Aflatoxigenic Contamination of Groundnut (Arachis hypogaea L.) Seed and its Management Using Seed Extract of Moringa oleifera Lam. and Rhizome of Zingiber officinale Rosc. in Katsina State, Nigeria

Studies on aflatoxin seed contamination of groundnut (Arachis hypogaea) in storage and its management using seed extract of Moringa oleifera and rhizome of Zingiber officinale was carried out on diseased seeds collected from Dutsin-Ma, Kurfi and Safana Local Government Areas of Katsina State, Nigeria between March and July, 2019. Aspergilus niger, A. flavus, A. ochraceus, A. tamari, A. parasitica, Rhizotonia spp, mucor spp and F. oxysporum were isolated. A. niger was the most frequently occurring pathogen in all the locations in March, 2019 with a range of 9 in Kurfi to 13 Dutsin-Ma and between 14 in Kurfi and 22 in Dutsin-Ma in July while the least was Mucor with a range of 3 in Dutsin-Ma and 6 in Kurfi both in July. Pathogenicity test conducted illicit rot in the healthy groundnut seeds. A. niger and A. flavus which were the most virulent pathogenic fungi responsible for aflatoxin contamination in groundnut seeds were controlled with the two extracts. Z. officinale was found to be more effective in the control of A. niger than M. oleifera at 40 g/L with inhibition of 60.32 % and at 120 g/L with inhibition of 87.33 % compared to M. oleifera which inhibited A. niger mycelial at 40 g/L by 59.79 % and at 120 g/L by 73.53 %. M. oleifera however, proved more efficacious in the management of A. flavus than Z. oficinale at 40 g/L and 80 g/L with percentage growth inhibition of 60.79 % and 62.47 %, respectively compared to a lower inhibition of 60.52 % and 60.94 % at 40 g/L and 80 g/L of Z. officinale, respectively. In both cases, the two extracts proved more effective on A. niger than A. flavus. It is therefore, recommended that extracts of Z. officinale and M. oleifera at different concentrations can be used to effectively manage rot pathogens of groundnut seeds in storage by farmers.