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(a) Map of Nigeria showing geopolitical zones where yam is produced and consumed. Source: Okorie et al. (2013). (b) Map of Nigeria showing states where the study was carried out. Source: Ekpo et al. (2013). (c) Schematic representation of the survey method. (d) Areas in which survey was carried out in south‐east (Ebonyi State) region of Nigeria. (e) Areas in which survey was carried out in south‐west (Osun State) region of Nigeria.
