Sphenostylis Stenocarpa (Ex

Article Sphenostylis stenocarpa (ex. A. Rich.) Harms., a Fading Genetic Resource in a Changing Climate: Prerequisite for Conservation and Sustainability

Catherine Veronica Nnamani 1,*, Sunday Adesola Ajayi 2, Happiness Ogba Oselebe 3, Christopher John Atkinson 4, Anastasia Ngozi Igboabuchi 5 and Eucharia Chizoba Ezigbo 1

1 Plant Taxonomy/Biosystematics and Conservation Biology Research Lab, Department of Applied Biology, Ebonyi State University, Abakaliki 840001, Nigeria; [email protected] 2 Department of Crop Production and Protection, Obafemi Awolowo University, Ile-Ife 220282, Nigeria; [email protected] 3 Department of Crop Production & Landscape Management, Ebonyi State University, Abakaliki 840001, Nigeria; [email protected] 4 Natural Resources Institute, University of Greenwich, Medway Campus, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK; [email protected] 5 Department of Biology, Nwafor Orizu College of Education, Nsugbe 240001, Nigeria; [email protected] * Correspondence: [email protected] or [email protected]; Tel.: +234-803-778-6269

Received: 1 May 2017; Accepted: 7 July 2017; Published: 12 July 2017

Abstract: The southeastern part of Nigeria is one of the major hotspots of useful plant genetic resources. These endemic species are associated with a rich indigenous knowledge and cultural diversity in relation to their use and conservation. Sphenostylis stenocarpa (ex. A. Rich.) Harms., (African Yam Bean (AYB)), is one such crop within the family of Fabaceae. Its nutritional and eco-friendly characteristics have value in ameliorating malnutrition, hidden hunger and environmental degradation inherent in resource-poor rural and semi-rural communities throughout Africa. However, lack of information from the custodians of this crop is limiting its sustainable development. Therefore, ethnobotanical surveys on the diversity, uses, and constraints limiting the cultivation and use of the crop in southeastern Nigeria were carried out. Five-hundred respondents were randomly selected and data collected through oral interviews and focused group discussion (FGD). Semi-structured questionnaires (SSQ) were also used to elicit information from a spectrum of AYB users comprising community leaders, farmers, market women and consumers in five States. Results showed that the majority of the respondents lacked formal education and were of the age group of 40–50 years, while the female gender dominated with limited access to land and extension officers. Seed coat colour largely determined utilization. Long cooking time, requirement for staking materials, aging of farmers and low market demand were among the major constraints limiting further cultivation and utilization of AYB. In-situ conservation was by hanging dried fruits by the fireside, beside the house, storing in earthenware, calabash gourds, cans and bottles. It is concluded that there is urgent need to scale up conservation through robust linkages between contemporary scientific domains and indigenous peoples in order to harness and incorporate the rich indigenous knowledge in local communities for enhanced scientific knowledge, biodiversity conservation and its sustainable utilization for food security.

Keywords: African Yam Bean; indigenous knowledge; genetic erosion; conservation; food security; Nigeria

Plants 2017, 6, 30; doi:10.3390/plants6030030 www.mdpi.com/journal/plants Plants 2017, 6, 30 2 of 16

1. Introduction The dependence of humans on plants for their livelihood is connected to the development of specific knowledge on plant value, use, management, and conservation [1,2]. The Convention on Biological Diversity [3] stresses the need to respect, preserve and maintain the knowledge, innovation and practices of indigenous communities relevant for the conservation and sustainable use of biological diversity. The direct relationship between biological and cultural diversity shows that the maintenance of the former can help preserve the latter while increasing the capacity of human to adapt to change [4]. Just as biological diversity underpins the resilience of natural systems, so does cultural diversity [5] and this increases the resilience of social systems. Indigenous people are the major custodians of knowledge on endemic biodiversity because of the long and intertwined associations between their survival and the utilization of plant species for food, traditional medicine and a diversity of other uses. Harnessing this information can strengthen research in the contemporary scientific domain on AYB. Ethnobotanical information is essential for assessing both the diversity and the adaptation characteristics of useful plants and this helps in understanding a plants’ micro-niches and the stability of environmental conditions. It is also useful in the collection of the genetic resources of these cultivated and economically important species in order to capture variation within these species [6]. Ethnobotany serves as an untapped reservoir of knowledge, especially with respect to the interactions between plants, people, folk taxonomy, plant mythology, ethnomedicine, food security, environment restoration and germplasm conservation. Unfortunately, the indigenous knowledge systems are fast eroding due to several anthropogenic factors such as colonialism, commercialization, globalization, modernization, breakdown of the African traditional family structures, developmentally-induced human displacements and urban migration, all of which have induced a lack of interest from the younger generation [7]. Nigeria is one of the hotspots for plants genetic resources and cultural diversity [8,9]. Hence, the various geographical zones provide a platform for the study of perceptions of the custodians of indigenous knowledge about plant genetic resources. Sphenostylis stenocarpa (ex. A. Rich.) Harms, commonly known as African yam bean (AYB), is a neglected and underutilized leguminous plant genetic resource of the subfamily Faboideae, family Fabaceae and a small genus represented by only seven species [10]. It is a perennial climbing species whose morphotypes may also be prostrate, or erect and about 1–3 m in height. Its leaves are trifoliate, 2.7 to 13 cm long and 0.2 to 5.5 cm broad. The inflorescence is a raceme that exhibits an acropetal mode of floral maturation with pink flowers blended with purple, with the slightly twisted backward characteristic of the Fabaceae [11]. The center of diversity of AYB is the northeast tropical Africa (Chad and Ethiopia), east tropical Africa (Kenya, Tanzania and Uganda), west-central tropical Africa (Burundi, Central African Republic and Zaire), West Africa (Cote d’Ivoire, Ghana, Guinea, Mali, Niger, Nigeria and Togo) and south tropical Africa (Angola, Malawi, Zambia and Zimbabwe) [12,13]. African yam bean is cultivated for its edible tubers and for its seeds which have high nutritional values. The amino acid (lysine and methionine) has been reported to be higher than those of pigeon pea, cowpea, and bambara groundnut [14]. Omeire [15], noted that the amino acid (g/100 g) profile of African yam bean comprised lysine (6.12), histidine (3.10), arginine (6.47), aspartic acid (9.12), glycine (3.90), alanine (4.05), valine (4.96), and phenylalanine (5.05). Its lysine and methionine contents were equal to or better than those of soybean protein [16], while equally comparable with whole chicken eggs and can meet the daily human requirement for protein [17]. Its protein profile compares favourably with that of other African root crops such as yams, sweet potatoes and has almost ten times the protein value of cassava tubers, while the essential proteins in AYB are similar to those in soybeans [18]. In spite of the extensive information on the morphological characterization for yield [11,13,19,20], biochemical profiles [21–23], physiological seed quality [24], and genetic diversity [25–28] of AYB, there is dearth of information on ethnobotanical knowledge on this highly-promising plant genetic resource. Therefore, the aim of this study was to carry out an ethnobotanical survey to develop a hub of indigenous knowledge on AYB and to complement this with the existing wealth of scientific knowledge. Plants 2017, 6, 30 3 of 17

