Control of Green Rot Fungus of <i>Arachis hypogaea </i>L. in Orage Using Plant Extracts

Abstract

Abstract. The antifungal activity of the ethanolic and aqueous fruit extracts of Zingiber officinale, Tetrapleura tetraptera, Garcinia kola and Cola nitida on the green rot fungus (Penicillium sp.) isolated from infected groundnut (Arachis hypogaea) seeds in storage were investigated in vitro. Various concentrations of the aqueous and ethanolic fruit extract ranging from 5g/100ml, 10g/100ml, and 15g/100ml were separately added to Potato Dextrose Agar (PDA) media. The fungus was inoculated into the media and incubated for seven days. Results of the in vitro studies showed that the ethanolic extracts had a significant inhibitory effect (p<0.05) on the radial growth of Penicillium sp. at all levels of concentration tested. Complete inhibition of the fungus was at 15g/100ml of ethanolic extracts of Garcinia kola and Tetrapleura tetraptera. The aqueous extracts showed less inhibitory effect as compared to the ethanolic extracts. The effective inhibition of ethanolic extracts as compared to the aqueous extracts may be attributed to the efficiency of the extraction solvent on the phytochemical content of the plant extracts. The application of botanical extracts for disease management could be less expensive, easily available, non-polluting and ecofriendly. The ethanolic fruit extracts of Garcinia kola and Tetrapleura tetraptera at the higher concentrations can be produced in large quantities and used as spray in controlling the green rot fungus of Arachis hypogaea in storage.