A glasshouse trial was conducted at field No. 2 at the Faculty of Agriculture, University Putra Malaysia, to evaluate the effect of different application times of microbial-enriched compost tea on the development of powdery mildew. The daily temperature of the glasshouse ranged from 25 to 30 C, and the RH was 85 %. The photoperiod ranged between 8 and 10 h. The melon F-1 seed variety ‘Emerald Jewel’ was used as a test plant. The seeds were directly sown in a pot measuring 12 cm in diameter, which was filled with the soil mixture consisting of top soil, peat (Kosas-Peat, Kosas PROFIL Sdn. Bhd.) and sand at a ratio of 3:2:1 (v/v/v). Plants were watered daily and fertilised with the recommended dose of NPK Green at a ratio of 15:15:15.