Trichoderma-based biocontrol solution for ceratocystis fimbriata in melina plantations

Overview

Melina (Gmelina arborea) is the second most planted forest species in Costa Rica, yet its plantations face significant losses from melina wilt, a disease caused by the pathogen Ceratocystis fimbriata. While silvicultural practices have helped manage the disease, no biocontrol strategies using antagonistic fungi have been developed for this pathosystem. This research proposes the use of native Trichoderma species isolated directly from melina trees as biological control agents against C. fimbriata. The work addresses a clear unmet need in forest health management and offers a sustainable, environmentally friendly complement to existing disease control practices.

Technical specifications

The project is anchored in a collection of biological materials maintained at the Forest Pathology Laboratory of the Instituto Tecnológico de Costa Rica (TEC):

• Six isolates of Trichoderma spp. recovered from Gmelina arborea across different regions of Costa Rica
• Seven strains of Ceratocystis fimbriata isolated from diseased melina trees in multiple geographic areas

Planned validation procedures include:

• In vitro dual culture assays using the dual method on three culture media (PDA, MEYA, and MEA), with five replicates per Ceratocystis/Trichoderma combination to assess antagonism
• Wood-block assays in which sterilized wood pieces are immersed in a C. fimbriata suspension and placed on PDA medium, with Trichoderma mycelium disks positioned at the center to evaluate colonization and pathogen suppression
• In vivo testing through inoculation of C. fimbriata in melina plants and branches to measure the antagonistic capacity of Trichoderma under living-tissue conditions

Technology readiness level

This research is at an early stage, corresponding to TRL 2–3 (technology concept formulation and experimental proof of concept). Initial observations during pathogen isolation from diseased melina trees revealed Trichoderma strains naturally inhibiting C. fimbriata growth, providing the basis for the hypothesis. The project is part of a broader TEC initiative on genetic improvement for disease resistance in teak and melina (Phase II). Systematic in vitro and in vivo validation studies are planned but have not yet been completed. The solution is not yet commercially available; further development is needed to confirm efficacy under field conditions and to define a scalable delivery method for plantation use.