Aromatic Plants from Plateau des Cataractes: Occurrence of the Citronella Chemotype of Cymbopogon flexuosus (Nees ex Steud.) W.Watson Acclimatized in Congo-Brazzaville.

Cymbopogon flexuosus var. flexuosus (citral chemotype) was introduced in a local plantation in 2006 at Plateau des Cataractes, Congo-Brazzaville to remedy the difficult adaptation and low production of essential oil of C. citratus, a source of citral. After some 10 years of acclimatization, C. flexuosus had adapted perfectly with a very high biomass and essential oil production. A citronella chemotype (Cymbopogon flexuosus var. albescens) was unexpectedly identified among lemongrass in the field, grown in a local experimental citronella plot covering 0.25 ha. Its essential oil was extracted by hydrodistillation and analyzed by GC and GC/MS to determine its chemotype. The citronella chemotype indicated by the chemical profile found was confirmed by descriptive statistics (radar plot) and by principal component analysis (PCA) and ascending hierarchical clustering (AHC).