The Development Of Trichoderma ST-6 Granules And Its Application Technology

Trichoderma species are an important fungi in the field of plant disease biocontrol.We isolated many Trichoderma strains to select some strains have good biocontrol roles against the soil-born diseases of watermelon,Atractgiodes macrocephaia and eggplant.Strain T-6 is a selected strain with strong antagonistic roles.We studied biology,identification and solid culturing condition of the strain T-6. Based on the study,the ST-6 granules agent was developed.The teclmiques and effect of ST-6 application in the field were also evaluated in this research.All the results are as the following:(1) The isolation and selection of Trichoderma strains.Ninety-eight Trichoderma strains were isolated through the pathogen induced method from 68 soil samples. Among them,13 strains were tested their antagonism against the plant pathogenic fungi,including Fusarium oxysporum of watermelon,Sclerotium rolfsii of Atractgiodes macrocephaia and Sclerotinia sclerotiorum of eggplant,on the dual culture in vitro.The results indicated the strain T-6 showed the strongest antagonistic against the tested fungi.(2) The research on biology and identification of strain T-6.The cultural temperate at 30℃is optimum for its hypha development and spores germination.The optimal media is PDA for hypha development,and OMA for spores formation.Hypha and spores develop better in the acidic environment.The growth of T-6 in different carbon and nitrogen sources was also studied.The strain T-6 was identified Trichoderma harzianum Rifai.(3) The production technology of ST-6 granules agent.The powdery of rice with 0.2-0.4 mm diameter and 40-50%humidity was the solid medium.After sterilization, 0.2%sucrose,0.2%NH₄NO₃ and 0.1%KH₂PO₄ were added into the sterilized powdery.The strain T-6 was inoculated by 4%of the solid medium,and cultured for 7-8 days with 65-90%humidity and 28℃～24℃～26℃fluctuant temperature.When the solid culture were enveloped by the T-6 culture,0.1%D or 0.4%A were added as a binders and bran was added as a coating agent.Then,the prepared agent was air-dryed at room temperature with airflow,and packed as the ST-6 granules agent.(4) The shelf-life of ST-6 and the effect of fungicide on ST-6 agent.ST-6 grains could be stored more than 16 monthes in room temperature under dry and dark environment. Six fungicides were tested for their virulence to T-6 and ST-6.Carbendazim and Prochloraz bad the strongest virulence with Ec50 as 0.2521 mg·kg^-1 and 0.03948 mg·kg^-1,respective.Thiram had little and metalaxyl-mancozeb had no effect on the strain T-6.Different fungicides had different roles to the ST-6 agent.After 3 days of the fungicides application,Carbendazim,Thiophanate-methyl and Prochloraz showed obvious effects on the and spore formation and germination of ST-6 agent.However, the effect on the spore formation was not significant after 7 days of the application. Diethofencarb,metalaxyl-mancozeb and thiram didn't inhibit the germination and formation of ST-6 spores after the application.(5) The application effect of the ST-6 agent s.The application techniques and control effect of ST-6 agent on the diseases,including watermelon wilt,blight of Atractgiodes macrocephaia and white blight of eggplant,were tested in the field tests.When the ST-6 agent was applied at 3 g per plant in the field tests,the incidences of the three diseases decreased by 73.62%,77.05%and 69.39%,respectively.We also applied ST-6 agent to control the three diseases in farmer field.The effects of controlling diseases were 72.96%,67.49%and 70.12%,and the yield were increased by 7.89%, 5.07%and 2.98%for watermelon,Atractgiodes macrocephaia and eggplant.(6) The safty and effect of ST-6 agent application on the development and yield of crops.The application was safe for watermelon,cucumber,melon,tomato,eggplant and Atractgiodes macrocephaia.The plants grew better than control without ST-6 application,and the disease incidences reduced and the yields increased by 3-15%.