University Extension can be a great resource for any ornamental grower looking for updates on disease management, from symptom identification to control tips.
Penn State University Extension features a section on its website devoted to diseases commonly found in chrysanthemums. Listed alphabetically, the site covers 14 of the most common diseases, the symptoms to watch for (including photos for many of the diseases), the primary pathogen, and cultural management recommendations.
The disease page was last updated on Aug. 8, 2017. Go to https://extension.psu.edu/chrysanthemum-diseases to learn more.