ABSTRACT

This study elucidates the efficacy of plant essential oils on the control of yam rot causing fungi Aspergillus niger. The experiment was conducted at the laboratories of both Soil and Crop Science Department, Faculty of Agriculture University of Benin, Edo State, Benin City. The specific objectives were to isolate and identify the fungi responsible for causing post-harvest rot of yam tubers, to evaluate the efficacy of plant essential oil on the control of pathogen (Aspergillus niger) responsible for yam rot and to determine the difference in the effectiveness between: Allium sativum, Citrus limon and Simmondsia chinensis to fungi diseases of yam (Dioscorea. Spp). Agar well-point inoculation method was employed to administer plant essential oil as treatment at 0.01%, 0.1% and 1% concentration inside the well created by cork-borer with the help of micro-pipette. 20ml of molten prepared Potato Dextrose Agar (PDA) were poured into the Petri dishes. The Petri dishes were incubated at room temperature for an interval of 48 – 96hours for fungal growth and spore formation. The study showed that none of the oils are superior to the other in terms of concentration and effectiveness but jojoba oil showed higher mean value and is more effective at 0.01% concentration it is therefore recommended to use jojoba oil at 0.01% concentration for the control of Aspergillus niger in post-harvest or stored yam as an alternative to synthetic fungicides in Nigeria.