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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Assessing land-use typologies and change intensities in a structurally complex Ghanaian cocoa landscape
Tutu Benefoh, Daniel ; Villamor, Grace B. ; Noordwijk, Meine van; Borgemeister, Christian ; Asante, Winston A. ; Asubonteng, Kwabena O. - \ 2018
Applied Geography 99 (2018). - ISSN 0143-6228 - p. 109 - 119.
Cocoa - Deforestation - Image-fusion - Intensity analysis - Land-use transitions

Cocoa plantation is a major land-use system that influences the functional structure of the forest landscape in Ghana. As a key driver of forest landscape dynamics, there is no adequate existing information on the nature, extent and magnitude of land-use change associated with cocoa expansion into forests. Therefore, we have studied the land-use transitions and intensities by using image-fusion on vegetation indices (VI) and a digital elevation model (DEM) to detect and distinguish cocoa plantation from the forest and other vegetation types. This was followed by intensity analysis based on historical land-use changes. With the VI-DEM image, we mapped out different cocoa plantations from the forest and other vegetations with a higher degree of success. The land-use categories were clustered into five main types (closed forest, open-forest, cocoa, lands-in-transition and settlement) to evaluate the transition and intensities from 1986 to 2015. The results showed two main transition patterns, namely 1) the conversion of forest to settlement and cocoa plantation; 2) the conversion of closed forests to open forest, due to logging and conversion of cocoa plantation to lands-in-transition (LIT). The intensity analysis further revealed that expansion in cocoa plantation instead targets least resisted open-forest and LIT areas with an isolated localised fragment of the fringes of forest reserves. Generally, the study revealed that the VI-DEM image-fusion technique is effective for detecting and isolating cocoa plantations, forest and other land-uses with high accuracy. Estimation of cocoa-led deforestation improved after isolating cocoa plantations. Cocoa expansions target more often open-forest and lands-in-transition than closed-forest. When cocoa expansion occurs in closed-forest, it is episodic, localised and coincides with the early stage of the boom-bust pattern.

Community-based malaria control in southern Malawi : A description of experimental interventions of community workshops, house improvement and larval source management
Berg, Henk van den; Vugt, Michèle van; Kabaghe, Alinune N. ; Nkalapa, Mackenzie ; Kaotcha, Rowlands ; Truwah, Zinenani ; Malenga, Tumaini ; Kadama, Asante ; Banda, Saidon ; Tizifa, Tinashe ; Gowelo, Steven ; Mburu, Monicah M. ; Phiri, Kamija S. ; Takken, Willem ; McCann, Robert S. - \ 2018
Malaria Journal 17 (2018)1. - ISSN 1475-2875
Community participation - Community workshops - Health education - House improvement - Integrated vector management - Larval source management - Malaria transmission - Vector control

Background: Increased engagement of communities has been emphasized in global plans for malaria control and elimination. Three interventions to reinforce and complement national malaria control recommendations were developed and applied within the context of a broad-based development initiative, targeting a rural population surrounding a wildlife reserve. The interventions, which were part of a 2-year research trial, and assigned to the village level, were implemented through trained local volunteers, or 'health animators', who educated the community and facilitated collective action. Results: Community workshops on malaria were designed to increase uptake of national recommendations; a manual was developed, and training of health animators conducted, with educational content and analytical tools for a series of fortnightly community workshops in annual cycles at village level. The roll-back malaria principle of diagnosis, treatment and use of long-lasting insecticidal nets was a central component of the workshops. Structural house improvement to reduce entry of malaria vectors consisted of targeted activities in selected villages to mobilize the community into voluntarily closing the eaves and screening the windows of their houses; the project provided wire mesh for screening. Corrective measures were introduced to respond to field challenges. Committees were established at village level to coordinate the house improvement activities. Larval source management (LSM) in selected villages consisted of two parts: one on removal of standing water bodies by the community at large; and one on larviciding with bacterial insecticide Bacillus thuringiensis israelensis by trained village committees. Community workshops on malaria were implemented as 'core intervention' in all villages. House improvement and LSM were implemented in addition to community workshops on malaria in selected villages. Conclusions: Three novel interventions for community mobilization on malaria prevention and control were described. The interventions comprised local organizational structure, education and collective action, and incorporated elements of problem identification, planning and evaluation. These methods could be applicable to other countries and settings.

