Production Of Biocontrol Agent SC11 And Research On The Combination Of Biocontrol Agents

Biocontrol agent (BCA) SC11, with strong colonization and competition, was used to suppress eggplant Verticillium wilt by degradating the cell wall of target agent. Based on the solid-state fermentation, the processing technique and the optimal auxiliary agents of actinomycete SC11 were tested. Three microbial inocula were produced: powder, granules and seed coating agent. The control and promotion effects to eggplant against Verticillium dahliae were also studied. Meanwhile, the combination of biocontrol agents SC11, Fo47 and 153 was tested to control infection of watermelon roots by Fusarium oxysporum f. sp. niveum, providing a theoretical basis for practical application with BCAs.1,With the inocula as indicator, we used orthogonal design test to optimize the solid-state fermentation and auxiliary agents of biocontrol agent SC11. The results indicated that its optimum conditions of solid-state fermentation should be substrate (rice powder), carbon source: maize straw (60mg/g), nitrogen source: millet powder (30mg/g), inoculum concentration (0.4mL/g), initial moisture content (400mg/g), incubation time (192h) and initial pH (7.6). The optimum conditions of auxiliary agents should be carrier: non-cultivated soil 100mg/g, dispersant: carboxymethylcellulose sodium 10 mg/g, protecting agent: humic acid 10 mg/g.2,On the basis of solid-state fermentation of biocontrol actinomycete SC11, three microbial inocula were produced: powder, granules and seed coating agent. The control and promotion effects to eggplant against Verticillium dahliae were also studied. The result indicated that the seed coating agent achieved the highest control effect with 69.98%, similar to the Carbendazol control of 73.26%. In the promotion experiment, seed coating agent reached significant growth and development of eggplant.3,The combinations of BCAs SC11,Fo47 and 153 were tested to control infection of watermelon roots by Fusarium oxysporum f. sp. niveum. The results indicated that sequential combination of SC11 and 153 was extraordinarily effective with control effect 89.47%, higher than other combinations. Simultaneous combination of SC11 and Fo47 resulted in the least control, indicating possible antagonism between the two agents. We concluded that there was feasible to combine BCAs, and the application time and space should be taken more attention.