Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Oil Palm Agroforestry Can Achieve Economic and Environmental Gains as Indicated by Multifunctional Land Equivalent Ratios
    Khasanah, Nikmatul ; Noordwijk, Meine van; Slingerland, Maja ; Sofiyudin, Mohammad ; Stomph, Dienke ; Migeon, Adrien F. ; Hairiah, Kurniatun - \ 2020
    Frontiers in Sustainable Food Systems 3 (2020). - ISSN 2571-581X
    carbon footprint - cocoa - ecosystem services - intercropping - land equivalent ratio (LER) - oil palm - pepper - WaNuLCAS model

    Driven by increased global demand for vegetable oil in the food and biofuel sectors, oil palm plantations based on monoculture technology have expanded into lowland tropical forests. Interest in diversified, mixed oil palm systems is increasing as these might increase efficiency of the use of land and other resources, reduce farmer risk, and decrease greenhouse gas (GHG) emissions per unit product. Land Equivalent Ratio for provisioning services (LERP) values above 1.0 show that at least some diversified systems use land more efficiently than monocultures and are thus “land sparing,” where monoculture LERP cannot exceed 1.0. Diversification also modifies climate and water regulating functions (“land sharing”) relative to a forest reference, as indicated in the LERR index. A “multifunctional” LERM indicator combines both; land sparing plus land sharing effects jointly determine expected regulating services. Empirical assessment of multiple ecosystem services in agricultural landscapes is assisted by models that synthesise process-based knowledge, especially for perennial systems where well-designed experiments require a full production cycle, and are costly and scarce. Agroforestry models explore spacing, intercropping and soil management options, predicting harvestable yields, impacts on water flows, nutrient leaching, and greenhouse gas emissions. We used the process-based Water, Nutrient and Light Capture in Agroforestry System (WaNuLCAS) model to explore mixed oil palm + cocoa and oil palm + pepper intercrop systems with modified (“double row”) planting patterns for Indonesian contexts and estimated consequences for the carbon footprint. The oil palm + cocoa intercrop provided a high LERP (1.4), while also replenishing more ground water and having a lower C footprint. This combination also has a return to labour equal to that in oil palm monocultures and a higher benefit cost ratio than the oil palm + pepper combination that maximizes Net Present Value. Oil palm + cocoa systems are also less sensitive to price uncertainty for oil palm, and buffer for oil palm and cocoa production risks, assumed to be independent of each other. Considerable economic and environmental system improvements appear to be feasible through mixed oil palm systems and diversification as a pathway to intensification deserves full attention of research and policy development.

    Scaling and institutionalization within agricultural innovation systems : the case of cocoa farmer field schools in Cameroon
    Muilerman, Sander ; Wigboldus, Seerp ; Leeuwis, Cees - \ 2018
    International Journal of Agricultural Sustainability 16 (2018)2. - ISSN 1473-5903 - p. 167 - 186.
    Africa - agricultural extension - Cameroon - cocoa - innovation
    The farmer field school (FFS) concept has been widely adopted, and such schools have the reputation of strengthening farmers’ capacity to innovate. Although their impact has been studied widely, what is involved in their scaling and in their becoming an integral part of agricultural innovation systems has been studied much less. In the case of the Sustainable Tree Crops Programme in Cameroon, we investigate how a public–private partnership (PPP) did not lead to satisfactory widespread scaling in the cocoa innovation system. We build a detailed understanding of the key dimensions and dynamics involved and the wider lessons that might be learned regarding complex scaling processes in the context of agricultural innovation systems. Original interview data and document analysis inform the case study. A specific analytical approach was used to structure the broad-based exploration of the qualitative dataset. We conclude that scaling and institutionalization outcomes were impeded by: the lack of an adaptive approach to scaling the FFS curriculum, limited investments and genuine buy-in by extension actors, a failure to adapt the management approach between the pilot and the scaling phase, and the lack of strategic competencies to guide the process. Our findings support suggestions from recent literature that pilots need to be translated and adapted in light of specific contextual and institutional conditions, rather than approached as a linear rolling-out process. These findings are relevant for the further spread of similar approaches commonly involved in multi-stakeholder scaling processes such as innovation platforms.
    Dietary epicatechin intake and 25-year risk of cardiovascular mortality: the Zutphen Elderly Study
    Dower, J.I. ; Geleijnse, J.M. ; Hollman, P.C.H. ; Soedamah-Muthu, S.S. ; Kromhout, D. - \ 2016
    American Journal of Clinical Nutrition 104 (2016)1. - ISSN 0002-9165 - p. 58 - 64.
    cardiovascular disease - cocoa - epicatechin - flavan-3-ols - tea
    Background: Prospective cohort studies have shown that the consumption of cocoa and tea is associated with lower risk of cardiovascular diseases (CVDs), and cocoa and tea have been shown to improve CVD risk factors in randomized controlled trials. Cocoa and tea are major dietary sources of the flavan-3-ol epicatechin.

    Objective: We investigated the associations of dietary epicatechin intake with 25-y CVD mortality in elderly Dutch men.

