Diseases of White Button Mushroom (Agaricus bisporus)- A Potential Threat to Mushroom Industry

Mushrooms have been used by humans for millennia. The commonly cultivated mushrooms include Agaricus, Lentinus, Flammulina, Pleurotusand Volvariella. In India, Button mushroom (Agaricusbisporus)is the most commonly cultivated mushroom followed by Pleurotus(Shah et al., 2013). Mushrooms are mainly subjected to bacterial, fungal and viral diseases. The production of fruiting bodies is severely afflicted by fungal, bacterial and viral pathogens that can cause diseases which have an effect on yield and quality (Potocnik et al., 2008). Improper pasteurization of compost and casing soil can be the major source of diseases. Once the disease is introduced in the farm it can be carried out by the different agencies like air, water, machines and workers (Munshi et al., 2010). Fungal diseases commonly occurring in white button mushrooms include dry bubble (Verticillium spp.), cobweb (Cladobotryumspp.), green mould in compost (Trichoderma harzianum) and green mould on casing (Trichoderma viride). Over the past two decades, green mould caused by T. aggressivum has been the most serious disease of button mushroom. Among bacterial diseases, bacterial blotch (Pseudomonas tolaasii) is most common disease of white button mushrooms. Dieback is the most commonly occurring viral disease which is caused by various virus strains (Gupta et al., 2018). These diseases are a major threat to the mushroom industries worth millions as the losses due to these diseases may go up to 100%. Depending upon the stage and severity of the infection, quality of compost and the prevailing environmental conditions, these diseases often cause complete crop failure (Munshi et al., 2010). Considerable losses in cultivation process occur due to lower productivity, decrease in quality and shortened shelf-life. Moreover, mushroom cultivation with its rapidity of cropping makes a suitable environment for augmentation of pathogen inoculum and thus makes its control more difficult (Todorovic et al., 2012).