Fungicides for the control of Mycogone perniciosa (Magn.), the cause of wet bubble on the cultivated mushroom

Two formulations of chlorothalonil (as Daconil 2787) were compared for their activity against Mycogone perniciosa Magn. on the cultivated mushroom Agaricus bisporus (Lange) Imbach. At the same does rates, the flowable formulation was more toxic than the wettable powder to both pathogen and host, but more marketable mushrooms were obtained from diseased plots treated with the flowable formulation at each dose rate (1.0, 0.5 and 0.1 g ai m^?2). Levels of disease control were related to dose rates, making it impracticable to lessen toxicity to mushrooms by reducing the dose rate. Fluotrimazole was less active than chlorothalonil against M. perniciosa and was more toxic to mushrooms.