storage insects on yam chips and their traditional ... · triusnigrescenslewis,xylocorisflavipes...

Hindawi Publishing CorporationThe Scientific World JournalVolume 2013 Article ID 484536 11 pageshttpdxdoiorg1011552013484536

Research ArticleStorage Insects on Yam Chips and Their TraditionalManagement in Northern Benin

Y L Loko1 A Dansi12 M Tamo3 A H Bokonon-Ganta4 P Assogba2

M Dansi1 R Vodouhegrave5 A Akoegninou6 and A Sanni7

1 Laboratory of Agricultural Biodiversity and Tropical Plant breeding (LAAPT) Faculty of Sciences and Technology (FAST-Dassa)University of Abomey-Calavi (UAC) PO Box 526 Cotonou Benin

2 Crop Aromatic and Medicinal Plant Biodiversity Research and Development Institute (IRDCAM) 071 BP 28 Cotonou Benin3 Institut International drsquoAgriculture Tropicale (IITA) 08 BP 0932 Cotonou Benin4 Service de la Protection des Vegetaux et du Controle Phytosanitaire Direction de lrsquoAgriculture BP 58 Porto-Novo Benin5 Bioversity International Office of West and Central Africa 08 BP 0932 Cotonou Benin6National Herbarium Department of Botany and Plant Biology Faculty of Sciences and Technology (FAST)University of Abomey-Calavi (UAC) PO Box 526 Cotonou Benin

7 Laboratory of Biochemistry and Molecular Biology Faculty of Sciences and Technology (FAST) University of Abomey-Calavi (UAC)PO Box 526 Cotonou Benin

Correspondence should be addressed to A Dansi adansi2001gmailcom

Received 20 January 2013 Accepted 11 February 2013

Academic Editors G E Brust A Ferrante and J R Qasem

Copyright copy 2013 Y L Loko et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Twenty-five villages ofNorthernBeninwere surveyed to identify the constraints of yamchips production assess the diversity of stor-age insects on yam chips and document farmersrsquo perception of their impacts on the stocks and their traditional management prac-tices Damages due to storage insects (639 of responses) and insufficiency of insect-resistant varieties (167 of responses) werethe major constraints of yam chips production Twelve insect pest species were identified among which Dinoderus porcellus Lesne(Coleoptera Bostrichidae) was by far the most important and the most distributed (9744 of the samples) Three predators (Tere-trius nigrescens Lewis Xylocoris flavipes Reuter and Alloeocranum biannulipesMontrouzier amp Signoret) and one parasitoid (Dinar-mus basalis Rondani) all Coleoptera Bostrichidae were also identifiedThe most important traditional practices used to control orprevent insect attack in yam chips were documented and the producersrsquo preference criteria for yam cultivars used to produce chipswere identified and prioritized To further promote the production of yam chips diversification of insect-resistant yam varietiesconception and use of health-protective natural insecticides and popularization of modern storage structures were proposed

1 Introduction

In economic terms yams (Dioscorea spp) are the worldrsquosfourthmost important tuber crop after potatoes cassava andsweet potatoes [1] They are cultivated in most tropical coun-tries but especially in West Africa where over 95 of theworldrsquos output is produced [1 2] They are the main sourceof carbohydrate for millions of people In West Africa manyyam species are cultivated but the African domesticatesknown as the Guinea yams (D cayenensis Lam-D rotundataPoir complex) are however the most important most pre-ferred and widely planted [3]

In Benin the fourth yam-producing country behindNigeria Ivory Coast and Ghana yam is among the mostimportant food crops [1] and has economic and socioculturalimportance [4] Yam is seasonal and the fresh tubers arehighly perishable Postharvest losses are very high rangingfrom 30 to 85 of the total production [4] In order to over-come this high perishability of the tubers and the irregularityof its availability throughout the year yams are traditionallyprocessed into dried chips or cossettes [5ndash7] hence rein-forcing food security [7] Unfortunately yam chips are oftenseverely attacked by insects which sometimes reduce wholeyam stocks into powder in very few months [8 9] Very little

2 The Scientific World Journal

Table 1 Administrative localisation of the ethnic areas and sites surveyed

N∘ Ethnic areas Districts Number of sites Selected villages1 Yom Djougou 6 Dewa Alfapara Pelebina Mone Gangamou Dangoussar2 Lokpa Djougou 4 Ouarlgou Yarakeou Pohomto Niagba-kabia3 Ani Bassila 2 Penessoulou Saramanga4 Nago Bassila 7 Modogui Ouanou Papane Agramarou Koko Agbassa Wari-Maro5 Taneka Copargo 3 Kataban Setrah Foungou6 Bariba Tchaourou 2 Woria Badekparou7 Peulh Tchaourou 1 Gakpenou

research attention has been given to storage insects attack onyam chips and traditional management practices in BeninGnonlonfin et al [10] reported the existence of many speciesof insects but focused their studymainly on their populationrsquosdynamics in stored yams chips Consequently the diversityof the insect species in the yam chips producing zone isstill unknown and farmersrsquo perception of the importance ofinsect damages in the stocks has never been assessed Tra-ditional management practices (including the storage struc-tures) used to prevent or control insect infestations havealso not been documented Yam chips are produced fromtubers of single-harvest varieties locally known as ldquoKokorordquocharacterized by their numerous small-sized tubers WithinKokoro yams many varieties of different agronomic andtechnological characteristics exist [11] but the yam chipsproducersrsquo variety preference or selection criteria have neverbeen studied Knowledge of farmersrsquo selection criteria will beuseful in designing concrete breeding programmes that couldfacilitate the adoption of improved varieties [12]

We report in this paper a survey conducted in the mostimportant yam chips producing zone of Benin in order to

(i) identify and prioritise the constraints related to theproduction of yam chips in Benin and farmersrsquo propo-sitions for overcoming these constraints

(ii) document farmersrsquo perceptions about insect pests onstored yam chips and traditional management prac-tices

(iii) assess the diversity and the importance of the storageinsects species in the most important yam chips pro-duction zone of Benin

(iv) Identify and prioritize the producersrsquo variety prefer-ence or selection criteria across study zones and eth-nic groups for popularization and breeding purposes

2 Material and Methods

21 Study Area The study was conducted in five districts(Djougou Copargo Ouake Bassila and Tchaourou) of theDepartments of Donga and Borgou in northern BeninThesedistricts are known to be the major yam chips productionzones of Benin [11 13] The inhabitants are members ofseven ethnic groups (Figure 1 Table 1) (Ani Bariba LokpaNago Peulh Taneka and Yom) and have a very longtradition in processing Kokoro yam tubers into chips orcossettes (Figure 2) The departments of Donga and Borgou

are located in a semiarid agroecological zone characterizedby unpredictable and irregular rainfall (800ndash1300mmyear)with only one rainy season (May to October) and a dryseason lasting for more than 5 months sometimes [14] Meanannual temperatures range from 26∘C to 28∘C and mayexceptionally reach 35∘C [15 16] Yam production in this areais intensive and essentially based on Kokoro yams [13] whichhave very variable yields from one season to another due toclimatic hazards [13]

