// Definition
A necrotrophic fungal pathogen affecting cannabis and many other plant species, previously misidentified as septoria leaf spot. Unlike septoria, alternaria has a wider host range and can jump between species including oaks, tomatoes, peppers, and grasses.
// From the Episode
Identified by Brandon Rust via Medicinal Genomics testing. The fungus does not require a living host -- its spores form on decaying, dead, or composted material. Spreads readily in water and rain. Requires integrated management: treat canopies, soils, compost inputs, and surrounding vegetation. Drip irrigation preferred over overhead watering.