    Design: We used data from the Zutphen Elderly Study, which was a prospective cohort study of 774 men aged 65–84 y in 1985. Epicatechin intake was estimated 4 times in 15 y with the use of the crosscheck dietary history method. Time-dependent Cox proportional hazards models were used to investigate repeated measures of epicatechin intake in relation to 25-y CVD mortality.

    Results: Mean intake of epicatechin was 15.2 ± 7.7 mg/d, and the major dietary sources were tea (51%), apples (28%), and cocoa (7%). During 25 y of follow-up, 329 men died from CVD, 148 died from coronary heart disease (CHD), and 72 men died from stroke. Risk of CHD mortality was 38% lower in men in the top tertile of epicatechin intake than in men in the bottom tertile of epicatechin intake (HR: 0.62; 95% CI: 0.39, 0.98). Epicatechin intake was also significantly associated with 46% lower risk of CVD mortality in men with prevalent CVD (HR: 0.54; 95% CI: 0.31, 0.96) but not in men who were free of CVD.

    Conclusions: We show, for the first time to our knowledge, that epicatechin intake is inversely related to CHD mortality in elderly men and to CVD mortality in prevalent cases of CVD. More studies are needed before conclusions can be drawn
    Upscaling sustainability initiatives in international commodity chains : Examples from cocoa, coffee and soy value chains in the Netherlands.
    Ingram, V.J. ; Judge, L.O. ; Luskova, Martina ; Berkum, S. van; Berg, J. van den - \ 2016
    Wageningen : Statutory Research Tasks Unit for Nature & the Environment (WOt-technical report 67) - 125
    value chains, soy, cocoa, coffee, policy, trade, development policy, sustainability, upscaling - waardeketenanalyse - basisproducten - cacao - koffie - glycine soja - duurzaamheid (sustainability) - handel - nederland - value chain analysis - commodities - cocoa - coffee - glycine soja - sustainability - trade - netherlands
    This study reports on the extent to which sustainability initiatives in the cocoa, coffee and soy value chains
    have been scaled up by companies. We have investigated how the private sector can be further stimulated to engage in, sustain and increase their involvement in actions to increase the sustainability of commodity chains with links to the Netherlands. The report analyses the motives for companies to join sustainability initiatives and their reasons for not engaging. It concludes with several recommendations on how government and value-chain stakeholders could further stimulate the scaling up of sustainability initiatives
    Kusheh, na minem Fatu, en mi na koko farmer Hello, I am Fatu and I am a cocoa farmer : a Digital Farmer Field School for training in cocoa production and certification in Sierra Leone
    Witteveen, L.M. ; Goris, Margriet ; Lie, R. ; Ingram, V.J. - \ 2016
    Wageningen : Wageningen UR Science Shop (Report /Wageningen UR, Science Shop 330) - ISBN 9789462577657 - 44
    agricultural extension - cocoa - farmers - information technology - sierra leone - landbouwvoorlichting - cacao - boeren - informatietechnologie - sierra leone
    This document reports on the development of a prototype Digital Farmer Field School (DFFS) called Kusheh, na minem Fatu, en mi na koko farmer (“Hello, I am Fatu and I am a cocoa farmer”). The DFFS provides an ICT-based alternative to traditional agricultural extension. More specifically, it offers a tablet-based substitute for the face-to-face certification training for cocoa farmers in Sierra Leone. The fact that gatherings of more than five people at a time were not allowed as a consequence of the Ebola outbreak triggered the development of the digital alternative to group training for cocoa farmers.
    Impact of UTZ certification on cocoa producers in Ghana, 2011 to 2014
    Waarts, Y.R. ; Ingram, V.J. ; Linderhof, V.G.M. ; Puister-Jansen, L.F. ; Rijn, F.C. van; Aryeetey, Richmond - \ 2015
    Wageningen : LEI Wageningen UR (Report / LEI Wageningen UR 2015-066) - ISBN 9789086157150 - 47
    cocoa - certification - farmers - small farms - peasant farming - ghana - cacao - certificering - boeren - kleine landbouwbedrijven - landbouw bedrijven in het klein - ghana
    This study evaluates the impact of the UTZ-Solidaridad cocoa programme in Ghana , by comparing the situation of a sample of farmers from six projects in 2014 with their situation in 2011, and by comparing the development over time for certified and uncertified farmers. We also analysed the programme’s inclusiveness and shed light on the effect of UTZ certification on hired labourers’ working conditions.
    Could nutrition sensitive cocoa value chains be introduced in Ghana? Report of a brief study that identifies opportunities and bottlenecks
    Vries, K. de - \ 2015
    Wageningen : Centre for Development Innovation, Wageningen UR (Report CDI / Wageningen UR, Centre for Development Innovation 15-105) - 22
    food consumption - households - gender relations - women - cocoa - undernutrition - nutrition - ghana - africa - west africa - voedselconsumptie - huishoudens - man-vrouwrelaties - vrouwen - cacao - ondervoeding - voeding - ghana - afrika - west-afrika
    This study looks at whether introducing nutrition sensitive cocoa value chains in Ghana is feasible and recommends how this could be done. After establishing the cocoa farming and nutrition context in Ghana, the study zooms in on one cocoa producing sub-district to collect detailed data in order to provide recommendations.
    Mineral nutrition of cocoa : a review
    Vliet, J.A. van; Slingerland, M.A. ; Giller, K.E. - \ 2015
    Wageningen : Wageningen UR - ISBN 9789462577053 - 57
    cacao - mineralenvoeding - bevruchting - kunstmeststoffen - mestbehoeftebepaling - vruchtbaarheid - voedingsstoffenbehoeften - voedingsstoffenbeschikbaarheid - grondanalyse - voedingsstoffentekorten - kaliummeststoffen - stikstofmeststoffen - fosformeststoffen - agrarische productiesystemen - overzichten - cocoa - mineral nutrition - fertilization - fertilizers - fertilizer requirement determination - fertility - nutrient requirements - nutrient availability - soil analysis - nutrient deficiencies - potassium fertilizers - nitrogen fertilizers - phosphorus fertilizers - agricultural production systems - reviews
    This literature review on mineral nutrition of cocoa was commissioned by the Scientific Committee of the Cocoa Fertiliser Initiative to address the following questions: What knowledge is currently available about mineral nutrition of cocoa? What are the current knowledge gaps? What are the key areas for further research?
    Certifications, child labour and livelihood strategies: an analysis of cocoa production in Ghana
    Owusu-Amankwah, R. - \ 2015
    Wageningen University. Promotor(en): Han Wiskerke; Guido Ruivenkamp, co-promotor(en): Joost Jongerden. - Wageningen : Wageningen University - ISBN 9789462574915 - 348
    cacao - productie - landbouw bedrijven in het klein - gemeenschappen - kinderarbeid - strategieën voor levensonderhoud - certificering - agrarische productiesystemen - ghana - cocoa - production - peasant farming - communities - child labour - livelihood strategies - certification - agricultural production systems - ghana


