Cobweb, a serious pathology in mushroom crops: A review

Cobweb is a fungal disease of commercially cultivated mushrooms. Several members of the ascomycete genus Cladobotryum sp. have been reported as causal agents. White button mushroom is the most frequently cited host, but a wide range of cultivated edible mushrooms suffer cobweb. The pathology causes production losses and reduces the crop surface available. The parasite produces a great number of harmful conidia that can be released easily and distributed throughout the mushroom farm to generate secondary points of infection. To prevent initial outbreaks, hygiene is of primary importance within the facilities dedicated to mushroom cultivation, while additional measures must be implemented to control and reduce cobweb if there is an outbreak, including chemical and biological methods. This review summarizes and discusses the knowledge available on the historic occurrence of cobweb and its impact on commercial mushroom crops worldwide. Causal agents, disease ecology, including the primary source of infection and the dispersal of harmful conidia are also reviewed. Finally, control treatments to prevent the disease from breaking out are discussed.