Giving seed-yams the credit they deserve

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Clean seed-yam production systems
Validated RNRRS Output. Home List by Audience List by Topic

Ways of producing ‘clean’ healthy seed-yams, and an innovative micro-credit scheme, are helping to combat falling yam yields and declining yam quality in West Africa. Because farmers use pieces of tuber to plant their next yam crop, any pests and diseases in the soil get carried over into that crop. Breaking that cycle is easy, however, using the ‘mini-sett’ technique – which involves dipping small pieces of tuber in a mix of insect- and fungus-killing pesticides before planting. A micro-credit facility is also proving valuable to seed-yam producers in Kogi State, Nigeria. These advances can be used throughout West Africa and India, where yam is an important staple food. Posters and fact sheets on yam pests and diseases, and on the ‘mini-sett’ system, are also available.

Project Ref: CPP25:
Topic: 1. Improving Farmers Livelihoods: Better Crops, Systems & Pest Management
Lead Organisation: Natural Resources Institute (NRI), UK 
Source: Crop Protection Programme

Contents: Description
Current Situation
Environmental Impact


Research Programmes:

  • Crop Protection Programme
  • International Institute of Tropical Agriculture
  • Gorta Foundation (Ireland)

Relevant Research Projects:

Recent Projects

R8416 (2005-2006) Up-scaling sustainable clean seed yam production systems for small-scale growers in Nigeria (Za0648/A1159)

R8278 (2003-2005) Evaluation and promotion of crop protection practices for “clean” seed yam production systems in Central Nigeria (Za0556/A1096).

Earlier or linked Projects

  • R7504 (2005-2006) A synthesis/lesson-learning study of the research carried out on root and tuber crops commissioned through the DFID RNRRS research programmes between 1995 and 2005.
  • R7582 (2000-2003) Development of integrated protocols to safeguard the quality of fresh yams A0946
  • EU-INCO-Dev (1999-2003) Yam: Cultivar selection for disease resistance and commercial potential in Pacific Islands
  • R7504 (1999-2000) Study of Factors Affecting the Uptake of Crop protection Research on Yams in Ghana.
  • E0054 Studentship (1998-2002) The diversity and genetic variability of viruses infecting yams.
  • R6694 (1996-2000) Identification of resistance to major nematode pests of yams in West Africa (IIP component)
  • R6691 (1996-2000) Control of yam diseases in forest margin farming systems in Ghana.
  • R6505 (1996-2000) Post-harvest constraints and opportunities for marketing of yam
  • Gatsby-JIC (1994-1999) Identification of yam virus variability
  • R5735CB (1992-1996) Control of Yam Anthracnose and Other Yam Pests
  • R5897 (1993-1996) Development of rapid tests for identification and differentiation of yam virus variability A0346
  • R5688 (1993-1996) Strategies for the control of yam anthracnose
  • R5675 (1992-1996) Epidemiology and control of Anthracnose disease of yams in Nigeria


Natural Resources Institute, University of Greenwich, Central Ave, Chatham, Kent. UK ME4 4TB. Lead contact    Dr. Lawrence Kenyon, e-mail:


  • International Institute of Tropical Agriculture, Oyo Road, Ibadan, Nigeria. Contacts  Dr. Danny Coyne, e-mail:   Dr. Biodun Claudius-Cole, Dr. Robert Asiedu, e-mail:
  • Diocesan Development Service (DDS), Idah, Kogi state, Nigeria. Contact: Sr. Nora McNamara and Mr. Moses Acholo,
  • Department of Geography, University of Reading, Reading RG6 6AB UK. Contact: Dr. Steven Morse, e-mail:

Research Outputs, Problems and Solutions:

Yams are an important staple food for many people in West Africa, India and the Pacific Island Countries. Their vegetative propagation by the planting of small yam tubers (seed yams) or pieces of tuber (setts) can result in the accumulation and perpetuation from season to season of pests and diseases. Because of the increasing human population in West Africa there is greater pressure on the land to produce food and farmers have to use shorter fallow periods. This is exacerbating the problem because there is insufficient time for populations of soil-borne pests and diseases to decrease and hence the disease-loading on harvested tubers is increasing. The outputs aimed to identify the causes of the apparent decline in yield and quality of yam production systems in West Africa and to develop cost-effective/sustainable methods or production systems to reverse the declining trend. The outputs comprise:

  1. Knowledge of methods to identify the pests, diseases and viruses of yam, and the results of surveys/observation and field experiments in Nigeria and Ghana revealing that lack of availability of healthy planting material is one of the main biotic constraints to production in these areas.
  1. A system based on adaptation of the mini-sett technique to local conditions which enables small-scale yam growers to produce “clean” seed yams (planting material) either for home use or for sale to other growers; validated through demonstration trials in farmers’ fields and on community land. 
  1. Extension materials in the form of posters and fact sheets on yam pests and diseases and the system for producing clean seed yams.
  1. Lessons learnt/knowledge of how to assess the socio-economic/livelihoods situation of resource-poor farmers in the yam-belt of West Africa and of how to use the information gathered to determine if seed yam production could be a viable option for them.
  1. A method for implementing a micro-credit scheme for seed yam producers and knowledge of what conditions are required for the scheme to be self-sustaining. It became apparent that lack of finance at critical periods in the yam growing calendar is a major impediment to many farmers being able to obtain (or keep in store) as much planting material, or to grow as much yam as they would like to.  The Farmer’s Economic Enterprise Development programme in Kogi State (with Gorta Foundation (Ireland) funding) is a low cost and business-plan based micro-credit scheme linked specifically to a crop production enterprise such as clean seed yam.

