E. Mohammadi Goltapeh - Department of Plant Pathology, College of Agriculture, Tarbiat Modares University, Tehran, Islamic Republic of Iran.
M. Shams-bakhsh - Department of Plant Pathology, College of Agriculture, Tarbiat Modares University, Tehran, Islamic Republic of Iran.
B. S. Pakdaman - Department of Microorganisms, Bio-resources and Biosafety, Agricultural Biotechnology Research Institute of Iran, Karaj, Islamic Republic of Iran.

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 ۹۹% inhibition of radial mycelial growth in Petri dishes at all concen-trations tested (۱۰-۴۰ µg a. i. ml-۱) in comparison to non treated dishes. Mancozeb caused ۴۳% and ۲۳% inhibition at ۲۵۰ and ۵۰۰ µg a. i. ml-۱ respectively and ۹۹% inhibition at concentration of ۱۰۰۰ µg a. i. ml-۱ and above. Diflubenzuro and malathion at ۱۰-۴۰ µg a. i. ml-۱ caused ۳۰-۴۱% and ۲۴-۵۴% inhibition, respectively. Formalin (۰.۵-۲.۰% v/v) inhib-ited growth of A. oligospora completely. However, calcium hypochlorite, sunflower and soybean oil cake at concentrations of up to ۲.۰% w/v caused less than ۳.۵% inhibition.

Agaricus bisporus, Arthrobotrys oligospora, Biocontrol, Disinfectant and Oil cakes