Occurrence of Verticillium fungicola var. fungicola on Agaricus bitorquis Mushroom Crops in Spain

Diseased fruit bodies of Agaricus bitorquis, with similar symptoms to those caused by dry bubble on Agaricus bisporus, were observed in some Spanish crops during summer 1999.Isola tes of Verticillium fungicola from A. bitorquis and A. bisporus were submitted to different temperatures and to prochloraz–Mn sensitivity tests.All the isolates collected from A. bitorquis and A. bisporus were identified as V. fungicola var. fungicola. Artifici al infections of A. bisporus and A. bitorquis with V. fungicola var. fungicola are also described in the present study.The appearance of natural infections of V. fungicola var. fungicola in A. bitorquis crops could well be due to the growing temperatures used in Spain, which are considerably below those used in other countries.