OIL PALM PRESSED FIBRE AS A NATURAL ANTIFUNGAL AGENT FOR WOUNDED DIOSCOREA ROTUNDATA

Abstract

Yam (Dioscorea rotundata Poir) is a staple food in Nigeria and Africa, providing about 200cal per capita. Its production is limited by many factors.  Of utmost concern, is the various handling wounds on the yam tubers that create entry points for pathogenic rot fungi. This study intended to use oil palm – pressed fibre (OPPF) as a biocide to treat the wounded tubers. The completely randomised design was adopted and treatments replicate to obtain mean percentages of weight loss. There was no fungal contamination recorded and no weight loss of the tubers. However, from days 8 and >8, six fungal pathogens were isolated and these included; Aspergillus, spp, Penicillium spp, Botrydioplodia theobromae, Fusarium moniliforme, Sclerotium rolfsii, and Rhizopus stolonifer. Similarly, the untreated (control) wounded samples also harboured same six fungal species of those recorded above, few days after incubation and weight losses of 2.09%, 3.70%, 4.19%, 6.66%, 11.97%, and 13.9% were recorded from the untreated samples. The presence of the fungal rot pathogens on the various wounded surfaces affected the viability of the tubers and caused weight losses. Highest % weight losses of 64.69% was recorded for B. theobromae, Penicillium spp and Sclerotium rolfsii, while lowest weight loss was recorded for Aspergillus spp at 45.5% and 49.87 on days 20 and >20 respectively.  The results showed that treatment with OPPF controlled the fungal contamination on the wounded surfaces, especially on short term.  Based on the findings of this study, we recommend OPPF as a biocide to treat various handling wounds of yam tubers and the subsequent preservation from pathogenic fungal rots