22 Site Selection and Survey Twenty-five villages (Table 1Figure 1) were randomly selected throughout the study areaand its ethnic zones for the survey Data were collected fromthe different sites during expeditions through the applicationof ParticipatoryResearchAppraisal tools and techniques suchas granary visits direct observation focus group discussionsand individual interviews using a questionnaire and the helpof translators from each area following Dansi et al [12]In each site local farmersrsquo associations were involved inthe study to facilitate the identification of the householdsto survey and the data collection Within villages 10 to 12households were randomly selected for individual interviewsusing the transect method described by Dansi et al [17] Ineach household the interviewee (head of household or hiswife or one of his wives in case of polygamy) was selectedby mutual agreement with the hosting couple according toChristinck et al [18] Apart from the socioeconomic data suchas age gender and educational level of the interviewees datacollected included the farmersrsquo perceptions of the constraintsof yam chips production the cossette storage structures andpractices the importance of damages caused by insects thetime of the infestation the farmersrsquo knowledge of the insectspecies the traditional management practices on the infestedstocks and the farmersrsquo preference criteria of kokoro varietiesused in the production of the chips Preference criteria ofkokoro varieties were identified and prioritized using thematrix scoring technique described by Defoer et al [19]Adoukonou-Sagbadja et al [20] and Dansi et al [12] In eachvillage samples (500 g) of infested yam chips were collecteddirectly from two to three randomly selected yam chipsstorage structures following Mendesil et al [21] and Koradaaet al [22] Initial weights of the samples to be collected weretaken using the numerical balance (model SF-400) Infestedsamples collected were preserved in plastic containers withperforated lids to allow for ventilationWith the aid of a planttaxonomist at the national herbarium of the University ofAbomey-Calavi insecticides andor insect repulsive plants

The Scientific World Journal 3

0 5 10 20 30 40Kilometers

VillageDistrict administrative center

District boundaryStudy area boundary

Study area

N

1∘09984000998400998400E 2

∘09984000998400998400E 3

∘09984000998400998400E

10∘09984000998400998400N

9∘09984000998400998400N

1∘09984000998400998400E 2

∘09984000998400998400E 3

∘09984000998400998400E

10∘09984000998400998400N

9∘09984000998400998400N

Figure 1 Map of Benin showing the geographical position of the surveyed villages

used in processing reported by interviewees we sampled andtheir scientific names were determined using the analyticalflora of Benin [16]

23 Incubation of the Samples and Isolation and Identificationof the Insects The labeled plastic containers containing thesamples of the infested chips were incubated for threemonthsunder laboratory conditions at temperature of 25ndash27∘C and70ndash80 relative humidity following the method describedby Eze et al [23] After the incubation period the sampleswere broken into particles of less than 05 cm using a handmortar and the insects were recovered through a 025mmnylon net sieve [24] Recovered insects were counted andconserved in a flask containing 70 alcohol for safeguardingand identification Speciesrsquo identification was done at theBiodiversity Center of the International Institute of TropicalAgriculture (IITA-Benin)

24 Statistical Analysis Data were analyzed through descrip-tive statistics (frequencies percentages means etc) to gen-erate summaries and tables at different (villages individuals)levels using SAS software [25]

3 Results

31 Characteristics of the Respondents The respondents werein majority (98) women Sixty-three (63) are illiterate and

47 attended primary school only Their ages varied from17 to 60 years with an average of 37 years In all the house-holds surveyed yam chips were produced for either homeconsumption and for the market (952 of the respondents)or for home consumption only (48)

32 Constraints of Yam Chips Production Six constraints(Table 2) related to yam chips production in Benin wererecorded They were all directly or indirectly linked to thestorage of the chips Among them damages due to storageinsects were the most important (639 of responses) fol-lowed by insufficiency of insect-resistant varieties (167 ofresponses) and the lack of natural human health preservinginsecticides (102 of responses) The other three constraints(lack of organised markets low availability of fresh kokoroyam tubers and the lack of appropriate and specific storagestructures) were of very low importance (only 11 to 45of responses) The majority of the yam chips producers(7212) estimated at 40ndash60 the importance of thedamage caused by the storage insects on the yam ships(Figure 2(a)) This however depends on the variety used theconservation structure and the drying level of the chipsFor the great majority (9294) of the respondents theinfestation of the cossettes in stock occurred during thefirst two months (Figure 2(b)) In order to minimize theseconstraints yam chips producers proposed six key solutions

4 The Scientific World JournalRe

spon

dent

s (

)

0

5

10

15

20

25

30

35

10 20 30 40 50 60 70 80 90 100Estimated storage loss ()

483 558892

2491

3383

1338

409 2970 149

(a)

010203040506070

[1ndash3

0]

[30ndash

60]

[60ndash

90]

[90ndash

120]

[120

ndash150

]

Oth

ers

Number of days

Resp

onde

nts (

)

6952

1598

334 223 149744

(b)

Figure 2 Farmersrsquo perception of (a) storage loss due to stored yamchips insect pests (b) the period of infestation of the yam chips

(Table 3) including diversification of good storage insect-resistant kokoro yam (302 of responses) development ofa natural human health preserving insecticides (242 ofresponses) enhancement of the production of kokoro yam(212 of responses) and development of fast drying areasfor the yam chips (195 of responses)

33 Farmersrsquo Knowledge of the Insect Pests Damaging YamChips in Stocks andDiversity Assessment In the study area allthe storage insects were traditionally classified in a singlegroup named Benonkpe in Ani Kokolibo in Nago Doridjiin Peulh Gbenenoukokonou in Bariba Dresse in Yom andPoucasse in Lokpa andTaneka All these six vernacular namesliterally mean beetles Farmers reported that these beetlesact by penetrating the chips and drastically reducing theirinternal parts into powdery waste (Figure 3) Although inter-viewees recognized storage insects asmajor constraint in yamchips production only 47 of them were able to differentiatesome speciesThe few respondents who attempted to identifyyam chips insect pests based their identification mainly onthe colour (4512 of responses) and the relative size (3218of responses) of the insects and on the symptoms of thedamage they caused (227 of responses)

The diversity analysis conducted on the total of 78samples collected and incubated revealed 12 species of insectsbelonging to four orders (Table 3) which are Coleoptera

Figure 3 Yam chips with insect infestation in Benin

Table 2 Yam chips production constraints in Benin

Constraints Percentage of responsesDamages caused by storage insects 639Insufficiency of insect-resistant varieties 167Lack of natural human health preservinginsecticides 102

Lack of appropriate and specific storagestructures 45

Insufficient availability of fresh kokoroyam tubers 36

Lack of organised markets 11

Table 3 Solutions for the constraints and their importance asproposed by the interviewees in the study area

Solutions Importance( of responses)

Diversification of good storage insect-resistantkokoro yam 302

Development of a natural human healthpreserving insecticides 242

Enhancement of the production of kokoro yam 212Development of fast drying areas for the yamchips 195

Development of efficient and specific yamchips storage structures 33

Establishment of a well-organised yam chipsgood market 16

(eight species) Hemiptera (two species) Hymenoptera (onespecies) and Psocoptera (undetermined species) Species ofthe order of Coleoptera were the most numerous and themost represented in the samples On average 223 insects ofthe order Coleoptera were counted by 500 g of yam chipsagainst 114 for all the other orders put together (Table 4)Among the species identified Dinoderus porcellus Lesne wasthe most represented It was found in 9744 of the collectedsamples and was also the most abundant in all the samplesin which it was found (Table 4) This was followed by thespecies Tribolium castaneum (Herbst) detected in 5256of the samples (Table 4) The other species were found inonly 2 to 10 samples out of the 78 samples collected and in


