Compatibilidade de Bacillus pumilus com Metarhizium anisopliae

Abstract

The objective of this study was to evaluate the compatibility of the microbiological fungicide, with Bacillus pumilus (CNPSo 3203) as the active ingredient, with the entomopathogenic fungus Metarhizium anisopliae (IBCB 425). Different doses of the microbiological fungicide, specifically 100, 400, and 800 mL ha-1, were tested, in addition to the control treatment. To assess vegetative growth and conidial production, the different product doses were mixed with the BDA culture medium, and subsequently, the fungus was inoculated. During the evaluations, the diameter of each colony was measured by taking the average diameter, and the produced conidia in the same colonies were disaggregated for counting. For conidial germination evaluation, a standard suspension of 1.0 × 106 conidia mL-1 was mixed with the sprays of the different doses of the microbiological fungicide and the control. To assess germination, an aliquot of 1.0 mL from each treatment was applied to Petri dishes containing solidified BDA. Afterwards, the percentage of germinated conidia was quantified. The experiment was conducted using a completely randomized design. Among the evaluated parameters, only germination was not affected by the microbiological fungicide. Vegetative growth and conidial production were reduced in the presence of the product. Regarding the IB (insecticidal bioassay), the lowest dose was classified as moderately toxic, while the remaining doses were classified as toxic. It was found that none of the doses of the microbiological fungicide were compatible with the fungus M. anisopliae.