Types of Research Output:

Product Technology Service Process or Methodology Policy Other

Major Commodities Involved:

Yams (Dioscorea species) are the main commodity. The outputs could also be adapted in some locations to other vegetatively propagated crops such as cassava, sweet potato, cocoyam, taro and banana.

Production Systems:

Semi-Arid High potential Hillsides Forest-Agriculture Peri-urban Land water Tropical moist forest Cross-cutting

Farming Systems: 

Smallholder rainfed humid Irrigated Wetland rice based Smallholder rainfed highland Smallholder rainfed dry/cold Dualistic Coastal artisanal fishing

Potential for Added Value:

The projects listed above (3) operated as a loose cluster feeding into each other and sharing resources and experiences as appropriate.

The storability and resilience to transport damage of yams is highly dependent on the quality and disease loading of the yams at harvest (R6505), which is determined by the health of the planting material used and how clean the land planted was. How carefully seed yams/planting material are handled and stored after harvest will also influence how clean/healthy the material is when it is planted the following season.

Most smallholder (less commercial) yam growers in West Africa also grow cassava, sweet potato and banana, sometimes even intercropped with yam, so IPM interventions for these vegetatively propagated crops could be included in this cluster. E.g. sweet potato (R8243, R8040) cassava (R8227, R8456) banana (R8342, R7567)

Farmer participation was encouraged in demonstrating and testing the seed-yam production system and this could be expanded or incorporated into a farmer-field-school (FFS) type of approach (R8457).

Virus diseases are a major tuber-borne constraint in vegetatively propagated crops such as yam, cassava, banana and sweet potato. It is important to have reliable and robust diagnostic tools to be able to screen germplasm of these crops prior to multiplication either for research/breeding or commercial purposes.  It may be appropriate to establish local laboratories with the basic facilities for performing disease diagnosis on all these crops (R6579, R7529, R6692).

Farmer-participatory breeding/selection as done for cassava (R8405) is a potentially useful approach for yam improvement and would be assisted by having a reliable method for propagation of the selected genotypes.

Lessons learnt through the root and tuber crop research projects have been compiled and synthesised in project R7504 (2005-2006) A synthesis/lesson-learning study of the research carried out on root and tuber crops commissioned through the DFID RNRRS research programmes between 1995 and 2005 (see report at Lessons learnt could also be valuably shared with other projects involved in the supply of clean planting material (seed) such as potato seed tubers (R8435) or other seeds (R8480).

Planting of a nitrogen-fixing woody legume either as a cover crop before yams or as an intercrop with yams could help restore soil fertility and reduce disease loading (including nematodes- R8296) in the soil, and provide cut sticks or live-staking for the yam plants.

The clean seed yam technology is being used to help conserve yam biodiversity in field gene-banks, and a similar approach could be used for conservation of other vegetatively propagated crops.


How the outputs were validated:

Output 1. The knowledge that the lack of clean/healthy yam planting material (because of shortening fallow periods) is a major constraint to increasing yam production was identified through the research activities of the project partners including surveys, focus groups, on-farm trials and working with farmers. Information derived through farmer discussions also suggests that perpetuation of seed-borne pests and disease was leading to loss of local cultivars/landraces, especially those most susceptible, which could be overcome or compensated for through development of healthy seed yam production systems.

Output 2. The development of an adaptation of the minisett technique to a viable system for producing clean seed yams and the validation of the system was undertaken initially through on-station trials before validating and introducing to farmers in a series of on-farm (farmers groups, local area councils) trials and demonstration plots where the adapted system was compared with the farmers’ local practice. The objective was that each group or farm generated a ‘rolling stock’ of clean material for generation of new material with excess provided to participating farmers to generate their own individual stocks, or alternatively sold on. Indications were that many developed further along this line following project conclusion. Validation on-farm involved a number of groups to help with contact of farmers and farmer groups, including NGO’s farmer led cooperative groups, individual farmers (small and large scale) and the national extension service. The on-station trials were research-partner led and cared for, while the on-farm plots were researcher led but to instil local ownership they were locally managed/cared for.  A cost-benefit analysis of the clean seed yam production system was undertaken through detailed analysis of the livelihoods of farmers taking up the system in Kogi state, Nigeria.

