GROWTH-INHIBITION OF AGARICUS-BISPORUS AND ASSOCIATED THERMOPHILIC SPECIES BY FUNGICIDES USED IN WHEAT CULTIVATION

Eight fungicides used on wheat were checked for their toxic effect in vitro on the mycelial growth of 3 strains of the edible mushroom Agari cus bisporus and 3 isolates of thermophilic fungi active in mushroom c omposting. At concentrations < 2 ppm, captan, maneb and chlorothaloni were not found to be toxic. Only tebuconazol significantly limited the radial growth of A bisporus mycelium. The IC50 values of benomyl, car bendazim, flusilazol, prochloraz and tebuconazol on mycelial growth of thermophilic fungi ranged from 0.1-0.7 ppm. The presence of fungicide residues in wheat straw may therefore affect the process of mushroom composting.