
Seed Systems

In areas where there is a prolonged dry season, sweetotato vines die due to lack of moisture or through being eaten by livestoc and so are not avialable to supply cuttings. When the rains come and farmers want to plant straight away, there are no planting materials available. Farmers typically then have to wait for the rains to cause vines to emerge from old roots that were left in the field, causing delays in planting. This lack of planting materials at the on-set of rains is a major constraint to sweetpotato farming in sub-Saharan Africa.
In order to ensure access to sufficient high quality planting materials at the start of the rains, dry season preservation is necessary. Dry season conservation methods selected vary based on the socio-ecological characteristics of the household.
The Triple S (Storage of roots in Sand then Sprouting) technology is being validated in new contexts in sub-Saharan Africa. Triple S can be used for conservation and multiplication of sweetpotato planting material in areas with an extended dry season.
At the start of the rains, local availability of adequate quantities of quality planting material is limited. However, farmers using the Triple S technology can plant earlier and take full advantage of the rains to obtain higher yields. Thus, they benefit from an early food crop, before cereals can be harvested.
Ensuring that households have control over their own seed source, by retaining healthy roots and sprouting them, reduces the need to transport perishable and bulky planting material over long distances, at high cost and often with high wastage. We will continue to adapt the Triple S technology for local conditions and develop appropriate strategies for scaling out to reach more farmers.

Seed systems are required for all crops. If effective, they provide farmers with sufficient quantities of vigorous disease-free planting material of the required varieties at an affordable price and in time for the planting season. Seed systems can range from those managed by farmers for their own use, those where some of the seed is bartered or traded with nearby farmers, to those where the seed is produced by national organizations or private companies following strict regulations and at large scale.
There needs to be capacity within the seed system to securely maintain pure disease free seed, to generate new varieties with attractive characteristics, and to multiply and disseminate seed. In societies where sweetpotato is considered a 'woman's crop', seed management practices and knowledge are normally in the 'woman's realm'. The gender context and dynamics of existing seed practices need to be understood.
In areas with prolonged dry seasons, farmers are unable to access sweetpotato planting material from their previous field crop, and so methods of preserving planting materials during the prolonged dry season and accessing them in time for the new season have developed. Many farmers just wait for the new rains to cause the few sweetpotato storage roots which were left behind in the field at the last harvest to sprout and to then produce foliage. Other methods include the preservation of planting materials in swamps, shady areas of the household yard, and around drainage areas.
In some areas, farmers purchase planting material form those with good access to water and who specialize in the supply of planting material. However, these sources may not always be accessible to the majority of smallholder farmers, in particular women farmers. It is therefore, important to have a reliable decentralized system where multipliers can maintain clean planting material for easy access by farmers.
Most projects and organizations tend to organize their own seed systems to supply clean planting materials to their target communities. However, under the umbrella of the SPHI, there are initiatives to test different technologies, farmer practices and internal and external quality assurance mechanisms for maintaining healthy seed production; and to help build appropriate and cost-effective external regulatory processes.
Whilst interventions to improve seed systems have frequently been achieved at pilot level, the challenge is much greater when it comes to working at the scale of impact required to bring the benefits of clean planting material and / or improved varieties to a wider geographical and higher population coverage.

Quality seed is the starting point for any successful agricultural venture and a functioning sweetpotato seed system contributes to food security and income generation. The transition between breeder and pre-basic (i.e. first generation or foundation) seed production is a major bottleneck in the functioning of an efficient seed system for sweetpotato. This is because of: limited incentives to maintain breeder seed; a lag in investment in human capacity and facilities for pre-basic seed production; inadequate coordination between seed demand and supply; together with unreliable funding streams.
There are initiatives to develop and test different seed system technologies and innovative partnership business models to increase the multiplication rate for sweetpotato and improve the consistent supply of quality, early generation seed.
These initiatives aim to strengthen technical, financial and institutional capacities for the sustainable production of pre-basic sweetpotato seed. They also explore innovative partnership business models between public research programmes and private entities that would contribute to the broad goal of developing commercially viable seed systems.
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2019 SPHI Brief 40. Scaling Triple S PLUS with gender responsive tools and diverse scaling partners.Triple S is currently being scaled in Ghana and Ethiopia by two scaling champions, using gender responsive tools and a scaling strategy developed with diverse partners. We used the theory of scalin...
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Triple S crossword puzzleA fun crossword puzzle that is been used during Triple S training sessions in Ethiopia
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Read More about Triple-SThis page contains Triple S content organized into categories like Training Materials, Farmer Handouts, Presentations, Publications, Videos and Training Events.Read More »
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Triple S VideosVideo 1: General video explaining Triple S for decision makers Farmers often obtain sweetpotato planting material from roots which have been overlooked during harvest and sprout when it rains. Howe...Read More »
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2019 SASHA Brief 15. Towards sustainable production of pre-basic seeds in Nigeria (2015-2019).Strengthened the capacity of national partners (National Root Crops Research Institute (NRCRI) and Bayero University(BUK)) to produce and manage high quality planting material of breeder, pre-basic...