    There have been various innovative initiatives by global and local actors in response to pressure on cocoa value-chain actors to free cocoa production from child labour (CL) and especially the worst forms of child labour (WFCL) and also to improve the livelihoods of farm families. Analyses of the implementation, implications and the appropriateness of these initiatives in driving change in the cocoa supply chain and improving the labour and income conditions in cocoa farms are limited, however. This study examines initiatives being led by the key actors in the value chain – the governmental initiative of a community-based child labour monitoring (CCLM) system (CCLMS), that led by business actors of third party voluntary cocoa certification (TPVCC), and farmers’ own way of diversifying income – in order to understand current developments in the cocoa value-chain and analyse the dynamics between the local and global actors and the effect of these dynamics for the reorganisation of the cocoa production system in Ghana.

    This thesis employs an interdisciplinary perspective and combines innovation theory with livelihood, social perspectives and other social science tools to empirically investigate the initiatives as they operate at micro-, meso- and macro-levels so as to ascertain their implications for farmers’ livelihoods and children’s social situations. It also reflects scholarly interest in understanding how global-level development interacts with and affects local-level development, and how globalisation shapes and mediates local influences within the cocoa production system.

    Firstly, the CCLMS study (Chapter 3) reveals three kinds of benefits to children: an expanded social network, a reduction in their participation in hazardous work and an improvement in school attendance. The findings show that absenteeism on the part of the pupils in a community with a CCLM intervention is approximately half that of two communities without intervention. In addition, it is observed that although children are involved in hazardous and non-hazardous activities in all the three communities involved in the study, the extent of their involvement in hazardous activities is higher in the communities without intervention.

    Secondly, third party certification (TPC) formulated by the business actors is a key innovation in the cocoa production system of Ghana. The study presented in Chapter 4 shows the potential of TPVCC to mobilise financial, human and social capitals to address gaps and

    dysfunctions and create a win-win situation for all the actors of the value chain. However, sector-wide standards that address sector specific needs taking into consideration the views of chain actors, especially farmers and their socio-cultural context will enhance compliance. This is because global or international standards cannot be imposed but are analysed, contested and adapted by farmers to suit on-the-ground practices. The study also shows the potential of TPVCC to address CL and livelihood issues, but these will yield better results if it is implemented in enhanced socio-economic conditions. Regardless of these positives, the net benefit of certification is unclear due to the difficulty in conducting proper cost-benefit analyses in the absence of proper documentation of farmer-level costs and other factors.

    Thirdly, the findings show that about 70% of farmers are diversifying into other (non-cocoa) farm and non-farm activities using largely indigenous resources, but on a small scale and at subsistence level. This condition means that the goal of farmers to supplement cocoa income and reduce risk is not achieved throughsuch a level of diversification. There is some indication of increasing importance of income and resources from non-farm activities, but income from cocoa continues to determine household income as well as the demand for non- farm goods and investment in the non-farm sector. This study also finds that children are involved in both farm and non-farm activities, which can be classified as hazardous and non- hazardous. Farmers, especially caretakers, producing at subsistence level are likely to use their children to supplement labour needs. Some policy recommendations are made in the areas of economic incentives and multi-stakeholder collaboration to stimulate the sector towards sustainability.

