Microorganisms associated with rot of minisetts of white yam (Dioscorea rotundata Poir)

Abstract

Two cultivars of white yam (Pona and Dente) minisetts were used in a study to identibr microorganisms causing rot in white yam. Laboratory analysis showed presence of Aspergillusflavus, A. niger, A. ochraceus, Aspergillus sp., A. tamari, C/adosporium sp. Corynebacterium sp. Fusarium sp. Penicillium sp. Rhizopus stolonifer and Trichoderma sp. Pona minisetts were more heavily infected and so suffered more severe rot than Dente minisetts. Among the pathogenic isolates, Sclerotium. rolfsii caused the most severe rot in both Pona and Dente, followed by A. niger and Fusarium sp. while the least were R. stolontfer, Trichoderma sp. and Corynebacterium sp. Use of disinfectants were suggested as pre-planting treatment to control the pathogens