Suppression of Root-Knot Nematode by Vermicompost Tea Prepared From Different Curing Ages of Vermicompost.

Suppression of root-knot nematodes (Meloidogyne spp.) by vermicompost tea (VCT) has been inconsistent. Greenhouse and laboratory trials were conducted to compare the effects of VCT prepared from different curing ages of vermicompost (VC) on root penetration, reproduction, and hatching of M. incognita. In the penetration experiment, zucchini (Cucurbita pepo) seedlings were drenched with VCT prepared from (i) uncured (UVC), (ii) partially cured (PVC), (iii) completely cured (CVC) vermicompost, and (iv) water or no vermicompost (NVC) 3 days prior to M. incognita inoculation. The experiment was repeated twice on cucumber (Cucumis sativus) and terminated one week after nematode inoculation. All three trials showed that UVC and PVC reduced (P ≤ 0.05) penetration of M. incognita compared with CVC and NVC. Two greenhouse trials showed that VCT from different curing ages of VC did not reduce the abundance of M. incognita juveniles in soil and eggs in roots 2.5 months after nematode inoculation. Two laboratory trials to examine hatching consistently showed that VCT from UVC and PVC suppressed hatching (P ≤ 0.05) compared with NVC, achieving 83.1% hatch reduction by UVC. Overall, VCT from UVC and PVC suppressed root penetration and hatching, but not the reproduction of M. incognita over time.