Improving food security by reducing the maize yield gap in Ghana
Asante, F. ; Ittersum, M.K. van; Jongeneel, R.A. ; Adjei-Nsiah, S. ; Akotsen, Clement - \ 2017
University of Ghana (Policy brief / Institute of Statistical, Social and Economic Research (ISSER) ) - 4 p.
Malaria control in rural Malawi : Implementing peer health education for behaviour change
Malenga, Tumaini ; Kabaghe, Alinune Nathanael ; Manda-Taylor, Lucinda ; Kadama, Asante ; McCann, Robert S. ; Phiri, Kamija Samuel ; Vugt, Michèle van; Berg, Henk van den - \ 2017
Globalization and Health 13 (2017)1. - ISSN 1744-8603
Behaviour change - Community workshops - Health animator - Health education - Implementation - Malaria
Background: Interventions to reduce malaria burden are effective if communities use them appropriately and consistently. Several tools have been suggested to promote uptake and use of malaria control interventions. Community workshops on malaria, using the 'Health Animator' approach, are a potential behaviour change strategy for malaria control. The strategy aims to influence a change in mind-set of vulnerable populations to encourage self-reliance, using community volunteers known as Health Animators. The aim of the paper is to describe the process of implementing community workshops on malaria by Health Animators to improve uptake and use of malaria control interventions in rural Malawi. Methods: This is a descriptive study reporting feasibility, acceptability, appropriateness and fidelity of using Health Animator-led community workshops for malaria control. Quantitative data were collected from self-reporting and researcher evaluation forms. Qualitative assessments were done with Health Animators, using three focus groups (October-December 2015) and seven in-depth interviews (October 2016-February 2017). Results: Seventy seven health Animators were trained from 62 villages. A total of 2704 workshops were conducted, with consistent attendance from January 2015 to June 2017, representing 10-17% of the population. Attendance was affected by social responsibilities and activities, relationship of the village leaders and their community and involvement of Community Health Workers. Active discussion and participation were reported as main strengths of the workshops. Health Animators personally benefited from the mind-set change and were proactive peer influencers in the community. Although the information was comprehended and accepted, availability of adequate health services was a challenge for maintenance of behaviour change. Conclusion: Community workshops on malaria are a potential tool for influencing a positive change in behaviour towards malaria, and applicable for other health problems in rural African communities. Social structures of influence and power dynamics affect community response. There is need for systematic monitoring of community workshops to ensure implementation fidelity and strengthening health systems to ensure sustainability of health behaviour change.
A comparative history of commercial transition in three West African slave trading economies, 1630 to 1860
Dalrymple-Smith, Angus - \ 2017
University. Promotor(en): Ewout Frankema; Elise van Nederveen Meerkerk, co-promotor(en): M. van Rossum. - Wageningen : Wageningen University - ISBN 9789463436199 - 283
slavery - history - colonialism - trade - commodities - gold - law - social change - economic change - west africa - slavernij - geschiedenis - kolonialisme - handel - basisproducten - goud - recht - sociale verandering - economische verandering - west-afrika

The nineteenth century ‘commercial transition’ from export economies based on slaves to ones dominated by commodities like palm oil has been a central theme in West African history. However, most studies have tended to focus on the impact of the change and assumed that its causes were largely a result of the British decision to abolish their transatlantic slave trade in 1807 and subsequently persuading or forcing other nations to do the same. This thesis makes two principal contributions to this debate. Firstly, it reviews new evidence which shows that the commercial transition in West Africa’s most important slave exporting regions, the Gold Coast, the Bight of Biafra and the Bight of Benin, can be predicted by the patterns of trade established in previous centuries. It then presents a model of analysis which sets out which interrelated factors shaped their export economies and ultimately determined how they responded to the changing political and economic environment of the Atlantic world from the seventeenth to the nineteenth centuries. This study offers an important comparative, long term quantitative perspective on the transition from slave exports to so-called ‘legitimate commerce’.

