The selective effect of the pyrethroid insecticide (Polytrin) on soil
fungi was studied at three doses when incorporated in soil or in agar
or liquid medium. Polytrin induced an inhibitory effect on soil fungi
after 2, 5 and 40 days when applied at certain levels and a stimulator
y effect after 20 days of treatment with the high dose. When incorpora
ted in the agar medium, Polytrin decreased the total counts of fungi,
particularly, Aspergillus and Penicillium at the high dose (10.0 ppm).
In liquid medium, it showed no significant effect except in case of A
. terreus which was significantly enhanced by the three doses.