Abstract: In order to improve the yield of Trichoderma water dispersing granule, and study the biocontrol effects of Trichoderma water dispersing granule on Cucumber Fusarium wilt, the nutritional conditions of the strain were optimized. The results showed that: within the scope of this study, the best formulation (mass fraction) of the adjuvant in the water dispersible granule of Trichoderma harzianum 33104 was carbon black 0.5%, K₃PO₄ 4%, carboxymethyl cellulose 5%, soluble starch 5%, tripoli 5% and sodium lignosulfonate 5%. The optimum formulation (mass fraction) of the adjuvant in the water dispersible granule of Trichoderma viride 33804 was carbon black 0.4%, CMC-Na 5%, PVP 5%, soluble starch 4%, kaolin 3% and sodium lignosulfonate 5%. Effects of Trichoderma atrovide and Trichoderma harzianum on the physiological characteristics of cucumber Jinyan 4 infected with Fusarium oxysporum were studied. Compared with the treatment group only inoculated with pathogens, both Trichoderma and Fusarium wilt pathogens inoculated at the same time or single inoculation could significantly improve the activities of antioxidant enzymes, proline content and chlorophyll content of cucumber, and reduce MDA content. Both Trichoderma species water dispersing granule showed good biocontrol effects, and effect of Trichoderma atrovide was better.

Key words: cucumber fusarium wilt, Trichoderma, water dispersible granule, biology control