Output 3.  Posters and information sheets were pre-tested with project partners and collaborating farmers

Output 4.  Lessons were learnt on how to assess the socio-economic/livelihoods status of farmers and assess if seed yam production is a viable option for them through farmer base-line surveys, the cost-benefit analyses mentioned above, and through the development of a micro-credit scheme (below).

Output 5.  The DDS FEED programme was first implemented in 2004 as a pilot scheme and based on the lessons learned was more fully implemented with certain criteria pertaining in 2005.

Where the Outputs were Validated:

Output 1 was verified in Nigeria (IITA-Ibadan, University of Agriculture -Makurdi, DDS-Kogi, Ekiti, Rivers, Oyo) and Ghana (CRI-Brong Ahafu, Ashani, MoFA -Northern and upper West Regions, University of Ghana, Accra) over several years starting from before the RNRRS.

Output 2. The clean seed yam production system was evaluated and demonstrated with seven groups in Ekiti, seven groups in Kogi, two growers in Oyo, six groups in Abuja, one group in Kwara and at six sites in Rivers state Nigeria in 2005 (See table in annex 1 for detail). Funds form the agro-input company (Dizzingoff) were also provided to further evaluate uptake of the system and provide support. The livelihoods/cost-benefit analysis was carried out with four farmers in Ekwuloko (Kogi) in 2004 and 2005, and to provide a comparison, with a further four farmers in the riverine area of Edeke (Kogi).

Output 3.  Extension materials were initially evaluated in Nigeria and Ghana, but have subsequently been distributed more widely through International Society for Tropical Root Crops (ISTRC) meetings and requests for template files have been received from Cote d’Ivoire, Costa Rica and Vanuatu so that they can be adapted to local language/conditions.

Output 4.  The farmer household baseline surveys on seed yam and ware yam production systems were undertaken in 2003 by DDS interviewing 98 farming households in Kogi State and IITA staff interviewing 122 households in Ekiti State.

Output 5.  Only DDS Farmer Council members could participate in the micro-credit scheme; they could not have a previous loan outstanding and they had to engage in clean seed yam production. Over 400 smallholders across Kogi state (not just in Ekwuloko and Alla-Olukudu) were provided with credit based on a business plan proposal to enable them to buy and plant yam planting material in the 2005 season.  All received guidance on how to treat the planting material and most grew some seed yams and some ware yams in order to spread their risks.

Current Situation

Who are the Users?

The extension materials (posters, calendars & fact sheets) are being used by project partners including Nigerian agric research and extension service and Plant Quarantine service, NGOs working with the project (e.g. Dizzengoff and Green Rivers project) for staff and farmer awareness and training. DDS currently has a membership of around 10,000 farmers and the information from the project has been widely disseminated to this group. The materials were also taken up and reproduced for use by the IFAD W Africa yam project and reproduced in French by Centre Suisse de Recherches Scientifiques en C�te d’Ivoire (CSRS). Electronic templates for the materials have been distributed to various researchers and agricultural staff in W Africa and in Costa Rica. These materials have also been disseminated internationally at International Society for Tropical Root Crops (ISTRC) meetings.

The clean seed yam production system is being used by some of the project partners and those who received extension materials and/or participated in demonstration days.

A version of the seed yam production system is being used to produce small ware yams (= breakfast yams) suitable for export by commercial growers and outgrowers in Ghana and Jamaica (though this is not directly attributed to this project)

The micro-credit scheme is being used by the DDS-FEED programme to promote and facilitate seed yams production by small-holder growers in Kogi State Nigeria..

Where the outputs have been used:

The extension materials were initially distributed in Nigeria mainly to project partners and associated organizations and farmers. Subsequently they were distributed more widely in Nigeria and through the IFAD and CSRS activities in other countries of West Africa, particularly Ghana, Benin, Togo and Cote d’ Ivoire.

The system of producing seed yams by treating sett pieces of ca 100g with insecticide+fungicide prior to planting has been used in the Caribbean (e.g. Jamaica) and South Pacific island countries for many years. In an adapted form it is being used to produce small, uniformly sized and shaped ware yams for export from Ghana and Jamaica.

NGOs, farmers and groups involved in the project are understood to be continuing the clean seed generation, while some larger scale farmers have continued to increase their acreage under the system.

The system is being demonstrated on President Obosanjo’s personal farm at the President’s request. Requests for greater promotion of the system by yam and seed producers in Nigeria not initially involved have been received by IITA. Farmers involved in the local area council in Abuja, were used in promoting the technology via television, which is expanding the number of farmers participating. The system has benefited by continued support and supply of inputs from Dizzengoff.  The system is now being used by the Green Rivers Project to produce their seed yam prior to delivery to farmers.

The DDS-FEED programme is continuing to operate the micro-credit scheme for clean seed yam production in Kogi State.

Scale of Current Use:

Yam virus diagnostics are only currently applicable to the research situation – they (or slight adaptations) are being used by IITA (Nigeria) and CIRAD (France, Guadeloupe and Vanuatu) and Secretariat of the Pacific Community (SPC, South Pacific Island countries) to screen germplasm prior to international exchange, in vitro conservation and for crop improvement by breeding.

