Articles
Investigating the potential of moringa leaf extracts (MLEs) as potential antifungal agents against Fusarium dry rot of potatoes
Article number
1378_14
Pages
105 – 112
Language
English
Abstract
Potato is an economically important crop in South Africa and is one of the most-consumed starch crops worldwide.
Potato production is, however, limited by Fusarium dry rot, a potato disease caused by different Fusarium spp.
Controlling these fungi has been problematic for the past decades, due to the resistance developed to the available fungicides.
This study was carried out to investigate the antifungal efficacy of moringa leaf extracts (MLEs) against Fusarium dry rot of potato.
Moringa leaf extracts were used curatively by pre-infecting tubers of two potato cultivars (Mondial and Valor) with the pathogen, Fusarium oxysporum, and, thereafter, treating tubers with various MLEs obtained with four solvents (acetone, ethyl acetate, methanol and water) and at different concentrations (30, 50, 80%). Further, a preventive study was carried out by pre-treating potato tubers with MLEs, before inoculation with F. oxysporum. The MLEs were found to be more effective as a preventive measure, as acetone-MLE (A-MLE) and methanolic-MLE (M-MLE) were able to prevent disease development, while water-MLE was able to delay disease development by at least one week in comparison with the control.
The MLEs were found to be less effective when used as a curative method.
Tubers treated with A-MLE had the smallest average lesion diameter (3.67 and 3.44 mm for Valor and Mondial, respectively). Tubers of both cultivars treated with ethyl acetate-MLE were prone to secondary infections by bacterial soft rot.
The ability of MLE to delay and slow disease development is an indication of its antifungal potential.
MLEs can be used in organic farming, reduce reliance on synthetic fungicides, and chemical pollution, and subsequently, lead to a greener environment.
Potato production is, however, limited by Fusarium dry rot, a potato disease caused by different Fusarium spp.
Controlling these fungi has been problematic for the past decades, due to the resistance developed to the available fungicides.
This study was carried out to investigate the antifungal efficacy of moringa leaf extracts (MLEs) against Fusarium dry rot of potato.
Moringa leaf extracts were used curatively by pre-infecting tubers of two potato cultivars (Mondial and Valor) with the pathogen, Fusarium oxysporum, and, thereafter, treating tubers with various MLEs obtained with four solvents (acetone, ethyl acetate, methanol and water) and at different concentrations (30, 50, 80%). Further, a preventive study was carried out by pre-treating potato tubers with MLEs, before inoculation with F. oxysporum. The MLEs were found to be more effective as a preventive measure, as acetone-MLE (A-MLE) and methanolic-MLE (M-MLE) were able to prevent disease development, while water-MLE was able to delay disease development by at least one week in comparison with the control.
The MLEs were found to be less effective when used as a curative method.
Tubers treated with A-MLE had the smallest average lesion diameter (3.67 and 3.44 mm for Valor and Mondial, respectively). Tubers of both cultivars treated with ethyl acetate-MLE were prone to secondary infections by bacterial soft rot.
The ability of MLE to delay and slow disease development is an indication of its antifungal potential.
MLEs can be used in organic farming, reduce reliance on synthetic fungicides, and chemical pollution, and subsequently, lead to a greener environment.
Authors
C.N. Mncube, I. Bertling, K.S. Yobo
Keywords
fungal inhibition, phytochemicals, phenolics, potato defence mechanism, Valor, Mondial, F. oxysporum
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