Chapter 1 shows that the speed and timing of the nineteenth century commercial transition differed considerably across the case study regions. Along the Gold Coast there was a sudden, and effectively total end to transatlantic slave trading after 1807. In the Bight of Biafra slave exports gradually declined until largely ceasing in the 1830s. Lastly in the Bight of Benin export slavery continued until the 1850s. The chapter argues that earlier studies have tended to ignore long term trends and also lack a comparative approach, as many are focused on individual regions. It then suggests a new model of analysis and dismisses two factors as irrelevant; the British slave trade patrol and changing demands for, or changing supply of, African slaves. The chapter argues that regional variations can be explained by five key factors: 1) the nature and duration of long-term trade relations; 2) the identity of the principal European trade partner; 3) certain aspects of the ecology of the different regions; 4) the regional political contexts; and 5) the development of institutions that either encouraged or discouraged elite participation in non-slave exports.

Chapter 2 provides a broad overview of each case study region’s patterns of trade from the fifteenth to the eighteenth Centuries based on secondary and primary qualitative sources. It then reviews quantitative evidence of commodity trading patterns from the earlier eighteenth century from British and Dutch commodity traders and slaving vessels that bought commodities. It argues that the expansion of slavery in the Bight of Biafra did not crowd out other forms of commerce. On the Gold Coast the early eighteenth century saw continued engagement in commodity exports while the slave trade expanded. However, by the 1780s, both slave and commodity exports seem to have begun to decline. In the Dahomean-controlled area of the Bight of Benin, there is no evidence of slavery crowding out other forms of commerce, as captives were always the only item of trade with the Atlantic world.

Chapter 3 investigates the extent to which the 18th century intensification of the trans-Atlantic slave trade boosted commercial agriculture in the coastal areas of West Africa and in particular in the case study regions. It explores the provisioning strategies of 187 British, French, Dutch and Danish slave voyages conducted between 1681 and 1807, and calls for a major downward adjustment of available estimates of the slave trade induced demand impulse. It shows that during the 18th century, an increasing share of the foodstuffs required to feed African slaves were taken on board in Europe instead of West Africa. However, there was considerable variation in provisioning strategies among slave trading nations and across main regions of slave embarkation. The Bight of Benin never significantly engaged in provisioning trade. Traders along the Gold Coast provided relatively large quantities of food to slaving vessels, but in the Bight of Biafra, British demand stimulated a considerable trade in foodstuffs. The chapter explains these trends and variation in terms of the relative (seasonal) security of European versus African food supplies, the falling relative costs of European provisions and the increasing risks in the late 18th century trade, putting a premium on faster embarkation times.

Chapter 4 uses a newly constructed dataset on the quantities and prices of African commodities on the coast and in British markets over the long eighteenth century and provides new insights into the changing nature of Britain’s non-slave trade. It improves on previous work by Johnson et al. (1990) and finds that earlier estimates of the volume and value of commodity trade have been underestimates and fail to account for regional changes in output. The data suggests that from the 1770s the focus of Britain’s commodity trade shifted from Senegambia to the Bight of Biafra and that in the later eighteenth century non-slave goods were primarily purchased by slave ships, not specialist bi-lateral traders. The chapter argues that these changes were motivated by a number of factors; conflicts between Atlantic powers, the prices of British trade goods and African imports, increasing levels of risk faced by British slave merchants and the fact that traders in the Bight of Biafra were both willing and able to supply desirable commodities.

Part 1 establishes that the Gold Coast had a far long history of commodity trading and seemed to have been moving away from the slave trade at the end of the eighteenth century. The region of the Bight of Benin controlled by Dahomey always focused exclusively on slaves. The Bight of Biafra had a considerable non-slave export economy that was growing at the end of the eighteenth century. Part 2 of the thesis applies the model of analysis to the case study regions.