It is difficult to estimate what the scale of use/uptake of the clean seed yam production system is currently or the scale in the increase of expansion of farmer participation since the detailed monitoring/surveillance was not included in the original projects. IITA continues to receive feedback, interest and requests for advice and help however, from previous participating groups and more. Dizzengoff also provides support to further assess agrochemical products that are already pre-mixed, which improves ease of application and reduces potential farmer contamination.

The FEED programme has provided credit to 120 Kogi State households in 2005 & 06 o enable them to grow seed yams. The credit was allowed to roll over for 2 years to ensure there was adequate funds to ensure the clean seed yams were not sold but available for the second year.

Policy and Institutional Structures, and Key Components for Success:

IITA, CIRAD and SPC have contributed to promoting some of the diagnostic tools for yam viruses

Dizzengoff (Agro-input supplies) have made significant contributions to the promotion of thclean seed production system by providing inputs of the fungicide and insecticide, which was otherwise the farmer’s greatest concern with this technology: supply and access to the products.

The organizations originally involved in the demonstration and promotion of the technology have also continued to generate healthy yam from yam originally provided by the project and promote the technology of producing healthy seed.

The Diocesan Development Services has been the main player in the promotion of the FEED programme micro-credit scheme. They have a network of several thousand farmers (may growing yams) in their mandate area of the Catholic Diocese of Idah (Kogi State). They are also highly active in helping farmers from outside of that area with training.

The International Institute of Tropical Agriculture have the CGIAR research mandate for yams and has links to or leads all the yam research and extension in West Africa including:

�         IFAD/WECARD/IITA/CSIR-CRI Yam Project (Ghana)

�         Roots and Tubers Expansion Programme (RTEP-Nigeria, IFAD)

�         The IFAD-supported Programme for Improving Livelihoods in Rural West and Central Africa through Productive and Competitive Yam Systems, administered by IITA, promotes the development and dissemination of improved varieties and addresses soil productivity constraints.

�         West African Seed and Planting Material Network (WASNET) – yam is one of the networks 11 priority crops currently.

Environmental Impact

Direct and Indirect Environmental Benefits:

Helps restore productivity on traditional yam lands so less need to extend yam cultivation into more marginal lands (which would result in rapid degradation of these more fragile lands) or forest reserve areas (as seen in the Ekwuloko study).  Might also stop growers shifting from yam to cassava cultivation – cassava is generally regarded as causing more rapid soil degradation than yam, especially on more marginal soils.

Greater germination/sprouting of less pest/disease-prone material would lead to less ‘sterile’ heaps that farmers prepare, but are unable to plant through deterioration of planting material. Greater sprouting through more viable planting material would also lead to fewer ‘missing’ hills planted, but not sprouted. This in turn leads to less land ‘waste’ in terms of being prepared and open to erosion, but not used to its potential. Greater productivity in general of the planted material creates better returns and consequently more efficient use of land, which should lead to less land needs if more productive.

Adoption of the outputs should help to maintain genetic diversity of yams; Varieties/land races are currently being lost due to pests and diseases and to inability to thrive on more marginal lands.

Adverse Environmental Impacts:

Not significant: The small quantities of pesticide used to dress setts is targeted at the seed crop so two seasons away from harvest of food crop, so there should be no detectable residues in the food crop, and it means you are focusing resources efficiently.

Coping with the Effects of Climate Change, or Risk from Natural Disasters:

YES:  Healthy yams have a relatively long dormancy period and can be stored for 3-4 months, so can provide food when other food crops are scarce.  Also, they are relatively less susceptible to drought/late arrival of rains after planting than are most other crops.


Annex 1.  Locations and partners where the clean seed yam production system was trialed/demonstrated (validated) in 2005.

State Partners Demonstration plots/trials
Ekiti �    ADP HQ Ekiti,

�    ADVL commercial farms (Ado Ekiti)

�    Ifaki farmers congress (group of 30)

�    Aramoko farmers group  (group of 8)

�    2 individual farmers (Aramoko)

�    farmers selected for on-farm trials (4)

�    1 demonstration plot

�    1 demonstration plot

�    1 demonstration plot

�    2 demonstration plots

�    4 demonstration trials in 2004 leading to 2 seed-to-ware trials in 2005

Kogi �    DDS

�    Idah local govt.

