Rendimento e composição de óleo essencial de cidró (Aloysia citriodora) em função da sazonalidade e densidades de plantio

Abstract

Aloysia citriodora is a medicinal plant rich in volatile oil, which serves as a raw material for pharmaceutical, cosmetic, food and therapy industries. This plant has a calming action, aids in digestion, and it is also used against diarrhea, asthma, migraine, fever and flu. The aim of this study was to evaluate the effect of seasonality on the production and chemical composition of the essential oil of A. citriodora, and quantify the essential oil content in different planting densities in the field, monitor the phenology of the species throughout the experiment and quantify the essential oil content in different planting densities in the field, as well as the influence of biotic and abiotic factors in its development. The study was conducted in the Department of Vegetable Crops Universidade Tecnológica Federal do Paraná – Campus Dois Vizinhos, from January 2009 to December 2011. The experimental design was a randomized block design in a factorial (3 x 11), being factor 1: planting densities of 1, 0.8 and 0.6 m2 plant-1; and factor 2: harvest times (Oct/2010, Nov/2010, Dec/2010, Jan/2011, Feb/2011, Mar/2011, Apr/2011, May/2011, Jun/2011, and ago/2011 Sep/2011). The variables were the content of essential oil obtained by hydrodistillation for different harvest dates and planting densities, chemically made in the Oil Gas Chromatograph for different harvest times; fresh mass production per hectare and production of oil in liters per hectare for planting densities. The results were submitted to analysis of variance homogeneity tests, and comparison tests of means. The essential oil content measured at different harvest times was influenced by seasonal and climatic conditions of the place, having the month of February resulted in higher average content of essential oil (0.5%). In relation to the phenology of the species has been observed that in October, November and December is the flowering period of the species, between January and February is the end of this cycle, with the presence of only a few flowers in the terminal branches. From March to May, with the arrival of autumn, is more pronounced loss of leaves. During June and July the plant is leafless, dormant vegetative stage, caused by low temperatures. In September the plant comes out of this numbness, presenting new leaves and shoots, caused by increased temperature, output of winter and input of spring. Lower density planting (1 m2 plant-1) resulted in higher production of essential oil (39.88 L ha-1) and fresh biomass (12,660 kg ha-1). The major chemical constituent of the oil was citral.