Therefore, the aim of this study was to carry out an ethnobotanical survey to develop a hub of indigenous knowledge on AYB and to complement this with the existing wealth of scientific Plants 2017, 6, 30 3 of 16 knowledge. This study sought to systematically bridge the knowledge gap by (a) identifying the socio-economic characteristics of respondents involved in AYB activities in five states of Thissoutheastern study sought Nigeria; to systematically (b) determine bridgethe uses the of knowledge AYB and phenotypic gap by (a) identifying variability thein seed socio-economic coat colour characteristicsand (c) identify of those respondents constraints involved limiting in the AYB use activities and production in five states systems of southeastern of AYB in southeastern Nigeria; (b) determineNigeria. the uses of AYB and phenotypic variability in seed coat colour and (c) identify those constraints limiting the use and production systems of AYB in southeastern Nigeria. 2. Results and Discussion 2. Results and Discussion 2.1. Social Background of Respondents 2.1. Social Background of Respondents Two-hundred-fifty-six (51.2%) of the 500 respondents were 50 years old and were involved eitherTwo-hundred-fifty-six in the cultivation and/or (51.2%) sales of of the AYB 500 respondentsproducts as a were source 50 yearsof food old and and income. were involved Two percent either in(2%), the 2.5% cultivation and 6.8% and/or of salesthe respondents of AYB products were as wi athin source the of age food limits and income.of <19, Two20–29 percent and 30–39, (2%), 2.5%respectively and 6.8% (Figure of the 1). respondents With respect were to withinthe level the of age education limits of 37.2% <19, 20–29 had andprimary 30–39, school-leaving respectively (Figurecertificates1). With while respect 34% tohad the no level formal of education education 37.2% (Figure had primary2). These school-leaving results are similar certificates to those while of 34%Mathibela had noet formalal. [29], education who reported (Figure that2). These64% of results traditiona are similarl healers, to thosewho ofwere Mathibela the custodians et al. [ 29 of], whoindigenous reported knowledge that 64% ofin traditional medicinal healers,plants in who the were Blouberg the custodians area of South of indigenous Africa, had knowledge no formal in medicinaleducation, plants while in 32% the Blouberghad primary area ofschool South certific Africa,ates, had nowith formal only education, 4% having while attended 32% had secondary primary schoolschool. certificates,The implications with only of these 4% having results attended are that secondarypotentially school.valuable The information implications on of these these plants results is arein the that hands potentially of the valuableolder generati informationon who on by these virtue plants of their is in theage hands have ofa diminishing the older generation involvement who byin virtueAYB cultivation. of their age Their have educational a diminishing levels involvement may not limit in AYB them cultivation. from documenting Their educational this knowledge levels may for notposterity limit themand for from the documenting benefit of people this knowledgeoutside the forlocal posterity community. and forWith the the benefit very oflow people involvement outside theof younger local community. people in farming With the in very general low and involvement specifically of in younger the cultivation people inof farmingAYB, it is in reasonable general and to specificallyassume that in there the cultivation will be a progressive of AYB, it is decline reasonable and toeventually assume that a substantial there will beloss a progressiveof indigenous decline AYB andcultural eventually knowledge a substantial and genetic loss diversity of indigenous over tempor AYB culturalal and knowledgespatial scales. and This genetic is in diversity line with over the temporalopinion of and Dania-Ogbe spatial scales. et Thisal. is[30], in linewho with suggested the opinion that of the Dania-Ogbe most significant et al. [30 ],global who suggestedthreat to thatbiodiversity the most significantis the erosion global of threat ethnobotanical to biodiversity knowledge is the erosion caused of ethnobotanical by the demise knowledge of the causedaging bycustodians the demise of this of theknowledge. aging custodians This situation of this is knowledge.worsened by This the situationweak linkages is worsened between by domain the weak of linkagesscience and between indigenous domain knowledge of science [31]. and indigenous knowledge [31].

300 256 250 186 200 150 100 34 50 10 14 0

Figure 1. Age range of respondents from the ﬁvefive states of southeastern, Nigeria.Nigeria. Plants 2017, 6, 30 4 of 16 Plants 2017, 6, 30 4 of 17

Plants 2017, 6, 30 4 of 17

34% 37% First Sch. Cert WAEC

34% BSc 0% 37% First Sch. Cert 9% MSC 4% 16% WAEC PhD BSc 0% 9% No Edu 4% 16% MSC PhD

Figure 2. Educational background status of respondents fromNo the Edu five states of South eastern, Nigeria. Figure 2. Educational background status of respondents from the ﬁve states of South eastern, Nigeria. 2.2. Gender and Marital Status of Respondents 2.2. Gender and Marital Status of Respondents FigureA gender 2. Educational disaggregation background of statusthe respondents of respondents in fr thisom thestudy five showedstates of Souththat theeastern, ratio Nigeria. of female to Amale gender involvement disaggregation in the cultivation of the respondents of and transactions in this study of AYB showed was approximately that the ratio of2:1, female 61.6% toto male 2.2. Gender and Marital Status of Respondents involvement34.8%. A inhigher the proportion cultivation (74.3%) of and of transactions the respondents of AYBinvolved was in approximately AYB cultivation 2:1, and 61.6% processing to 34.8%. A higherwereA genderproportionmarried disaggregation women (74.3%) while of of the the the proportions respondentsrespondents of in involvedsi thisngle studyindividuals, in showed AYB cultivationwidows that the and ratio and widowers of processingfemale were, to were marriedmalerespectively, involvement women while0.7%, in thethe19.2%, proportionscultivation and 5.8% of of and(Figure single transactions individuals,3). The ofdominance AYB widows was ofapproximately and the widowers female gender2:1, were, 61.6% in respectively, AYBto 0.7%,34.8%.cultivation 19.2%, A higher and and proportion 5.8%indigenous (Figure (74.3%) knowledge3). Theof the is dominance respon not uniquedents to ofinvolved Nigeria, the female in as AYB similar gender cultivation findings in AYB andwere processing cultivation reported for and werethe marriedBaka tribe women in Cameroon while the[32] proportionsand the Masai of insi ngleKenya individuals, [33] for knowledge widows associatedand widowers with thewere, sales indigenous knowledge is not unique to Nigeria, as similar ﬁndings were reported for the Baka tribe in respectively,of indigenous 0.7%, plants. 19.2%, The andresults 5.8% are (Figurealso in agreement3). The dominance with the report of the by femaleYahaya gender[34] who in reported AYB Cameroon [32] and the Masai in Kenya [33] for knowledge associated with the sales of indigenous cultivationthat 77.9% and of indigenousmarried smallholder knowledge farmers is not unique compared to Nigeria, to 22.1% as singlesimilar women findings were were involved reported in for rice plants.thefarming Baka The tribe resultsin inAwe Cameroonare Local also Government [32] inagreement and the AreaMasai with of in NasarawaKenya the report [33] Statefor by knowledge Yahayain Nigeria.[ associated34 The] who high reported with proportion the sales that of 77.9% of marriedof femaleindigenous smallholdergender plants. was viewedThe farmers results by one comparedare ofalso the in respondents agreement to 22.1% singlewith as follows: the women report “Africa by were YahayaYam involved Bean [34] is regardedwho in ricereported as farming minor in Awethatand Local 77.9% women’s Government of married crop; not smallholder worthy Area ofto engage Nasarawa farmers the energycompared State and in laboursto Nigeria. 22.1% of thesingle The men. highwomen They proportion have were the involved patience/endurance of female in rice gender wasfarming viewedof its rigorous inby Awe one attentions Local of the Government an respondentsd hard-to-maintain Area as follows:of practices Nasarawa “”.Africa AYB State also Yam in servesNigeria. Bean isas regardedaThe supplementary high as proportion minor source and of women’s of crop;female notincome worthy gender for female to was engage viewed farmers. the by energy Theone culturalof and the labours respondents characterist of the as men.ics follows: of Theythe study “ haveAfrica area, the Yam patience/endurance where Bean isthere regarded is often as ofminor a its wide rigorous attentionsandage women’s gap and between hard-to-maintaincrop; not partners, worthy to isengage practices exacerbated the”. energy AYB by and the also labours fact serves that of thethe as men. amajority supplementary They haveof the the respondents patience/endurance source of lived income in for femaleof itsrural farmers.rigorous areas. attentions This The provides cultural and hard-to-maintain some characteristics reasoning practices for of the the”. dominance AYB study also area, serves of wherewomen as a theresupplementaryupon whose is often shoulders asource wide of agethe gap incomeresponsibility for female of farmers. meeting The household cultural characterist food requicsirements of the study usually area, fallswhere after there their is often older a wide male between partners, is exacerbated by the fact that the majority of the respondents lived in rural areas. agecounterparts gap between are partners, no longer is ableexacerbated to undertake by the manual fact that labour. the majority of the respondents lived in Thisrural provides areas. This some provides reasoning some for reasoning the dominance for the dominance of women of upon women whose upon shoulders whose shoulders the responsibility the of meetingresponsibility household of meeting food requirementshousehold food usually requ fallsirements after theirusually older falls male after counterparts their older aremale no longer Widower , Gender, 0 ablecounterparts to undertake are manualno longer labour. able to undertake5.8 manual labour.