Chapter 5 argues that that for the Gold Coast and more particularly the Asante empire British abolition policies and the slave forts can explain the timing of the end of transatlantic slavery but not why it ended. Following the model of analysis, the chapter shows that the presence of gold determined both long term political development and the nature of the region’s trade relationship with the Atlantic. In addition, gold became essential as a means of marking status and wealth at all levels of society and for domestic exchange. This meant that slaves were always essential for the production of gold, meaning that there was an important competing domestic market for coerced labour. Over the eighteenth-century gold became scarcer leading to slaves being pulled out of the Atlantic market to focus on production. In addition, well-developed trade relations with the interior and a rise in demand from the Islamic states in the Sokoto caliphate led to an expansion of kola exports which demanded yet more labour. Most importantly, the chapter argues that both households and elite groups could profit more from commodity than slave exports which explains the rapid move away from the transatlantic slavery and towards the production of commodities.

In Chapter 6 it is argued that in the Bight of Biafra, the slave and commodity trades were not only compatible but complementary. The region’s riverine transport networks, long established coastal-interior trade relations and suitability for the growing of yams, palm oil and tropical hardwoods meant that the provisioning and commodity trades could function alongside slave exports. The relatively late opening of central Igboland to the Atlantic slave markets meant that the region did not see the influx of wealth in the seventeenth century that spurred the development of states in the other case study areas. Instead the region followed a different institutional path which saw the development small political entities linked together through the Aro trade network. Elites in the interior and at the coast were reliant on trade for both power and status, but not specifically the slave trade. As a result, abolition was not a serious economic shock as commodities and slaves had always been traded side by side. As in Gold Coast both commoners and elites benefited from commodity trading. Atlantic goods allowed many more people to purchase goods to improve their standards of living, while elites benefitted from the less volatile commodity trade. Furthermore, the British state also perhaps unintentionally supported the development of the palm oil trade through its customs policies. Eventually, this led to palm oil crowding out slave exports through greater demands for domestic labour.

Chapter 7 investigates why the region of the Bight of Benin controlled by Dahomey only ever exported slaves. It shows that this region possessed no gold and had less favourable geography for commodity exports than the Bight of Biafra. The early expansion of export slavery in the seventeenth century spurred the development of states and elites who were entirely dependent on slave exports to maintain their wealth and power. It led to the development of a militaristic culture and institutions based on large scale slave raiding that were highly effective as a means of controlling and harnessing elite violence, generating wealth and defending the state from powerful external threats and economic competition. The demands of the army and elites took much of the kingdom’s potential labour away from households. In addition, constant warfare led to a serious demographic decline across the region further reducing the amount of available labour. The chapter argues that it was never in the interests of elites to switch to an alternative economic system and there was, until the 1850s, always sufficient external demand. In the end abolition efforts were a necessary condition to ending the slave trade.

Chapter 8 concludes with a summary of the main contributions of thesis; the importance of long term patterns of trade in determining nineteenth century commercial transition and a modified model of analysis to explain the diverging trajectories of the different case study regions. It also argues that the impact of Britain’s abolition campaign should be reassessed. In the Gold Coast and the Bight of Biafra it was not an important factor in ending transatlantic slavery, while in the Bight of Benin it was. The chapter ends with suggestions for future research.

