Introduction
Powdery mildew caused by G. cichoracearum DC. is one of the most common diseases of melons (Cucumis melo L.) grown under both field and greenhouse conditions in Malaysia. The vast majority of melon growers presently rely on synthetic fungicides to control powdery mildew. Fungicides that contain active ingredients such as chlorothalonil, difenoconazole, triadimefon, triforine and benzimidazole are commonly used to control powdery mildew but with
variable degrees of success. The frequent application of these fungicides is associated with an increase in
environmental pollution, health hazards and development of resistance in microbial pathogens