Table 4 Results of the samples incubated at the laboratory showing the species of insects used and their relative abundance

Types of insects Infested samples () Average count for 500 g Percentage of abundance(500 g) Rank

Dinoderus porcellus 76 (9744) 20872 8903 1Psocoptera spp 19 (2436) 883 377 2Tribolium castaneum 41 (5256) 612 261 3Lasioderma serricorne 4 (513) 33 141 4Sitophilus zeamais 10 (1282) 257 109 5Xylocoris flavipes 10 (1282) 246 105 6Cryptolestes pusillus 10 (1282) 126 054 7Carpophilus dimidiatus 7 (897) 085 036 8Teretrius nigrescens 5 (641) 013 005 9Carpophilus binotatus 3 (385) 009 004 10Alloeocranum biannulipes 5 (641) 009 004 11Dinarmus basalis 2 (256) 003 001 12

very few numbers Among the 12 species of insects identifiedthree (Teretrius nigrescens Lewis Xylocoris flavipes Reuterand Alloeocranum biannulipesMontrouzier amp Signoret) werepredators and one (Dinarmus basalis Rondani) was a para-sitoid Xylocoris flavipes was found in 1282 of the samplesand appeared to be the most abundant predator

34 Traditional Yam Chips Storage Systems and Duration ofthe Conservation In all the households surveyed yam chipswere stored inside houses and rooms in various containersThe great majority (9777) of producers used maize bags(madewith syntheticmaterials) of various sizes as containersdepending on the quantity of chips to be conserved Onlyfew producers (223) preferred to store in large-sized andhermetically closed plastic buckets jars or barrels to preventinsect infestations No specific structure was dedicated tostorage of yam chips Interviewees reported that storageperiod varied from 1 to 13 months with an average of 8months For 4982 3197 and 1821 of the respondentsstorage duration of yam chips varied between 1 and 5months5 and 10 months and 10 and 15 months respectively

35 Traditional Control Systems of Yam Chips Storage InsectsPests Under traditional storage conditions intervieweesused seven strategies to reduce losses due to insects (Table 5)Among those the most important were regular inspectionand exposure of chips to sunlight to repel insects (3593of responses) use of insect-resistant varieties (2680 ofresponses) and use of insecticide andor insectrsquos repulsiveplants during preparation (2645 of responses) The otherstrategies such as shaking of the yam chips to remove insectsalong powdery waste use of insecticides treatment withpepper powder and minimising frequent opening of storagestructures to avoid entrance of the insects were poorly used(Table 5) According to interviewees severely infested stocksof yam chips were sold (6617 of responses) used for homeconsumption only (2454 of responses) or simply thrownaway (929 of responses)

Table 5 Farmersrsquo management practices for the control of yamchips insect pests

Management practices Importance( of responses)

Exposure of the infested yam chips to sun 3593Use of insect-resistant varieties 2680Use of insecticide andor insectrsquos repulsiveplants during preparation 2645

Sifting of yam chips to remove insects alongpowdery waste 859

Use of insecticides 112Treatment with pepper powder 074Minimising frequent opening of storagestructures to avoid entrance of the insects 037

The study revealed that eight species of plant were used toprevent infestation of the yam chips or to control insect pests(Table 6) Among these species three (Bridelia ferrugineaBlighia sapida and Khaya senegalensis) were reported to beinsecticide while four (Piliostigma thonningii Lophira lance-olata Tectona grandis and Sorghum bicolor) were said to bedyes and insect repulsive (Table 6) Cassava leaves were alsoused during the parboiling to harden the chips Piliostigmathonningii and Sorghum bicolor were known and used acrossall the ethnic groups while the other species apart fromTectona grandis were each used in only one ethnic groupThe number and types of species of plants varied from oneethnic group to another YomandPeulh used only two speciesof plant Lokpa and Ani used four species and Nago usedfive For the different plant species identified the plant parts(leaves or bark) used the application or treatment methods(infusion or fumigation) and the frequencies of utilizationacross ethnic groups are summarized in Table 6

Throughout the study zone 37 kokoro yam cultivars usedto produce chips were listed as tolerant to storage insectsThenumber of cultivars reported varies across ethnic areas Eightcultivars were reported with the Nago Bariba and Lokpa


Table 6 List of plants used to protect yam chips against storage insect pests and their utilisation methods

Species Part used Role Method ofapplication

Percentage of farmers using the plants across ethnic groupsPeulh Nago Ani Taneka Bariba Lokpa Yom

Piliostigma thonningii Leafbark Dye Infusion 4286 1940 15 3030 1667 2647 3030Lophira lanceolata Leaf Dye Infusion mdash 746 mdash mdash mdash mdash mdashBlighia sapida Leaf Insecticide Infusion mdash 597 mdash mdash mdash mdash mdashBridelia ferruginea Leafbark Insecticide Infusion mdash mdash 5 mdash mdash mdash mdashKhaya senegalensis Bark Insecticide Fumigate mdash mdash mdash mdash 1111 mdash mdashTectona grandis Leaf Dye Infusion mdash 1940 5 1212 mdash 1471 mdash

Manihot esculentus Leaf Hardening ofthe yam chips Infusion mdash mdash mdash mdash mdash 294 mdash

Sorghum bicolor Stemoil cakes Dye Infusion 5714 4777 75 5758 7222 5588 6970

seven with the Yom four with the Taneka and only twowith the Ani (Table 7) In each ethnic area certain cultivarsweremore commonWith theNago ethnic groupOguidigboAdakada Tabane and Omonya were the most importantwhile with the Bariba ethnic group the most listed cultivarswere Otoukpannan Tchakatchaka and Yakanougo (Table 6)

36 Farmerrsquos Preferences Criteria for Kokoro Yam Cultivars forChips Production Throughout the study zone kokoro yamcultivars used for chips production were selected amongthe existing diversity based on eight criteria Among themthe quality of the paste made with the flour the storageaptitude of the chips and the quality of the Wassa-Wassa(local couscous made with yam chipsrsquo flour) were the mostimportant and represent altogether 7408 of the responses(Table 8) The number and importance of the criteria alsovaried across ethnic groups With the Nago and the Peulhstorage aptitude was the most important criterion while withthe other ethnic groups the quality of the paste came at thefirst position (Table 8) The quality of Wassa-Wassa whichwas the third most important criterion among the LokpaAni and Yom people was not even mentioned by the Baribapeople Similarly the fast drying quality of the cultivarswhich was important to the Nago the Taneka and the Aniwas not listed among the Peulh people and had very lowvalues with the other ethnic groups While all the eightcriteria were listed by the Lokpa ethnic group all but one wasrecorded with the Taneka and the Yom and only four wereidentified with the Peulh (Table 8)

4 Discussion

The respondents were in majority women This can beexplained by the fact that in all ethnic groups of the studyarea women were the sole processors of kokoro yam tubersinto chips The few males interviewed responded on behalfof their wives who gave way to them out of respect Theculture of the people was also evident in the yam productionsystem where tasks had been traditionally divided accordingto genderMenwere in charge of themost important activitiesin terms of labour requirements while foods processing andtransformation of the yam tubers into chips among otheractivities were devoted to women [4] According to Bricas

and Vernier [26] the commercialization of yam chips is byfar more economically profitable than the one of fresh tubersThis could justify the importance that women in the studyarea gave to commercialization as a means of substantiallyimproving their household income