Vegetable Business Opportunities in Ghana: 2016
Saavedra Gonzalez, Y.R. ; Dijkxhoorn, Youri ; Koomen, I. ; Maden, E.C.L.J. van der; Herms, Sjoerd ; Joosten, Frank ; Asante Mensah, Samuel - \ 2016
Wageningen UR (GhanaVeg Sector Reports ) - 84 p.
Insecticide Spray Regime Effect on Cowpea Yield and Financial Returns in Northern Ghana
Larbi, Asamoah ; Kotu, Bekele ; Nurudeen, Abdul Rahman ; Akakpo, Daniel ; Asante, Mary ; Mellon, Shaibu - \ 2016
- 1 p.
Did the price-related reforms in Ghana's cocoa sector favour farmers?
Quarmine, W. ; Haagsma, R. ; Huis, A. van; Sakyi-Dawson, O. ; Obeng-Ofori, D. ; Asante, F. - \ 2014
International Journal of Agricultural Sustainability 12 (2014)3. - ISSN 1473-5903 - p. 248 - 262.
cointegration
It is generally hypothesized in the innovation systems literature that institutions can create production incentives for farmers. This paper examines whether the introduction in 1984 of the Producer Price Review Committee (PPRC) in Ghana's cocoa sector has improved the transmission of world prices to farmers. We test how fast and to what extent world prices have been transmitted, and also address the stability of the prices received by cocoa farmers. For the period 1960–2011, the results were as follows: (1) the production of cocoa beans depended positively on the prices farmers received and negatively on price variance; (2) the establishment of the PPRC provided higher prices for farmers; and (3) the PPRC's use of the flexible freight on board (FOB) price-setting rule resulted in a better price transmission than the employed cost-plus-margin approach. However, under the FOB price-setting rule, producer price variance rose sharply. We conclude that, although FOB pricing mechanisms are often recommended for markets where prices are institutionally determined, stabilization policies should be factored in to protect farmers against international price fluctuations.
Factors Affecting the Adoption and use of NERICA Varieties among Rice Producing Households in Ghana
Asante, B.O. ; Wiredu, A.N. ; Dogbe, W. ; Asuming-Boakye, A. ; Nsiah Frimpong, B. ; Haleegoah, J. - \ 2013
Asian Journal of Agriculture and Rural Development 3 (2013)10. - ISSN 2304-1455 - p. 721 - 735.
This paper uses cross sectional data which were collected from 200 smallholder rice producers in Ghana, to examine the factors influencing the adoption and extent of use of NERICA rice varieties in Ghana. About 57.93 per cent of the sampled rice producers allocated 35.77 per cent of their land to NERICA accounting for about 33.13 per cent of seeds planted. The Tobit regression model suggests fertilizer use, existence of other complementary projects in the area, proportion of active persons in household, access to alternative income sources, distance to seed source and education as key factors influencing the quantity of seeds planted as well as the proportion of land allocated to the NERICA varieties. With the exception of distance to seed source, all the other factors positively influenced the extents of adoption. The findings suggest the need to ensure availability of NERICA seeds within acceptable distances to farming communities. This could be achieved through identification of certified rice seed growers in strategic locations throughout the country and supported with necessary logistics to produce NERICA seeds at reasonable proximities to rice producing communities. This could also be enhanced through establishment of linkages with existing institutions and projects to compliment promotional efforts
Incentives for smallholders to enhance the production of quality cocoa beans in Ghana: the role of institutions
Quarmine, W. - \ 2013
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 - cocoa - cocoa beans - agricultural policy - quality - certification - community participation

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.

Incentives for cocoa bean production in Ghana: Does quality matter?
Quarmine, W. ; Haagsma, R. ; Sakyi-Dawson, O. ; Asante, F. ; Huis, A. van; Obeng-Ofori, D. - \ 2012
NJAS Wageningen Journal of Life Sciences 60-63 (2012). - ISSN 1573-5214 - p. 7 - 14.
management
This paper investigates the institutional factors that constrain farmers’ incentives to enhance the quality of cocoa beans in Ghana. Data were collected at three levels of aggregation in the cocoa bean value chain: village, district, and national level. Multi-stage cluster sampling was employed to sample 120 farmers and 12 purchasing agents of licensed buying companies from 12 villages in Assin Foso, Suhum, Dormaa and Wasa Akropong cocoa districts. Convenience sampling was used to sample key informants from relevant organizations and service providers at district and national levels. The study revealed that, even though quality is important to all categories of actors in the cocoa sector, interactions among them are hampered by problems of information asymmetry that result especially in farmers evading recommended practices. While cocoa sector policies ensure the export of premium quality cocoa, policies have not sufficiently alleviated the information problem especially in the relation between farmers and cocoa purchasing agents. It explains why Ghanaian farms have not been able to reach their full potential to produce more than 1,000,000 metric tons of premium quality cocoa annually. Amongst other options, self-selection policies, such as quality testing with price premiums, are recommended for testing as potential incentive mechanisms that address information asymmetry.
Living on the edge: physiological and behavioural plasticity of African antelopes along a climatic gradient
Shrestha, A.K. - \ 2012
University. Promotor(en): Herbert Prins; Steven Bie, co-promotor(en): Sip van Wieren. - S.l. : s.n. - ISBN 9789461733856 - 135
antilopen - taurotragus oryx - connochaetes taurinus - aepyceros melampus - klimaatverandering - microklimaat - diergedrag - thermoregulatie - microhabitats - warmtestress - adaptatiefysiologie - antelopes - climatic change - microclimate - animal behaviour - thermoregulation - heat stress - adaptation physiology

