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ARS Home » Pacific West Area » Hilo, Hawaii » Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center » Tropical Plant Genetic Resources and Disease Research » Research » Research Project #442088

Research Project: Developing Biologically-based Approaches for Coffee Leaf Rust (CLR) Management

Location: Tropical Plant Genetic Resources and Disease Research

Project Number: 2040-21000-016-013-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Jun 3, 2022
End Date: Jun 3, 2025

Objective:
Evaluate the potential of elite isolates of anti-CLR antagonistic fungi, either individually or in combination, as tools for the management of H. vastatrix with particular reference to variety Typica.

Approach:
Brazil-based scientists will establish a dialogue with Hawaii-based scientists on existing research results obtained during the past six years of research on the use of fungi as antagonists of H. vastatrix by the Brazilian team. The complete collection of fungal isolates obtained from coffee during surveys in house will be maintained and available for the experiments in Brazil and abroad. In vitro (leaf disk) and in planta experiments will be conducted with var. Typica following the procedures described in Salcedo-Sarmiento et al. (2021) and performance will be compared with results obtained with var. Catuaí. Selected endophytic antagonists (Aspergillus, Cordyceps, Clonostachys, Trichoderma, etc.) will be evaluated for their ability to establish and persist endophytically in var. Typica. Endophytic antagonists will be confirmed through re-isolation and identification using morphology and molecular tools. The “bodyguard-effect” of selected endophytes will be evaluated on var. Typica plants treated with the endophytes and exposed to H. vastatrix in greenhouse tests (Salcedo-Sarmiento et al., 2021). Protection provided by spraying with mycoparasitic antagonists as “contact mycofungicides” against H. vastatrix will also be evaluated using greenhouse tests (Salcedo-Sarmiento et al., 2021). Microplot experiments in the field will be conducted to evaluate the levels of disease severity of CLR in a range of treatments on varieties Typica and Catuaí with applications of mycoparasites, endophytes and their combination in parallel with treatments with contact chemical fungicides and registered biological fungicides. The minimum inoculum concentration for effective CLR control will be determined for the best biocontrol agents, or combination of agents. The safety of use of Calonectria hemileiae as a potential mycofungicide will be elucidated. For the best biocontrol agents, an adequate protocol for mass production of inoculum and for inoculum storage will be developed.