Effect of five pesticides on the mycelial growth of some soil and pathogenic fungi.

The effect of three doses (the lowest is the recommended dose in the field) of 5 pesticides namely: Ceresan, Orthocid (fungicides), VCS-438 (herbicide), and Dursban and Dipterex (insecticides) on the mycelial dry weight of Aspergillus fumigatus. Fusarium moniforme, Pencillium italicum, and Sclerotium ceprivorum was tested 2, 4, 6, 8 and 10 days after treatment. All the pesticides induced inhibition of mycelial growth of the test fungi. Only VCS-438 at the low dose was stimulatory to F. moniliforme after 4 and 6 days and to P. italicum after 4 days. The rate of inhibition was influenced by the type of fungus, the age of the mycelium, and the dose of the pesticide. At the end of the experiment the two fungicides were detoxified by the test fungi with a rate higher than that of the other pesticides.