First Report of Calonectria Leaf Spot on Ohelo in Hawaii

This is the first documented report of Calonectria leaf spot disease affecting Vaccinium reticulatum, commonly known as ohelo, a native Hawaiian shrub. The study identified Calonectria pseudocolhounii as the causative pathogen through morphological and molecular analysis, including β-tubulin gene sequencing. Symptoms included severe leaf spots, stem lesions, and defoliation in greenhouse-grown ohelo plants in Hilo, Hawaii, but no natural outbreaks were observed in Hawaii Volcanoes National Park or along Saddle Road. Koch's postulates were fulfilled by successfully re-isolating the fungus from artificially inoculated ohelo seedlings, confirming its pathogenicity. Ohelo berries are culturally significant and serve as a food source for the endangered nene goose.

Keith, L. M., Matsumoto, T. K., & Zee, F. T. P. (2013). First Report of Calonectria Leaf Spot on Ohelo in Hawaii. Plant Disease, 97(7), 990. https://doi.org/10.1094/pdis-09-12-0887-pdn