    Integrating ecosystem services into the tropical commodity value chain : cocoa, soy and palm oil
    Berg, J. van den; Ingram, V.J. ; Judge, L.O. ; Arets, E.J.M.M. - \ 2014
    Wageningen : Statutory Research Tasks Unit for Nature & the Environment (WOT Natuur & Milieu) (WOt-technical report 6) - 101
    ecosysteemdiensten - theobroma cacao - cacao - glycine soja - palmoliën - waardeketenanalyse - basisproducten - duurzaamheid (sustainability) - tropen - innovaties - ecosystem services - theobroma cacao - cocoa - glycine soja - palm oils - value chain analysis - commodities - sustainability - tropics - innovations
    This technical report explores the governance options available to the Dutch government to promote the sustainable use and maintenance of ecosystem services in tropical commodity value chains with Dutch links. It examines how ecosystem services can be given a more explicit role in public and market mechanisms, using the cocoa, soy, palm oil and timber chains as case studies. The document presents a discourse analysis of the way Dutch policies and practice address ecosystem services, updating the report of a forerunner study on the timber chain (Van den Berg et al. 2013). The discourse analysis indicates that the term ecosystem services still lacks a clear definition in Dutch policy, with ecosystem services largely being seen as an economic issue, which can be solved by market drive, voluntary and multi-actor value chain based solutions. The report presents results of a detailed examination of specific cases of innovation in sustainability initiatives and payments for ecosystem services projects in the cocoa chain, the Round Table for Responsible Soy (RTRS) and the Round Table for Sustainable Palm Oil (RSPO). Lessons learnt from the analysis of these cases include the need to simplify what is meant by ecosystem services – for example using the term natural capital - to make it more appealing and intuitive, particularly for business. More evidence is needed on the impact of certification and how it maintains or enhances ecosystem services. Internationally agreed impact indicators are also recommended. The array of available certification schemes could be harmonised. A mix of policy instruments appears to offer more scope for the government, using market based ‘carrots’ and incentive-based ‘sticks’ (such as tax incentives and pilot projects) to stimulate new partnerships and initiatives. Challenges include giving ecosystem services an explicit role in policysupported innovations, and engaging with all value chain stakeholders, particularly community and consumer organisations.
    Updating cocoa stories
    Witteveen, L.M. ; Rijn, A. van - \ 2014
    Wageningen : Wageningen UR
    cacao - cacaobonen - ghana - nederland - gewasbescherming - schimmelbestrijding - bestrijdingsmethoden - gewasproductie - verwerkingskwaliteit - kennis van boeren - geschiedenis - cocoa - cocoa beans - ghana - netherlands - plant protection - fungus control - control methods - crop production - processing quality - farmers' knowledge - history
    The history of cocoa production and the current cocoa story. It's a story about commercial interest, pest control, cocoa products and the importance of education of farmers to make the cocoa chain more sustainable
    The impact of UTZ certification of cocoa in the Ivory Coast 2008 to 2013
    Ingram, V.J. ; Waarts, Y.R. ; Vugt, S.M. van; Ge, L. ; Wegener, L. ; Puister-Jansen, L.F. - \ 2014
    Wageningen : LEI Wageningen UR - 16
    ivoorkust - afrika - certificering - cacao - theobroma cacao - cacaoproducten - duurzaamheid (sustainability) - cote d'ivoire - africa - certification - cocoa - theobroma cacao - cocoa products - sustainability
    In 2008, various value chain partners in Ivory Coast adopted the UTZ Code of Conduct and became UTZ certified to enhance sustainability in the cocoa supply chain. As part of the certification programme, cooperatives and are receiving training on farm management organisational capacity building. This brochure paints a picture of the situation on farms by mid-2013. It provides information about how the UTZ Certified cocoa programme in Ivory Coast is helping farmers to increase their knowledge and use good agricultural practices (GAPs) in line with the UTZ Certified Code of Conduct. The lessons learned from these results will be used to improve the quality of the programme.
    Impact of UTZ Certification of cocoa in Ivory Coast. Assessment framework and baseline
    Ingram, V.J. ; Waarts, Y.R. ; Ge, L. ; Vugt, S.M. van; Wegner, Lucia ; Puister-Jansen, L.F. - \ 2014
    Den Haag : LEI Wageningen UR (LEI report 2014-010) - ISBN 9789086156764 - 174
    cacao - ivoorkust - duurzame ontwikkeling - theobroma cacao - kwaliteit voor voedselverwerking - houdbaarheid (kwaliteit) - opslagkwaliteit - bedrijfsvergelijking in de landbouw - certificering - cocoa - cote d'ivoire - sustainable development - theobroma cacao - food processing quality - keeping quality - storage quality - farm comparisons - certification
