Efficacy and effects on yield of different fungicides for control of wet bubble disease of mushroom caused by the mycoparasite Mycogone pemiciosa

Carbendazim, iprodione, prochloraz-Mn, thiabendazole and thiophanate-methyl were tested in vitro and in vivo for their effect on Mycogone pemiciosa, the mycoparasite that causes wet bubble disease of white button mushroom. In vitro experiments showed that prochloraz-Mn (ED50 = 0.006-0.064 mu g ml(-1)) and carbendazim (ED50 = 0.031-0.097 mu g ml(-1)) were the most effective fungicides for inhibiting the mycelial growth of M. perniciosa, while iprodione (ED50 = 1.90-3.80 mu g ml(-1)) was the least effective. The resistance factors calculated for the five fungicides were between 1.4 and 2. The results obtained suggest that there is very little risk that M. perniciosa will develop resistance to the fungicides assayed. The in vivo efficacy of fungicides for control of wet bubble was studied in two mushroom cropping experiments, which were artificially infected with two doses of M. perniciosa, 10(6) and 10(7) spores m(-2), respectively. There was, in the low dose inoculum experiment, a very high degree of effectiveness (96.5-100.0%) with all the fungicides assayed. However, iprodione performed poorly (20.5-24.4%) compared with the other fungicides (88.7-100.0%) in the high concentration inoculum experiment. The most effective treatments for controlling wet bubble did not improve the biological efficiency of Agaricus bisporus. (C) 2010 Elsevier Ltd. All rights reserved.