Flower‐Shaped Supramolecular Polymer Enabling Biofilm Eradication, Improved Foliar Affinity, and Bacterial Disease Management

ABSTRACT The management of bacterial plant diseases is impeded by biofilm fortifications and the poor foliar affinity of conventional antimicrobials. Supramolecular assemblies have recently emerged as promising biofilm‐eradicating agents with enhanced surface adhesion. Yet, supramolecular polymers, although endowed with comparable or even greater potential, remain largely untapped in this arena. Herein, we introduce NOP@CB[8], a flower‐like supramolecular polymer self‐assembled in water from a de novo designed cationic pyridinium salt (NOP) and cucurbit[8]uril (CB[8]). Acting as a multifunctional agent, NOP@CB[8] disrupts bacterial membranes, perturbs redox equilibrium, disintegrates biofilms, and concurrently enhances foliar affinity. These combined attributes endow NOP@CB[8] with potent in vivo efficacy, exhibiting protective and curative efficacies of 56.1% and 51.2%, respectively, at 200 µg mL −1 against rice bacterial leaf blight, thereby surpassing both free NOP (47.9%/43.1%) and thiodiazole copper (TC, 36.2%/33.7%). Remarkably, NOP@CB[8] delivers high control efficacy with uncompromised safety toward both target and non‑target organisms, even demonstrates enhanced safety in zebrafish relative to free NOP. Extending its scope to citrus and kiwifruit cankers, NOP@CB[8] achieves approximately 80% protective and over 60% curative efficacy, consistently outperforming NOP and TC. Together, this study delineates a green alternative for crop protection and a conceptual framework for next‐generation functional supramolecular polymers.