�    Igalamela Local govt

�    Oforachi farmers group (6)

�    Edeke women farmers (4)

�   Farmers selected for on-farm trials (4)

�    1 multiplication & 1 demonstration

�    1 demonstration plot

�    1 demonstration plot

�    1 demonstration plot

�    1 demonstration plot

�    4 demonstration trials in 2004 leading to 4 seed-to-ware trials in 2005

Oyo �    AlamAgro – Commercial farmer in Oyo

�    Mrs Otiti – Commercial farmer

�    1 multiplication & 1 demonstration

�    1 multiplication & 1 demonstration

Abuja �    Gwagwalada area council

�    Kwali area council

�    12 farmers in Kwali area council

�    18 farmers in Gwagwalada area council

�    Peace farmers (group of >20)

�    IITA field station

�    1 demo

�    1 demo

�    1 demo

�    1 demo

�    1 demo

�    1 demo

Kwara �    Joseph Foundation (NGO) & Ganmo Farmers association (>10) �    1 demonstration and 1 multiplication
Rivers �    Green River Project (AGIP petroleum) &

�    Food for All International (FFAI)-NGO

�    5 demonstration plots

�    1 demonstration & 1 multiplication


Table 1.  Importance of yam in DFID-PSA countries

Country Population, Number of Persons (millions) Prevalence of under-nourishment in total population (%) Minimum Dietary Energy Requirement (kcal/person/day) Quantity yam produced (1000 tonnes) Calories/day/ capita (kcal) provided by yam Percentage of calorie requirement provided by yam (%)
Bangladesh 146.7 30 1780 0 0 0.0
Cambodia 14.1 33 1770 0 0 0.0
China 1311.6 12 1940 0 0 0.0
India 1065.4 20 1820 0 0 0.0
Indonesia 219.9 6 1840 0 0 0.0
Nepal 25.2 17 1810 0 0 0.0
Pakistan 153.6 24 1770 0 0 0.0
Viet Nam 81.4 16 1840 0 0 0.0
East Africa
Ethiopia 70.7 46 1720 310 10 0.5
Kenya 32 31 1840 7.7 1 0.1
Rwanda 8.4 33 1750 4 1 0.1
Sudan 33.6 26 1840 137 10 0.5
Tanzania, Utd Rep 37 44 1810 11 1 0.1
Uganda 25.8 19 1770 0 0 0.0
Southern Africa
Lesotho 1.8 13 1850 0 0 0.0
Malawi 12.1 35 1790 0 0 0.0
Mozambique 18.9 44 1890 0 0 0.0
South Africa 45 4 1960 0 0 0.0
Zambia 10.8 46 1820 0 0 0.0
Zimbabwe 12.9 47 1840 0 0 0.0
West Africa
DR Congo 52.8 74 1830 12 8 0.4
Ghana 20.9 11 1860 3892 301 15.1
Nigeria 124 9 1830 26587 197 10.8
Sierra Leone 5 51 1820 0 0 0.0

Table 2.  Non DFID-PSA countries where yam production and consumption occurs

Country Population, Number of Persons (millions) Prevalence of under-nourishment in total population (%) Minimum Dietary Energy Requirement (kcal/person/day) Quantity yam produced (1000 tonnes) Calories/day/ capita (kcal) provided by yam Percentage of calorie requirement provided by yam (%)
C�te d’Ivoire 16.6 13 1850 3050.00 320 17.5
Benin 6.7 12 1800 2257.25 373 20.7
Togo 4.9 24 1830 570.00 221 12.1
Central African Republic 3.9 44 1800 350.00 189 10.6
Colombia 44.2 13 1830 310.20 15 0.8
Cameroon 16 26 1860 286.49 29 1.6
Chad 8.6 35 1810 230.00 53 2.8
Brazil 178.5 7 1900 230.00 2 0.1
Haiti 8.3 46 1940 197.00 53 2.9
Japan 127.6 -2.5 1920 170.00 3 0.2
Cuba 11.3 -2.5 1940 167.02 12 0.6
Gabon 1.3 5 1850 155.00 168 8.7
Jamaica 2.7 9 1930 148.00 117 6.1
Burkina Faso 13 15 1800 89.69 16 0.9
Congo, Republic of 3.7 33 1830 84.86 4 0.2
Venezuela,Bolivar Rep of 25.7 18 1850 69.88 6 0.3
Guinea 8.5 24 1830 40.00 11 0.6
Solomon Islands 0.5 21 1780 29.00 167 9.4
Philippines 80 18 1810 28.53 1 0.1
Panama 3.1 23 1830 26.50 19 1.0
Liberia 3.4 50 1820 20.00 14 0.7
Dominican Republic 8.7 29 1920 16.35 5 0.3
Mali 13 29 1800 12.43 3 0.2
New Caledonia 0.2 10 1920 11.00 60 3.1
Burundi 6.8 66 1800 9.91 4 0.2
Dominica 0.1 8 1930 8.00 103 5.4
Fiji Islands 0.8 5 1920 5.20 16 0.9
Guyana 0.8 8 1880 4.20 13 0.7
Comoros 0.8 60 1830 4.00 14 0.8
Samoa 0.2 4 1870 2.60 36 1.9
Mauritania 2.9 10 1840 2.50 2 0.1
Saint Vincent/Grenadines 0.1 10 1900 2.20 20 1.1
Portugal 10.1 -2.5 1970 2.10 1 0.1
Sao Tome and Principe 0.2 10 1770 1.50 23 1.3
Barbados 0.3 -2.5 1980 0.60 7 0.4
Grenada 0.1 7 1910 0.40 11 0.6
Saint Lucia 0.1 5 1900 0.11 2 0.1
Belize 0.3 4 1810 0.03 1 0.1

