Nanoemulsión de aceite esencial de Laureliopsis philippiana (Losser) Schodde: actividad insecticida contra la polilla del tomate (Tuta absoluta Meyrick).
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Date
2022
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Publisher
Universidad de Concepción.
Abstract
Tuta absoluta Meyrick constituye una grave amenaza para la producción de tomate en el mundo. Las actuales estrategias de control incluyen el uso de aceites esenciales (AEs) y sus formulaciones. Laureliopsis philippiana (Losser) Schodde, especie arbórea nativa de Chile, cuyo AE tiene reconocida actividad biológica frente a otras plagas, podría tener efecto insecticida sobre T. absoluta. Por ello los objetivos de este estudio fueron determinar la estabilidad de una
nanoemulsion (NE) a base de AE de L. philippiana y evaluar el efecto insecticida de la NE y el AE puro contra T. absoluta. La estabilidad de la NE se midió durante un período de 35 días, con mediciones realizadas cada 7 días, mientras que la eficacia de la NE para controlar T. absoluta se comparó con la del AE puro. Los resultados indicaron que la NE se mantuvo estable durante todo el período de evaluación, promediando al final del experimento un tamaño de partícula de 40,60 nm, un potencial zeta de -14,54 mV, un índice de polidispersión (PDI) de 0,30 y un nivel de pH de 4,64. La NE de L. philippiana tras 4 horas de fumigación mostró una mayor actividad insecticida contra T. absoluta que el AE puro, con valores de CL50 y CL90 de 4,6 y 27,8 µL L-1, mientras que el AE puro dio lugar a valores de 27,1 y 75,3 µL L-1 respectivamente. Estos resultados corresponden al primer reporte de las propiedades insecticidas del AE de L. philippiana contra T. absoluta. La NE resultó mucho más eficiente que el AE puro sobre todo a bajas concentraciones y se mantuvo estable por más de 4 semanas.
Tuta absoluta Meyrick is one of the most serious pests of tomatoes worldwide. The current strategies of pest control for T. absoluta include essential oils (EOs) and its formulations. Biological activity of Laureliopsis philippiana (Losser) Schodde EO, a tree species native from Chile, has been demonstrated against pests. Hence, the aims of this study were to determine the stability of the L. philippiana oil- based nanoemulsion (NE) and to evaluate the insecticidal effects of pure and NE forms of the EO against T. absoluta. Emulsion stability was measured over a 35-day period, with measurements conducted every 7 days, while the efficacy of the NE to control T. absoluta was compared to that of the pure EO. The results indicate that the NE remained stable during the whole evaluation period, averaging at the end of the experiment a particle size of 40.60 nm, zeta potential of – 14.54 mV, polydispersity index (PDI) of 0.30 and a pH level of 4.64. The L. philippiana NE after 4 h fumigation showed greater insecticidal activity against T. absoluta than pure EO, with LC50 and LC90 values of 4.6 and 27.8 µL L-1, whereas the EO resulted in values of 27.1 and 75.3 µL Lu1, respectively. These results are the first report of the insecticidal properties of the EO of L. philippiana against T. absoluta. The biological activity exerted by the oil was significantly enhanced when developed as a NE as it remained stable for more than four weeks and was much more efficient in the control of T. absoluta than pure EO, particularly at low concentrations.
Tuta absoluta Meyrick is one of the most serious pests of tomatoes worldwide. The current strategies of pest control for T. absoluta include essential oils (EOs) and its formulations. Biological activity of Laureliopsis philippiana (Losser) Schodde EO, a tree species native from Chile, has been demonstrated against pests. Hence, the aims of this study were to determine the stability of the L. philippiana oil- based nanoemulsion (NE) and to evaluate the insecticidal effects of pure and NE forms of the EO against T. absoluta. Emulsion stability was measured over a 35-day period, with measurements conducted every 7 days, while the efficacy of the NE to control T. absoluta was compared to that of the pure EO. The results indicate that the NE remained stable during the whole evaluation period, averaging at the end of the experiment a particle size of 40.60 nm, zeta potential of – 14.54 mV, polydispersity index (PDI) of 0.30 and a pH level of 4.64. The L. philippiana NE after 4 h fumigation showed greater insecticidal activity against T. absoluta than pure EO, with LC50 and LC90 values of 4.6 and 27.8 µL L-1, whereas the EO resulted in values of 27.1 and 75.3 µL Lu1, respectively. These results are the first report of the insecticidal properties of the EO of L. philippiana against T. absoluta. The biological activity exerted by the oil was significantly enhanced when developed as a NE as it remained stable for more than four weeks and was much more efficient in the control of T. absoluta than pure EO, particularly at low concentrations.
Description
Tesis para optar al grado de Magíster en Ciencias Agronómicas.
Keywords
Tepa, Aceites esenciales, Polilla del tomate