Among the constraints related to yam chips production inthe study area damages caused by storage insects stood outas the most important Similar results were reported by Osuji[27] and Adedire and Gbaye [28] in Nigeria The importanceof the damages raised by the respondents is key indicator ofthe urgent necessity to develop control strategies against thestorage insects

Sun drying of infested chips was the major method usedby farmers to control these insect pests This method whichis the oldest known technique of conservation of the agro-alimentary products also presents several disadvantagesChalal et al [29] reported that sun drying directly exposesthe products to dust and to ultraviolet rays which can causethe deterioration of food vitamins Among the solutionsproposed by farmers were diversification of good storageinsect-resistant kokoro yams and development of naturalhuman health preserving insecticides These two proposi-tions which call the attention of plant geneticist and breederson one hand and industrial chemists on the other indicatethat producers are very concerned about their health Thenumerous cases of food poisoning that were associated withthe use of cotton insecticides on yam chips recorded theselast years in the country and which led to the death of manypersonsmay have contributed to this health consciousness InNigeria Adedoyin et al [30] and Adeleke [31] also reportedpoisoning due to the consumption of yam flour (treated withinsecticide) in some families in Ilorin and Kano

Our study revealed that in the different samples ofinfested yam chips collected and analyzed Dinoderus porcel-lus was the most represented This species which is knownto be mostly associated with dried yams [32] has alreadybeen reported as the most important pest of stored yamchips in Nigeria [27 28 32] Dinoderus porcellus particularlyinfests well-dried chips [27 28] Therefore it is possiblethat the few samples in which it was absent were notwell dried or had relatively higher moisture contents Thepresence of Psocoptera spp Carpophilus dimidiatus andCarpophilus Binotatus in the samples without Dinoderus


Table 7 Kokoro yam cultivars tolerant to storage insect pests andtheir importance across ethnic areas

Ethnic areas Insect-resistantvarieties

Importance (numberof farmers)

Ani Demkpenai 14Awanawou 11

Otoukpannan 18Tchakatchaka 16Yakanougo 15

Bariba Omonya 8Singor 6

Ankakorouwoura 1Gaboubaba 1

Kourakourogouroko 1Azowi 17Iootchra 14Moghoun 12

Lokpa Kounto 10Kparokoume 8Soprova 6Tougbana 4Tedoman 1Oguidigbo 54Adakada 45Tabane 41

Nago Hounbonon 33Kokorogbambe 26Kokorolakolako 18Kokoroagbale 13Adjawoungbo 5Atawouraı 27

Taneka Souwoukou 19Gree 7

Djessoume 4Koutonouman 51

Biboı 44

Yom Assinakpeina 39Adjogba 17Mouhame 3

Aye 2Satchila 2

porcellus supports this hypothesis as they are known as insectsassociated with wet food products [33] Tribolium castaneumand Psocoptera spp were also found in not negligible numberof the samplesThe red flour beetle Tribolium castaneum is acommon and one of the most important stored product pestsassociated with a wide range of durable commodities (barleybran cacao ginger maize millet cassava chips nutmegpeanut pepper rice sorghum etc) and food-processingfacilities worldwide [34ndash36] were also found Its presence in

the samples examined is not surprising as it has already beenreported by Vernier et al [9] Soldati et al [37] and Oni andOmoniyi [32] In some yam chips samples collected outsideour study area Vernier et al [9 38] and Gnonlonfin et al[10] identified five other species which were not found in ourstudies These included Dinoderus bifoveolatus (Wollaston)Palorus subdepressus (Wollaston) Rhyzopertha dominica (F)C quadricollis (Guerin-Meneville) Gnatocerus maxillosus(F) and Prostephanus truncatus In order to have an exhaus-tive list of all the stored-products insect pests associated withyam chips in Benin and map their geographical distributionfurther studies need to be conducted by including the remain-ing part of the country A good knowledge of the diversityof the species will be of great utility for the yam breederswho may like to select kokoro cultivars producing tubersthat are tolerant to storage insect pests For example TheLaboratory of Agricultural Biodiversity and Tropical PlantBreeding of the University of Abomey-Calavi (Benin) andthe Global Crop Diversity Trust (Rome Italy) are currentlyintroducing yam chips technology to the arid zone of thedepartment of Atakora (far northwest of Benin) where theenvironment is quite suitable for fast drying of the chips Tosucceed however it will be necessary to reckon with kokorocultivars tolerant to storage insect pests

To control insect pests and diseases in crops IntegratedPest Management (IPM) is recommended [39] IPM pro-motes biological control based on the use of the naturalenemies of pests (predators and parasitoids) and the geneticcontrol through growing of pest and disease tolerant or resis-tant cultivars [40] Among the natural enemies encounteredin the infested yam chips Xylocoris flavipes is known as aneffective polyphagous predator of eggs larvae and chrysalis ofcoleopteran insects [41]This natural enemy is also a predatorof larvae of T castaneum [42] and is frequently associatedwith the insects of cereals stocks [43] According to Helbig[44]X flavipeshas some interesting biological characteristicsthat make it a potential control agent of storage insect pestsUnfortunately it was reported that X flavipes only eliminatespopulations of small-sized insects but not larger insects orinsects with internal feeding such as D porcellus [45] Abiannulipes on the other hand (Montrouzier amp Signoret) isknown as a predator of the large-sized storage insect pestsincluding L serricorne (F) andTribolium castaneum [46ndash48]A biological control program combining these predators willbe useful in eliminating various types of insects and will helpcontrol the insect pestsrsquo complex associated with yam chips

It appeared from our study that yam chips producers alsoused diverse plants to protect chips against insect attacksPhytochemical studies conducted by Dumaine et al [49]revealed that none of the four plant species (L lanceolata Tgrandis P thonningii and B ferruginea) used in the studyareas has insecticidal or insect repulsing effects HoweverAkinpelu and Obuotor [50] found that P thonningii barkextract has a bactericidal activity which is also important forimproving the sanitary conditions of the chips Among theplants used Blighia sapida Bridelia ferruginea and Khayasenegalensis are even believed and rightly so to have insec-ticide properties by the Nago the Ani and the Bariba people(Table 6) In fact the bark extract of K senegalensis has been


Table 8 Famerrsquos preference criteria of good kokoro yam cultivar for chips production in the study area and across ethnic groups

Preferences criteria Study area( of responses)

Ethnic groups ( of responses)Nago Peulh Bariba Taneka Lokpa Yom Ani

Quality of the paste 3562 2303 2143 4138 3815 3125 3565 3214Storage aptitude of the chips 265 3199 5714 3793 245 2396 2261 2857Quality of Wassa-Wassa 1196 411 714 0 354 2292 1304 1786Colour of the paste 967 1233 1429 1379 27 625 1304 357Flour richness of the yam chips 305 274 mdash mdash 79 729 0 mdashCrushing facility of the chips 102 mdash mdash mdash 26 208 087 mdashTaste of the paste 483 mdash mdash 345 mdash 521 1044 357Fast drying 735 258 mdash 345 2061 104 435 1429

proved to be antifungal [51] antibacterial [52 53] and insectantifeedant [54] Mitchell and Ahmad [55] reported that Bsapida has acaricide and insecticide properties Similarly ithas been shown that all the fruit components (skin aril andgranulates oil) of this plant have repulsive properties againststock insects such as Callosobruchus maculatus Cryptolestesferrugineus T castaneum and S zeamais [55ndash58] Experi-ments should be conducted to assess the effects of the extractof these three species on insect pests that damage stored yamchips

