ABSTRACT

Microorganism associated with white spoilt yam (Dioscorea rotundata) were studied. Fungi and bacteria were isolated from five spoilt white yam tubers and identified following characterization and test were conducted to determine the pathogens among the isolates. Results obtained, shows the presence of some fungi species including Aspergillus, Fusarium Rhizopus , Penicilum Botryodiplodia, Mucor and Yeast and bacteria including Staphylococcus, Escherichia , Proteus, Bacillus, Streptococcus, Pseudomonas and Erwnia species. In the fungal isolate, Aspergillus Botryodiplodia and yeast had 100% occurrence in Fusarium, Rhizopus and Penicillum had 80% 60% and 60% respectively. Staphylococuss , Pseudomonas and Bacillus species also had 100% occurrences whereas Proteus and Erwinia species had 80% occurrence each. E.coli reveals 40% occurrence and streptococcus 20%.Only that of the fungi species , Fusarium , Aspergillus and Botryodiplodia were pathogenic and caused rot of length 21.7mm,17.3mm and 24.7mm respectively. Penicillum caused minor rot of 12,7mm and was considered to be slightly pathogenic while Rhizopus , yeast and Mucor did not cause rot. Erwinia species was the only bacteria that caused rot (pathogen) while the other isolates were non pathogenic. The high occurrence level of the pathogenic fungi in the rot yams were considered to be of concern, and recommendations were made on control measures to be taken.