Compatibility of essential oils with Beauveria bassiana (Balls.) Vuil

Abstract

Insect pests are a primary agricultural concern, as they can cause productivity losses. The use of pesticides has been the main means of controlling pests. Despite its significant contribution to agriculture, its indiscriminate use harms the environment. The awareness about the risks of agrochemicals using natural enemies such as fungi and alternative controls, such as essential oils, can be an alternative control. The objective of this work was to evaluate the fungicidal activity of oils essentials of Cymbopogon citratus, Cinnamomum camphora var. linaloolifera, and Thymus vulgaris on the entomopathogen Beauveria bassiana. Bioassays followed a completely randomized design in a 3x6 factorial scheme, in which one factor was the essential oils of C. camphora, C. citratus, and T. vulgaris, and the other factor was the four essential oil concentrations, plus two controls. The evaluations took place on the 3rd, 7th, and 14th day. Each treatment had five repetitions, and each repetition was a plate. When assessing compatibility with the entomopathogenic fungus, it was verified that the essential oils showed antifungal activity at all concentrations tested for that non-target organism. Thus, it is advised against the concomitant use of this entomopathogen and the tested essential oils. However, both control tools can be used at different times, with rotation and intercalation of the two methods, following the IPM practices.