Compatibility of the entomopathogenic fungus Beauveria bassiana with some plant extracts and chemical pesticides

The compatability of biological control agents with pesticides is a central concern in integrated pest management programs. Beauveria bassiana (Bals.) Vull is one of the entomopathogenics fungus. The fungal vegetative growth might change due to chemical pesticides that are used for protect of plants. The aim of this study was to evaluate the compatibility of Achillea millefolium L. and Metha pulegium extracts with fipronil, phosalone, sulfur and benomyl pesticides with B. bassiana.

 The experiment was done based on a complete randomized design at Tabriz Azad University Iran, during 2018. PDA fungal cultivation medium was amended with plant extracts and chemical pesticides at concentrations of 250, 500, 750 and 1000 µl/l and the fungal vegetative growth was evaluated. Extraction was done by using acetone and methanol as solvents. Medium without pesticide and extract was used as control treatment.

The highest inhibition in fungal mycelium development was observed in 250 and 500 µl/l of benomyl. Inhibition in fungal mycelium development in 750 µl/l was as follows: phosalone and benomyl > sulfur and fipronil >M. pulegium > A. millefolium extract. In 1000 µl/l pesticides had the highest inhibition in its development. The fungal vegetative growth showed that no significant difference between the acetonic and methanolic extracts of A. millefolium and M. pulegium.

The results showed that extracts of A. millefolium, M. pulegium and fipronil in low concentration were compatible whit B. bassiana and it seemed that using of them with the defined concentration along the Entomopathogenic fungi could be propper in management integrated program.