Compatibility of the fungus Beauveria Bassiana (Bals.) Vuill. (Deuteromycetes) with extracts of neem seeds and leaves and the emulsible oil

Abstract

Neotropical Entomology 34(4): 601-606 (2005) ABSTRACT -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.

Plant-mediated effects on entomopathogenic fungi: how the olive tree influences fungal enemies of the olive moth, Prays oleae

“…The presence of leaves inhibited the sporulation and spore viability of both entomopathogenic fungi, although the effect was more pronounced with P. formosa. A reduction of conidia viability was also reported for B. bassiana exposed to different extracts of the neem tree (Azadirachta indica) (Depieri et al 2005). By contrast, in the present study, the germination and radial growth of both fungi were not statistically affected by the presence of leaves.…”

Compatibility between Calpurnia aurea leaf extract, attraction aggregation, and attachment pheromone and entomopathogenic fungus Metarhizium anisopliae on viability, growth, and virulence of the pathogen

“…It can be therefore envisaged to use the leaf extracts of this plant in combination with entomopathogenic fungi in a kairomone-baited trap system for autodissemination of fungal conidia in the field. However, plant extracts can affect entomopathogenic fungi negatively (Duarte et al 1992;Malo 1993;Marques et al 2004;Depieri et al 2005) and subsequently, the control of the target pest (Akbar et al 2005;Mohan et al 2007). For instance, Depieri et al (2005) reported that aqueous seed extract from Azadirachta indica A. Juss.…”

“…However, plant extracts can affect entomopathogenic fungi negatively (Duarte et al 1992;Malo 1993;Marques et al 2004;Depieri et al 2005) and subsequently, the control of the target pest (Akbar et al 2005;Mohan et al 2007). For instance, Depieri et al (2005) reported that aqueous seed extract from Azadirachta indica A. Juss. (Meliaceae) (Neem) reduced conidial vegetative growth and production of Beauveria bassiana (Bals.)…”

Growth and insect assays ofBeauveria bassianawith neem to test their compatibility and synergism

“…They are also reported to affect metamorphosis of insects leading to a decrease in their population (Mathur & Nigam 1993;John 1999;Gahukar 2000;Filotas et al 2005). The compatibility of isolates of B. bassiana with azadirachtin formulations has been investigated previously (Rodríguez et al 1997;Bajan et al 1998;Gupta et al 1999;Depieri et al 2005). However, few isolates were tested and contradictory results have been reported.…”