Chips producers reported that the importance of thedamages is a function of the yam cultivars used and listed 37kokoro yam landraces producing tubers rarely attacked by thestorage insect pests Due to the existence of numerous syn-onymies in farmer-named yam cultivars [11] these listed lan-draces may not all correspond to 37 different genotypesTherefore agromorphological characterization coupled withmolecular analysis should be carried out to identify duplicatesand establish the equivalence between recorded names fol-lowing Tamiru et al [59] and Kombo et al [60] Moreoverand as recommended by Vernier et al [38] it will be alsoimportant to assess by a well-elaborated trial the effectivenessof the tolerance of the chips derived from the tubers of thesevarieties to storage insect pests The use of resistant varietiesremains themost economically profitable and the best healthymethod of combating chips storage insect pests Because ofthis kokoro yams in the chips production zone should bestrengthened with more high yielding cultivars that are suit-able for chips and resistant to storage insect pests Accordingto Dansi et al [11] such cultivars exist in the traditionalagriculture and could be identified through participatoryevaluation Within the existing diversity cultivars to be usedfor the chips are selected based on diverse criteria amongwhich those related to the quality of the foods (Wassa-Wassapaste) made with the yam chips flour and the technologicalcharacteristics of the chips are the most important (6666of the responses) This result is expected because in Beninchips are only made and used for food purposes In thepreference criteria identified aspects related to conservationcome in second position indicating that producers really giveparticular importance to insect damagesThe variation of thepreference criteria noted across ethnic groups is frequent andhas been already reported in many crops such as cowpea[61] banana and plantain [62] maize [63] telf [64] sorghum

[65] yam [11] and even fonio [12] The fast drying criteriaimportantly raised by the Nago the Taneka and the Aniethnic groups should be seriously considered as it influencesthe hygienic quality of the chips and their market valueNago Taneka and Ani people mostly produced chips foreconomic purposes through commercialization One under-stands therefore how important fast drying could be to them

5 Conclusion

This study has allowed us to identify several constraints thathamper yam chips production in northern Benin Attacksby storage insects were the major constraints identifiedYam chips were infested by various insects of which themost important was Dinoderus porcellus Several plants aretraditionally used to fight these insects Following farmersrsquorequests efforts should be directed towards diversification ofgood kokoro cultivars which are tolerant to storage insects Inthis framework and to identify such cultivars we recommendthe participatory evaluation of existing kokoro yam theidentification of duplicates and clarification of synonymiesand the assessment of the tolerance of the chipsmanufacturedwith tubers produced by the identified varieties

Acknowledgments

This research was sponsored by the Ministry of HigherEducation and Scientific Research of Benin The authorsare grateful to Dr Goergen Georg who is in charge of theInsect Museum of the International Institute of TropicalAgriculture (Cotonou Benin) for his assistance during theidentification of the insects and to Dr H Yedomonhan(National Herbarium Department of Botany and Plant biol-ogy University of Abomey-Calavi) for the identification ofthe plant species They thank all the chips manufacturersand agricultural technicians they met for fruitful discussionsduring the survey

References

[1] FAO FAOSTAT Database Food and Agriculture OrganizationRoma Italy 2010 httpwwwfaoorg

[2] J M Babajide O Q Bello and S O Babajide ldquoQuantita-tive determination of active substances (preservatives) in Pil-iostigma thonningii and Khaya ivorensis leaves and subsequent


transfer in dry-yamrdquo African Journal of Food Science vol 4 no6 pp 382ndash388 2010

[3] H D Mignouna and A Dansi ldquoYam (Dioscorea ssp) domes-tication by the Nago and Fon ethnic groups in Beninrdquo GeneticResources and Crop Evolution vol 50 no 5 pp 519ndash528 2003

[4] M N Baco S Tostain R L Mongbo O Dainou and CAgbangla ldquoGestion dynamique de la diversite varietale designames cultivees (Dioscorea cayenensismdashD rotundata) dans lacommune de Sinende au nord Beninrdquo Plant Genetic ResourcesNewsletter vol 139 pp 18ndash24 2004

[5] N Akissoe D J Hounhouigan N Bricas P Vernier C MNago and O A Olorunda ldquoPhysical chemical and sensoryevaluation of dried yam (Dioscorea rotundata) tubers flour andamala a flour-derived productrdquo Tropical Science vol 41 no 3pp 151ndash155 2001

[6] D J Hounhouigan A P Kayode N Bricas and C M NagoldquoDesirable culinary and sensory characteristics of yams inurban Beninrdquo Benin Journal of Agricultural Sciences vol 21 no12 pp 2815ndash2820 2003

[7] J M Babajide O O Atanda T A Ibrahim H O Majolagbeand S A Akinbayode ldquoQuantitative effect of lsquoabafersquo (Piliostigmathionnigii) and lsquoagehursquo (Khaya ivorensis) leaves on the micro-bial load of dry-yam lsquogbodorsquordquo African Journal of MicrobiologyResearch vol 2 pp 292ndash298 2008

[8] E Ategbo N Bricas J Hounhouigan et al ldquoLe developpementde la filiere chips drsquoigname pour lrsquoapprovisionnement des villesau Nigeria au Benin et au Togordquo in Actes du Seminaire Inter-national Cirad-Inra-Orstom-Coraf pp 339ndash341 MontpellierFrance Juin 1997

[9] P Vernier G Goergen R Dossou P Letourmy and J ChaumeldquoUtilization of biological insecticides for the protection ofstored yam chipsrdquoOutlook onAgriculture vol 34 no 3 pp 173ndash179 2005

[10] G J B Gnonlonfin K Hell A B Siame and P FandohanldquoInfestation and population dynamics of insects on storedcassava and yams chips in Benin West Africardquo Journal ofEconomic Entomology vol 101 no 6 pp 1967ndash1973 2008

[11] A Dansi H D Mignouna J Zoundjihekpon A SangareR Asiedu and F M Quin ldquoMorphological diversity cultivargroups and possible descent in the cultivated yams (DioscoreacayenensismdashD rotundata) complex in Benin Republicrdquo GeneticResources and Crop Evolution vol 46 no 4 pp 371ndash388 1999

[12] A Dansi H Adoukonou-Sagbadja and R Vodouhe ldquoDiversityconservation and related wild species of Fonio millet (Digitariaspp) in the Northwest of Beninrdquo Genetic Resources and CropEvolution vol 57 no 6 pp 827ndash839 2010

[13] Y L Loko A Dansi C Linsoussi et al ldquoCurrent status andspatial analysis of Guinea yam (Dioscorea cayenensis Lam -Drotundata Poir complex) diversity in Beninrdquo Genetic Resourcesand Crop Evolution In press

[14] S Adam and M Boko Le Benin Les editions du Flamboyant EDICEF 1993

[15] A C AdomouVegetation patterns and environmental gradientsin Benin implications for biogeography and conservation [PhDthesis] University of Wageningen Wageningen The Nether-lands 2005

[16] A AkoegninouW J van der Burg and L J G van derMaesenFlore Analytique du Benin Backhuys Publishers 2006

