Ecofriendly Nanoemulsion to Promote the Wetting and Spreading of Droplet on Soybean Leaves for Regulating the Sheath Blight

As an alternative to synthetic pesticides, essential oils can be used to treat various diseases that affect food safety, such as soybean sheath blight, which poses fewer health and environmental risks. However, conventional formulations, such as emulsions, often bounce, drift, and splash, which results in low pesticide utilization. The splashing phenomenon is especially serious on the hydrophobic soybean leaf surface, leading to the ineffective utilization of pesticide formulations. To this end, our goal is to develop a formulation with exceptional wetting and spreading properties on hydrophobic soybean leaf surfaces by using nanotechnology. We have successfully constructed anise oil nanoemulsions (AO NEs) as an alternative to conventional emulsion formulations. Anise oil microemulsion and anise oil submicroemulsion were selected as control groups to study the spreading performance of emulsions with different sizes. With smaller particle sizes, AO NE exhibited significantly improved wetting and spreading characteristics on the hydrophobic surface of soybean leaves. It also demonstrated excellent inhibition against the pathogen Rhizoctonia solani. AO NE effectively addresses the rebound and spatter problems of traditional emulsions without the addition of extra additives. The agricultural applications of nanoemulsions for delivering essential oils have great potential to increase pesticide utilization.