| China has a large population,grain is a foundation of the human existence.The grain problem seems particularly important.It is related with the sustainable development of economy,and the social stabilization.With the development of the science and technology,the grain storage problem is serious as the grain production is increasing.The stored grain is often damaged by pests.For a long time,the chemical and phosphine-suffocating is the usual treatment method presently,they both can kill out most of the pests,the pesticide residual and the damage to the pesticide operator after using it.People pay more attention to the green grain storage technology recently.This study selected five biological pesticides which including Spinosad,Osthole,Pyrethrins,Matrine and Azadirachtin for the research of Emulsion in water.Spinosad,Osthole,Pyrethrins,Matrine and Azadirachtin all come from nature and finally will belong to nature.The biological pesticides wait for a characteristic with its nature,free from contamination,and the advantage of chemical pesticides,make researchers have a special liking to it.A variety of complex components is of great significance in delaying the development of insecticide-resistance of the pest.The Emulsion in water is a new way to the grain protectant,replace organic reagent with water,has the characteristics of excellent stability,high security,good solubilization,efficient transfer ability.The formulation,detection method and pharmacodynamic test of the three compound pesticides is established on the basis of getting the optimal proportion.The following aspects were studied in this thesis:(1)The dosage of emulsifier,thickeners,antifreezes were studied through a lot of experiments.On the basis of the single-factor experiments,response surface methodology(RSM)was used to explore the optimal formulation.The results are shown below:The optimum formulation of 5% Osthole-Spinosad EW: Osthole: Spinosad=80:1(g/g)5%;Tween20-span20=3:7(g/g)5.15%;xanthan gum 0.18%;ethylene glycol 4.5%;defoamer 0.02%,add water to 100%;The optimum formulation of 5% Pyrethrins-Matrine EW: Pyrethrins-Matrine = 1:3(g/g)5%;Tween-80 6.2%;xanthan gum 0.17%;ethylene glycol 4.3%;defoamer 0.02%,add water to 100%;The optimum formulation of 5% Matrine-Azadirachtin EW: Matrine-Azadirachtin =2:3(g/g)5%;Tween-20-Span20=1:1(g/g)4.2%;xanthan gum 0.18%;ethylene glycol 5.25%;defoamer 0.02%,add water to 100%;(2)A method for quality control of the three kinds of emulsion in water is established by testing and analyzing various indexs based on the national standards.The content of Spinosad,Osthole,Pyrethrins,Matrine and Azadirachtin is determined by High Performance Liquid Chromatography(HPLC).The size of three EW are less than 1.5μm,the cold and hot storage stability of the EW are qualified.(3)The results of pharmacodynamics test in granary for the qualified EW shows that the three EW had obvious repellent action to Sitophilus zeamais by mannul husk carrier.The corrected death rate of Spinosad-Osthole EW 、Pyrethrins-Matrine EW、Matrine-Azadirachtin EW were 82.70%、96.76%、70.33%,the average mortality were 86.80%、97.66%、76.59%. |
