Essential oils of Bursera morelensis and Lippia graveolens for the development of a new biopesticides in postharvest control

Abstract

Fruit and vegetable crops that are not consumed immediately, unlike other agricultural products, require economic and time investments until they reach the final consumers. Synthetic agrochemicals are used to maintain and prolong the storage life of crops and avoid losses caused by phytopathogenic microorganisms. However, the excessive use of synthetic agrochemicals creates health problems and contributes to environmental pollution. To avoid these problems, less toxic and environment-friendly alternatives are sought. One of these alternatives is the application of biopesticides. However, few biopesticides are currently used. In this study, the biopesticide activity of Bursera morelensis and Lippia graveolens essential oils was evaluated. Their antifungal activity has been verified in an in vitro model, and chemical composition has been determined using gas chromatography-mass spectrometry. Their antifungal activity was corroborated in vitro, and their activity as biopesticides was subsequently evaluated in a plant model. In addition, the persistence of these essential oils on the surface of the plant model was determined. Results suggest that both essential oils are promising candidates for producing biopesticides. This is the first study showing that B. morelensis and L. graveolens essential oils work by inhibiting mycelial growth and spore germination and are environment-friendly biopesticides.

Effect of the Essential Oils of Bursera morelensis and Lippia graveolens and Five Pure Compounds on the Mycelium, Spore Production, and Germination of Species of Fusarium

“…The essential oils (EOs) of the plants B. morelensis (voucher IZTA 42123) and L. grave-olens (voucher MCM8) were obtained by the hydrodistillation method. Subsequently, the essential oils were analyzed by gas chromatography/mass spectrometry (GC/MS) [ 15 ]. Of the essential oil components, five pure compounds present in one or both essential oils were selected.…”

“…These strains were selected because they belong to the genus Fusarium , which has a tremendous economic impact on agriculture and produces many plant diseases [ 1 ]. Additionally, in the previous study of our research group, it was observed that they rapidly developed symptoms on a plant model and were highly sensitive to essential oils, which made them suitable test microorganisms for the study [ 15 ].…”

“…In a previous study conducted by our research group, the in vitro antifungal activity of the essential oils of B. morelensis and L. graveolens was evaluated [ 15 ], so in the present work, the antifungal activity in vitro of the five pure compounds present in both essential oils was measured to later compare the effect produced by the essential oils and the pure compounds. The radial growth inhibition method was used to determine the medium fungicidal concentration (CF 50 ).…”

“…These low-molecular-weight compounds give them antifungal activity [ 12 ]. The essential oils of the species Bursera morelensis and Lippia graveolens have in vitro and in vivo antifungal activity [ 13 , 14 , 15 , 16 ]. In a previous study, the chemical composition of both essential oils was analyzed, and the main components were identified.…”

“…In a previous study, the chemical composition of both essential oils was analyzed, and the main components were identified. In the same work, it was shown that these essential oils are not persistent during the postharvest control of Fusarium species [ 15 ]. However, the antifungal activity of essential oils and pure compounds has not been compared, nor has the effect of essential oils and pure compounds on the mycelium and spores of some Fusarium species been studied.…”