Climate change, habitat loss and fragmentation individually or synergistically force species to
live in a sub-optimal condition in terms of climate and resource posing threat to fitness and
survival of the species. Hence, a very pressing issue for biodiversity conservation at present is
to understand if species are able to keep pace with these rapidly changing environment
conditions. To persist with these changes, phenotypic plasticity of behaviour and physiology
may be the most likely response for long-lived endothermic species because of their longer
generation times. Therefore, the central aim of this thesis is to investigate intra- and intervariability
of behavioural and physiological adaptation of range of African antelopes along
spatio-temporal scales in their natural habitats.
With the aim to understand the behavioural plasticity of African antelopes to the climatic
stress, in Chapter 2, I investigated effect of heat stress on diurnal activity pattern of three
species of antelopes of different body size and feeding types namely, eland Taurotragus oryx
(≈ 420 kg; mixed feeders), blue wildebeest Connochaetes taurinus (≈180 kg; grazer) and
impala Aepycerus melampus (≈ 50 kg; mixed feeder) across season and extreme climatic
condition as indicated by the 10 hottest days. During summer when the heat stress was its
highest, the heat stress negatively influenced diurnal activity of all the three species.
However, they shifted the timing of their activity more to the early morning (eland) or late in
the evening, or both (wildebeest and impala) to avoid heat stress and maximize intake of food
in a season when forage is abundant. During the spring and the 10 hottest days over the entire
study period, only the diurnal activity of the larger antelopes (eland and wildebeest) was
negatively influenced by the heat stress whereas the smaller impala was unaffected.
Therefore, these large African antelopes apparently suffer from heat stress during spring and
the extreme hottest days due to their limited capacity to dissipate heat.
In chapter 3, to understand possible behavioural adaptation of the largest African antelope
eland against the thermal stress, I investigated the daily and seasonal selection of
microhabitats based on altitude and microclimate at the southern limits of its distributional
range. Eland actively selected lower altitudes with warm microclimates during the winter and
the five coldest days when the ambient conditions were below its thermal neutral zone. In
contrast, eland did not select higher altitudes or cooler climate when it was warm in the
summer. However, selection of cooler microhabitats was only evident in the three extremely
hottest days when the heat stress was close to the upper end of its thermal neutral zone.
Hence, the eland was able to use diverse topography as a thermal refuge to buffer the adverse
effect of both cold and very hot condition.
In the fourth chapter, to study behavioural response of African antelopes to variation in food
resources which is predicted to exacerbate due to climate change and habitat loss and
fragmentation, I investigated adaptation of home range sizes of eland, impala (both mixed
feeders) and wildebeest (a grazer) over time (seasons) and between two climatically
contrasting areas in South Africa, taking Mapungubwe National Park as the core area and
Asante Sana Game Reserve as the edge area. This comparative study not only showed the
home range size of wildebeest in Mapungubwe was larger during the resource-poor dry
season compared to the resource-rich wet season but their home range size in the core area
was also a four to seven times larger in the dry season than those in the edge area. In contrast,
the home range size of impala was 3-14 times larger in the edge area than those in the core
area. Surprisingly, the home range size of eland neither differs across any season within study
areas nor between Asante Sana and Mapungubwe, while their average year-round home
range size in core area was larger than that in edge area. These results suggest that the home
range size of these African antelope is most likely a response to resource quality and
