Evaluation of Moringa oleifera Leaves and Stems Bark crude extract for controlling potato wilt caused by Fusarium species.

Abstract Fungal infections cause significant losses in many economic crops. Chemical control may be available to effectively and extensively reduce the effects of the most fungal disease but field application of these chemical fungicides may present a danger to the health of humans, animals, and the environment. This study was aimed to assess the antifungal activities of crude extracts of Moringa oleifera Lam. stems bark and leaves against Fusarium species. Four crude extracts (acetone and ethanol extract of stem bark and leaf) were tested for their effect on 10 Fusarium isolates at three different concentrations (40 mg/ml, 60 mg/ml, and 80 mg/ml) and at 100µg/ml (0.1 mg/ml) of positive control using agar-well diffusion method. All the quantitative data generated were analyzed by using SPSS statistical software for window version 20. At 40 mg/ml, concentration, zones of inhibition were recorded by; acetone crude extract of leaf: 11.00±1.00, 12.000±1.00 mm, at 60 mg/ml; 12.33±0.58, 15.33±0.58 mm, and at 80 mg/ml; 16.33±1.53 mm and acetone crude extract of stem bark: at 40 mg/ml; 9.00±1.00 mm, 6.67±1.155, at 60 mg/ml; 12.00±1.00, 14.67±0.58 and at 80 mg/ml; 15.67±1.53mm respectively; and by ethanol crude extract of leaf: at 40 mg/ml; 9.00±1.00,11.33±1.56 mm, at 60 mg/ml; 12.33±0.58 mm and at 80 mg/ml;16.00±1.00 mm and stem bark: at 40 mg/ml; 6.67±1.15 mm, 11.00±1.00, at 60 mg/ml;11.33±1.56, 12.00±1.00 mm, and 14.67±0.58 mm respectively at the respective concentration. From the recorded effect, acetone crude extract of the leaf at a concentration of 60 mg/ml and 80 mg/ml (p=0.073, and 0.493 respectively), and acetone crude extract of stem bark at a concentration of 80 mg/ml (p=0.201) and ethanol crude extract of the leaf at a concentration of 80 mg/ml (0.143) had non-significant growth effect on Fusarium species compared with the positive control (P> 0.05). Ethanol crude extract of stem bark at all the different concentrations had significant differences compared with the positive control (p=0.000, 0.000, 0.00, 0.00, and 0.012 respectively). Ethanol and2 acetone extract of leaves have a minimum inhibitory concentration of 12.5 mg/ml and 6.25 mg/ml respectively and in the case of bark 25mg/ml and 12.5mg/ml respectively. The findings of this study revealed that each plant part possesses an antifungal effect on tested fungal strains varying with the type of solvent used and concentration, which might validate its traditional uses in treating potato wilts. Furthermore, extraction using the different solvent systems for each part of the plant may be useful to get more effective extracts.