Widow , Widower , 19.2 Gender,Male 0 , 38.4 5.8 , 0 Widow , 19.2 Male , 38.4 Married , , 0 74.3 Female , 61.6

Married , 74.3 Female , 61.6 Marital Single , 0.7 , 0 status, 0

Figure 3. Gender and marital status of respondents. Marital Single , 0.7 , 0 status, 0

Figure 3. Gender and marital status of respondents. Figure 3. Gender and marital status of respondents. Plants 2017, 6, 30 5 of 16 Plants 2017, 6, 30 5 of 17

2.3. Visit of Extension Ofﬁcers,Officers, SizeSize ofof FarmFarm LandLand andand SourcesSources ofof IncomeIncome The majority (68%) of thethe respondentsrespondents did notnot receivereceive informationinformation or adviceadvice fromfrom extensionextension ofﬁcersofficers whilewhile 32%32% claimedclaimed to have hadhad contact with them. Similarly, 11%, 43%, 34% and 12% of thethe respondents normally receive social grantsgrants fromfrom aa farmers’farmers’ council,council, aa ChristianChristian organization,organization, ageage grade or a cooperativecooperative society, respectivelyrespectively (Figure(Figure4 4).). AremuAremu etet al.al. [ [35],35], notednoted thatthat thethe knowledgeknowledge and application of extension education principles helped extension workers to determine farmers’ needs, constraints, priorities andand opportunities connectedconnected toto theirtheir farmingfarming activities.activities. They concluded thatthat itit alsoalso gavegave themthem thethe opportunityopportunity to teach farmersfarmers the value of improved agricultural practices; recommending suitable crops for differentdifferent agro-ecologicalagro-ecological zones andand encouragingencouraging the adoptionadoption ofof appropriate technologies.technologies. The The low low level level of farmer-extension of farmer-extension contacts contacts in this studyin this could study be implicatedcould be asimplicated a majorcontributory as a major contributory factor to AYB fact beingor to anAYB underutilized being an underutilized crop. crop.

70 60 50 40 30 20 10 0

Figure 4.4. Extension officer’s ofﬁcer’s visits, size size of farmland and source of help for farming activities for respondentsrespondents inin thethe ﬁvefive statesstates ofof southeastern,southeastern, Nigeria.Nigeria.

The result also indicated that 41.6% of the respondents had a farm size of less than 0.25–1.50 The result also indicated that 41.6% of the respondents had a farm size of less than hectares, 35.9% had between 1.51–2.43 hectares while 18.3% had about 2.2–3.22 hectares (Figure 4). 0.25–1.50 hectares, 35.9% had between 1.51–2.43 hectares while 18.3% had about 2.2–3.22 hectares Only 1.9% had a farm size that was more than four hectares. These observations are in agreement (Figure4). Only 1.9% had a farm size that was more than four hectares. These observations are with the findings of Nze and Eboh [36] who reported that 70% of respondents in the three in agreement with the ﬁndings of Nze and Eboh [36] who reported that 70% of respondents in the agricultural zones of Enugu State had access to ≤3 ha farm land. This could also be attributed to the three agricultural zones of Enugu State had access to ≤3 ha farm land. This could also be attributed land tenure system of ownership where women do not have access to land ownership in to the land tenure system of ownership where women do not have access to land ownership in southeastern Nigeria. southeastern Nigeria. Famoriyo [37] noted that under the customary rules of land tenure, each individual member of Famoriyo [37] noted that under the customary rules of land tenure, each individual member a landholding family was entitled to a portion of land, enough to feed himself and the members of of a landholding family was entitled to a portion of land, enough to feed himself and the members ‘his family’, suggesting that men owned land and they apportion it as deemed fit to women. On the of ‘his family’, suggesting that men owned land and they apportion it as deemed ﬁt to women. contrary, in the study with the Amawbia community in Awka South L.G.A. of Anambra State, On the contrary, in the study with the Amawbia community in Awka South L.G.A. of Anambra State, Osita [38] noted that farmland allocated to women for cultivation was to keep them busy and to Osita [38] noted that farmland allocated to women for cultivation was to keep them busy and to enable enable them to feed their households from their farm products, and to enable them to cushion the them to feed their households from their farm products, and to enable them to cushion the effects of effects of poverty and food insecurity. poverty and food insecurity. 2.4. Local Nomenclature of African Yam Bean In southeastern Nigeria, AYB goes by a multiplicity of names based on locality and dialect. At Ngwu Uzuakoli community in Bende LGA of Abia State, AYB is called “Odudu” while in Umuahia Plants 2017, 6, 30 6 of 16

