Effect of six fungicides on Lecanicillium (Verticillium) lecanii (Zimm.) Zare & Gams.

The objective of the present study was to evaluate the effect of six fungicides on the entomopathogenic fungus Lecanicillium (Verticillium) lecanii (Zimm.) Zare & Gams), isolate Y–57. The assays were carried out in vitro with the following concentrations of the fungicides: 10, 100, 200, 500, 1000 and 2000 mg kg -1 . The inhibition of the fungus colony growth, the fungicide effect on spore production capacity and the conidia germination were evaluated. Difenoconazol and tebuconazol, belonging to the triazols group, were most effective on L. lecanii growth and spore production and germination, and chemicals were classified as toxic by the OILB scale and very toxic according to the compatibility scale using the T value. Cuprous oxide was lightly toxic for the OILB scale and toxic according to the compatibility scale since it affected the spore germination at lower concentrations than field dose. Metalaxyl was lightly toxic for the OILB scale and compatible with L. lecanii. Mancozeb was not effective on the fungus for the OILB scale and moderately toxic according to the compatibility scale, while zineb was lightly toxic for the OILB scale and moderately toxic according to the compatibility one.