Pomegranate peel extract as a sustainable plant protection agent against Xanthomonas campestris pv. campestris: mechanisms and applications

Black rot, caused by Xanthomonas campestris pv. campestris (Xcc), poses a significant threat to crucifer crops worldwide. This study investigates pomegranate peel extract (PGPE) as a sustainable and eco-friendly alternative to chemical control for managing Xcc. PGPE, rich in bioactive polyphenols, demonstrated strong antimicrobial activity, inhibiting bacterial growth, motility, and biofilm formation under in vitro conditions. In vivo applications of PGPE, both as a foliar spray and seed coating, effectively reduced black rot symptoms and controlled seed-borne infections, with higher concentrations showing efficacy comparable to copper-based and hot-water treatments, respectively. Importantly, PGPE exhibited no phytotoxicity, maintaining plant health and seed germination. The use of PGPE not only provides an environmentally safe alternative to synthetic bactericides but also promotes the valorisation of agro-industrial waste, aligning with sustainable principles. These findings highlight PGPE as a promising tool for effective black rot management, paving the way for broader applications in plant protection.