Chemical and Biological Control of Wet Bubble Disease (Hypomyces perniciosus) in Mushroom Crops

Wet bubble disease (WBD) is globally becoming a major problem in mushroom crops. The effectiveness of the application of different chemical (chlorothalonil, metrafenone and prochloraz-Mn) and Bacillus (B. subtilis and B. amyloliquefaciens strains) -based products for the control of WBD in artificially inoculated mushroom crops was studied. Six trials were carried out, with three different inoculum rates. The effect of fungicides on mushroom productivity and disease incidence was assessed. The effectiveness of the treatments is statistically related to the harshness of the disease. The greatest reductions in disease incidence were achieved after treatments with chemical fungicides, notably prochloraz-Mn. When the outbreak was strong, the low calculated incidence reduction values for metrafenone treatments advised against their application. The results also indicated the low effect of both bio-fungicides, at the doses and timing evaluated, for the control of this mushroom disease.