2.4. Local Nomenclature of African Yam Bean In southeastern Nigeria, AYB goes by a multiplicity of names based on locality and dialect. Plants 2017, 6, 30 6 of 17 At Ngwu Uzuakoli community in Bende LGA of Abia State, AYB is called “Odudu” while in Umuahia NorthNorth Local Local Government Government Area Area in in Abia Abia State State itit isis known as as “Akidi”. “Akidi”. However, However, in Anambra in Anambra and Imo and Imo States,States, it is it known is known as “Okpodudu”as “Okpodudu” while while inin EnuguEnugu State, State, there there are are an an array array of local of local names names among among manymany towns. towns. It is It known is known as as “Uzoaki” “Uzoaki” in in Awgu,Awgu, Aninri,Aninri, Nkanu Nkanu North North and and East East Local Local Government Government AreasAreas while while in Nsukka, in Nsukka, Udeni, Udeni, Igboeze Igboeze SouthSouth IgboezeIgboeze North, North, and and Igbo-Etiti Igbo-Etiti South South AYB AYB is called is called “Ijiriji”. Extending towards the southern part of southeast, Nigeria, to Ebonyi State, African yam “Ijiriji”. Extending towards the southern part of southeast, Nigeria, to Ebonyi State, African yam bean bean is called “Uzoaki” in Afikpo and Ohaozara areas while in Izzi, Ikwo and Ohaukwu LGAs it is is called “Uzoaki” in Aﬁkpo and Ohaozara areas while in Izzi, Ikwo and Ohaukwu LGAs it is known known as “Azama”. These multiplicities of names were based on the status and or position of this as “Azama”.crop in the These trado-cultural multiplicities settings of names of some were of the based local on communities. the status and It is or a positionfood prepared of this for crop the in the trado-culturallabourers when settings they of are some hired of to the work local on communities. farm. They eat It the is food a food in preparedthe morning for and the will labourers keep on when theydrinking are hired water to work without on farm.getting They famished eat thefor a food very inlong the time. morning In an idiomatic and will way, keep they on drinkingrefer to the water withoutcrop getting as ‘6 to famished6’, meaning for that avery when long you time.eat AYB In by an 6 idiomatic am, while way, working, they you refer will to not the need crop to as eat ‘6 to 6’, meaningagain that till when6 pm. youAYB eatis also AYB a bycrop 6 am,that whilesustains working, the people you when will notother need crops to eatare againscarce tillor are 6 pm. all AYB is alsocultivated a crop that on the sustains farm. the people when other crops are scarce or are all cultivated on the farm.

2.5. Diversity2.5. Diversity in Seed in Seed Coat Coat Colour Colour and and Pattern Pattern ofof thethe AYB Accessions Collected Collected from from Southeastern Southeastern Nigeria Nigeria A wideA wide variation variation in seed in seed coat coat colours colours and and patterns patterns in AYBin AYB accessions accessions was was observed observed in in this this study. study. The existence of this natural variation across these accessions is very obvious. Colour The existence of this natural variation across these accessions is very obvious. Colour variation ranges variation ranges from very light brown to completely black, variegated brown with black shading to fromblack very lightvariegated. brown Others to completely were milky black, with variegated black eye; milky brown with with brown black eye shading and black to black (Figure variegated. 5). OthersThese were variations milky with could black prove eye; to milkybe useful with to brownboth farmers eye and and black conservation (Figure 5biologists). These variationsin providing could provesimple to be usefulidentification to both of farmers genetic andvariation, conservation its storage biologists and future inproviding development simple within identiﬁcation potential of geneticbreeding variation, programmes. its storage and future development within potential breeding programmes.

FigureFigure 5. Diversity 5. Diversity in seedin seed coat coat colours colours and andpatterns patterns in SphenostylisSphenostylis stenocarpa stenocarpa (ex.( eA.x. Rich.) A. Rich.) Harms. Harms. (African(African yam yam bean) bean) accessions accessions from from ﬁve five states states in in southeast,southeast, Nigeria. Nigeria. Photo Photo by byNnamani. Nnamani.

FAO [39] noted that traditional varieties have higher stability to adapt to climate variability, FAOchange [39 and] noted low-input that agriculture traditional under varieties marginal have envi higherronments stability thereby to facilitating adapt to a climate higher level variability, of changeresilience and low-input for farmers agriculture in facingunder food production marginal environments risks. This diversity thereby is facilitatingparamount afor higher varietal level of resiliencebreeding for farmersas noted in by facing [40]. foodThey productionconcluded that risks. when This breeders diversity need is paramount to develop fornew varietal crops with breeding as noteddesirable by [ 40characteristics]. They concluded such as yield that whenpotential, breeders greater needseed quality, to develop pest newand disease crops withresistance, desirable characteristicspreference suchis given as yieldthe species potential, with diverse’ greater seedgenetic quality, traits, which pest and are diseaseof immense resistance, importance preference to is givenfarmers the speciesand conservation with diverse’ biologists genetic. Seed traits, coat patterning which are also of immenseappears to importancedetermine the to choice farmers of and selection of seeds for cultivation and cooking. Although there were diverse and mixed views about conservation biologists. Seed coat patterning also appears to determine the choice of selection of the seed coat pattern, a higher percentage of the respondents preferred the variegated black and seeds for cultivation and cooking. Although there were diverse and mixed views about the seed brown seed colour to the milk and white seeds (Figure 5). This was based on their assumption that coat pattern,the black a and higher brown percentage variegated of seeds the respondents were, in their preferred opinion, more the variegated proteinous blackand yielded and brown more seed colourwhen to thegrown. milk This and is whitein line seedswith the (Figure report5 of). Ikhajiagbe This was and based Mensah on [41] their who assumption noted that the that yield the of black and brownblack seeds variegated of AYB per seeds hectare were, was in significantly their opinion, greater more (1542 proteinous kg ha−1) compared and yielded to either more the when brown grown. This isvariant in line (1304 with kg the ha− report1), or the of milky Ikhajiagbe variant and (1259 Mensah kg ha−1 [).41 The] who wide noted range that of diversity the yield inherent of black in seeds of AYB per hectare was signiﬁcantly greater (1542 kg ha−1) compared to either the brown variant Plants 2017, 6, 30 7 of 16

(1304 kg ha−1), or the milky variant (1259 kg ha−1). The wide range of diversity inherent in AYB could havePlants contributed 2017, 6, 30 to the continuous availability of the crop despite a general level of neglect and7 of 17 limited exploitation in Africa [13]. AYB could have contributed to the continuous availability of the crop despite a general level of 2.6. Foodneglect Utilization and limited of Africanexploitation Yam in Bean Africa [13].

