Control of Verticillium fungicola on Agaricus bisporus

Stefanie Kalkhove, Roeland Berendsen, Mayken Wadman, Luis Lugones, Han Wösten

Pathogenic fungi are a major problem in the cultivation of edible mushrooms, such as those of Agaricus bisporus (the white button mushroom). The most important pathogen ofA. bisporus is Verticillium fungicola, causing dry bubble disease. During the last decade V. fungicola has become less sensitive to the only approved chemical (prochloraz) that is still effective to treat infection. Moreover, it is expected that prochloraz will be banned from commercial mushroom growing. Therefore, alternative strategies to control the disease are urgently needed. This proposal aims at using 1) antagonistic bacterial strains and/or 2) antifungals that are produced by A. bisporus. These approaches have so far not been used to prevent infection of A. bisporus with V. fungicola and could also be effective against other pathogens.

The Netherlands are the third largest producer of white button mushrooms in the world and the largest producer in Europe. In 2002 the Dutch production amounted about 280 million kg of mushrooms representing a value of 300 million €. Damage caused by V. fungicola is estimated at 10 million € annually but is expected to increase significantly in the near future because of the expected ban of the fungicide and the observed resistance. The research described in this proposal is of utmost importance for the mushroom industry. Therefore, this proposal is supported by seven organizations and companies. A plan has been agreed upon how to effectively disseminate the results to the Dutch mushroom industry.