Produção de biomassa, teor e composição química do óleo essencial de Melissa officinalis L. sob omissão denutrientes e em consórcio com Achillea millefolium L

Abstract

The cultivation of medicinal, aromatic and herb plants and also of essencial oil has been expanding. The essential oil production can be influenced by several factors, such as mineral nutrition and the adopted cultivation systems. It is necessary to promote the improvement of cultivation techniques and knowledge about the nutritional requirement in the increase of biomass accumulation, in the production and chemical composition of the oils. Melissa officinalis L. is an expanding plant in the market, it has a low essential oil content which makes it necessary to develop studies to evaluate its vegetative growth, as well as factors that increase its production. The consortium with Achillea millefolium L. can contribute to the production of secondary metabolites increase. Therefore, the objective of this work was to evaluate the influence of nutrients in the growth, production and chemical composition of essential oil in M. officinalis L. and also of the intercropping with an A. millefolium L. The consortium of M. officinalis L. and A. millefolium L. was done, arranged in four treatments: monocrop of M. officinalis L., A. millefolium L. monocrop, and the intercropping, in a randomized block design with seven replicates. Nine treatments with omissions of N, P, K, Ca, Mg, S, Fe, Zn and Complete, with four replications in a randomized design, conducted under the missing element technique in the Hoagland & Arnon’s nutrient solution in hydroponic cultivation in M. officinalis L. were analyzed. In the experiments were evaluated: the vegetative growth (dry biomass, photosynthetic pigments and leaf area), production and essential oil chemical analysis (volatile fraction and qualitative and quantitative analysis by gas chromatography). The increasing order of nutrient limitations for vegetative growth is N = Fe >K = Ca = P >Zn >S >Mg, and for oil production it is C = Fe >S=Ca >Zn=P=K >>Mg. The intercropping M. officinalis L. and A. millefolium L. allows an increase in the essential oils content, but a lower dry matter production of M. officinalis L. and it does not interfere in the chemical composition of the essential oil. The omission of essential nutrients in M. officinalis L. interferes with the production of biomass, content and chemical composition of the oil, especially because of the nutrients N, Fe, Ca and S. The omission of Mg increases the chlorophyll, carotenoids, and the content of essential oil. Thereby, we can establish a production technique and a proper nutritional requirement management by linking production and the essential oil content.