Table 3. DFID-RNRRS projects concerning yam

R-Number Title Lead Organization Start End Cost
R8416 Up-scaling sustainable clean seed yam production systems for small-scale growers in Nigeria Natural Resources Institute 01/04/2005 30/01/2006 �71,569
R8278 Evaluation and promotion of crop protection practices for “clean” seed yam production systems in Central Nigeria Natural Resources Institute 01/01/2003 30/03/2005 �196,509
R7254(C) Overcoming major constraints to yam breeding International Institute of Tropical Agriculture, Nigeria 01/04/1999 30/03/2002 �236,831
R6691 Control of yam diseases in forest margin farming systems in Ghana Department of Agriculture. University of Reading 01/07/1996 30/06/2000 �323,208
R6505 Relieving post-harvest constraints and identifying opportunities for improving the marketing of fresh yam in Ghana. Natural Resources Institute 01/01/1996 30/03/2000 �217,710
R5983 Factors influencing the occurrence of yam tuber rots in West Africa Overseas Development Group, School of Development Studies, University of East Anglia 01/10/1993 30/03/1996 �75,700
R5897 Development of rapid tests for identification and differentiation of yam virus variability Natural Resources Institute 01/10/1993 31/03/1996 �106,280
R5738 Epidemiology and controlof anthracnose disease of yam in Nigeria University of Reading 01/10/1992 30/03/1996 �70,060
R5688 Strategies for the control of yam anthracnose Department of Agriculture. University of Reading 01/04/1993 30/03/1996 �231,990
R5346 Biology of yam anthracnose (Colletotrichum) Natural Resources Institute 01/04/1992 31/03/1995 �21,885
R5345 Epidemiology and control of yam anthracnose University of Reading 01/05/1990 30/03/1993 �120,070
R5259 An examination of Dioscorea spp (yam) for nematode resistance and its incorporation into improved cultivars Natural Resources Institute 01/04/1992 31/03/1996 �127,900

