Preparation of abamectin nanocapsule suspension concentrate by electrostatic self-assembly and its control efficacy on cucumber root-knot nematode

To improve the mobility of abamectin in soil and its effect on controlling crop root-knot nematode, abamectin 3% nanocapsule suspension concentrate was prepared by electrostatic self-assembly method, and the storage stability and release performance were measured. The soil mobility of nanocapsules was evaluated by soil leaching test and soil thin-layer chromatography. The toxicity against the second-stage juvenile (J₂) of Meloidogyne incognita and field application effect was investigated. The average particle size (D₅₀) of abamectin nanocapsules was 276.81 nm. In the release solution, the cumulative release was 57.59% at 60 min, whereas that of abamectin 3% EC was 94.53%. The horizontal and vertical movement distance of abamectin nanocapsule suspension concentrate in soil was significantly greater than that of abamectin 3% EC. The LC₅₀ value of abamectin nanocapsule suspension concentrate and EC against the J₂ of root-knot nematodes at 24 h were 0.257 and 0.427 mg/L, respectively. Under the same pesticide usage, the control efficacy of abamectin 3% nanocapsule suspension concentrate using flood irrigation and soil mixing methods were 21.82% and 4.81% respectively, which were higher than that of abamectin 3% EC at 60 days after treatments. The control efficacy of abamectin 3% nanocapsule suspension concentrate were 28.98% and 19.79% higher than that of abamectin 3% EC at 100 days after treatment using flood irrigation and soil mixing methods, respectively. Therefore, abamectin nano-formulations can enhance its mobility in soil and improve the control effect on cucumber root-knot nematode. This study provides a reference for the development of nano-pesticide preparations suitable for soil application.