Preparation of a cellulose nanocrystals/surfactant stabilized pickering emulsion systems with improved foliar affinity and bioactivity against Pseudomonas Syringae pv. Actinidiae

With the demand for natural polymers, cellulose nanocrystal (CNC)-based Pickering emulsion systems (PE) have been introduced in agricultural control due to their high stability. Surfactants further reduce surface tension and enhance the spreading and deposition of pesticide formulations. In controlling bacterial canker in kiwifruit, conventional formulations often exhibit high-resistance, but poor spreading, and deposition, resulting in unsatisfactory efficacy. Therefore, selecting highly effective and low-toxicity formulations is critical for kiwifruit production. In this study, the plant extract—P-Cymene (PC, identified via laboratory screening) was used as a model compound with strong antibacterial activity to prepare CNC/surfactant synergistically stabilized Pickering emulsions (PC@PE). The CNC employed was the type I cellulose nanorods exhibiting structural integrity, and strong electronegativity, enabling the formation of oil-in-water Pickering emulsions. PC@PE stabilized with CNC and the surfactant SK-551 demonstrated high stability across temperature, pH, and ionic strength variations. Rheological analysis confirmed that PC@PE behaves as a non-Newtonian liquid with gel-like properties. PC@PE exhibited a surface tension of 25.90 mN·m −1 , a contact angle of 9.40° on kiwifruit leaves, a deposition of 48.36 mg·cm −2 , and an EC 50 value of 69.089 mg·L −1 against Pseudomonas syringae pv. actinidiae ( Psa ), indicating enhanced leaf affinity and biological activity. These results highlight the effectiveness of PC against Psa , expand the application of Pickering emulsions in agricultural disease management, and provide a new approach for controlling bacterial canker in kiwifruit.