2.6.The Food corresponding Utilization of African multiple Yam uses Bean of AYB recorded in most of communities is a feature of the cultural diversity in these agro-ecological zones. The array of menus for which AYB is used for food The corresponding multiple uses of AYB recorded in most of communities is a feature of the in southeasterncultural diversity Nigeria in these was agro-ecological wide for a homogenous, zones. The array linguistically of menus for and which culturally-knitted AYB is used for food group of respondents.in southeastern The majorityNigeria was of thewide respondents for a homogenous have, good linguistically knowledge and culturally-knitted of this species as group part of their diet.respondents. However, the The older majority informants of the respondents (64.3%) were have more good knowledgeable knowledge of this in thisspecies than as thepart younger of their ones (23%)diet. while However, 12.7% the had older no knowledge informants (64.3%) of other were uses mo ofre AYB knowledgeable except as snack. in this Thisthan couldthe younger be attributed ones to preference(23%) while of exotic 12.7% foods had no to knowledge indigenous of foods other anduses lackof AYB of interestexcept as by snack. younger This could generation. be attributed toIn preference Abia State, of exotic it is roasted foods to and indigenous eaten as foods snack and (Figure lack of 6interesta) or cooked by younger as pottage, generation. or mixed with “Ugba” (PentaclethraIn Abia State, macrophylla it is roasted), “Okporoko”and eaten as snack (stock (Figure ﬁsh) and 6a) servedor cooked as delicacyas pottage, at or festive mixed events with such “Ugba” (Pentaclethra macrophylla), “Okporoko” (stock fish) and served as delicacy at festive events as traditional marriage, the new yam festival and burial ceremonies (Figure6b). This is one of the most such as traditional marriage, the new yam festival and burial ceremonies (Figure 6b). This is one of cherished foods given to a visitor in some communities of Abia State. the most cherished foods given to a visitor in some communities of Abia State.

(a) (b) (c)(d)

(e) (f) (g)(h)

Figure 6. Diversity of foods prepared from Sphenostylis stenocarpa accessions in the five states of Figure 6. Diversity of foods prepared from Sphenostylis stenocarpa accessions in the ﬁve states of southeast Nigeria. (a–h): AYB in association with other crops eaten in southeast Nigeria. southeast Nigeria. (a–h): AYB in association with other crops eaten in southeast Nigeria. (a) Fried (a) Fried AYB and eating with palm kneel as a snack. (b) Food prepared from AYB with dried AYBcock-yam and eating and with “Akpaka—oil-bean palm kneel as seed a snack; (Pentaclethra (b) Food macrophylla prepared). (c from) AYB AYB withwith Yam. dried(d) AYB cock-yam cooked and “Akpaka—oil-beanas pottage. (e–f) seedAYB prepared (Pentaclethra as mio-mio macrophylla cake );called (c) AYB Ugbagidi with in Yam; Agwu (d )LGA AYB in cooked Enugu asState. pottage; (e–f)( AYBg) AYB prepared prepared as with mio-mio ground cake maize called (Ayaraya Ugbagidi Oka) in and Agwu Akpaka. LGA (h in) Researcher Enugu State; enjoying (g) AYB herself prepared withwith ground the maizedelicacy (Ayaraya of AYB Oka) at andUbani Akpaka; market (h )in Researcher Abia State. enjoying Source: herself 2016 withField the Survey. delicacy of AYBPhoto at Ubani © Nnamani. market in Abia State. Source: 2016 Field Survey. Photo © Nnamani.

Among the communities in Anambra State it is cooked with yam (Figure 6c–d) and served as Among the communities in Anambra State it is cooked with yam (Figure6c–d) and served as pottage or made into flour and fried as balls. In Ebonyi State it is roasted or eaten as snack with palm pottagekernel or madeor cooked into flourwith andyam friedor as as thickener/ balls. Incondiment Ebonyi State for itsoup. is roasted Respondents or eaten in as Enugu snack withState palm kernelreported or cooked that withAYB yamis made or asinto thickener/condiment flour and used to prepare for soup. moin-moin Respondents (Figure in 6e–f) Enugu or cooked State reported as that AYBpottage is mademixed into with flour vegetables, and used Pentaclethra to prepare macrophylla moin-moin, dried (Figure fish6 (Figuree–f) or cooked6d–h) and as pottageserved as mixed withdelicacy vegetables, on festivePentaclethra events such macrophylla as traditional, dried marriage fish (Figure and naming6d–h) ceremonies. and served It is as also delicacy roasted on and festive eventseaten such as assnack traditional with soft marriage palm kernel. and It naming could be ceremonies. cooked with It yam is also and roasted served andas pottage eaten asor snackmade with soft palminto flour kernel. and Itmixed could with be cookedmaize flour with to yam prepare and foo-foo, served and as pottage served with or made “okra” into (lady’s flour finger) and mixed withsoup. maize flour to prepare foo-foo, and served with “okra” (lady’s finger) soup. Plants 2017, 6, 30 8 of 16

ThesePlants 2017 observations, 6, 30 corroborate with the report by Naskashima et al. [42] who noted8 of 17 that indigenous communities, in China, Bolivia and Kenya, favoured the cultivation of varieties of traditionalThese crops observations over a single corroborate high-yielding with but the also report high-risk, by Naskashima mono-cropping et al. [42] system who innoted rural that settings. The discoveryindigenous of communities, these diverse in menus China, in Bolivia which and AYB Kenya, is prominent favoured in southeasternthe cultivation Nigeria of varieties is consistent of traditional crops over a single high-yielding but also high-risk, mono-cropping system in rural with the report by [43] that AYB in Ghana, is used extensively in various dietary preparations and this settings. The discovery of these diverse menus in which AYB is prominent in southeastern Nigeria is has potentiallyconsistent with supplemented the report theby [43] protein that requirementsAYB in Ghana, of manyis used families extensively throughout in various the dietary year. They observedpreparations that the and maintenance this has potentially of diverse supplemente traditional cropd the varietiesprotein requirements and access to of seeds many were families essential toolsthroughout for the adaptation the year. and They survival observed of that poor the rural main farmers.tenance of This diverse enables traditional them to crop conserve varieties germplasm and and provideaccess to a seeds contingency were essential when conditionstools for the are adapta not favourable.tion and survival of poor rural farmers. This However,enables them it was to observedconserve fromgermplasm the respondents and provide in thesea contingency zones that when they wereconditions not awareare not of AYB havingfavourable. tubers underground which they could equally use. However, it was observed from the respondents in these zones that they were not aware of AYB 2.7. Incomehaving Extractabletubers underground from the Saleswhich of they AYB could in the equally Five States use. of Southeastern Nigeria

Figure2.7. Income7 shows Extractable a summary from the Sales of the of averageAYB in the income Five States generated of Southeastern from Nigeria the sales of products, seeds and the diversity of menus derivable from AYB. The study showed that the highest income of N16,000 Figure 7 shows a summary of the average income generated from the sales of products, seeds ($180and USD) the wasdiversity generated, of menus particularly derivable from in Abia AYB. State, The study from theshowed sales that of preparedthe highest food income of diverseof menusN16,000 from ($180 AYB, USD) sold inwas the generated, open markets, particularly and in from Abia road State, hawkers from the (Figuresales of7 prepared). The least food income of was recordeddiverse menus from from Ebonyi AYB, on sold the in sales the open of AYB market seedss, and and from other road food hawkers menus. (Figure Thus, 7). AYBThe least provides a goodincome complementary was recorded sourcefrom Ebonyi of income on the for sales the of resource-poor AYB seeds and rural other andfoodsemi–rural menus. Thus, dwellers AYB in southeasternprovides Nigeria.a good complementary This conﬁrms thesource opinion of inco ofme Legwaila for the et resource-poor al. [44] that foodrural security and semi–rural and poverty alleviationdwellers in in rural southeastern communities Nigeria. can This be confirms improved the opinion by diversifying of Legwaila the et existingal. [44] that few food staple security crops to includeand underutilized poverty alleviation plants. in Theyrural communities concluded that can thebe improved few staple by crops diversifying exploited the in existing dry conditions few of Botswanastaple crops could to include not improve underutilized the lives plants. of resource-poor They concluded rural that householdsthe few staple without crops exploited incorporating in dry conditions of Botswana could not improve the lives of resource-poor rural households without alternatives such as indigenous food plants. incorporating alternatives such as indigenous food plants.

