Abstract: China is the world’s largest producer of Zanthoxylum bungeanum Maxim., yet as by-products of the prickly ash industry, the plant protection potential of its branches and leaves remains largely untapped. To evaluate the antimicrobial potential of prickly ash branch and leaf extracts and explore their utility in plant disease management, the optimal extraction method was established, and samples collected in different growth stages were compared. Results indicated that the extract obtained from samples collected in September using n-hexane exhibited the strongest antifungal activity, achieving an inhibition rate of 82.00%. A nano-gel system was successfully fabricated using chitosan-cinnamic acid (CS-CA) as the carrier and the Z. bungeanum extract as the active ingredient. The resulting nanoparticles had an average size of 466 nm. In antifungal assays against Alternaria alternata, the causal agent of apple leaf spot disease, the nano-gel formulation at 0.24 mg/mL demonstrated notably sustained inhibitory efficacies of 96.50% after 7 days and 60.64% after 21 days, respectively, which were significantly superior to those of the unformulated extract. The above results provide a promising strategy for the development of effective and durable botanical pesticides. Future studies should focus on optimizing the nano-gel preparation process and exploring its potential for controlling other plant diseases.

Key words: Zanthoxylum bungeanum branches and leaves extract, nanogel, physical characterization, antifungal activity