availability specific to the local habitat.
With an attempt to investigate physiological plasticity of African antelopes over a spatiotemporal
context, in Chapter 5, I compared intraspecific variation of body temperature, as
measured by amplitude, of the eland, blue wildebeest and impala in the two climatically
contrasting areas: one with a less seasonal pattern and a mild winter (Mapungubwe National
Park) and the other with a more seasonal pattern and a long and cold winter (Asante Sana
Game Reserve). The 24-hour amplitude of body temperature of both mixed feeder (eland and
impala) did not differ between the study sites, regardless of season. In contrast, the grazer
(wildebeest) at a less seasonal site exhibited not only a higher variability in the 24-hour
amplitude of body temperature (Tb)(~4ºC) but also a lower daily minimum body temperature
by ~2 ºC compare to the normothermic level during the dry season than the wildebeest at a
seasonal site. Further, the variation in Tb amplitude were influenced both by temperature
(positive effect) and rainfall (negative effect), a proxy for food availability only among the
wildebeest from less seasonal site. This suggest that these physiological response of higher
variability of Tb amplitude and reduced minimum Tb among the wildebeest in Mapungubwe
is a response to nutritional stress rather than a response to cold climate.
These behavioural (home range) and physiological (body temperature) response of African
antelopes to stressful conditions are specific for species and habitats. The smallest impala,
which is a mixed feeder, maintained homeothermy even though they were exposed to
stressful habitats by selecting the most productive habitat, i.e., riparian habitat in
Mapungubwe. In Asante Sana, impala maintained homeothermic status by extending their
dry season home range size when their principle food Acacia Karoo was not available. The
largest antelope (eland) maintained homeostasis by ranging over large areas to track
heterogeneously distributed resources, which is only possible due to their large size and
ability to cope with lower quality food. Eland in Mapungubwe had larger home range sizes
compared to Asante Sana which was most probably due to the poor quality of the habitat in
Mapungubwe. Interestingly, the wildebeest in Mapungubwe did not maintain homeothermy
particularly in dry season. Not only their amplitude of Tb was much larger (~4ºC) and
Minimum Tb lowered by 2 ºC compared to normothermic level, they also extended their
home range size four to seven folds compared to the wildebeest in Asante Sana. This failure
to maintain homeothermy and extension of home range size was due to nutritional stress and
therefore these antelopes are living in a physiologically stressful environment. With the
predicted increase in the frequency and intensity of drought periods in southern Africa due to
climate change, wildebeest, and other grazers, will likely experience greater nutritional stress
in the future.
To conclude, this thesis shows importance of studying behavioural and physiological traits
among a range of species along temporal and spatial scales in their natural habitats to
understand the adaptive capacity, therefore sensitivity of animal species. Apparently,
homeothermic mammals cannot cope well with heat stress, which negatively influence the
larger ones more than the smaller ones. However, mammals can overcome these stresses by
shifting time of their activity to cooler parts of the day or by selecting optimal microhabitats
that minimize absorption of heat at high temperatures or that maximize the absorption of heat
at low temperatures. The behavioural (larger home range size) and physiological (reduced
body temperature) response of wildebeest, a grazer to dry season but not that of the mixed
feeder emphasizes that grazers will become more nutritionally stressed than mixed feeders at
times of low rainfall. With the predicted increase in low rainfall events in many parts of the
world and changes in vegetation structure in savannas due to climate change, browsers and
mixed feeders will be likely to benefit more in future than the ruminant grazers.

