Scientific publications
Sylvie Kwanga Nguikwie
D. Fotio
B. Dongmo
P. H. Amvam Zollo
Augustin Ephrem Nkengfack
Vibeke Leth
Leif Poll
Other affiliations: Royal Agricultural University
Journal of Essential Oil Research
Essential oils and fractions isolated from Cymbopogon citratus, Ocimum gratissimum and Thymus vulgaris were tested for their activities and level of stability against Alternaria padwickii and Bipolaris oryzae, two seed-borne fungi of rice. Three active fractions were identified with MFC of 300 ppm for O. gratissimum and 400–500 ppm for T. vulgaris compared to the oils with MFC of 800 and 1000 ppm, respectively, on A. padwickii and 600 and 500 ppm, respectively, on B. oryzae. The chemical composition revealed that the fractions were concentrated in oxygenated monoterpenes, whereas the oils were rich in monoterpene hydrocarbons. Two active fractions identified from C. citratus oil displayed MIC of 500–600 ppm compared to the oil with MIC of 900 ppm and 800 ppm for A. padwickii and B. oryzae. The storage effect revealed that the oils and fractions from O. gratissimum and T. vulgaris kept their activity after six days of storage, unlike those from C. citratus.
