P-217 - Foliar and seed-borne fungal pathogens impacting tomato production in Hawai’i

Tomato (Solanum lycopersicum) is the most widely cultivated and consumed vegetable crop globally, ranking among the top in harvested area and production volume. In Hawai’i, local tomato production supplies around 80% of the state’s demand. Although the tropical climate allows for year-round cultivation, the persistent high temperatures, frequent rainfall, and elevated humidity create conditions conducive to fungal disease proliferation. Accurate identification of the existing pathogens is crucial for implementing effective disease control measures. As such, this study aimed to conduct a comprehensive survey of foliar and seed-borne fungal pathogens affecting commonly grown tomato genotypes in Hawai’i. Symptomatic leaf samples were collected from screenhouses and open-field systems across multiple locations on O’ahu. Seed samples were obtained or purchased from local sources. Foliar pathogens were isolated on Potato Dextrose Agar and V8 Agar (n = 40 leaf samples per genotype per location), while seed-borne pathogens were detected using blotter method and agar plating (n = 40 seeds per genotype). Pathogen identity was confirmed through morpho-cultural characterization and DNA Sanger sequencing. Preliminary results showed a diverse range of fungal pathogens, varying in distribution across genotypes and locations. Understanding the prevalence and distribution of these pathogens will aid in the development of targeted chemical and biological approaches to mitigate disease impact and support sustainable tomato production in Hawai’i.