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

• Published in: Neotropical entomology 2005-08, Vol.34 (4), p.601-606
• Main Authors: Depieri, Rogério A.(Instituto Agronômico do Paraná Lab. Entomologia ,CBP ,D/Café), Martinez, Sueli S.(Instituto Agronômico do Paraná Lab. Entomologia), Menezes Jr., Ayres O.(Universidade Estadual de Londrina Depto. Agronomia)
• Format: Article
• Language: English
• Subjects: Azadirachta indica; Beauveria bassiana; biological control; controle biológico; Deuteromycetes; ENTOMOLOGY; entomopathogenic fungus; fungo entomopatogênico; selectivity; seletividade
• ISSN: 1519-566X; 1678-8052; 1678-8052
• DOI: 10.1590/S1519-566X2005000400010

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. A compatibilidade de uma formulação comercial de óleo emulsionável de nim (Azadirachta indica A. Juss.), do extrato aquoso de sementes e do extrato aquoso de folhas de nim com Beauveria bassiana (Bals.) Vuill., foi avaliada in vitro. Foram conduzidos três experimentos para avaliar o efeito de cada um dos produtos no crescimento vegetativo do fungo, e na produção e viabilidade dos conídios. Os produtos foram incorporados ao meio de cultura (PDA+E) e distribuídos em placas de Petri, nas concentrações, 0,15; 1,5 e 15% (extrato aquoso de folhas), 1; 2 e 4% (extrato aquoso de sementes) e 0,5; 1 e 1,5% (óleo emulsionável). Com base no crescimento vegetativo e na produção de conídios, os extratos aquosos de sementes e de folhas e o óleo emulsionável de nim foram caracterizados segundo o modelo T para classificação de compatibilidade de produtos. Os extratos de sementes e de folhas mostraram-se menos prejudiciais a B. bassiana que o óleo emulsionável. Esse produto, nas concentraçõe