PubMed · 2026-06-29
Combining soil-drench and foliar spray applications of beneficial Bacillus bacteria cut poplar leaf blight disease severity by 86.7% in field trials. The two methods work through distinct but complementary routes: soil application restructures the root-zone microbial community for lasting protection, while foliar spray triggers rapid immune responses in leaves.
Combined root-drench plus foliar spray reduced the leaf blight disease index by 86.7% compared to untreated controls.
Root-drenching enriched beneficial rhizosphere genera including Rhodanobacter and Apiotrichum, whose abundance correlated positively with leaf defense parameters.
The combined treatment strongly activated both salicylic acid and jasmonic acid immune signaling pathways, with significant upregulation of the pathogenesis-related gene PR-1 and elevated antioxidant enzyme activities.