Influência das condições de cultivo sobre a produção de óleo essencial do capim citronela (Cymbopogon nardus)

The production of active principles by medicinal plants can be influenced by the cultivation environment. The study of these conditions is essential to produce a better quality plant material. Thus, this paper aimed to evaluate the effect of the use of organic fertilization on the growth, on biomass production and on the essential oil content and composition of citronella grass (Cymbopogon nardus) under the edaphoclimatic conditions of Juiz de Fora-MG. The extraction of the essential oil was carried out through hydrodistillation using an adapted Clevenger equipment and the identification of the chemical compounds by gas chromatography coupled to mass spectrometry. The plants presented in the treatment with organic fertilizing, at 174 days of transplant, a production of fresh biomass of 1071.75 g plant-1, estimating a productivity of 21.44 t ha-1. The content of essential oil was of 1.06% in the treatment without fertilizing and 0.82% in the treatment with fertilizing. The technique of GC-MS allowed the identification of 14 chemical compounds in the citronella grass essential oil. The majority compounds of the oil were trans-β-geraniol, citronellal and β-citronellol. The results allow to estimate a productivity of volatile oil of 79.20 kg ha-1 for the treatment with fertilizing and 64.45 kg ha-1 for the treatment without fertilizing. In the first treatment a lower oil content and a higher production of biomass were obtained resulting in a higher production of essential oil for hectare.