Split-root experiments and quantitative real time PCR were used to examine if vermicompost tea (VCT) drenching could induce host-plant resistance against root-knot nematodes (Meloidogyne incognita). Two greenhouse trials were conducted where cucumber (Cucumis sativus) roots were split into half; one part of the roots was drenched with VCT, and the other part received M. incognita inoculum. Control plants were drenched with water. Root penetration by M. incognita was lower in plants drenched with VCT as compared to the control (P ≤ 0.05) in both trials. Quantitative real time PCR was used to measure relative expression of defense-related genes, CHIT-1, PAL-1, β-1,3-Glucanase, LOX-1 and PR-1 on cucumber. Plants were: 1) drenched with VCT 2 days prior to M. incognita inoculation, 2) inoculated with M. incognita only, or 3) received no VCT or nematodes as the control. Plants drenched with VCT showed an up-regulation of CHIT-1 at 2 days, PAL-1 at 2 and 8 days, LOX-1 at 2 and 5 days, and down-regulation of PR-1 at 0 and 5 days after M. incognita inoculation. Up-regulation of CHIT-1, PAL-1 and LOX-1 by VCT drenching supported the hypothesis that VCT imitated Induced Systemic Resistance (ISR) on cucumber
