Annals. Food Science and Technology 2013 Available on-line at www.afst.valahia.ro Volume 14, Issue 2, 2013 330 ANTIFUNGAL POTENCIES OF LEAF EXTRACTS OF Glyphaea brevis AND Spondias mombin ON FUNGI IMPLICATED IN DRY ROT OF POSTHARVEST YAM Chima Ngumah*, Jude Ogbulie, Justina Orji Federal University of Technology Owerri, Department of Microbiology, P.M.B 1526 Owerri, Nigeria. *E-mail: ccngumah@yahoo.com Abstract The sensitivities of selected fungal pathogens implicated in dry rot of postharvest yam to leaf extracts of Glyphaea brevis and Spondias mombin were evaluated. The cup-plate agar method was used to estimate the sensitivities of the ethanol leaf extracts of Glyphaea brevis and Spondias mombin on Aspergillus niger, Fusarium oxysporum, and Penicillium oxalicum. All the cold ethanol leaf extracts showed potencies on all test pathogens, while hot ethanol extract of Spondias mombin showed no potency on Penicillium oxalicum. The lowest minimum inhibitory concentration obtained for Spondias mombin and Glyphaea brevis were 1 x 10 -4 mg/mL of cold extract on Aspergillus niger, and 4.0 x 10 -4 mg/mL of hot extract on Aspergillus niger, respectiviely. The lowest potencies were seen on Fusarium oxysporum for both leaf extracts. Phytochemical analysis of the leaves revealed the presence of saponins and glycosides in Glyphaea brevis; and saponins, tannins, alkaloids, flavonoids, and phenols in Spondias mombin. This study reveals the antifungal properties of the leaf extracts of Glyphaea brevis and Spondias mombin, which are commonly used in the construction of traditional yam barns in Mbaise (south-east Nigeria). The results of this study justify the exploitation of leaf extracts of Glyphaea brevis and Spondias mombin for use as an appropriate bio-alternative to existing chemical methods in the preservation of postharvest yam. Keywords: sensitivity, fungal pathogen, dry rot, post-harvest yam, leaf extract, Glyphaea brevis, Spondias mombin. Submitted: 11.07.2013 Reviewed: 6.08.2013 Accepted: 30.08.2013 1. INTRODUCTION Yams are monocotyledonous plants that belong to the genus Dioscorea in the family Dioscoreaceae (IITA, 2009). Yams serve as staple food for millions of inhabitants of the tropics and sub-tropics (Ezeike, 1995). The statistics for production are inconsistent; however the International Institute of Tropical Agriculture (IITA) reported that 52 million tons of yams were produced worldwide in 2007 (IITA, 2009). Ninety six percent of this came from Africa; the main producers being Nigeria with 71% of world production, Côte D’Ivoire 8.1%, Benin 4.3% and Ghana 3.5% (FAO, 2004). According to Okigbo (2003), in Nigeria there is an estimated loss of about $0.13m per annum (which is about 10% of the total value of yam produced per annum) in storage. These losses are attributed by many researchers to rot caused by bacteria, fungi and nematodes (Amusa et al., 2003). The storage diseases of yam can be categorized into 3 based on the symptoms and the causal agents: dry rot, soft rot, and wet rot (Amusa and Baiyewu, 1999). Dry rot alone accounts for over 80% of postharvest yam loss in storage (Coyne et al., 2006). Dry rot of yam is caused by fungal pathogens, of which species of Penicillium, Aspergillus, and Fusarium are of high pathogenecity (Amusa and Baiyewu, 1999). In Nigeria comprehensive treatment of post harvest yam before or during storage is not very common. This is basically due to insufficiency or the outright absence of appropriate logistics, infrastructure, funds, and skill (Amadioha and Obi, 1999). In south-east Nigeria, traditional yam barns where postharvest yams are stored and preserved till the next planting season are usually erected using live rooted growing shrubs as the main vertical framework. Yam tubers are then tied upon these shrubs using natural plant–based fibres (usually from oil palm and raffia palm leaf fronds) (Fiagan, 1995). There is a traditional belief by local farmers that yams tied to these live shrubs are much better