200 Seeds sold during planting 180 Seeds sold during harvest 160 Verity of cooked menu Seeds sold by traders 140

120

100

0 Abia Anambra Ebonyi Enugu Imo

Figure 7. Income extractable from the sales of AYB in the five states of southeastern Nigeria (USD). Figure 7. Income extractable from the sales of AYB in the ﬁve states of southeastern Nigeria (USD). Furthermore, experience has shown that many African rural communities actually rely on Furthermore,indigenous plants experience for food security has shown and asthat source many of cash African income rural between communities cropping seasons. actually It has rely on indigenousbeen established plants for that food neglected security and asunderutilized source of cash species income in southeastern between cropping Nigeria seasons.were potential It has been establishedsources thatof high neglected levelsand of essential underutilized nutrients species which in southeasterncontributed to Nigeria the daily were requirement potentialsources and of highmaintenance levels of essential of good nutrients health whichof the contributedresource-poor to rural the daily households. requirement It has and a direct maintenance impact ofon good alleviating poverty, building a sustainable future for these people who are dependent on it as health of the resource-poor rural households. It has a direct impact on alleviating poverty, building a source of livelihood [45]. sustainable future for these people who are dependent on it as source of livelihood [45]. Plants 2017, 6, 30 9 of 16

2.8. Other Uses of African Yam Bean in the Five States of Southeastern Nigeria In all the states, AYB was utilized for many other livelihood services. Respondents enumerated situations where the integration of AYB was crucial for the wellbeing of the people as summarized in Table1. The ability of the indigenous communities to integrate and interact with their natural surroundings has been a positive approach in their resilience, survival and sustainable development. The utilitarian value of AYB in the communities examined spanned the ﬁve states studied. Such utilitarian value includes the use of dried AYB snacks by diabetic patients, extract of mashed cooked AYB to induce lactation after childbirth and the use of the fried ground seed coat to treat strokes (Table1). This conforms with the expectation implied in the ‘Convention on the Protection and Promotion of the Diversity of Cultural Expressions’ that the recognition of the links between biological and cultural diversity is often embedded with acknowledging the importance of indigenous knowledge and local peoples’ participatory roles in protecting and conserving biodiversity. This is because cultural diversity is a rich asset for safeguarding the vitality of societies; preserving cultural customs and practices and know-how that should be conserved [46].

Plants 2017, 6, 30 11 of 17 2.9. Constraints to Cultivation and Utilization of AYB AYB2.9. Constraints utilization to Cultivation and production and Utilization in southeastern of AYB Nigeria is beset with a plethora of problems. Speciﬁcally,AYB the utilization challenges and production confronting in southeastern its use and Nigeria cultivation, is beset determinedwith a plethora for of this problems. study, are summarizedSpecifically, in Figurethe challenges8. Many confronting of the respondents its use and can cultivation, be classed determined as aging for farmers this study, (77.3%), are and it wassummarized suggested thatin Figure the long 8. Many cooking of the time respondents (76.6%) and can lowbe classed product as marketaging farmers demand (77.3%), (71.6%) and were it the mostwas intractable suggested problems that the long confronting cooking time AYB (76.6%) cultivation and low and product utilization market in demand southeastern (71.6%) Nigeria. were the Other most intractable problems confronting AYB cultivation and utilization in southeastern Nigeria. constraints identiﬁed were the lack of staking materials (61.3%), postharvest diseases (59.9%) and poor Other constraints identified were the lack of staking materials (61.3%), postharvest diseases (59.9%) awarenessand poor on awareness the nutritional on the values nutritional of AYB values (57.1%), of AYB an (57.1%), important an important staple as staple well as as well a crop as a ofcrop immense of culturalimmense value incultural southeastern value in Nigeria. southeastern Among Nigeria. the strategies Among the for shorteningstrategies for the shortening long cooking the long time was soakingcooking seeds time overnight was soaking before seeds cooking overnight and/or before adding cooking the petiolesand/or adding of paw-paw the petioles (Carica of papayapaw-paw) to AYB seeds(Carica while papaya cooking) to to AYB reduce seeds the while challenge cooking of longto reduce cooking the time.challenge These of challengeslong cooking could time. be These attributed to weakchallenges linkage could between be attributed research to and weak indigenous linkage between knowledge. research and indigenous knowledge.

Poor availability of AYB seeds Long cooking time of AYB seed Lack of staking materials Poor seed quality Low yield of AYB Low awareness on nutritional values High cost of labour Lack of finance Aging of farmers Postharvest diseases

Constraints on utilization & cultivation of AYB & cultivation on utilization Constraints Low demand and market for AYB

0 102030405060708090 % Response

FigureFigure 8. Constraints 8. Constraints on on the the utilization utilization and and cultivationcultivation of of AYB AYB in in southeastern southeastern Nigeria Nigeria as determined as determined by databy data from from the 2016the 2016 ﬁeld field survey. survey.

2.10. Conservation and Management Indigenous communities in the study area depend on plant genetic resources for livelihood sustenance. They have developed selective conservation methods to protect these plants including AYB. Conservation of AYB is accomplished through the collection of dried fruits at maturity when the green fruits become brownish within the months of December to February. This is usually after harvesting the yams (Dioscorea spp.) with which AYB was staked with in the farm. The most common in situ conservation techniques used were restrictions on use (eating just a fraction of the entire seeds harvested), hanging the dried fruits beside the cooking fire ether inside the kitchen or outside, beside the house and or storing the seeds in calabash gourds, earthenware, plastic cans and bottles. Some of the respondents just tie up the dried fruits in bundles and place them on any dry platform outside the house (Figure 9).

Plants 2017, 6, 30 10 of 16

Table 1. Other uses of African Yam Bean in the ﬁve states of southeastern Nigeria.