    Since 2008 UTZ Certified has implemented a programme in Ivory Coast to enhance sustainability in the cocoa supply chain through the implementation of the UTZ Code of Conduct. The programme has supported farmers to become organised into cooperatives, receiving training on farm management and organisational capacity building, and become certified. Starting off with four cooperatives, two traders and Solidaridad as partners, it has grown into a large scale programme. By June 2012 86 cooperatives were certified, 44,624 farmers reached, and 128,582 tons of certified cocoa had been produced from an estimated farm area of 219,100 hectares. Eight traders and the Sustainable Trade Initiative (IDH) are now partners, who are implementing certification as part of broader activities to support cocoa farmers, their cooperatives and communities. As of June 2013, a further 103 cooperatives were in the process of certification. This report serves two purposes: it provides a baseline of farm-level situation as of mid-2013, which can be used to measure changes in indicators in future impact assessments. It also provides an initial assessment of impacts by comparing different groups of cocoa farmers. It provides information about the inclusiveness of the UTZ Certified cocoa programme in Ivory Coast. It evaluates how certification and related activities have affected farmers’ knowledge and implementation of good agricultural practices, social and environmental issues in line with the UTZ Certified Code of Conduct and assesses the added value of certification. Lessons learned are drawn from the results, feeding recommendations to improve the quality and effectiveness of the programme.
    Monitoring and estimating the consumption of certified sustainable cocoa and coffee in the Netherlands : availability and application of data
    Logatcheva, K. - \ 2014
    Wageningen : LEI Wageningen UR (Memoradum / LEI 14-055) - 14
    cacao - koffie - duurzaamheid (sustainability) - consumptie - monitoring - cocoa - coffee - sustainability - consumption - monitoring
    Er zijn verschillende instanties die (niet-)systematische informatie verzamelen over de Nederlandse koffie- en cacaosectoren die bruikbaar is om het behalen van de doelstellingen van de intentieverklaringen in de koffie in cacaosectoren12 te meten: individuele bedrijven en sectororganisaties, publieke en private instellingen voor marktonderzoek. Volgens de Koninklijke Nederlandse Vereniging van Koffie en Thee (KNVKT) was het marktaandeel van duurzaam gecertificeerde koffie op de Nederlandse markt in 2012 40%. Dit gegeven zal systematisch en periodiek worden geactualiseerd op de website van de KNVKT. Andere informatie die de monitoring van de resultaten van de inspanningen van de sectoren in Nederland mogelijk zou kunnen maken, is echter beperkt door hoge kosten en complexiteit van de koffie- en cacaoketens. De sectoren worden gedomineerd door grote internationale bedrijven die in meerdere landen actief zijn. Voorts is er sprake van een grote differentiatie van soorten consumentenproducten, met name in de cacaosector. Adhocinformatie maakt slechts een enkele (grove) schatting voor een bepaalde periode mogelijk. Volgens deskundigen uit het cacaoverwerkingssegment was het aandeel gecertificeerde duurzame cacao in consumentenproducten die verkocht zijn op de Nederlandse markt in 2012 niet hoger dan 25%. Andere verzamelde (ad-hoc)informatie over de cacaomarkt geeft geen aanleiding om deze schatting te verwerpen. Het onderzoek naar koffiesector is verricht in 2012 met enkele relevante updates in 2013. Het onderzoek naar cacaosector is verricht in 2012 en 2013 met enkele relevante updates voor 2014.
    Towards sustainable cocoa: Assessment of Cargill and Solidaridad cocoa farmer support activities in Côte d’Ivoire 2008-2012
    Ingram, V.J. ; Waarts, Y.R. ; Vugt, S.M. van; Ge, L. ; Wegner, L. ; Puister-Jansen, L.F. - \ 2013
    Wageningen : LEI Wageningen UR (LEI ) - 24
    cacao - cacaobonen - kleine landbouwbedrijven - boeren - boerenorganisaties - duurzaamheid (sustainability) - good practices - ghana - afrika - cocoa - cocoa beans - small farms - farmers - farmers' associations - sustainability - good practices - ghana - africa
    A touch of cocoa; Baseline study of six UTZ-Solidaridad cocoa projects in Ghana
    Waarts, Y.R. ; Ge, L. ; Ton, G. ; Mheen-Sluijer, J. van der - \ 2013
    The Hague : LEI, part of Wageningen UR (LEI-report : Market & chains ) - ISBN 9789086156436 - 183
    cacao - cacaobonen - kleine landbouwbedrijven - boeren - boerenorganisaties - duurzaamheid (sustainability) - landarbeiders - good practices - ghana - afrika - cocoa - cocoa beans - small farms - farmers - farmers' associations - sustainability - farm workers - good practices - ghana - africa
    Incentives for smallholders to enhance the production of quality cocoa beans in Ghana: the role of institutions
    Quarmine, W. - \ 2013
    Wageningen University. Promotor(en): Arnold van Huis; D. Obeng-Ofori; F. Asante, co-promotor(en): Rein Haagsma. - Wageningen : Wageningen UR - ISBN 9789461738080 - 165
    theobroma cacao - cacao - cacaobonen - landbouwbeleid - kwaliteit - certificering - bewonersparticipatie - ghana - theobroma cacao - cocoa - cocoa beans - agricultural policy - quality - certification - community participation - ghana

