Compatibility of neem and beauveria

The compatibility of a commercial formula of emulsible neem oil (Azadirachta indica A.
Juss.) and of aqueous extracts of neem seeds and leaves with Beauveria bassiana (Bals.) Vuill. was evaluated
in vitro. Three experiments were conducted to evaluate the effect of each product on the fungus vegetative
growth and on conidia production and viability. The products were incorporated to a culture medium
(BDA+E) and distributed into petri dishes, in the following concentrations: 0.15%; 1.5% and 15% (leaf
aqueous extract), 1%; 2% and 4% (seed aqueous extract) and 0.5%; 1% and 1.5% (emulsible oil). Vegetative
growth and conidia production were the basis for characterization of the aqueous extracts of seeds and
leaves and of the emulsible oil, using the T classification model for compatibility of products. Seed and leaf
extracts were less harmful to B. bassiana than the emulsible oil. Under the tested concentrations, the oil
was not compatible with B. bassiana, inhibiting conidia vegetative growth significantly and decreasing
production and viability of conidia, particularly at higher concentrations. Neem seed and leaf extracts were
compatible with the entomopathogen in all concentrations. The seed extracts reduced conidia vegetative
growth and production, but it did not affect the viability of spores. Leaf extract at 15% had a small negative
impact on vegetative growth, and on production and viability of conidia, but it was still compatible with the
fungus B. bassiana, according to the T model.