Cladobotryum spp. – Cobweb disease
Cobweb is the common name given to a fungal disease affecting Agaricus bisporus crops in mushroom growing regions worldwide.
It is caused by species of the genus Cladobotryum (formerly Dactylium), primarily Cladobotryum mycophilum and Cladobotryum dendroides. The pathogen grows rapidly over the casing surface and colonizes mushrooms at all stages of development with a white aerial mycelium, causing a destructive soft rot. Cladobotryum sporulates heavily and the spores are easily spread around the farm causing secondary infections. Spores landing on mushroom caps incite browning, causing loss of quality.
Until the early 1990s, cobweb outbreaks had little impact and were easily controlled by available fungicides and routine hygiene practices. But during the early 1990s, the incidence and severity of cobweb on British mushroom farms increased and in 1994/95 the disease reached epidemic proportions, regularly causing up to 40% crop loss.
