Abstract:
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Objective 】 To study the effects of synergists on reduction and synergism to control cotton aphids with imidacloprid and thiamethoxam in the hope of providing theoretical data base for scientific and efficient use of synergists and pesticides. 【
Methods 】 Through field plot spray test, we determined the suitable dosage of synergist, and the control effect of imidacloprid and thiamethoxam was compared by adding synergist on the basis of 10%, 20% and 30% reduction. 【
Results 】 0.15% field Max EC had obvious synergistic effect on imidacloprid and thiamethoxam, and the suitable dosage was 450.0-675.0 mL/hm
2; 1 day after application, the control effects of 70% imidacloprid WG and 25% thiamethoxam WG were 65.5%-81.4% and 62.2%-78.5% respectively, and the control effects of 10% and 20% reduction and adding synergist were significantly higher than that of conventional dosage, while the control effects of 30% reduction and conventional dosage had no significant difference; 3 days after application, the control effects of 70% imidacloprid WG and 25% thiamethoxam WG were 68.4%-85.2% and 63.5%-79.6% respectively, and the control effect of 10% and 20% reduction and adding synergist were significantly higher than that of conventional dosage, and there was no significant difference between 30% reduction and conventional dosage; 7 days after application, the control effect of 70% imidacloprid WG and 25% thiamethoxam WG with 10%-30% reduction was 59.2%-78.5% and 56.5%-71.1% respectively, and the control effect of 10% and 20% reduction and adding synergist were significantly higher than that of conventional dosage, and there was no significant difference between 30% reduction and conventional dosage. 【
Conclusion 】 0.15% fieldor Max EC has obvious reduction and synergistic effect on imidacloprid and thiamethoxam, and the suitable dosage is 450.0-675.0 mL/hm
2. When the dosage of imidacloprid and thiamethoxam was reduced by 10%-20%, the control effect of synergist was significantly higher than that of conventional dosage, and there is no significant difference between 30% reduction and conventional dosage. Using synergists has good application value to reduce the use of insecticides and improve the control effects.