The most common plant pathogens on ornamental plants in Ohio are fungi, bacteria, viruses, and nematodes.
Fungi are by far the most common type of plant pathogens.
Plant pathogenic fungi cause many different symptoms, including leaf spots, wilts, curled leaves, dieback, enlargements or galls, and stunted or dead plants. Fungi can spread through rhizomorphs, sclerotia, or by microscopic spores. Rhizomorphs are rootlike or cordlike masses of hyphae that can contaminate soil and plant parts. Sclerotia are compact masses of hyphae that can persist for relatively long periods in soil. Sclerotia, rhizomorphs, and some types of spores may survive for long periods in or on plants or in soil.