[17] A Dansi A Adjatin H Adoukonou-Sagbadja et al ldquoTradi-tional leafy vegetables and their use in the Benin RepublicrdquoGenetic Resources and Crop Evolution vol 55 no 8 pp 1239ndash1256 2008

[18] K V Christinck B Kshirsagar E Weltzien and P J Bramel-Cox ldquoParticipatory methods for collecting germplasm expe-riences with famers of Rajasthan Indiardquo Plant RessourcesNewsletter vol 121 p 129 2000

[19] T Defoer A Kamara and H De Groote ldquoGender and varietyselection farmersrsquo assessment of local maize varieties in South-ern Malirdquo African Crop Science Journal vol 5 no 1 pp 65ndash761997

[20] H Adoukonou-Sagbadja A Dansi R Vodouhe and K Akpa-gana ldquoIndigenous knowledge and traditional conservation offonio millet (Digitaria exilis Digitaria iburua) in Togordquo Biodi-versity amp Conservation vol 15 no 8 pp 2379ndash2395 2006

[21] E Mendesil C Abdeta A Tesfaye Z Shumeta and H JifarldquoFarmersrsquo perceptions andmanagement practices of insect pestson stored sorghum in Southwestern Ethiopiardquo Crop Protectionvol 26 no 12 pp 1817ndash1825 2007

[22] R R Koradaa S K Naskara and S Edison ldquoInsect pestsand their management in yam production andstorage a worldreviewrdquo International Journal of PestManagement vol 56 no 4pp 337ndash349 2010

[23] S C Eze J E Asiegbu B N Mbah G C Orkwor and RAsiedu ldquoEffects of four agrobotanical extracts and three typesof bags on the control of insect pests and moulds of stored yamchipsrdquo Journal of Agriculture Food Environment and Extensionvol 5 no 1 pp 8ndash12 2006

[24] A Delobel ldquoLes cossettes de manioc un important reservoirdrsquoinsectes des denrees stockees en Afrique centralerdquo Revue deZoologie Africaine vol 106 no 1 pp 17ndash25 1992

[25] SAS ldquoUserrsquos guiderdquo SAS Institute Cary NC USA 1996[26] N Bricas and P Vernier Dossier la transformation de lrsquoigname

Bulletin du reseau TPA N∘ 18 5ndash12 2000 httpinfotpagretorgfileadminbulletinbulletin18pdf

[27] F N C Osuji ldquoObservations on beetles attacking dried yamsand yam flour from three Nigerian marketsrdquo Tropical StoredProducts Information vol 39 pp 35ndash38 1980

[28] C O Adedire and O A Gbaye ldquoSeasonal prevalence and lifehistory of the yam beetle Dinoderus porcellus (Lesne) (Cole-optera Bostrichidae)rdquo Nigerian Journal of Experimental andApplied Biology vol 3 pp 323ndash329 2002

[29] N Chalal A Bellhamri and L Bennamoun ldquoEtude drsquounsechoir solaire fonctionnant en mode direct et indirectrdquo Revuedes Energies Renouvelables pp 117ndash126 2008 SeminaireMaghrebin sur les Sciences et les Technologies de Sechage(SMSTS rsquo08)

[30] O T Adedoyin A Ojuawo O O Adesiyun F Mark and E AAnigilaje ldquoPoisoning due to yamflour consumption in five fam-ilies in Ilorin CentralNigeriardquoWestAfrican Journal ofMedicinevol 27 no 1 pp 41ndash43 2008

[31] S I Adeleke ldquoFood poisoning due to yam flour consumption inKano (Northwest) Nigeriardquo Online Journal of Health and AlliedSciences vol 8 no 2 p 10 2009

[32] M O Oni and A O Omoniyi ldquoStudies on temperature influ-ence on oviposition and development of immature stages of theyam beetleDinoderus porcellus Lesne Coleoptera Bostrichidaeon dried yam speciesrdquo Journal of Agricultural Science vol 4 no2 pp 213ndash218 2012

[33] R J Bartelt and M S Hossain ldquoChemical ecology of Car-pophilus sap beetles (Coleoptera Nitidulidae) and developmentof an environmentally friendly method of crop protectionrdquoTerrestrial Arthropod Reviews vol 3 no 1 pp 29ndash61 2010


[34] JM Turaki BM Sastawa B G J Kabir andN E S Lale ldquoSus-ceptibility of flours derived from various cereal grains to infes-tation by the rust-red flour beetle (Tribolium castaneumHerbst)(Coleoptera Tenebrionidae) in different seasonsrdquo Journal ofPlant Protection Research vol 47 no 3 pp 279ndash288 2007

[35] N E S Lale and B A Yusuf ldquoInsect pests infesting stored pearlmillet Pennisetum glaucum (L) R Br in Northeastern Nigeriaand their damage potentialrdquo Cereal Research Communicationsvol 28 no 1-2 pp 181ndash186 2000

[36] S A Babarinde G O Babarinde and O Olasesan ldquoPhysicaland biophysical deterioration of stored plantain chips (MusaSapientum L) due to infestation of Tribolium castaneum herbst(Coleoptera Tenebrionidae)rdquo Journal of Plant ProtectionResearch vol 50 no 3 pp 303ndash306 2010

[37] L Soldati G J Kergoat and F L Condamine ldquoPreliminaryreport on the Tenebrionidae (Insecta Coleoptera) collectedduring the SANTO 2006 expedition to Vanuatu with descrip-tion of a new species of the genus Uloma Dejean 1821rdquo Zoosys-tema vol 34 no 2 pp 305ndash317 2006

[38] P Vernier R A Dossou and P Letourmy ldquoLa fabricationdrsquoigname a partir de Dioscorea alata influence de la variete etdu type de chips sur le sechage la conservation et les qualitesorganoleptiquesrdquo African Journal of Root and Tuber Crops vol3 pp 62ndash67 1999

[39] O C Eneh ldquoEnhancing Africarsquos environmental managementintegrated pestmanagement forminimizing of agricultural pes-ticides pollutionrdquo Research Journal of Environmental Sciencesvol 5 no 6 pp 521ndash529 2011

[40] G W Norton E G Rajotte and V Gapud ldquoParticipatoryresearch in integrated pest management lessons from the IPMCRSPrdquoAgriculture andHumanValues vol 16 no 4 pp 431ndash4391999

[41] J Brower andM A Mullen ldquoEffects of Xylocoris flavipes (Hem-iptera Anthocoridae) releases on moth populations in experi-mental peanut storagesrdquo Journal of Entomological Science vol25 no 2 pp 268ndash276 1990

[42] A Russo G E Cocuzza and M C Vasta ldquoLife tables of Xylo-coris flavipes (Hemiptera Anthocoridae) feeding on Triboliumcastaneum (Coleoptera Tenebrionidae)rdquo Journal of Stored Prod-ucts Research vol 40 no 1 pp 103ndash112 2004

[43] R T Arbogast and J E Throne ldquoInsect infestation of farm-stored maize in South Carolina towards characterization of ahabitatrdquo Journal of Stored Products Research vol 33 no 3 pp187ndash198 1997

[44] J Helbig ldquoEfficacy of Xylocoris flavipes (Reuter) (Het Antho-coridae) to suppress Prostephanus truncatus (Horn) (ColBostrichidae) in traditional maize stores in Southern TogordquoJournal of Applied Entomology vol 123 no 8 pp 503ndash508 1999