Abia Anambra Ebonyi Enugu Imo Yes (dried plant after Fodder and part used - - Yes (dried plant after harvesting seed) - harvesting seed) Dried YAB snacks are Dried YAB snacks are Dried YAB snacks are Dried YAB snacks are Dried YAB snacks are recommended recommended for diabetic recommended for diabetic recommended for diabetic recommended for diabetic for diabetic patients. It makes them patients. It makes them patients. It makes them patients. It makes them patients. It makes them feel full. feel full. feel full. feel full. feel full. Eating AYB induces sleep Eating AYB induces sleep - as a result of its relaxing as a result of its relaxing ability (Insomnia) ability (Insomnia) Fried and ground seed is Fried and grinded seed is used to Medicine -- - used to treat stroke. treat stroke. Extract of mashed AYB after cocking is used to induce lactation in mothers Extract of mashed AYB Extract of mashed AYB after birth. after cooking is used to after cocking is used to The seed coat of roasted AYB is used in induce lactation in induce lactation in the treatment of stroke by a traditional mothers after birth. mothers after birth healer in Ehandiagu found in Nsukka LGA (Clem Uroko). Used as special food Used as special food Used as special food Used as special food Used as special food during festivals Cultural during festivals during festivals during festivals during festivals Women crop Women crop Women crop Women’s crop Women crop Poorer people crop Poorer people crop Poorer people crop Poorer people crop Poorer people crop Source: Field survey 2016. Plants 2017, 6, 30 11 of 16

2.10. Conservation and Management Indigenous communities in the study area depend on plant genetic resources for livelihood sustenance. They have developed selective conservation methods to protect these plants including AYB. Conservation of AYB is accomplished through the collection of dried fruits at maturity when the green fruits become brownish within the months of December to February. This is usually after harvesting the yams (Dioscorea spp.) with which AYB was staked with in the farm. The most common in situ conservation techniques used were restrictions on use (eating just a fraction of the entire seeds harvested), hanging the dried fruits beside the cooking ﬁre ether inside the kitchen or outside, beside the house and or storing the seeds in calabash gourds, earthenware, plastic cans and bottles. Some of the respondents just tie up the dried fruits in bundles and place them on any dry platform outside the housePlants 2017 (Figure, 6, 30 9 ). 12 of 17

a b c

Figure 9.9. SphenostylisSphenostylis stenocarpa.stenocarpa.( a()a) Mature Mature but but not not ready ready to harvestto harvest the fruitsthe fruits of the of African the African yam bean;yam (bean.b) dried (b) fruits;dried fruits, (c) dried (c) harvesteddried harvested fruits stored fruits besidestored thebeside house the by house one ofby the one respondents. of the respondents. Photo © AdewalePhoto © Adewale and Nnamani. and Nnamani.

All these conservation methods often expose the seeds to pathogens thereby making them All these conservation methods often expose the seeds to pathogens thereby making them vulnerable to spoilage. This is in line with the reports by the UNESCO [46] that seeds of AYB were vulnerable to spoilage. This is in line with the reports by the UNESCO [46] that seeds of AYB were usually heavily infected with quite a number of pathogens. With respect to this, considerable efforts, usually heavily infected with quite a number of pathogens. With respect to this, considerable efforts, programs and policies should be made to aid the conservation of AYB seeds in the study zones. This programs and policies should be made to aid the conservation of AYB seeds in the study zones. This is is in line with the report of [47] that, to conserve underutilized species effectively, holistic in line with the report of [47] that, to conserve underutilized species effectively, holistic approaches approaches which include both the ex-situ and in-situ techniques must be planned to complement which include both the ex-situ and in-situ techniques must be planned to complement the local the local conservation strategies. conservation strategies. The remaining seeds of the 34 accessions of AYB used in this project were conserved ex-situ in The remaining seeds of the 34 accessions of AYB used in this project were conserved ex-situ in the the germplasm conservation unit of the Biotechnology Research and Development Centre, Ebonyi germplasm conservation unit of the Biotechnology Research and Development Centre, Ebonyi State State University Abakaliki, Nigeria and germplasm screening laboratory, Department of Crop University Abakaliki, Nigeria and germplasm screening laboratory, Department of Crop Production Production and Protection, Faculty of Agriculture, Obafemi Awolowo University, Ile-Ife, Nigeria. and Protection, Faculty of Agriculture, Obafemi Awolowo University, Ile-Ife, Nigeria.

3. Conclusions and Recommendations Globally it is recognized that indigenous knowledgeknowledge and its institutional systems provide the foundation for participatory strategies for eco-friendlyeco-friendly and societally sustainable development. This survey on the voice of the custodians of AYB in thisthis zonezone hashas actuallyactually contributed to the wealth of knowledge about AYB andand itsits sustainingsustaining potentialpotential inin foodfood securitysecurity resilienceresilience andand development.development. The social characteristics of respondents involved in AYB activities indicated that the preponderance of the elderly, whowho areare fastfast agingaging withwith littlelittle oror nono formalformal education,education, was high. While these traditional custodians of AYB areare passingpassing awayaway duedue toto oldold age, the younger generation has not shown enough interest in this crop. Furthermore, there was high variability in seed coat colours and patterns and this has a direct relationship with choice of selection of AYBAYB seedsseeds forfor cultivationcultivation andand use.use. However, inadequateinadequate information from extension ofﬁcers,officers, a lack ofof stakingstaking materials,materials, long cooking time, low market demand, lack of appropriate conservation measures and unstable sources of income were among the factors against the cultivationcultivation and use of AYB. Apparently, the results from this study showed that this rich indigenous knowledge could provide a guiding light for informed scientific inquiry to address current challenges. Protection of indigenous knowledge and its promotion among the scientific domain is urgently needed to conserve and develop this crop [48]. As an integral component of the menu of the majority of the agrarian communities in this zone, it could play a significant role on food security and economic development. This study has unveiled some baseline data on the extensive dietary preparations and other latent uses of AYB in addressing food security and sustainable development of these resource-poor rural communities. Urgent local and national in-situ and ex-situ conservation approaches are highly needed to ensure the continuous existence of this highly promising fading plant genetic resource in the face of change. The National Research Council [49] stressed the need for preliminary surveys, which could quickly be converted into advisory services to farmers who are the keepers of Africa’s age-old yam bean heritage. This, they noted, could be done throughout the AYB zones with the aim of creating more awareness of its multipurpose assets, conserving the germplasm and improving the potentials of this crop.

Plants 2017, 6, 30 12 of 16

Apparently, the results from this study showed that this rich indigenous knowledge could provide a guiding light for informed scientific inquiry to address current challenges. Protection of indigenous knowledge and its promotion among the scientific domain is urgently needed to conserve and develop this crop [48]. As an integral component of the menu of the majority of the agrarian communities in this zone, it could play a significant role on food security and economic development. This study has unveiled some baseline data on the extensive dietary preparations and other latent uses of AYB in addressing food security and sustainable development of these resource-poor rural communities. Urgent local and national in-situ and ex-situ conservation approaches are highly needed to ensure the continuous existence of this highly promising fading plant genetic resource in the face of change. The National Research Council [49] stressed the need for preliminary surveys, which could quickly be converted into advisory services to farmers who are the keepers of Africa’s age-old yam bean heritage. This, they noted, could be done throughout the AYB zones with the aim of creating more awareness of its multipurpose assets, conserving the germplasm and improving the potentials of this crop.

