Alelopatia do óleo essencial de Piper marginatum Jacq. e o potencial antigerminativo de suas nanoemulsões

Abstract

Essential oils are a potential source of bioproducts due to the presence of a complex composition of chemical constituents with a broad spectrum of biological activities. Among the activities already identified, there is the allelopathic potential, this biological action directs research for the development of bioherbicides, for the control of weeds in cultivars. In this context, this study aimed to evaluate the allelopathic an antigerminative effects of essential oil from P. marginatum leaves of species grown in a germination chamber. Two bioassays were carried out in a completely randomized design, with 5 treatments with different concentrations: 0.001; 0,01; 0.1 and 1% essential oil and 1% surfactant for the control treatment and another with water only, for bioassay II, 4 treatments were used with blank formulations containing 1% and 0.5% essential oil and for the control treatment containing only water, with three replications each. The seeds were placed to germinate with the respective treatments in acrylic boxes containing germitest paper, in a germination chamber, with a photoperiod of 12 hours. Percentage, mean time, germination speed index and root length were evaluated. The results showed that the essential oil of P. marginatum had an inhibitory effect on the germination of tomato and lettuce seeds. However, the effect of the essential oil was more pronounced on tomato seeds, where all the variables tested were affected. On the other hand, in lettuce seeds, only germination and radicle length were significantly affected. When specifically analyzing the effect of formulations containing essential oil of P. marginatum on chive and lettuce seeds, it was observed that the concentrations of 1% and 0.5% significantly reduced the percentage of sprouted chive seeds. In addition, other important variables such as germination speed index (IVG) and chive radicle size were also affected by the formulations. For lettuce seeds, the effect of P. marginatum essential oil was observed only on the radicle size variable, which had its growth significantly reduced with the application of the formulations. Based on these results, it is concluded that the essential oil of P. marginatum may be a promising alternative to inhibit the germination of tomato, lettuce and chive seeds. However, it is important to note that its inhibitory effect may vary between different plant species and concentrations used.