| With the greater increasing investment risks in synthesize and production of novel pesticides, the longer market period and the more rapid development of pest resistance, the supply of efficient pesticides appear to be in great shorter. The rational combination among different pesticides play an important role in the following aspects: pest resistance control, improving control effect, decreasing the cost, a good harvest, prolonged application longevity of pesticides and lesser environment pollution.According to the physical and chemical characters of abamectin, fenpropathrin, phoximand , pyridaben, the acaricides were produced to be EC by selecting proper solvents and emulsifters, and toxicity of the EC was tested using the carmine spider mite, Tetranychus cinnabarinus (Boisduval), as bioassay target. Based on the toxicity assays, the optimal combinated pesticide with abamectin was selected from the other three pesticides by the co-toxicity factor method. Meanwhile, the combination between abamectin and fenpropathrin with 9 various ratios were evaluated with the co-toxicity coefficient method. Furthermore, the optimal combination was obtained on the basis of mathematical model between the co-toxicity coefficient and the ratio. Also the potted tests with small samples were carried out in lab trials and a set of analysis method about products quality was established. The main research methods and results could be summarized as follows:1 Screening of the optimal combination and ratio.With the slide-dip method, the bioassay of abamectin, fenpropathrin, phoximand and pyridaben on T. cinnabarinus were carried out. The results showed that the LC50 values of abamectin, fenpropathrin, phoximand and pyridaben were 0.06112 + 0.00475mg/L, 2606.07+ 352.97mg/L, 318.17 +27.74mg/L,and 47.89+ 2.49mg/L, respectively. It suggested that the toxicity of abamectin was the highest while that of fenpropathrin expressed the lowest. The experiments on combination of the other three pesticides with abamectin indicated that the group factors of theco-toxicity between abamectin and fenpropathrin were the highest (22.0-28.5) , and thus this group was considered as the optimal combination.Based on combination destination and their different activities, the concentration of abamectin-fenpropathrin was determined as 10%. The 10% abamectin-fenpropathrin EC at 9 kinds of ratios were evaluated by applying the co-toxicity coefficient method. The results showed that the co-toxicity coefficients of this combination at 9 kinds of ratios were all above 200 and took on a quite good synergism prospective. Using SPSS to establish mathematical model of the co-toxicity coefficient and arcsine value of the proportion in combination acaricide, it can acquired the mathematical model of abamectin-fenpropathrin was r=-30179.08+769.24X-4.8472X2. (x refer to the ratio) . Account the coefficient of above model, it was achieved that the equation (Y'=769.24-9. 6944X) If Y'=0, then X=7935. It can draw a conclusion that the highest co-toxicity coefficient was 340.09 by putting X=79.35 to the corresponding model, and the most significant synergism appropriate optimal ratio between abamectin and fenpropathrin was 1:28 or so.2 The result of adjuvant selecting showed that the better formula of 10% abamectin -fenpropathrin EC is the following which comprises by weight.On a basis of the optimal combination and ratio, the two catalogues of surfactants were selected and the optimal prescription of the 10% abamectin -fenpropathrin EC was described as follows:(1) abamectin 0.35% (mass fraction, same as follows.)(2) fenpropathrin 9.65%(3) Emulsification 6% (mixture between 1 QR-11 and 28 QR-9)(4) Solvent 84%( mixture between 20 xylene and 1 ethyl chloroacetate )3 Establishment of Quality standard of the 10% abamectin-fenpropathrin ECA set of quality analysis method for the 10% abamectin-fenpropathrin EC was established. The results indicated that the linear relation...
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