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2019 SASHA Brief 14. What motivates vine multipliers to continue once project support has ended? A case study from the Lake Zone, Tanzania.In the Lake Zone, Tanzania, between 2009-2012, 88 decentralized vine multipliers (DVMs) were established by the Marando Bora project. Five years later, the follow up study traced 81 of the DVMs. 4...
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2019 SASHA Brief 13. Early generation seed production for roots, tubers and bananas is financially viable for private sector seed companies in East Africa.CIP conducted a financial feasibility study for a private seed company engaged in early generation seed (EGS) production for root, tuber and banana crops. The study showed that the business is fina...
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2019 SASHA Brief 12. A new method for estimating sweetpotato early generation seed requirements to supply commercial and institutional markets.A user-friendly tool to estimate the requirements for Early Generation Sweetpotato Seed (EGS) is now available for use by public sector seed producers. The method was first used in Uganda to estima...
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2019 SASHA Brief 10. Is sweetpotato root production cost-effective when using planting material conserved in protected structures in high virus pressure areas?Two methods of protected vine conservation beds (insect protected net tunnel (Fig. 1) and miniscreenhouse (Fig. 2)) were compared with an open field control to assess cost effectiveness for quality...
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2019 SASHA Brief 09. Efficiency of insect-proof net tunnels in reducing virus-related seed degeneration in sweetpotato.Affordable insect-proof net tunnels proved effective in reducing virus-related degeneration in sweetpotato in Tanzania. Re-infection in high virus pressure area was prevented for up to 20 months an...
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2019 SASHA Brief 08. Pre-basic sweetpotato vine multiplication using a sandponics system.A nutrient media for multiplying pre-basic sweetpotato vines under a sandponics system was optimized. The vine multiplication rate for pre-basic seed multiplication increased by 22% using sandponic...
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Early Maturing Sweetpotato DataBase 20170915Database for early bulking (the <100-day sweetpotato): Early bulking: Information for 49 early bulking released / launched varieties were uploaded in a database on the “sweetpotato knowledge por...
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BATATA DOCE material de plantio SISTEMA TRIPLO SThe following brochure illustrates how to use the Triple S system for conservation of sweetpotato planting material. It is written in Portuguese, but is also available in English.
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Assuring availability of sweetpotato planting material: scaling out “Triple S” in northern UgandaUnder the five-year HarvestPlus led project ‘Developing and Delivering Biofortified Crops in Uganda’, CIP scientists are leading the component to adapt and refine the technology to local conditions...
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From seed security to food security: validating ‘Triple S’ seed conservation technology in new contextsThis flyer outlines the progress made between 2014 and 2015 regarding the validation of Triple S (Storage in Sand and Sprouting) technology in the Southern Nations Nationalities and Peoples’ Region...
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SASHA Brief: Towards improved seed system management: use of affordable net tunnels and decentralized inspection schemesIncreased sweetpotato production in sub-Saharan Africa is hampered by high incidence of virus diseases. Work is going on to test whether healthy seed production can be maintained through a combinat...
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POSTER: EFFECT OF TUNNEL SCREEN ON RATE OF SWEETPOTATO VINE MULTIPLICATION FOR INCREASED FOOD PRODUCTION AND INCOMEThis poster presents a study whose objective was to assess the effect of tunnel screen on vine multiplication rate of “Apomuden” and “Ogyefo” varieties.
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Sweetpotato planting material: the Triple S System - Storage, Sand, SproutingFarmers often obtain sweetpotato planting material from roots which have been overlooked during harvest and sprout when it rains. However, the roots sprout only when it rains and planting material ...
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Net tunnels to protect sweetpotato planting material from disease a guide to construct and maintain tunnelsThere is high demand for clean planting materials (sweetpotato vines). Given the need for community-level vine multipliers to have better and more affordable access to quality, disease-free (“clean...
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Sweetpotato vine management for confined food production in a space life-support systemSweetpotato (Ipomea batatas L.) ‘Whatley–Loretan’ was developed for space life support by researchers at Tuskegee University for its highly productive, nutritious storage roots. This promising cand...Read More »
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Rapid Multiplication and Dissemination of Sweetpotato Varieties with High Yield and ß-Carotene ContentThe project aimed at reducing food insecurity, poverty and malnutrition among small-scale farmers in eight districts of central Uganda. This was to be achieved through increased multiplication, dis...
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Sweet potato seed systems training manual for farmersThis manual was developed by putting together a comprehensive reference technical tool for training trainers of trainers (TOTS), trainers and trainees. Although a lot of technical relative informat...