Plants 2017, 6, 30 13 of 17 4. Materials and Methods 4. Materials and Methods 4.1. Study Area 4.1. Study Area The study area was the southeastern geo-political zone of Nigeria, comprising of Abia, Anambra, Ebonyi, EnuguThe andstudy Imo area states was regarded the southeastern as the Igbo geo-politic land. Ital is zone located of withinNigeria, longitudes comprising 5 ◦of30 0Abia,and 9◦300 E Anambra,◦ Ebonyi,0 Enugu◦ 0 and Imo states regarded as the Igbo land. It is located2 within longitudes and latitudes5°30′ and 4 30 9°30and′ E 7and00 latitudesN, occupying 4°30′ and a land7°00′ areaN, occupying of about a 75,488 land area km of(Figure about 75,48810) and km bordered2 by the Cross(Figure River 10) and State bordered to the by east,the Cross Akwa River Ibom Stateto to the east, south, Akwa Edo Ibom and to Deltathe south, States Edo toand the Delta west, and Kogi andStates Benue to the States west, to and the Kogi north and [50 Benue]. Temperature States to the in north the study[50]. Temperature area is characterized in the study by area two is distinct alternatingcharacterized seasons of by uniformly two distinct high alternating temperature seasons of of 37 uniformly◦C. The high aridity temperature of the dry of season37 °C. The is accentuated aridity by the dust-ladenof the dry harmattan season is accentuated winds (Northeast by the dust-laden (NE) Trades harmattan Winds). winds The mean(Northea monthlyst (NE) Trades temperatures Winds). oscillate The mean monthly temperatures oscillate between 23.3 °C and 27.7 °C with a seasonal bimodal between 23.3 ◦C and 27.7 ◦C with a seasonal bimodal annual rainfall of 1500–2500 mm. With respect to annual rainfall of 1500–2500 mm. With respect to vegetation, the age-long anthropogenic activities vegetation,have the given age-long rise to anthropogenica derived mosaic activities of lowland have rainforest given risevegetation to a derived type that mosaic houses of a lowlandrelic of the rainforest vegetationtropical type rainforest that houses vegetation a relic belt of the [50]. tropical rainforest vegetation belt [50].

Figure 10. Data collection sites for Sphenostylis stenocarpa in southeast Nigeria. Figure 10. Data collection sites for Sphenostylis stenocarpa in southeast Nigeria. 4.2. Sample Size Representative samples of 10 respondents were selected randomly from 10 Local Government Areas (LGA) in a state, giving a total number of 500 respondents across the five states (Figure 10). The respondents included community heads, farmers, drivers and vendors of AYB in these communities. The selected 500 respondents were restricted to those were above 18 years of age and older. The 34 accessions collected from the study areas after the research were conserved ex-situ in the germplasm conservation unit of the Biotechnology Research and Development Centre, Ebonyi State University Abakaliki, Nigeria and the germplasm screening laboratory of the Department of Crop Production and Protection, Faculty of Agriculture, Obafemi Awolowo University, Ile-Ife, Nigeria. Plants 2017, 6, 30 13 of 16

4.2. Sample Size Representative samples of 10 respondents were selected randomly from 10 Local Government Areas (LGA) in a state, giving a total number of 500 respondents across the ﬁve states (Figure 10). The respondents included community heads, farmers, drivers and vendors of AYB in these communities. The selected 500 respondents were restricted to those were above 18 years of age and older. The 34 accessions collected from the study areas after the research were conserved ex-situ in the germplasm conservation unit of the Biotechnology Research and Development Centre, Ebonyi State University Abakaliki, Nigeria and the germplasm screening laboratory of the Department of Crop Production and Protection, Faculty of Agriculture, Obafemi Awolowo University, Ile-Ife, Nigeria.

4.3. Seed/Plant Collection Verbal pre-informed consent was obtained from the participants before they were interviewed. Interviews were conducted in the local language using guided semi-structured questionnaires and research assistants who were conversant with the local languages. These questionnaires were structured in line with the specific objectives of the study and were administered in the form of an oral interview scheduled in order to ensure that responses to the questions are correctly filled. The interviews were structured and covered questions pertaining to the uses of AYB, production and utilization constraints. The research questions were focused on (i) identifying the socio-economic status of the respondents; (ii) determining the uses, variability in seed coat colour and patterns; (iii) identifying the effects of climate change including those constraints limiting the use and production system of AYB; (iv) also requested was their knowledge of climate change effect on crops (with particular emphasis on AYB); (v) other uses such as its nutritional, medicinal, and cultural values including income extractable from AYB; and (vi) the demand profile of AYB in these communities. Rapid rural appraisal (RRA) and focal group discussion (FGD) were used to elicit farmers and stakeholders’ awareness and knowledge about climate change, its impact on their major staples; status of AYB and the challenges of cultivating it, while semi-structured interview schedules were used to collect quantitative information from the selected respondents. Farmers of AYB responded to a five-point scale survey employed to determine the magnitude of their responses: to a very great extent, five points; to a great extent, four points; to some extent, three points; to a little extent, two points; and to a very little extent, one point.

4.4. Income Extraction Validation The nutritional, medicinal, and cultural values, including income and demand proﬁle of AYB in these communities were accessed. Various vendors and different actors on AYB within the local markets participated in this study. The prices for this crop in the various zones as accruing from various transactions were sourced and recorded. Economic evaluation of the plant and its multipurpose uses were inventoried, rating these, and then converting these prices from the local currency to its USA dollar equivalent.

4.5. Data Analysis Data obtained from the questionnaires were processed into a data matrix, percentages and analysed. Data were analysed using simple averages, mean scores and standard deviations with Statistical Analysis System (SAS) to realize the objectives.

Acknowledgments: We appreciate African Academy of Science (AAS) and Association of Commonwealth Universities (ACU) for the award of a “Climate Impact Research Capacity and Leadership Enhancement (CIRCLE) to the first author for this project”. We are indebted to the Department for International Development (DfID) for funding CIRCLE and to the custodians of African yam bean, and Dept. of Crop Production and Protection, OAU, Nigeria for hosting this project. However, neither the findings nor the views expressed, however, necessarily reflect the policies of the UK Government. Plants 2017, 6, 30 14 of 16

Author Contributions: Catherine Veronica Nnamani and Happiness Ogba Oselebe conceived and wrote the proposal. Catherine Veronica Nnamani designed the experiment, performed the experiments, analysed the data, and wrote up the manuscript, Sunday Adesola Ajayi supervised, designed the experiment and interpreted the data. Christopher John Atkinson restructured the proposal and corrected the manuscript while Anastasia Ngozi Igboabuchi and Eucharia Chizoba Ezigbo were involved in sample collections and the field survey together with Catherine Veronica Nnamani. Conflicts of Interest: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data and in the writing of the manuscript, however, the funders’ have provided grant to publish this research work in an Open Access Journal.

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