sensitivity of the nematophagous fungus arthrobotrys oligospora to fungicides, insecticides and crop supplements used in the commercial cultivation of agaricus bisporus

the effect of various pesticides (diflubenzuro, malathion, mancozeb and carbendazim), disinfectants (calcium hypochlorite and formaldehyde) and oil cakes (sunflower and soy-bean oil cakes) commonly used as supplements in mushroom cultivation on the growth of the nematophagous fungus, arthrobotrys oligospora, was studied under in vitro conditions. carbenazim caused 99% inhibition of radial mycelial growth in petri dishes at all concen-trations tested (10-40 µg a. i. ml-1) in comparison to non treated dishes. mancozeb caused 43% and 23% inhibition at 250 and 500 µg a. i. ml-1 respectively and 99% inhibition at concentration of 1000 µg a. i. ml-1 and above. diflubenzuro and malathion at 10-40 µg a. i. ml-1 caused 30-41% and 24-54% inhibition, respectively. formalin (0.5-2.0% v/v) inhib-ited growth of a. oligospora completely. however, calcium hypochlorite, sunflower and soybean oil cake at concentrations of up to 2.0% w/v caused less than 3.5% inhibition.