Table 4. Sub-Saharan African country NARS

Angola Instituto de l’Investigac�o Agron�mica Program de Raizes e Tuberculos
Benin Centre B�ninois de la Recherche Scientifique et Technique
Benin Institut National des Recherches Agricoles du B�nin (INRAB)
Botswana Department of Agriculture Research
Burkina Faso Centre National de la Recherche Scientifique et Technique (CNRST)
Burkina Faso Institut de l’Environnement et de Recherches Agricoles (INERA)
Burkina Faso Centre de Recherches des Trypanosomoses Animales (CRTA)
Burundi Institut des Sciences Agronomiques du Burundi (ISABU)
Burundi Institut de Recherche Agronomique et Zootechnique de la P.O.L. Burundi
Cameroon Minist�re de Recherche Scientifique et Technique
Cameroon Direction de la Recherche et de la Planification
Cameroon Institut de Recherche Agricole pour le D�veloppement (IRAD)
Cape Verde Institut National d’Investigations Agraires (INIA)
Cape Verde National Institute for Agrarian Research Development (INDIA)
Central African Republic Institut Centrafricain de Recherche Agronomique (ICRA)
Central African Republic Charg� de Mission Agriculture
Congo Minist�re de l’Education Nationale, de Recherche Scientifique et Technique
Congo Direction G�n�ral de la Recherche Scientifique et Technique
Congo Centre de Recherche et d’Initiation des Projets de Technologie (CRIPT)
Congo(Democratic Republic) Institut National pour l’Etude et la Recherche Agronomique (INERA)
Cote d’ivoire Minist�re de l’Enseignment Sup�rieur de la Recherche Scientifique
Cote d’ivoire Institut des Savanes (IDESSA)
Cote d’ivoire Institut des For�ts (IDEFOR)
Cote d’ivoire Centre Ivoirien de Recherches Economiques et Sociales (CIRES)
Eritrea Agricultural Research and Extension Department
Ethiopia Institute of Agricultural Research (IAR)
Gabon Minist�re de l’Agriculture, de l’Elevage et du D�veloppement Rural
Gabon Institut de la Recherche Agronomique et Foresti�re (IRAF)
Gabon Centre d’Introduction et d’Adaptation du Mat�riel, V�g�tal Vivrier, Fruitier et Maraicher (CIAM)
Gabon Centre National de la Recherche Scientifique et Technique (CENAREST)
Gambia National Agricultural Research Institute (NARI)
Ghana Ministry of Food and Agriculture (MoFA)
Ghana Department of Crop Services
Ghana Ministry of Food and Agriculture
Ghana Council for Scientific and Industrial Research (CSIR)
Ghana Crops Research Institute
Ghana Savanna Agricultural Research Institute (SARI)
Guin�e bissau M. le Ministre du D�veloppment Rural
Guin�e bissau Instituto Nacional da Pesquisa Agraria (INPA)
Guin�e conakry Minist�re de l’Agriculture, des eaux et for�ts (MAEF)
Guin�e conakry Institut de la Recherche Agronomique de Guin�e (IRAG)
Guin�e equatoriale Ministry of Agriculture and Fishery
Guin�e equatoriale Council for Scientific and Technical Research (CICTE)
Kenya Kenyan Agricultural Research Institute (KARI)
Lesotho Department of Agricultural Research
Madagascar Centre National de la Recherche Appliqu� au D�veloppement Rural
Malawi Chief Agricultural Research Officer
Malawi Ministry of Agriculture
Malawi Agricultural Research and Extension Trust (ARET)
Mali Institut d’Economie Rurale
Mali Comit� National de la Recherche Agronomique
Mali Minist�re du D�veloppement Rural et l’Environnement
Mauritania Centre Regional de Recherche Agronomique du D�veloppement Agricole (CNRADA)
Mauritius Agricultural and Extension Unit
Mauritius Food and Agricultural Research Council
Mozambique Instituto Nacional Investigacao Agronomica (INIA)
Namibia Ministry of Agric., Water and Rural Development
Namibia Department of Agriculture and Rural Development
Niger Institut National de Recherches Agronomiques du Niger (INRAN)
Nigeria Institute of Agricultural Research & Training (IAR&T)
Nigeria Institute of Agricultural Research (IAR)
Nigeria National Root Crops Research Institute (NRCRI)
Nigeria National Cereal Research Inst. (NCRI)
Nigeria National Horticultural Research Institute (NIHORT)
Nigeria National Seed Services
Nigeria Forestry Research Institute
Nigeria Federal Agricultural Coordination Unit (FACU)
Nigeria National Agricultural Extension & Liaison Services (NAERLS)
Nigeria Lake Chad Research Institute
Nigeria Institute for Agricultural Research
Nigeria Department of Agric. Sciences, Ministry of Agriculture
Rwanda Institut des Sciences Agronomiques du Rwanda (ISAR)
Sao tome et principe Centre de Culturas Alimentaires de Mesquita (CCAM)
Senegal Institut S�n�galais de Recherches Agricoles (ISRA)
Sierra leone National Agricultural Research Coordinating Council (NARCC)
Sierra leone Institute of Agricultural Research (IAR)
Sierra leone Rice Research Station (RRS)
South Africa Agricultural Research Council
Swaziland Ministry of Agriculture and Cooperatives
Swaziland Malkerns Research Station
Tanzania Research & Training
Tanzania A.R.I.
Tanzania Department of Research and Training, Ministry of Agriculture
Tchad Minist�re du D�veloppement Rural
Tchad Direction de la Recherche et de la Technologie Agricole
Togo Institut National des Cultures Viviri�res (INCV)
Togo Institut Togolais de Recherche Agricole (ITRA)
Uganda National Agricultural Research Organization (NARO)
Zambia SADC Plant Genetic Resources Center (SPGRC)
Zambia Crops and Soils Research
Zanzibar Ministry of Agriculture, Livestock and Natural Resources
Zimbabwe Department of Research and Specialist Services
Zimbabwe Ministry of Agric. Lands & Rural Resettlement


Nigeria Roots and Tubers Expansion Programme

Population pressure on the land has significantly reduced soil fertility in many parts of the country. For poor farmers coping with declining soil fertility and crop yields, fertilizers are expensive and frequently unavailable, and shifting to cassava production is often the best option. Cassava grows better than yam in low fertility conditions. In the poorest communities roots and tubers make up a high proportion of the family diet.

The long-term objective of the programme is to commercialize root and tuber production in order to improve the living conditions, income, food security and nutritional health of the poorest smallholder households in the programme area. It particularly targets small-scale farmers with less than 2 ha of land per household. The programme uses the existing extension service system to introduce improved varieties of roots and tubers as well as better cultivation techniques. Since women play a major role in cassava and other food crop production, processing and marketing, the programme encourages them to participate in research trials and demonstrations. Specific programme objectives include:

�                  developing improved root and tuber production technologies to improve productivity

�                  multiplying improved planting material

�                  developing processing techniques and marketing activities

�                  collaborating with NGOs for farmers’ training

The programme has improved availability and access to new varieties of planting materials, and has also enhanced the processing and marketing of products. The programme introduces trade policies to expand the breadth of demand for root and tuber products, and cassava in particular. It will also help targeted communities purchase equipment for processing.

Contact information

Mr. Ade Adeniji

Programme Coordinator RTEP

68 Ajalorun Street

2130 Ijebu-Ife Ode

Federal Department of Agricultaure


Tel: +234 8055178766/8034730231; 37-432933

Facts and figures

Total cost: US$36.0 million

IFAD loan: US$23.0 million

Duration: 2001-2010

Geographical area:

25 states, mostly in the southern and middle-belt states

Directly benefiting: 560,000 households

Status: ongoing


�      Federal Ministry of Agriculture and Rural Development

�      Food and Agriculture Organization (FAO)

�      International Development Association

Ghana Root and Tuber Improvement and Marketing Programme

The programme’s development goal is to enhance the food security and incomes of poor rural households in Ghana, with special emphasis on women and other vulnerable groups. Its specific objective is to build up competitive, market-based and inclusive commodity chains for roots and tubers, supported by relevant, effective and sustainable services that are accessible to the rural poor. It will support the emergence both of an inclusive private sector that is deeply anchored in the realities of Ghana and of a stronger public sector capable of improving the policy and regulatory environment and delivering the required public goods.

