Cucumber (Cucumis sativus L.) is one of the most important economically crops, which belongs to family cucurbitaceae. The economic importance of this crop appears in both local consumption and exportation purposes. Cucumber is grown either in the open field or under protected houses. The cultivated area of cucumber in 2003 growing season reached about 11881 feddan in open field which yielded 88575 ton fruits, in addition to 13267 greenhouses, yielded about 44771 ton fruits. Cucumber powdery mildew caused by Sphaerotheca fuliginea (Schlectend: Fr.) Pollacci. This disease can cause damage to all plant parts including leaves, stems and fruits especially under protected house conditions and causing considerable reduction of quantity and quality of cucumber yields. Disease control is generally achieved by the use of fungicide. Thus, the present work was conducted to founding alternative non-chemical methods to fungicides and reducing fungicides use to control of cucumber powdery mildew disease under protected houses.