Abstract:

The paper aims to study the wettability of scalecide solution commonly used in farmland on sisal leaves, and choose suitable adjuvants to improve the utilization of insecticides. The critical surface tension of sisal leaf was determined by Zisman method, and compared with the surface tension values of 7 insecticides at the recommended dosage, and the surface tension values after adding different concentrations of organosilicone adjuvant. The critical surface tension of sisal leaf was 23.89 mN/m. The surface tension of the 7 insecticides ranged from 35.72 to 72.51 mN/m, which were all higher than the critical surface tension of sisal leaf, and the wettability of the solutions was poor. Organosilicone adjuvants could reduce the surface tension of the insecticides. By adding 500 mg/L silicone to 45% chlorpyrifos EC 450 mg/L, 200 mg/L silicone to 4.5% beta-cypermethrin EC 45 mg/L and to 70% imidacloprid WG 350 mg/L, and 100 mg/L silicone to the other four insecticides, the surface tension of the solutions was lower than the critical surface tension of sisal leaf and the wetting effect of the solutions was good. Therefore, the adjustment and addition of adjuvants can improve the effect and the utilization rate of pesticides in the process of sisal disease and pest control.

Key words: organosilicone adjuvant, insecticide, sisal leaves, wettability, surface tension, critical surface tension