Contact information

Mr Mohamed Manssouri Country programme manager
IFAD Via del Serafico, 107
00142 Rome, Italy
Tel: +39 0654592330 Fax: +39 0654593330

Facts and figures

Total cost: US$27.6 million

IFAD loan: US$18.7 million

Duration: 8 years 

Geographical area: nationwide

Directly benefiting: 180,000 households

Status: About to start??

Ghana Root and Tuber Improvement Programme

Roots and tubers are extremely important crops in rural Ghana. They are a source of both food and income. In the northern regions, the yam harvest marks the end of the lean period while families wait for their main staples, sorghum and millet, to ripen. Cassava is a staple in central Ghana and is a major element of food security since it can be stored in the ground and harvested when needed. Sweet potato and cocoyam (taro) are important in the more humid zones in the south.

All three categories of roots and tubers are the staple foods of urban dwellers, especially the urban poor. The goal of this IFAD project is to enhance food security and improve the income of resource-poor farmers by facilitating access to new but proven technologies to boost production of root and tuber crops.

The project’s objectives are to:

�                  develop a sustainable system for multiplication and distribution of improved planting materials for roots and tubers

�                  develop an integrated pest management system, including biological control, to reduce the incidence of disease and pests

�                  strengthen on-farm adaptive research and increase the availability of new cropping, storage and processing techniques

�                  empower resource-poor farmers, particularly women, to ensure that they have unimpeded access to improved technologies

Contact information

Mr Akwasi Adjei Adjekum National Programme Coordinator
Root and Tuber Improvement Programme (RTIP)
B.P. Box 7728
Kumasi, Ghana
Tel: +233 5133159/25835 Mobile: +277568287
Fax: +233 5125835

Facts and figures

Total cost: US$10.1 million 

IFAD loan: US$9.2 million 

Duration: 1999-2005

Geographical area: nationwide

Directly benefiting: 750,000 households

Status: closed

Relevant Research Projects, with links to the
Research for Development (R4D) web site
and Technical Reports:

R4D Project Title Technical Report
R5675 Agricultural services and related research priorities in sub-Saharan Africa
R5688 Strategies for the control of yam anthracnose
R5735CB Improving the health of seed yams in West Africa
R5897 Development of rapid tests for identification and differentiation of yam virus variability
R6505 Relieving post-harvest constraints and identifying opportunities for improving the marketing of fresh yam in Ghana.
R6579 Identification, vector relationships, epidemiology and control of virus and bacterial diseases of banana.
R6691 Control of yam diseases in forest margin farming systems in Ghana.
Main Report. Annex.
R6692 Novel techniques for detection and characterisation of fungi causing Fusarium wilt and Sigatoka leaf spots of banana and plantain in East Africa
R6694 Identification of resistance to major nematode pests of yams. (Dioscorea) in West Africa
R7504 Study of factors affecting the uptake and adoption of outputs of crop protection research on yams in Ghana
R7529 Epidemiology, vector studies and control of banana streak virus in East Africa highland bananas
R7567 Integrated management of banana diseases in Uganda.
Main Report. Photographic Plates.
R7582 Development of integrated protocols to safeguard the quality of fresh yams
  • Enhancing the production and supply of good quality yams in Ghana
R8040 Rapid multiplication and distribution of sweet potato varieties with high yielding and B-carotene content
R8227 Promotion of control measures for cassava brown streak disease.
Main Report. Annex 1, Annex 2, Annex 3, Annex 4, Annex 5.
R8243 Working with farmers to control sweet potato virus disease in East Africa
R8278 Evaluation and promotion of crop protection practices for “clean” seed yam production systems in Central Nigeria
R8296 Promotion of sustainable approaches for the management of root-knot nematodes on vegetables in Kenya. Main Report.
Annex 1, Annex 2, Annex 4, Annex 5, Annex 6, Annex 7a, Annex 7c.
R8342 Promotion of improved IPM practices for banana diseases and pests in Uganda
R8416 Up-scaling sustainable clean seed yam production systems for small-scale growers in Nigeria
R8435 Sustainable Potato Seed – Tuber Management and Marketing Through Commercialization (SPOMMAC).
Main Report. Annex 3, Annex 4, Annex 5, Annex 7 to 11, Annex 12.
R8456 Extending the control of cassava mosaic disease and cassava whiteflies in East Africa
R8457 Extending control of sweet potato diseases in East Africa
R8480 The Good Seed Initiative – sharing the learning from CPP programmes into pro-poor seed systems in East Africa