| Trichoderma has been internationally recognized as a biocontrol microbe and widely used in vegetable disease control for many years, and Trichoderma has been proved with multiple function including biological control, promoting growth, environmental remediaiton etc.and those functions has become great interests which scientists attempt to develop worldwide. However so far lack of commercial Trichoderma based–products shows high disease control efficiency in agriculture production worldwide. Since the Trichoderma processing arts actually are not good enough to generate high quality products with stable performance in field conditions. In this study, we, from the wide type Trichoderma library, screened a strain of Trichoderma that showed very significant effects of promoting vegetable growth and controlling vegetable soil-borne disease. And then, we optimized chlamydospore fermentation process and improved formulation technique to create a kind of versatile Trichoderma wettable powder against cucumber powdery mildew. Furthermore, it was demonstrated that those Trichoderma powder performed well in the disease control and soil remediation in field experiments in Shanghai and Jiangsu. Major research results are summarized as follows.1. Screening Trichoderma strain: Firstly, we screend Trichoderma strains with fast growth high sporulation and inhibition rates, and then, we measured the volatilize and nonvolatilize materials released from Trichoderma and assayed the chitinase activity of those strains, eventually we measure Trichoderma strain activity in vivo condition in the presence of pathogen.Through all screening processeses mentioned above, we finally obtained a best Trichoderma strain, SH2303.2. Fermentation optimization: The liquid fermentation medium was formed based on single-factor-optimized screening and orthogonal design. The best fermentation formulation was optimized as follows: beef extracts 0.1g/100mL, NH4H2PO4 0.5g/100 mL, Na3PO4 0.3g/100mL, corn flour 4g/100mL, CuSO4.5H2O 0.006g/100mL, ZnSO4.7H2O 0.006g/100mL, and MnSO4.H2O 0.002g/100mL, pH4. The culture fermentation was carried out at 28℃, 240r/m with sample loading volume of 32% (80 mL/250 mL), mycelial age of 1.5d and 1.5% of inoculum. 3. Preparation of wettable powde: The optimized formulation was determined as Trichoderma chlamydospore powder 1%, kaolin89%, dispersing agent NNO 9.1%, stabilizer potassium nitrate 0.25%, additive protective agent lecithin 65%, The Trichoderma powder was prepared strictly following national standards.4. Preparation of Trichoderma powder: A multi-functional Trichoderma powder was prepared with the rice husk, bran, and diatomaceous earth as carrier. The product had not only function of biological control, but also promotion of vegetable growth, as well as improvement in soil and vegetable quality. The combined use of Trichoderma powder with different proportions of organic fertilizer experiments indicated that using Trichoderma and organic fertilizers at the same time was able not only to effectively control fungal diseases, but also significantly reduce the amount of fertilizer used into soil. Above all, the mixed use of different powders (H6, D9, P6) enabled to generate multiple results including biocontrol of disease, the promotion of crop growth, soil environment remediation. |
