This investigation was conducted in a private organic farm in Wadi El-Malak district, Ismailia Governorate, Egypt, to evaluate some biocontrol agents i.e. Trichoderma album, T. harzianum, T. viride , biocides i.e. Blight stop (T. harzianum), Bio Zeid (T. album) and natural compound i.e. humic acid and micronic sulfur treatments in the controlling powdery mildew disease of mango cv. Keitt during the two successive seasons in 2021 and 2022. All treatments proved effective in decreasing the Incidence and severity of powdery mildew disease caused by Oidium mangiferae and increased productivity, yield components, quality, chemical components, and enzyme activity of mango cv. Keitt compared to untreated plants. Mango cv. Keitt which was treated with blight stop at the rate of 1: 50 caused the highest decrease in disease incidence, severity (71.01 and 92.10%) and recorded also, the highest increase in yield being 35.5 Kg/tree; fruit quality "total soluble solids (TSS), being 19.50 and 20.46%, total acidity, being 0.71and 0.73%, ascorbic acid being 54.68 and 54.77 mg/100g FW and total sugar, being 14.60 and 14.70%"; biochemical analysis i.e. total chlorophyll (4.71 mg/100 g FW), total carotenoids (6.77 mg/100 g FW and total protein (3.38%); total phenol content and the enzyme activities of peroxidase (PO) and polyphenol oxidase (PPO) during both growing seasons, followed by T. harzianum isolate. On the contrary, humic acid showed the least effective treatment. No clear significant differences were noticed between the other treatments in comparison with untreated plants.