    Cocoa beans from Ghana have a reputation of being of consistent quality. As such they sell at a premium on the international market. As a result of this quality reputation, Ghana is able to sell over 70% of its annual produce in forward markets. This trading practice ensures that farmers are protected from price fluctuation in the international market. Consequently, farmers, buyers, scientists and policy makers agree that sustaining Ghana’s premium quality position on the international market should be a central component of cocoa sector policies in Ghana.

    Over the years, therefore, policy and programme attention has been placed on ensuring that the produce supplied by farmers is of superior quality. Some of these efforts have included development of clearer quality parameters, establishment of cooperative societies, market liberalization, introduction of competition in the cocoa market, and farmer extension reforms among others. In spite of the attention paid to quality, evidence is emerging that farmers can do more to enhance the quality of their produce. For example, nationwide, disease infestation alone results in loss of up to 35% of the potential crop. Also, the surge in poorly fermented and not thoroughly dried produce has been amply described in the literature. These quality issues would not arise if farmers were to improve their rate of adoption of the several recommended quality-enhancing technologies developed by scientists.

    The question is therefore frequently asked: why does the rate of adoption of recommended technologies by farmers fall below the expectation of policy makers and scientists? Drawing mainly from new institutional economics, this thesis argues that the adoption by farmers of quality-enhancing technologies is hampered by the rules (or institutions) that govern interactions in the internal cocoa market of Ghana. The central object of this thesis is to gain an insight into what institutional factors are and how they can be altered to provide effective incentives for Ghanaian cocoa farmers to enhance the production of quality cocoa beans.Five specific objectives were addressed. First, impact of specific price-related institutional reforms on producer incentives was analysed. Second, the study identified relevant institutional factors constraining smallholders from enhancing the production of quality cocoa beans. These two studies set the stage for experimentation with alternative institutional mechanisms which might motivate cocoa farmers to enhance the quality of their produce. Hence, the third objective explored agricultural knowledge institutions by comparing the effectiveness of participatory and conventional extension methods on accumulation of knowledge and adoption of quality-enhancing technologies. The fourth and fifth objective of this study then focused on what alternative institutions may be designed to govern cocoa beans trade to ensure that Ghana sustains its good premium quality reputation. The fourth objective of this study assessed the influence of incentive mechanisms designed by certification programs on farmers’ effort to enhance the quality of cocoa beans they produce. The fifth objective then attempted to determine the extent to which farmers respond to a price differentiation structure which builds in mechanisms of rewards and punishments.

    Having introduced the thesis in the first chapter, Chapter 2 addressed three questions: (1) did prices and the variation of these prices influence cocoa supply?; (2) to what extent did institutional reforms affect the stability of producer prices? and (3) how did cocoa price-related institutional reforms affect the transmission of world price to producers? A time series econometrics approach was employed in this study. To assess the impact of prices on farmer behaviour, a double-logarithmic ordinary least squares (OLS) regression was estimated. Cocoa production was regressed on current and lagged producer prices and on a number of control variables, including the price of maize. To answer the question of how cocoa price-related institutional reforms affected the transmission of world price to producers, specific reform eras were first identified. These were: (1) before and after the introduction of the Producer Price Review Committee (PPRC); and (2) before the use of cost-plus-margin price rule; during the cost-plus-margin price rule; and during the percentage F.O.B. pricing rule. Next, a co-integration and error correction approach was employed to analyse the impact of these reform periods on the transmission of world prices to producers. The results confirmed economic theory in that increases in the producer price provided sufficient incentives for farmers to increase their output while the variation or instability of this price was a disincentive. The institutional reforms led to increases in prices but did little to stabilize producer prices over the years. These results pointed to the important role institutions can play in shaping farmer incentives.

    The time series data employed in the analyses of institutions failed to account for the perspectives of stakeholders. Chapter 3 therefore employed a cross-sectional approach to investigating how institutions shape the incentive for smallholders to enhance the quality of their produce. A number of formal and informal institutions work together to constrain farmers’ capacityand willingness to enhance the production of quality cocoa beans. Farmer knowledge institutions, especially the organization of cocoa extension, have resulted in low contact hours between farmers and extension agents. This affected the knowledge and hence capacity of farmers to utilize relevant technological innovations which could enhance the quality of their produce. Farmers’ unwillingness to enhance the quality of their cocoa beans any further also arises from institutional factors like land tenure contracts, corruption, and rent-seeking behaviour of cocoa buyers,whichaffect their income position. Farmers do not have enough countervailing power to deal with these problems because they are often very weakly organized. The willingness of farmers to enhance the quality of their produce is also influenced by an asymmetric information problem. This problem arises because buyers do not determine the quality features of the produce before or even after sale transaction. This asymmetric information is attributed to the lack of market governance structuresthat ensure thatcocoa beans are graded before purchase from farmers. The absence of grading before purchase results in payment of uniform pricesfor all quality grades. In the absence of a pay-for-quality policy farmers will rather not invest extra labour in furtherenhancing produce quality.

    In Chapter 4, the effectiveness of participatory and conventional extension methods of extension on accumulation of knowledge and adoption of quality-enhancing technologies was compared. Farmers involved in participatory research were compared with those involved in conventional extension in terms of knowledge accumulation, yields and bean quality. It was found that using recommended technologiescan enhance the cocoa bean quality 17% more than current practices. At a cocoa price of US$ 1.86 per kilogramme, profits per hectare were with recommended technologies about 8% higher than with farmers’ practices, just because recommended technologies yielded higher volumes of cocoa. If cocoa prices at the farm gate would be differentiated by quality, the relative profitability of using good agricultural practices would even be higher.Being trained through participatory methods resulted in significant improvement in farmers’ knowledge. Their gain in knowledge did not motivate farmers to enhance cocoa bean quality, butrather farmers selected specific yield-enhancing technologies for adoption. This chapter confirmed that as long as there is a lack of market incentives farmers are unwilling to adopt quality-enhancing recommended technologies.