[45] T ImamuraMMurata andAMiyanoshita ldquoReviewbiologicalaspects and predatory abilities of hemipterans attacking stored-product insectsrdquo Japan Agricultural Research Quarterly vol 42no 1 pp 1ndash6 2008

[46] K T Awadallah A I Afifi and I I El-Sebaey ldquoThe biology ofthe reduviidAllaeocranumbiannulipes (Mon et Sign) a preda-tor of stored product insect pestsrdquo Bulletin of the EntomologicalSociety of Egypt vol 69 pp 169ndash181 1990

[47] D P Rees ldquoThe effect of Teretriosoma nigrescens Lewis (Cole-optera Histeridae) on three species of storage Bostrichidaeinfesting shelledmaizerdquo Journal of Stored Products Research vol27 no 1 pp 83ndash86 1991

[48] M Camara C Borgemeister R H Markham and H MPoehling ldquoElectrophoretic analysis of the prey spectrum of

Teretrius nigrescens (Lewis) (Col Histeridae) a predator ofProstephanus truncatus (Horn) (Col Bostrichidae) in MexicoHonduras and Beninrdquo Journal of Applied Entomology vol 127no 6 pp 360ndash368 2003

[49] F Dumaine D Dufour CMestres et al ldquoEffect of yamDioscor-ea cayenenis-rotundata post-harvests treatments on yam chipsqualityrdquo in Potential of Root Crops for Food and IndustrialResources Twelfth Symposium of the International Society forTropical Root Crops (ISTRC) September 10ndash16 2000 TsukubaJapan M Nakatani and K Komaki Eds vol 12 of Symposiumon Potential of Root Crops for Food and Industrial Resources p394 Cultio Corporation Tsukuba Japon 2002

[50] D A Akinpelu and EM Obuotor ldquoAntibacterial activity of Pil-iostigma thonningii stem barkrdquo Fitoterapia vol 71 no 4 pp442ndash443 2000

[51] S AMAbdelgaleil FHashinaga andMNakatani ldquoAntifungalactivity of limonoids from Khaya ivorensisrdquo Pest ManagementScience vol 61 no 2 pp 186ndash190 2005

[52] M Nakatani S A M Abdelgaleil S M I Kassem et al ldquoThreenew modified limonoids from Khaya senegalensisrdquo Journal ofNatural Products vol 65 no 8 pp 1219ndash1221 2002

[53] D KubmarawaM E Khan AM Punah andMHassan ldquoPhy-tochemical screening and antimicrobial efficacy of extractsfrom Khaya senegalensis against human pathogenic bacteriardquoAfrican Journal of Biotechnology vol 7 no 24 pp 4563ndash45662008

[54] M Sale N De J H Doughari and M S Pukuma ldquoIn vitroassessment of antibacterial activity of bark extracts of Khayasenegalensisrdquo African Journal of Biotechnology vol 7 no 19 pp3443ndash3446 2008

[55] S A Mitchell and M H Ahmad ldquoA review of medicinal plantresearch at the University of the West Indies Jamaica 1948ndash2001rdquo West Indian Medical Journal vol 55 no 4 pp 243ndash2692006

[56] M R M Ekue B Sinsin O Eyog-Matig and R FinkeldeyldquoUses traditional management perception of variation andpreferences in ackee (Blighia sapida KD Koenig) fruit traitsin Benin implications for domestication and conservationrdquoJournal of Ethnobiology and Ethnomedicine vol 6 article 12 14pages 2010

[57] A Khan F A Gumbs and A Persad ldquoPesticidal bioactivityof ackee (Blighia sapida Koenig) against three stored-productinsect pestsrdquo Tropical Agriculture vol 79 no 4 pp 217ndash2232002

[58] A Khan and F A Gumbs ldquoRepellent effect of ackee (Blighiasapida Koenig) component fruit parts against stored productinsect pestsrdquo Tropical Agriculture vol 80 no 1 pp 19ndash27 2003

[59] M Tamiru H C Becker and B L Maass ldquoDiversity distri-bution and management of yam landraces (Dioscorea spp) inSouthern Ethiopiardquo Genetic Resources and Crop Evolution vol55 no 1 pp 115ndash131 2008

[60] G R Kombo A Dansi L Y Loko et al ldquoDiversity of cassava(Manihot esculenta Crantz) cultivars and its management inthe department of Bouenza in the Republic of Congordquo GeneticResources and Crop Evolution vol 59 no 8 pp 1789ndash1803 2012

[61] LW Kitch O Boukar C Endondo and L L Murdock ldquoFarm-er acceptability criteria in breeding cowpeardquo Experimental Agri-culture vol 34 no 4 pp 475ndash486 1998

[62] C S Gold A Kiggundu A M K Abera and D KaramuraldquoSelection criteria of Musa cultivars through a farmer partici-patory appraisal survey in Ugandardquo Experimental Agriculturevol 38 no 1 pp 29ndash38 2002


[63] G Abebe T Assefa H Harrun T Mesfine and A R M Al-Tawaha ldquoParticipatory selection of drought tolerant maizevarieties using mother and baby methodology a case study inthe semi-arid zones of theCentral RiftValley of EthiopiardquoWorldJournal of Agricultural Sciences vol 1 no 1 pp 22ndash27 2005

[64] G Belay H Tefera B Tadesse G Metaferia D Jarra and TTadesse ldquoParticipatory variety selection in the Ethiopian cerealtef (Eragrostis tef )rdquo Experimental Agriculture vol 42 no 1 pp91ndash101 2006

[65] A Teshome D Patterson Z Asfew J K Torrance and J TArnason ldquoChanges of Sorghum bicolor landrace diversity andfarmersrsquo selection criteria over space and time EthiopiardquoGenetic Resources and Crop Evolution vol 54 no 6 pp 1219ndash1233 2007

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Game Theory

Journal ofApplied Mathematics



Complex Systems

Journal of

ISRN Operations Research



Abstract and Applied Analysis


Industrial MathematicsJournal of


OptimizationJournal of

ISRN Computational Mathematics



Mathematical Problems in Engineering


Complex AnalysisJournal of

ISRN Combinatorics



Geometry

ISRN Applied Mathematics


International Journal of Mathematics and Mathematical Sciences


thinspAdvancesthinspin

DecisionSciences

HindawithinspPublishingthinspCorporationhttpwwwhindawicom Volumethinsp2013


MathematicsJournal of


Algebra

ISRN Mathematical Physics


Discrete MathematicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2013


Table 1 Administrative localisation of the ethnic areas and sites surveyed

N∘ Ethnic areas Districts Number of sites Selected villages1 Yom Djougou 6 Dewa Alfapara Pelebina Mone Gangamou Dangoussar2 Lokpa Djougou 4 Ouarlgou Yarakeou Pohomto Niagba-kabia3 Ani Bassila 2 Penessoulou Saramanga4 Nago Bassila 7 Modogui Ouanou Papane Agramarou Koko Agbassa Wari-Maro5 Taneka Copargo 3 Kataban Setrah Foungou6 Bariba Tchaourou 2 Woria Badekparou7 Peulh Tchaourou 1 Gakpenou

research attention has been given to storage insects attack onyam chips and traditional management practices in BeninGnonlonfin et al [10] reported the existence of many speciesof insects but focused their studymainly on their populationrsquosdynamics in stored yams chips Consequently the diversityof the insect species in the yam chips producing zone isstill unknown and farmersrsquo perception of the importance ofinsect damages in the stocks has never been assessed Tra-ditional management practices (including the storage struc-tures) used to prevent or control insect infestations havealso not been documented Yam chips are produced fromtubers of single-harvest varieties locally known as ldquoKokorordquocharacterized by their numerous small-sized tubers WithinKokoro yams many varieties of different agronomic andtechnological characteristics exist [11] but the yam chipsproducersrsquo variety preference or selection criteria have neverbeen studied Knowledge of farmersrsquo selection criteria will beuseful in designing concrete breeding programmes that couldfacilitate the adoption of improved varieties [12]

