Inhibitory Efficacy of Lemon-Grass (Cymbopogon citratus) Extracts on Some Selected Fungal Root Pathogens
Published: 2023-05-18
Page: 81-87
Issue: 2023 - Volume 6 [Issue 2]
Onuoha Udumma Nsofor
Department of Microbiology, College of Natural Sciences, Michael Okpara University of Agriculture, Umudike, P.M.B. 7267, Umuahia, Abia State, Nigeria.
Alaebo Prince Ogochukwu *
Department of Biochemistry, College of Natural Sciences, Michael Okpara University of Agriculture, Umudike, P.M.B. 7267, Umuahia, Abia State, Nigeria.
Ukpabi-Ugo Jacinta Chigozie
Department of Biochemistry, College of Natural Sciences, Michael Okpara University of Agriculture, Umudike, P.M.B. 7267, Umuahia, Abia State, Nigeria.
Enya Emmanuel
Department of Microbiology, College of Natural Sciences, Michael Okpara University of Agriculture, Umudike, P.M.B. 7267, Umuahia, Abia State, Nigeria.
Okakpu Joseph Chinemelu
Department of Biochemistry, College of Natural Sciences, Michael Okpara University of Agriculture, Umudike, P.M.B. 7267, Umuahia, Abia State, Nigeria.
Anah Joel Okwuchukwu
Department of Biochemistry, College of Natural Sciences, Michael Okpara University of Agriculture, Umudike, P.M.B. 7267, Umuahia, Abia State, Nigeria.
Ugwu Paschal
Department of Biochemistry, College of Natural Sciences, Michael Okpara University of Agriculture, Umudike, P.M.B. 7267, Umuahia, Abia State, Nigeria.
Okolie Jennifer Chisom
Department of Biotechnology, School of Biological Sciences, Federal University of Technology, Owerri, P.M.B. 1526, Owerri, Imo State, Nigeria.
Onwuatuelo Chizitere Onyinye
Department of Human Anatomy, Faculty of Basic Medical Science, University of Nigeria, Enugu Campus , P.M.B. 01129, Enugu State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
The organisms Aspergillus niger, Fusarium moniliforme, Botryodiplodia theobromae, Rhizopus spp., and yeasts were isolated from rotten cassava tubers. A pathogenicity test was carried out on healthy cassava tubers using the previously isolated organisms. Aspergillus niger, Fusarium moniliforme, and Botryodiplodia theobromae were found to be pathogenic against cassava. The inhibitory efficacy of leaf extracts of Cymbopogon citratus (lemongrass) on the fungal root pathogens isolated was investigated in vitro using the agar-well diffusion method. The extraction solvents used were ethanol and water, which caused inhibition of the three pathogens with varying diameters. Twenty-four millimetres was the highest zone diameter of inhibition recorded, and 11 millimetres was the lowest zone diameter of inhibition. The minimum inhibitory concentration (MIC) ranged from 25–1000 mg/ml, while the minimum fungicidal concentration (MFC) ranged from 50–200 mg/ml, depending on isolates and extracting solvent. Ethanolic extracts showed greater antifungal activity than aqueous extracts.
Keywords: Lemmon-grass, Aspergillus niger, Fusarium moniliforme, Botryodiplodia theobromae, Rhizopus spp, cassava tubers