    In Chapter 5,the question of how certification programs influence farmers to enhance the production of quality cocoa beans was addressed. The study identified the determinants of the choice between being an independent farmer and being a certified farmer. The study showed that farmers with a high marginal utility of income participated in certification. Furthermore, farmers that for some reason were constrained in their capacity to apply extra effort to their pre-harvest and post-harvest activities, by lack of time or health conditions, were not likely to join the certification program. Having joined certification programs a number of incentive mechanisms were used to coordinate farmers’ production activities to ensure they supply quality cocoa beans. First, certification programs organize farmers into producer organizations which use their internal rules of rewards and punishments to strictly enforce quality requirements. Also, certification programs employ traceability mechanisms where every cocoa bean can be traced to the farm where it was produced. Hence the information asymmetric problem is completely resolved. Additionally certification programs pay a higher price for the quality of produce they purchase. These mechanisms were not available to independent farmers. As a result of thesedifferences in trading practices and incentive mechanisms, certified farmers put up 17% more pre-harvest and 20% more post-harvest effort in their production practices than independent members. This explains why certified farmers recorded 52% higher yields and 12% better quality than independent farmers.

    In Chapter 6an alternative market governance mechanism to certification was experimented with. The impact of price differentiation with self-selection was tested by offering farmers in the Suhum district a menu of price; the regular producer price for lower quality Grade II cocoa beans and the higher price for Grade I cocoa. To receive the higher price however farmers were to pay a fee (of 1kg of cocoa beans) and had to have their beans tested. If the produce met the high standard set by the buyer, the seller received the high price (whichis equivalent to 3kg of cocoa), otherwise he or she just received the regular market price and the test fee would become his or her cost.The results showed that faced with this menu, farmers exposed to this test-cum-fee price option significantly improved the quality of their cocoa beans by 2.7% more than control farmers. Other factors which significantly impacted on the quality of farmers’ produce were previous involvement in farmer participatory research (Chapter 4) and dependence on cocoa as a main source of livelihood. A central aim of test-cum-fee price mechanism is to stimulate farmers to supply only their best quality produce. Over the two seasons of the experiment farmers who were exposed to the test-cum-fee price mechanism increased the proportion of their produce which was sold for a premium by 28%. The quality of these beans sold for a premium also improved over the experimental period by 3%. This self-selection behaviour is explained by farmers’ risk preferences, perception about the new price mechanisms, and their capacity to enhance their quality of their cocoa beans.

    In Chapter 7, the main findings of the study were summarisedand their policy implications were discussed. The study’s limitations were highlighted and some ideas for future research were proposed. Problems with cocoa bean quality at farmgate have been attributed to asymmetric information between farmers and buyers. As a result of this information problem, buyers are unwilling to pay for quality. This thesis puts forward two governance structures which can address the asymmetric information problem. First, it is demonstrated that certification of producer organizations with mechanisms of traceability, group control and price premiums can completely resolve the information problem. This thesis shows that another governance structure with a win-win potential to address the information problems in Ghana’s cocoa industry is price differentiation with self-selection mechanisms. Policy makers therefore need to pay closer attention to these mechanisms if Ghana is to sustain her position as a net supplier of premium quality cocoa beans.

    Microbial ecology of the cocoa chain : quality aspects and insight into heat-resistant bacterial spores
    Líma, L.J.R. - \ 2012
    Wageningen University. Promotor(en): Marcel Zwietering, co-promotor(en): Rob Nout. - S.l. : s.n. - ISBN 9789461734334 - 311
    cacao - theobroma cacao - cacaoproducten - fermentatie - micro-organismen - bacteriële sporen - hitteresistentie - voedselveiligheid - cocoa - theobroma cacao - cocoa products - fermentation - microorganisms - bacterial spores - heat resistance - food safety

    Cocoa beans (Theobroma cacaoL.) are the basis for chocolate and cocoa powder production. The first step in the production of these food products consists of a spontaneous fermentation of the beans in the tropical producing countries, in order to allow the formation of the essential precursor compounds of the cocoa flavour. Following this stage, cocoa beans are industrially transformed into a range of different products.

