ASSESSMENT OF ANTIFUNGAL ACTIVITY OF Azadirachta indica AND SILVER NANOPARTICLES

ABSTRACT

Plants diseases are caused by bacteria, fungi or viruses and can range in severity from mild leaf or fruit damage to death. This study was aimed at determining the antifungal activity of ethanolic and aqueous extract of Azadirachta indica leaves alone and in combination with silver nanoparticles against some selected phytopathogenic fungi. Three fungi were isolated from agricultural soil obtained from different locations. Antifungal activities of Azadirachta indica aqueous and ethanolic extract and in combination with silver nanoparticle were performed using the food poisoning method. Penicillium chrysogenum, Aspergillus niger and Aspergillus tamarii used in this study were isolated from the agricultural soil. From the results A. indica aqueous extracts only showed significant inhibition against P. chrysogenum with radial growth inhibition ranging from 40.33±5.85mm (75% conc.) to 52.83±7.67mm (50% conc.) while no marked inhibition was observed by the ethanolic extracts against any of the test fungi. Silver nanoparticles showed significant inhibition against P. chrysogenum with radial growth inhibition ranging from 24.17±2.09mm (25% conc.) to 50.83±5.59mm (100% conc.) while no marked inhibition observed against any of the test fungi. Silver nanoparticles combined with either aqueous or ethanolic extract of A. indica showed no inhibitory activity against A. niger and A. tamarii, but showed remarkable inhibition against P. chrysogenum with radial growth inhibition ranging from 23.50±2.78mm (25% conc.) to 50.83±0.83mm (100% conc.) when combined with aqueous extract and 47.17±12.85mm (50% conc.) to 59.83±4.78mm (100% conc.) when combined with ethanolic extract. Silver nanoparticles alone or in combination with extracts of A. indica have great potentials for the combat of several plant diseases caused by P. chrysogenum. These substances may also be screened for antifungal activity against plant pathogens that have similar characteristics with Penicillium chrysogenum. Also, silver nanoparticles should be tested on other plant pathogens; even its combination with other plant extracts should be tested.