Antifungal Activity of the Essential Oil of Cymbopogon citratus (Poaceae) Against Phaeoramularia angolensis

The essential oil of Cymbopogon citratus grown in Ngaoundere- Cameroon was extracted by hydrodistillation with a yield of 0.4 % (w/w). The chemical analysis, carried out by gas chromatography and gas chromatography coupled with mass spectrometry revealed that the extract is rich in geranial (32.2 %), myrcene (27.0 %) and neral (25.7 %), also the chemical composition of the fractions was determined. The antifungal activity was evaluated by incorporation technique. We have observed that citral, considered as a reference compared to fractions, is very active against P. angolensis with a Minimal inhibitory concentration (MIC) of 400 ppm. Also, oil fractions 10 and I I which are very rich in neral and geranial presented comparable efficacy with MIC of 500 ppm slightly more potent than the crude extract which presented an identical MIC to that of a reference fungicide (600 ppm). On the other hand, until 5000 ppm, no MIC was obtained with fraction 4 of this same extract. From the results achieved, the antifungal activity of the essential oil of C citratus may be mainly due to the presence of neral and geranial. This essential oil could constitute an alternative to synthetic fungicides mostly used for Citrus fruit crops, due to high neral and geranial contents.