RESEARCH AND EXTENSION | TOMATO
Survey and management of fungal tomato diseases
Tomato (Solanum lycopersicum L.) is a widely cultivated and consumed vegetable crop worldwide. In Hawai'i, tomatoes are grown in commercial farms, small-scale operations, and backyard gardens. The state's tropical climate characterized by high temperatures, frequent rainfall, and elevated humidity creates ideal conditions for fungal disease development. Disease occurrence and severity are further influenced by tomato genotype and growing conditions. Identifying the prevalent pathogens and implementing targeted disease management strategies will help improve crop productivity and minimize yield losses.
Scope of the Project
Foliar and seed-borne fungal diseases on tomato were identified by conducting a survey on various locations in the island of O'ahu. Disease incidences (%) were recorded to check the most prevalent pathogens. Biocontrol products and fungicide efficacy assessment will be tested against the major pathogens identified.
Existing Survey Sites
Tomato leaf samples were collected in Spring 2025 from three tomato-growing areas in O'ahu. We plan to expand the survey to additional farms within O'ahu and neighboring islands to obtain a more comprehensive, statewide survey.
Identification and Quantification
Symptomatic leaf samples were plated onto PDA and V8 agar media. After incubation, pathogens were identified based on their morpho-cultural characteristics, which were further confirmed through molecular assays. Disease incidence (%) for each tomato genotype and location were also recorded.
Detected Pathogens
Stemphylium
Alternaria
Cladosporium
Colletotrichum
Fusarium
Fungal Diseases of Tomato Handout
