Studies On Micro-emulsion Of Abamectin And Three Kind Of Pyrethroids Mixing Formulation

The bioassay of abamectin, combined with lambda-cyhalothrin, beta-cyfluthrin and bifenthrin, respectively, on Myzus persicae Sulzer as target insect were evaluated with the co-toxicity coefficient method and the optimum ratio was determined finally. The potted tests with Lab-products were carried out and the method of products quality analysis was also established. The main research methods and results could be summarized as follows:1 Selecting of the optimal ratioWith the topical application,the bioassay of abamectin, lambda-cyhalothrin,beta-cyfluthrin, bifenthrin on Myzus persicae Sulzer were carried out. The results showed that the LD50 values of abamectin, lambda-cyhalothrin, beta-cyfluthrin, bifenthrin were 1.03×10^-5μg/ insect, 2.43×10^-4μg/ insect, 2.45×10^-4μg/ insect, 1.60×10^-4μg/ insect. respectively. The optimal ratio of the combination of abamectin and the three chemicals (lambda-cyhalothrin, beta-cyfluthrin and bifenthrin) with the measurement of CTC was selected. The results showed that all formulas' CTC were over 120 except for the abamectn·vlambda-cyhalothrin-8# and there were synergized effects of the formulas above; the highest CTC of 5% abamecthrlambda-cyhalothrin-8#, 5% abamectin·beta-cyfluthrin -2# (0.3%+4.7%), 5% abamectin-bifenthrin-1# (0.2%+4.8%) were 151.047, 272.141 and 223.090, respectively. Thus the three kinds of proportions above were considered to be the optimal ratios.2 Formula determination of three mixture Micro-emulsionsThe optimum formulas of the three mixture Micro-emulsions were determined finally after the selection of adjuvant on the basis of optimum ratio (Table 1) 3 The standard and analysis method of the three mixture MEsThe methods of HPLC and GC were applied to measure the contents of the main active substances (abamectin, lambda-cyhalothrin, beta-cyfluthrin and bifenthrin) in the three combined MEs and the results indicated that under the chosen condition the acreages of the efficient contents were nice related with their chroma by linearity. The standard windages of abamectin were between 0.001-0.003; and that of ambda-cyhalothrin, beta-cyfluthrin and bifenthrin were 0.020,0.014,0.019, respectively; the abnormal changing coefficient of abamectin ranged from 0.363% to 0.990%, and those of ambda-cyhalothrin, beta-cyfluthrin and bifenthrin were 0.423%, 0.297%, 0.395%, respectively. The resource above showed the analysis condition was stable and of high repeatability, and thus the efficient contents of the three mixture MEs' sample products were fit for the GB.Stability of emulsifier solution, pH, heat-stock, cool-stock and lucid temperature range character of the compound were detected based on the recommended methods by FAO, CIPAC, and GB, respectively. The result showed the three were stable, uniform and forming no precipitate; the pH range of the 5% abamectin·lambda-cyhalothrin ME ranged from 4.4 to 6.0, decomposes ratio of abamectin and lambda-cyhalothrin were 3.607%, 4.229%, and the same data of 5% abamectin·beta-cyfluthrin ME and 5% abamectin·bifenthrin ME were 4.6-5.8, 3.557%, 4.286% and 4.8-6.0, 4.286%, 3.557%, respectively. So the three mixture MEs' Thermal decomposition rates were all under 5%, there was no precipitate and delamination after their chilling; their lucid temperature range were -5℃-60℃, -2℃-56℃, -5℃-58℃. The results suggested that the quality index of the 10% abamectin-fenpropathrin ME of lab product were acceptable.4 Control effect in the fieldAccording to the modified pesticide effect test method, the control effects of the three MEs on Myzus persicae Sulzer and Pieris rapae Linn were studied. The results indicated the three's effects were pretty good, and showed the fine perdurability and quick effects, and the result just inosculated with the characteristic of the abamectin and pyrethroids. The recommended dosages for Myzus persicae Sulzer of 5% abamectin·lambda-cyhalothrin ME, 5% abamectin·beta-cyfluthrin ME, 5% abamectin·bifenthrin ME were 360mL /hm²-450mL /hm² (2000-2500×),257mL/hm²-300mL/hm² (3000-3500×),300mL/hm²-360mL/hm² (2500-3000×),and 450mL/hm²-600mL/hm² (1500-2000×),300mL/hm² 360mL /hm² (-2500-3000×),360mL /hm²-450mL/hm² (2000-2500×) for Pieris rapae Linn.