Impact of Bacillus subtilis QST713 mushroom grain spawn treatment on yield and green mould control

SUMMaRY A biofungicide based on Bacillus subtilis QST713 was tested for impact on yield and efficacy against a Trichoderma aggressivum f. europaeum T77 strain from Serbia by coating mushroom grain spawn and comparing the results with the chemical fungicide prochloraz manganese in a mushroom growing room. The tested B. subtilis QST713 strain did not inhibit mycelial growth of Agaricus bisporus in plots free of the pathogen, showing an impact on yield of 91.95%, which was not significantly different from an untreated control. As for the efficacy of the fungicides used against T. aggressivum f. europaeum T77, there were no significant differences between a prochloraz manganese casing treatment, and B. subtilis QST713 coating on mushroom grain spawn, as the efficacy was 70.37 and 53.09%, respectively. These results implied that the biofungicide based on B. subtilis could serve as a harmless alternative to synthetic fungicides in mushroom production, especially during serious compost green muold outbreaks caused by T. aggressivum . Furthermore, the biofungicide should be applied alone because an antagonistic reaction was detected between the fungicide prochloraz and B. subtilis QST713.