ANTIFUNGAL ACTIVITIES OF SOME PLANTS EXTRACTS COMPARED TO GEOPHAGY CLAY ON Dioscorea Rotundata

ABSTRACT

Yam is an economic crop grown purposely for its tuber, it constitute an important part of the diet in many African countries. Hence this study evaluated the antifungal activities of some plants extracts compared to geophagy clay on Dioscorea rotundata (white yam) rot pathogens. Samples were obtained from local market in Benin City, Edo State Nigeria. The diseased yam tubers were packaged in a sterile polyyethene bags and transported to the laboratory for mycological analysis. Standard Microbiological Techniques was used to determine the microbial contents in the samples. The fungi isolated and characterized from the white yam rot were Aspergillus niger, Penicillium oxalicum and Botryodiplodia theobromae. The highest occurring fungal isolate was Aspergillus niger (50%), while the least occurring was Penicillium oxalicum (19.23%). The effect of the mycelia extension growth rate of the fungi (Aspergillus niger) ranged from 10±0.0 on day 0 to 85.0±0.0 for combination of Ocimum gratissimum plus Vernonia amagdalina, and Ocimum sanctum. However geophagy clay ranged from 10±0.0 to 80.0±0.0. The results for the mycelia extension growth rate of Botryodiplodia theobromae and Penicillium oxalicum from day 0 to day 6 also ranged 10±0.0 on day 0 to 85.0±0.0. The result revealed that both plant extracts and geophagy clay could be an alternative to fungicides for controlling plant pathogens. The use of these natural products will therefore, reduce over dependence on the use of synthetic chemicals by farmers in controlling yam fungal pathogen as well as reducing cost of management.