Abstract: The evaluation was carried out to determine the ability of Talaromyces flavus, MT-06based products in management of cucumber powdery mildew, caused by Sphaerotheca fuliginea. The results showed that the effectiveness of strain MT-06 was dependent on its concentration in pot tests. In particular, 10fold dilution of mycelium mixed liquid have the best effect, with the preventive effects of 87.86% and the curative effects of 84.89% compared to the control after spraying 11 days, while the effect of the other treatments of strain MT-06 are similar to the chemical fungicide triadimefon. The effect of fermented liquid decreased with the prolonging of time; however, the effect of mycelium mixed liquid and spore suspension kept stable for a long time. The colonization test of strain MT-06 on cucumber plants showed that petiole colonization rate is higher than that of the leaves. The petiole colonization rate of mycelium mixed liquid and spore suspension was 100%, except when sprayed the spore suspension at the concentration of 1×105 mL-1 was 85%, while the highest colonization rate on cucumber leaves was 40%. Therefore, the biocontrol efficiency of strain MT06 may be partially attributed to the ability of colonization on cucumber plants. Overall, these results showed that strain MT-06 played an important role in managing powdery mildew on cucumber plants．

Key words: Talaromyces flavus, cucumber powdery mildew, MT-06, colonization