Wood vinegar as a supporting active ingredient and neem oil dispersant in a nanoemulsion system and their bioactivity

Biopesticides are eco-friendly solutions because they have low toxicity and specific targets. Neem oil (Azadirachtaindica) has the potential to enhance the antifeedant properties of wood vinegar against insect pests. Therefore, thisstudy aims to evaluate a nanoemulsion mixture of neem oil and wood vinegar viz-a-viz their characteristics andefficacy against polyphagous insects like Spodoptera litura. This formulation involved the mixture of wood vinegarand various concentrations of neem seed oil (10, 20, 30, and 40 %), alongside surfactant, and water, to form an oil-in-water (o/w) nanoemulsion. Furthermore, the formulations were then studied for their physicochemicalproperties and bioactivity. However, the 30 % formulation showed the best characteristics at 33.78 nm dropletsize, with a polydispersity index and an antifeedant activity of 0.176 and 90.4%, respectively. The best activity(98.6%) was observed in the combination of 40 % neem oil and 2 % tar.