peroxide 1.5%, potassium silicate 15 Cm3/L, ascorbic acid 100 ppm, salicylic acid 50 ppm, followed by copper sulfate 20 ppm zinc sulfate 20 ppm. On the contrary, N1P2K2 followed by ferrous sulfate 30 ppm, magnesium sulfate 30 ppm and eminent were the lowest treatments in enzymes activity compared with control treatment.