Application of organic fertilizers to medicinal aromatic plants usually has a positive effect on biomass and essential oil production. Plectranthus neochilus Schlechter was cultivated with three organic fertilizer sources. This study evaluated the biomass production and content, yield and chemical composition of the essential oil. The seedlings, after acclimatization, were transplanted to 10L pots and placed under a protected environment. The experiment consisted of four treatments and four replications, with five pots per plot. The treatments included: without organic fertilizer (control); cattle manure 60 t ha-1; chicken manure 30 t ha-1; and organic compost 60 t ha-1. Plants were harvested at 120 days after planting. Part of the fresh leaves was used for the essential oil extraction and the remaining material was oven-dried for dry mass determination. The oil composition was determined by gas chromatography-mass spectrometry (CG-MS). The organic fertilizer sources showed differences between treatments related to biomass production, biomass distribution, essential oil yield and chemical composition in Plectranthus neochilus. The use of different organic ferilizers did not change the content of volatile oil.
Biomass; Plectranthus neochilus Schlechter; organic fertilizers