We report in this paper a survey conducted in the mostimportant yam chips producing zone of Benin in order to

(i) identify and prioritise the constraints related to theproduction of yam chips in Benin and farmersrsquo propo-sitions for overcoming these constraints

(ii) document farmersrsquo perceptions about insect pests onstored yam chips and traditional management prac-tices

(iii) assess the diversity and the importance of the storageinsects species in the most important yam chips pro-duction zone of Benin

(iv) Identify and prioritize the producersrsquo variety prefer-ence or selection criteria across study zones and eth-nic groups for popularization and breeding purposes

2 Material and Methods

21 Study Area The study was conducted in five districts(Djougou Copargo Ouake Bassila and Tchaourou) of theDepartments of Donga and Borgou in northern BeninThesedistricts are known to be the major yam chips productionzones of Benin [11 13] The inhabitants are members ofseven ethnic groups (Figure 1 Table 1) (Ani Bariba LokpaNago Peulh Taneka and Yom) and have a very longtradition in processing Kokoro yam tubers into chips orcossettes (Figure 2) The departments of Donga and Borgou

are located in a semiarid agroecological zone characterizedby unpredictable and irregular rainfall (800ndash1300mmyear)with only one rainy season (May to October) and a dryseason lasting for more than 5 months sometimes [14] Meanannual temperatures range from 26∘C to 28∘C and mayexceptionally reach 35∘C [15 16] Yam production in this areais intensive and essentially based on Kokoro yams [13] whichhave very variable yields from one season to another due toclimatic hazards [13]

22 Site Selection and Survey Twenty-five villages (Table 1Figure 1) were randomly selected throughout the study areaand its ethnic zones for the survey Data were collected fromthe different sites during expeditions through the applicationof ParticipatoryResearchAppraisal tools and techniques suchas granary visits direct observation focus group discussionsand individual interviews using a questionnaire and the helpof translators from each area following Dansi et al [12]In each site local farmersrsquo associations were involved inthe study to facilitate the identification of the householdsto survey and the data collection Within villages 10 to 12households were randomly selected for individual interviewsusing the transect method described by Dansi et al [17] Ineach household the interviewee (head of household or hiswife or one of his wives in case of polygamy) was selectedby mutual agreement with the hosting couple according toChristinck et al [18] Apart from the socioeconomic data suchas age gender and educational level of the interviewees datacollected included the farmersrsquo perceptions of the constraintsof yam chips production the cossette storage structures andpractices the importance of damages caused by insects thetime of the infestation the farmersrsquo knowledge of the insectspecies the traditional management practices on the infestedstocks and the farmersrsquo preference criteria of kokoro varietiesused in the production of the chips Preference criteria ofkokoro varieties were identified and prioritized using thematrix scoring technique described by Defoer et al [19]Adoukonou-Sagbadja et al [20] and Dansi et al [12] In eachvillage samples (500 g) of infested yam chips were collecteddirectly from two to three randomly selected yam chipsstorage structures following Mendesil et al [21] and Koradaaet al [22] Initial weights of the samples to be collected weretaken using the numerical balance (model SF-400) Infestedsamples collected were preserved in plastic containers withperforated lids to allow for ventilationWith the aid of a planttaxonomist at the national herbarium of the University ofAbomey-Calavi insecticides andor insect repulsive plants





Study area

N

1∘09984000998400998400E 2

∘09984000998400998400E 3

∘09984000998400998400E

10∘09984000998400998400N

9∘09984000998400998400N

1∘09984000998400998400E 2

∘09984000998400998400E 3

∘09984000998400998400E

10∘09984000998400998400N

9∘09984000998400998400N





3 Results





spon

dent

s (

)

0

5

10

15

20

25

30

35


483 558892

2491

3383

1338

409 2970 149

(a)

010203040506070

[1ndash3

0]

[30ndash

60]

[60ndash

90]

[90ndash

120]

[120

ndash150

]

Oth

ers

Number of days

Resp

onde

nts (

)

6952

1598

334 223 149744

(b)










































4 Discussion



















Biboı 44


Aye 2Satchila 2













5 Conclusion


Acknowledgments


References









































































Game Theory




Complex Systems

Journal of















ISRN Combinatorics



Geometry






DecisionSciences





Algebra





Volume 2013





Study area

N

1∘09984000998400998400E 2

∘09984000998400998400E 3

∘09984000998400998400E

10∘09984000998400998400N

9∘09984000998400998400N

1∘09984000998400998400E 2

∘09984000998400998400E 3

∘09984000998400998400E

10∘09984000998400998400N

9∘09984000998400998400N





3 Results





spon

dent

s (

)

0

5

10

15

20

25

30

35


483 558892

2491

3383

1338

409 2970 149

(a)

010203040506070

[1ndash3

0]

[30ndash

60]

[60ndash

90]

[90ndash

120]

[120

ndash150

]

Oth

ers

Number of days

Resp

onde

nts (

)

6952

1598

334 223 149744

(b)










































4 Discussion



















Biboı 44


Aye 2Satchila 2













5 Conclusion


Acknowledgments


References









































































Game Theory




Complex Systems

Journal of















ISRN Combinatorics



Geometry






DecisionSciences





Algebra





Volume 2013


spon

dent

s (

)

0

5

10

15

20

25

30

35


483 558892

2491

3383

1338

409 2970 149

(a)

010203040506070

[1ndash3

0]

[30ndash

60]

[60ndash

90]

[90ndash

120]

[120

ndash150

]

Oth

ers

Number of days

Resp

onde

nts (

)

6952

1598

334 223 149744

(b)










































4 Discussion



















Biboı 44


Aye 2Satchila 2













5 Conclusion


Acknowledgments


References









































































Game Theory




Complex Systems

Journal of















ISRN Combinatorics



Geometry






DecisionSciences





Algebra





Volume 2013
























4 Discussion



















Biboı 44


Aye 2Satchila 2













5 Conclusion


Acknowledgments


References









































































Game Theory




Complex Systems

Journal of















ISRN Combinatorics



Geometry






DecisionSciences





Algebra





Volume 2013














Biboı 44


Aye 2Satchila 2













5 Conclusion


Acknowledgments


References









































































Game Theory




Complex Systems

Journal of















ISRN Combinatorics



Geometry






DecisionSciences





Algebra





Volume 2013









5 Conclusion


Acknowledgments


References









































































Game Theory




Complex Systems

Journal of















ISRN Combinatorics



Geometry






DecisionSciences





Algebra





Volume 2013







































































Game Theory




Complex Systems

Journal of















ISRN Combinatorics



Geometry






DecisionSciences





Algebra





Volume 2013

storage insects on yam chips and their traditional ... · triusnigrescenslewis,xylocorisflavipes...

Documents