Explore Of ASB’s Dosage And Developing The Fermentation Craft And Wettable Powder Of It’s Components

Biopesticide plays a more and more important part in the control of plant disease in recently years. ASB developed by Nanjing agricultural university biopesticide research laboratory, was used to control several soil-borne plant disease. The control efficiency was validated to be reliably by a devil of field experiments. But which dosage of it acquires the best control efficiency and a low cost was still unknown. What’s more, the formulation of ASB was aqua, and the active component of which was low relatively. Storage and transportation were not convenient was another shortcoming. To aim directly at the problem above, we carried out the following studies:Firstly, we expored the dosage. Four different concentration (4 liters per acreage,6 liters per acreage,9 liters per acreage and 12 liters per acreage) were tested vary from once to three times. The result indicated that ASB used at 6 liters per acreage or 9 liters per acreage from the transplantation day three times every fifteen days acquire the best effect. Plant hight, the diameter of the stem, the number of flower buds、the number of leaves, the area of the biggest leaf and the number of fruits of peppers treated by ASB raised by 11.45% to 203.75%. Content of Vitamin C, crude Protectionein, soluble suger and dry matter were also increased. The control efficiency of pepper Phytophthora blight was 95.94% when ASB used at 6 liters per acreage three times by harvest time. In 2011, we have validated the result in Shouguang and Huaian, acquiring nearly the same effect. This study was the first time to search for an optimal dosage of ASB. Allowing for the cost and labour intensity, ASB used at 6 liters per acreage three times every fifteen days after transplantation was more suitable for controlling pepper Phytophthora blight.To increase the content of the active component in ASB, the single factor experiments and orthogonal experiments were adopted to optimize the liquid fermentation medium and conditons of the biocontrol agnet of Bacillus subtilis SM21. The results indicated that the constituents of medium, the filling volume of shaking flask, the rotation speed and the temperature were the major factors that affect the yield of SM21. The composition of glucose 0.25%, starch soluble 0.25%, soybean flour 1%, tryptone 0.25%, CaCl2·2H2O 0.1%, NaCl 0.1% and K2HPO4 0.05% was selected to be the medium formula, and the fermentation conditions were the filling volume 200 ml in 1L shaking flask, inoculum 1%, 28℃, shake at 220 r/min for 48 h, and initial pH at 6.5. The seed fluid was prepared by the optimization culture media for 24 h. Under the optimized fermentation conditons the production of spores was up to 1.56×109 CFU/ml, and the rate of spores was more than 91%.Whereafter, the formulation of the wettable powder of the component AR156 was developed. The optimal formula and craft were confirmed as follows,100 g white carbon black mixed with 300 ml fermentation broth and 1.5 g lactose was dried in 65℃ for 12 h until the moisture capacity decreased to about 25%. Got the initiate product by adding 8.0 g arabic gum,7.0 g KH2PO4 and disintegration, the active component of which was 1.05×1010 CFU/g. In pH 7.0 and 4℃, the active component could maintain in 6.21×109 CFU/g one year later in the dark. The formulation could promote the formation of biofilm in aqueous, and the biocontrol efficiency of tomato wilt by it in the greenhouse was 85.76%.Eventually, in the frequent soil-applied pesticide, phenazino-1-carboxylic acid, dexon and paraquat may effect the survival rate of one or more components of ASB significantly, the survival rate was all below 70% after co-culture. When used mixed with phorate, chlorpyrifos, glyphosate, phoxim and quan-shajing, the biocontrol efficiency of ASB decreased significantly, the lowest of which was 75.60%. The effect of pesticide to the biocontrol efficiency may decrease by adopting a reasonable measure.As above mentioned in a word, this study acquired the optimization dosage of ASB, and explored the fermentation craft of the component SM21, meanwhile, manufactured the wettable powder of another component AR156, which established the foundation of ASB’s formulation. The usage directions of ASB were given when chemical pesticide was present, which will guide its’application.