Neem-based oil-in-water (O/W) emulsion as a biopesticide

Abstract

Neem tree (Azadirachta indica) is well-known to contain active components, such as azadirachtin (AZA), nimbin, and nimbidin that are potent to eliminate pesky insects. These active components can be found in large numbers in the neem oil. The favourable properties of neem oil to kill pests with minimum impacts to the ecosystem makes it veritably attractive to replace synthetic chemical pesticide. In this research, the neem oil is mixed with water and emulsifiers in the homogenizer to generate oil-in-water (O/W) emulsions. The droplet size, the size distribution, the stability, and the effectiveness of emulsion are analysed to determine the best formulation of neem-based biopesticide. The results showed that the formulation of 10%- w neem oil and 5%-w non-ionic emulsifier Lutensol® TO 6 produces the most stable emulsion with d32 of 0.50 μm. The fastest mortality rate for Musca domestica larvae is achieved at 20 ppm and 8 minutes with emulsion formulae of 10%-w neem oil and 5%-w non-ionic emulsifier Lutensol® TO 8.