BackgroundEnvironmentally　responsive　nanoscale　biocide　delivery　system　enhances　smart,　regulated,　and　synergistic　biocide　application　with　precise　biocide　release.　In　this　study,　pectin-modified　dendritic　mesoporous　silica　nanoparticles　(DMSNs)　was　used　as　a　carrier　to　successfully　construct　a　microenvironment-responsive　(pH,　temperature　and　enzyme)　eugenol　nano-biocide　delivery　system　for　the　control　of　Ralstonia　solanacearum　infection.ResultsThe　results　showed　that　the　specific　surface　area,　pore　size　and　surface　activity　of　DMSNs　significantly　influence　the　biocide　loading　of　eugenol,　and　the　biocide　loading　capability　was　up　to　72.50%.　Eu@DMSNs/Pec　had　significant　pH　and　pectinase　stimulating　effects,　with　varying　release　amounts　under　different　temperature　conditions.　Compared　with　eugenol　alone,　Eu@DMSNs/Pec　significantly　enhanced　the　efficacy　of　eugenol.　DMSNs　assisted　eugenol　to　induce　peroxidation　damage,　produce　ROS　(center　dot　O2-,　center　dot　OH　and　1O2),　achieve　synergistic　antibacterial　effects,　and　had　better　rain　erosion　resistance　and　foliar　retention　rate　based　on　pectin　wettability　and　adhesion.　Eu@DMSNs/Pec-FITC　showed　demonstrated　efficient　transport　characteristics　in　tomato　roots,　stems　and　leaves,　which　enhanced　the　control　effect　on　tomato　bacterial　wilt.　In　addition,　Eu@DMSNs/Pec　exert　minimal　influence　on　tomato　seed　germination　and　root　growth,　and　have　low　toxicity　to　non-target　organisms　such　as　earthworms.　Therefore,　Eu@DMSNs/Pec　environment-responsive　nano-controlled　release　nanocarrier　can　effectively　achieve　accurate　biocide　release　and　reduce　biocide　dosage.ConclusionThis　work　not　only　provides　a　pectin-modified　DMSNs-based　eugenol　nanoscale　biocide　delivery　system　in　response　to　specific　environmental　conditions　of　R.　solanacearum　infection　but　also　elucidates　the　eugenol　biocide　loading,　selective　release　ability　and　antibacterial　mechanism　of　the　system.