A tea tree oil-based nanoemulsion for controlling root-knot nematodes in vitro

This study aims to develop a sustainable and environmentally friendly nanoemulsion to control root-knot nematodes (RKN). Some nano-formulations have been prepared using gum Arabic and tea tree oil. Thirteen samples were prepared using different ratios of tea tree oil, GA, and Tween 80, including 1:1:0, 1:2:0, 1:1:1, and 1:0:1. The nematicidal efficacy of these formulations was evaluated against hatchability and mortality of juveniles of root-knot nematodes. Samples 2C, 3C, 4C, and 5C exhibited droplet sizes of 42.7 nm, 40.6 nm, 93.6 nm, and 144.8 nm, respectively. Nanoformulation 5C showed the highest nematicidal activity, a significant increase of 23.9%. Samples 5C (23.9%) and 3C (10.70%) demonstrated pronounced toxic effects based on the toxicity index. samples 3C (19%), 5C (13%), and 4C (11%) led to decreased hatching rates of root-knot nematode eggs. These results demonstrated that nanoemulsion exhibited potent nematicidal activity against root-knot nematode, especially sample 5C, which contained equal amounts of tea tree oil, and gum Arabic. Furthermore, nanoemulsion formulations reduced the hatching rate of nematode eggs, suggesting their potential application in controlling plant parasitic nematodes. Therefore, this nanoemulsion can be considered as a potential alternative to synthetic insecticides for the control of plant-parasitic nematodes. This study provides a novel and environmentally friendly method to develop nanoemulsion formulations from natural oils with promising biological properties for sustainable nematode management strategies.