Accepted 26th October, 2020.
This study was carried out to investigate the effects of plant extracts:Monodora myristica and Allium sativum and synthetic fungicide on seed borne fungal pathogens of Egusi melon (Citrillus colocynthis). Melon seeds were incubated for seed health test using blotter paper method. A total of ten seeds were plated in each 9cm Petri dish. The anti-fungal effects of methanol extracts of test plants as well as synthetic fungicide were studied in an in-vitro experiment against the seed borne fungal pathogen at 5%, 15% and 25% concentrations. The design used was a Factorial in a Completely Randomized Design with three replications. Means were separated using Least Significant Difference (LSD) at 5% Probability level. The result showed that up to 84% germination was obtained in the seed health/ viability tests of Egusi melon seeds. The result of isolation and identification of fungi pathogen from the different components of melon seeds showed that there were more incidence of fungi pathogen in the whole Melon seeds followed by the germ cell while the least was that of the shell. The only fungi pathogen identified was Aspergillus flavus which was common in all the components of melon seeds incubated and assessed. The results also showed that the plant extracts and synthetic fungicides inhibited the growth of the fungus in culture. The effect of synthetic fungicide (75.00%) and that of Monodora myristica extract (75.00%) were statistically same in days 2 and 3 but the effect of the synthetic fungicide (75.00%) was significantly higher (p>0.05) than Monodora myristicaextract on day 4 and 5 where Monodora myristica had 64.42% and 63.02% respectively The result also showed that the higher the concentration of plant extracts, the higher the percentage growth inhibition of the fungus. The result as well revealed that there was a depreciation in the effects of plant extracts on radial growth inhibition of test fungus with time. From the result of this investigation, it is recommend that plant extracts used in this research could be an alternative to synthetic fungicides since they showed similar effectiveness in inhibiting growth of fungus responsible for spoilage of melon seeds.
Keywords: Melon seeds, component assessment, fungi organisms, plant extracts, synthetic fungicide.