    In the first part of this thesis, the state of literature of cocoa bean fermentation was revisited with the aim of interlinking post-harvest processing practices and characteristics of the fermenting microbiota, with the quality of commercial cocoa beans obtained. This literature survey resulted in the identification of a number of research needs that can be used to design agricultural and operational measures, towards improving the quality of commercial cocoa beans. The second part of this thesis addressed the occurrence, levels and diversity of bacterial Thermoresistant Spores (ThrS) in commercial cocoa powder and in cocoa being transformed to cocoa powder in an industrial setting. Thermoresistant Spores were defined as spores which survive a heat-treatment of at least 100°C for 10 min, as opposed to the standard treatment at 80°C for 10 min for Total Spores (TS) determination. It was found that strains of Bacillus licheniformis and of the B. subtilis complex were the predominant species in the ThrS library and that strains of B. subtilis complex, including B. subtilis subsp. subtilis formed the most heat-resistant spores in situ and in vitro. Interestingly, a high heat-resistant spore phenotype was associated with diverse genotypes. In addition, a strategy was devised in order to identify biomarkers of spore heat-resistance. The comparison of physicochemical and ultrastructural properties among spores of different heat-resistance allowed the identification of manganese as a potential physiological biomarker for B. subtilis subsp. subtilis spores heat-resistance. On the other hand, a study of various genomic features conducted across strains of the phylum of Firmicutes, did not yield genomic biomarkers related to spore high heat-resistant phenotype, suggesting the primary role of spore physicochemical composition and ultrastructural characteristics as determinant factors of spore differential heat-resistance.

    In conclusion, this study presents suggestions to delve into the functionality of the microbiota involved in cocoa bean fermentation and to improve the quality of commercial cocoa beans. Furthermore, it contributes towards the understanding of the ecology of high heat-resistant aerobic bacterial spores in the cocoa chain and provides knowledge regarding their heat-resistance. The data gathered in this thesis are useful input for predictive modelling and to assist in the production of safe and high quality food.

    Some Phenolic Compounds Increase the Nitric Oxide Level in Endothelial Cells in Vitro
    Appeldoorn, M.M. ; Venema, D.P. ; Peters, T.H.F. ; Koenen, M.E. ; Arts, I.C.W. ; Vincken, J.P. ; Gruppen, H. ; Keijer, J. ; Hollman, P.C.H. - \ 2009
    Journal of Agricultural and Food Chemistry 57 (2009)17. - ISSN 0021-8561 - p. 7693 - 7699.
    rat thoracic aorta - dependent relaxation - red wine - blood-pressure - peanut skins - grape seeds - green tea - flavonoids - synthase - cocoa
    The vasorelaxing properties of chocolate and wine might relate to the presence of phenolic compounds. One of the potential mechanisms involved is stimulation of endothelial nitric oxide (NO) production, as NO is a major regulator of vasodilatation. This study aimed to develop an in vitro assay using the hybrid human endothelial cell line EA.hy926 to rapidly screen phenolic compounds for their NO-stimulating potential. The assay was optimized, and a selection of 33 phenolics, namely, procyanidins, monomeric flavan-3-ols, flavonols, a flavone, a flavanone, a chalcone, a stilbene, and phenolic acids, was tested for their ability to enhance endothelial NO level. Resveratrol, a well-known enhancer of NO level, was included as a positive control. Of the 33 phenolics tested, only resveratrol (285% increase in NO level), quercetin (110% increase), epicatechingallate (ECg) (85% increase), and epigallocatechingallate (EGCg) (60% increase) were significant (P = 0.05) enhancers. Procyanidins showed a nonsignificant tendency to elevate NO level. Concentration-dependent correlations between enhanced NO level and endothelial nitric oxide synthase (eNOS) expression were demonstrated for the three polyphenols tested (resveratrol, ECg, and EGCg). Thus, an easy screening tool for change in cellular NO level was developed. Use of this assay showed that only a limited number of phenolic compounds might enhance NO level with an increased amount of eNOS enzyme as a possible contributing mechanism.
    Efficient isolation of major procyanidin A-type dimers from peanut skins and B-type dimers from grape seeds
    Appeldoorn, M.M. ; Sanders, M.B. ; Vincken, J.P. ; Cheynier, V. ; Guerneve, C. Le; Gruppen, H. - \ 2009
    Food Chemistry 117 (2009)4. - ISSN 0308-8146 - p. 713 - 720.
    performance liquid-chromatography - low-density-lipoprotein - reversed-phase hplc - antioxidant activity - proanthocyanidins - cocoa - polymerization - fractionation - separation - extract
    In order to fully explore the biofunctional potential of proanthocyanidins (PA), isolated and well-characterised PA dimers are of great importance. Current methods to obtain pure A- and B-type dimers are laborious, because they comprise multiple chromatographic steps, often yielding only one or two specific dimers. In the current study, an efficient isolation procedure is described, to isolate a large variety of A-type dimers from peanut skins and B-type dimers from grape seeds. Yields increased 20-400 times for A-type dimers and about 10 times for B-type dimers compared to other methods with a lesser number of chromatographic steps. Dimers isolated from peanut skins were identified as; epicatechin-(2-O-7, 4-8)-catechin (A1), epicatechin-(2-O-7, 4-8)-epicatechin (A2), epicatechin-(2-O-7, 4-6)-catechin, epicatechin-(2-O-7, 4-8)-entcatechin, isolated from peanut skins for the first time, and epicatechin-(4-6)-catechin (B7). Dimers from grape seeds were identified as; epicatechin-(4-8)-catechin (B1), epicatechin-(4-8)-epicatechin (B2), catechin-(4-8)-catechin (B3) and catechin-(4-8)-epicatechin (B4)
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