| Ivermectin is a new antibiotics insecticide, which is one of the products out of avermectin structural transformation.It is made from avermectin B1 component in which the 22,23-bit unsaturated bond were reduced selectively by Wilkinson catalyst. Although, ivermectin has a lower biological activity than avermectin, it does be with a better stability, lower toxicity, and no cross-resistance. Many researchers have found that ivermectin also has good control effect against agricultural insects, and mites.At the present time, it's mainly used for prevention and control of livestock parasites, and rarely applied in agriculture.Therefore, the development of ivermectin as a pesticide will have broad market prospects.Chlorpyrifos belongs to organophosphate pesticides, with insecticidal acticities in stomach poisioning action, contact toxicity, and fumigation effect. Its residual period is long in the soil,but short when on the leaves. Therefore, it has a better control effect on insects in soil,when grown with leafy vegetables, cotton, apples, rice, sugar cane and other crops.But the price of ivermectin is very high which limit the market. In order to overcome the shortcomings, the compounds of ivermectin and chlorpyrifos will have a good prospect. In this study, we not only developed the best ratio of ivermectin and chlorpyrifos, but also abtained the ivermectin·chlorpyrifos 20% emulsion in water, and had a product quality analysis, which was valuable for expanding the application of Ivermectin in the field of agriculture.The main research methods and results are as follows:1.The bioactivity of ivermectin and abamectin were measured to Laphygma exigua Hubner, Tetranychus cinnabarinus(Boisduval)and Meloidogyne incognita Chitwood, respectively. According to LC50, the bioactivity of abamectin was 1.5 to 2.4 times more than that of ivermectin. The LC50 value of resistant strains of T. cinnabarinus to ivermectin and abamectin was 0.080mg/L,0.230mg/L respectively. The abamectin resistant strains of T. cinnabarinus(10 times)was no resistance to ivermectin.2.When the ratio of ivermectin to chlorpyrifos is 1:9,1:12,1:19,1:39,1:79,1:132.2, the CTC values of T. cinnabarinus were 95.22,104.06,99.64,144.89,296.98, 181.93,respectively; the CTC values of the L. exigua were 172.79,137.04,152.13, 185.96,193.48,159.48,respectively. From the result, the CTC values was highest when the ratio was 1:79. So, there was a significant synergism.3.According to a specific proportion of ivermectin and chlorpyrifos and the physicochemical properties of the two pesticides emulsions in water, research was made on the preparation of 20% of ivermectin·chlorpyrifos emulsions in water, and the satisfactory formulation as follows: formulations of 20% ivermectin·Chlorpyrifos EW: Ivermectin 0.25%(mass fraction,the same as follows) Chortyrifos 19.75% Solvent 15%(A:B=3:1) Emulsifier 8% C Antifreeze 5% Urea Water add to 100%4. According to the relevant national standards and 20% water emulsion of ivermectin·chlorpyrifos, the quality control indexes of the product was developed as follows: Appearance milky white viscous liquid Ivermectin≥0.25 Chortyrifos≥19.75 PH value 6.8 Emulsion stability(diluted 200 times)acceptable Persistent foaming 20ml Dumping of acceptable Stability after cold stockpile acceptable Stability after warm stockpile acceptable5.Based on the field efficacy trial norms, the field trials of Ivermectin·Chlorpyrifos 20%EW were conducted. The results showed that 20% ivermectin·Chlorpyrifos EW had a significant effect on the control of T. cinnabarinus and P. xylostella. The dosages of the EW were 45-90 g/hm2 and 90-135 g/hm2 when in control of T. cinnabarinus and P. xylostella. 6.The cost of 20% ivermectin Chlorpyrifos EW was less than 48% Chlorpyrifos EC and 1.8% Avermectin EC,and the control effect was better than Chlorpyrifos and Ivermectin EC.So the formula has a broad prospect in agriculture. |
PDF Full Text Request