Body temperature variation of South African antelopes in two climatically contrasting environments
Shrestha, A.K. ; Wieren, S.E. van; Langevelde, F. van; Fuller, A. ; Hetem, R.S. ; Meyer, L.C.R. ; Bie, S. de; Prins, H.H.T. - \ 2012
Journal of Thermal Biology 37 (2012)3. - ISSN 0306-4565 - p. 171 - 178.
oryx oryx-leucoryx - climate-change - rattus-fuscipes - plant phenology - water economy - national-park - patterns - precipitation - physiology - food
To understand the adaptive capacity of a species in response to rapid habitat destruction and climate change, we investigated variation in body temperature (Tb) of three species of antelope, namely eland, blue wildebeest and impala, using abdominally-implanted temperature data loggers. The study was conducted at two climatically contrasting environments in South Africa, one with a less seasonal and mild winter (Mapungubwe National Park) and the other with a more seasonal, long and cold winter (Asante Sana Game Reserve). Since the habitat with long and cold winters would be suboptimal for these African antelopes, which evolved in less seasonal and hot environments, antelopes in Asante Sana were expected to exhibit a larger amplitude in Tb and a lower minimum body temperature (MinTb) during winter to reduce Tb and the ambient temperature (Tb-Ta) gradient to save energy. In both eland and impala, 24-hour body temperature amplitude did not differ between the study sites, regardless of season. Conversely, wildebeest in Mapungubwe showed a higher variability in the 24-hour amplitude of body temperature and also a lower MinTb during winter and spring than the wildebeest in Asante Sana. This variation in Tb among Mapungubwe wildebeest was influenced by both the amplitude of ambient temperature (positive) and cumulative rainfall (negative), which was not the case for wildebeest in Asante Sana. We propose that the low MinTb of wildebeest in Mapungubwe was the result of nutritional stress during winter and spring; an evident response even during a year of average rainfall. Therefore, these wildebeest apparently live in a physiologically stressful environment. With the predicted increase in the frequency and intensity of drought periods in southern Africa, wildebeest, and other grazers, will likely experience greater nutritional stress in the future.
Institutional experiments for assessing farmers’ response to price and non-price incentives to produce quality cocoa beans
Quarmine, W. ; Haagsma, R. ; Sakyi-Dawson, O. ; Obeng-Ofori, D. ; Asante, F. ; Huis, A. van - \ 2011
In: Proceedings of the CoS-SIS Bamako Workshop: Mid-term evaluation and adjustments in the CoS-SIS Programme. - - p. 52 - 57.
Factors which constrain farmers' incentives to enhance the quality of cocoa beans produced in Ghana
Quarmine, W. ; Haagsma, R. ; Asante, F. ; Sakyi-Dawson, O. ; Obeng-Ofori, D. ; Huis, A. van - \ 2011
In: Proceedings of the CoS-SIS Cotonou, Benin Workshop,Convergence of Sciences: Strengthening Agricultural Innovation Systems Programme, Bamako, Mali, 26 - 29 October, 2010. - Wageningen : Wageningen University - p. 65 - 74.
Estimating least-developed countries' vulnerability to climate-related extreme events over the next 50 years
Patt, A.G. ; Tadross, M. ; Nussbaumer, P. ; Asante, K. ; Metzger, M.J. ; Rafael, J. ; Goujon, A. ; Brundrit, G. - \ 2010
Proceedings of the National Academy of Sciences of the United States of America 107 (2010)4. - ISSN 0027-8424 - p. 1333 - 1337.
natural disasters - adaptive capacity - adaptation - projections - impacts
When will least developed countries be most vulnerable to climate change, given the influence of projected socio-economic development? The question is important, not least because current levels of international assistance to support adaptation lag more than an order of magnitude below what analysts estimate to be needed, and scaling up support could take many years. In this paper, we examine this question using an empirically derived model of human losses to climate-related extreme events, as an indicator of vulnerability and the need for adaptation assistance. We develop a set of 50-year scenarios for these losses in one country, Mozambique, using high-resolution climate projections, and then extend the results to a sample of 23 least-developed countries. Our approach takes into account both potential changes in countries' exposure to climatic extreme events, and socio-economic development trends that influence countries' own adaptive capacities. Our results suggest that the effects of socio-economic development trends may begin to offset rising climate exposure in the second quarter of the century, and that it is in the period between now and then that vulnerability will rise most quickly. This implies an urgency to the need for international assistance to finance adaptation.
Practical applications: prospects and pitfalls
Motarjemi, Y. ; Asante, A. ; Adams, M.R. ; Nout, M.J.R. - \ 2001
In: Fermentation and Food Safety / Adams, M.R., Nout, M.J.R., Gaithersburg, Maryland, USA : Aspen Publishers - ISBN 9780834218437 - p. 253 - 274.
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