ABSTRACT

The study was carried out to investigate the antimicrobial activity of magnesium oxide (MgO) nanoparticles synthesized using Moringa leaf extract and two precursor salts (MgO and MgNO3) against fungal pathogen isolated from diseased cassava. Magnesium oxide nanoparticles was synthesized using Moringa plant extract and the phytosynthesized nanoparticles was characterised using UV- VIS spectrophotometer. In order to investigate the antimicrobial activities of the nanoparticles, diseased cassava plants was obtained from Ovia North-East Local Government in Edo State and fungal pathogen was isolated from the leaves of the diseased plant. The isolated fungus was identified as Phoma sp. The antifungal activities of magnesium oxide nanoparticles synthesized with Moringa plant extract using two different precursor salts (Magnesium oxide and Magnesium nitrate) on the test pathogen were investigated using the food poisoning method for fungus. This was carried out by growing the test pathogen on potato dextrose agar (PDA) supplemented with different concentrations (0%, 50%, 100%), each of magnesium oxide nanoparticles, Moringa plant extract, magnesium oxide and magnesium nitrate precursor salts solutions. The results obtained from this study indicated that magnesium oxide nanoparticles synthesized with magnesium oxide precursor salt in 50% and 0% (control) concentration were effective in inhibiting the growth of the test pathogen. In addition, it was further investigated that the synergy between magnesium oxide and magnesium nitrate precursor salts in the following volume of 2.5ml of MgO and 7.5ml of MgNO3 inhibited the growth of the pathogen (Phoma sp.). The findings from this study suggested that magnesium oxide nanoparticles has potential in the control of phytopathogens. Further studies should be carried out to investigate the use of the test nanoparticles in the management of plant pathogens in vivo.