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Video: Clean seed system for Orange-fleshed sweetpotato productionAssuring access to quality disease free planting material in Kenya - Kenya Plant Health Inspectorate Service leads the way. The film describes & shows the entire process of virus removal and pr...Read More »
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Degeneration in sweetpotato due to viruses, virus‐cleaned planting material and reversion: a reviewThis review examines viral degeneration in sweetpotato in different regions of the World, particularly that caused by Sweet potato chlorotic stunt virus (SPCSV) and Sweet potato feathery mottle vir...Read More »
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Determining the Pan-African sweetpotato virome: understanding virus diversity, distribution and evolution and their impacts on sweetpotato production in AfricaFood security remains a huge challenge for the millions of Africans dependent on agriculture for their subsistence. A low-level agricultural productivity and a high percentage of poor and undernour...
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HQU - Sweetpotato NCM-ELISA Virus Detection - OP021These operational procedures are for NCM-ELISA, an immuno-enzymatic test that uses nitrocellulose membranes instead of the polystyrene microtitration plates as a support for the reagents used in th...
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HQU - Sweetpotato Indicator plant diagnostic procedure - OP022This OP explains how to use grafting - a technique whereby cut tissue surfaces of different plants are placed in close contact to effect a union. Grafting is considered to be a universal method for...
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HQU - Sweet Potato Virus Indexing Procedure - OP023This standard procedure has been established based on current information for virus testing of sweetpotato germplasm, with the recognition that it will need to be revised as new information becomes...
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Utility of thermotherapy and meristem tip for freeing sweetpotato from viral infectionSweetpotato, (Ipomoea batatas L.), is vegetatively propagated crop. Due to the following cycles of propagation, viruses are accumulated, which contributes to the decline of sweetpotato yield and qu...
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Sweetpotato virus indexing procedure - OP23Virus indexing combines knowledge of viruses with methodologies for their detection to assure the effective safe movement of sweetpotato germplasm. Due to low virus titers and the absence of sympto...
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Health status testing and virus elimination in sweetpotato - OP18Virus elimination will be carried out in all materials maintained or generated at CIP, and prior to its distribution. The virus elimination technique is based on thermotherapy and meristem culture....
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Indicator plant diagnostic procedure - OP22This OP explains how to use grafting - a technique whereby cut tissue surfaces of different plants are placed in close contact to effect a union. Grafting is considered to be a universal method for...
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NCM-ELISA detection of sweetpotato viruses - OP21These operational procedures are for NCM-ELISA, an immuno-enzymatic test that uses nitrocellulose membranes instead of the polystyrene microtitration plates as a support for the reagents used in th...
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Sweetpotato virus indexingA set of slides on how to undertake virus indexing.
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Presentation: Antisera productionThis presentation elaborates the antisera production and downstream process to develop virus detection methods.
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NCM-ELISA - Slide setA set of slides that illustrates the procedures for undertaking the NCM-ELISA.
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Health status testing and virus elimination in sweetpotato - OP18Virus elimination will be carried out in all materials maintained or generated at CIP, and prior to its distribution. The virus elimination technique is based on thermotherapy and meristem culture....
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Elimination of bacterial contaminants from sweetpotato in vitro cultures - OP53Controlling internal or superficial bacterial contamination from sweet potato in vitro cultures can be difficult. Contaminants are not easy to detect visually, and most methods reported for bacteri...
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Production of virus free sweetpotato planting materials using horticultural fleeceSweetpotato (Ipomea batatas) is one of the most important staple crops in densely populated parts of Eastern Africa and is quickly becoming an important supplementary staple in the southern part of...
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SP Virus synergismThis is a presentation on detecting virus infections on plants by examining their leaves. The data is supported by images of leaves infected with different viruses.
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In vitro methods for pathogen elimination and international distribution of sweet potato germplasmThis document discusses several in vitro methods for eliminating pathogens such as thermotherapy, meristem culture, chemotherapy and routine testing; as well as the issue of international distribut...
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From Laboratory to Market: Government-private sector contribution to improve sustainable development of sweetpotato productionSweetpotato vegetative cuttings Abees cultivar were collected and serologically tested using ELISA and Western blot analysis techniques. Thermotherapy followed by Meristem tip culture technique was...
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Sweetpotato IPPM FFS curriculum and ideas for learning activitiesThis sweetpotato IPPM curriculum gives an insight into sweetpotato variety selection, experimentaion, strengths and weaknesses of farmers’ experiments, an introduction to some the principles of exp...
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Sweetpotato IPPM FFS curriculum and ideas for learning activitiesThis sweetpotato IPPM curriculum gives an insight into sweetpotato variety selection, experimentaion, strengths and weaknesses of farmers’ experiments, an introduction to some the principles of exp...
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2019 SPHI Brief 30. HARVESTPLUS enhancing on-farm access to vitamin A sweetpotato pathogen-tested planting material in Uganda: Strategies for sustainable adoption.On-farm performance of sweetpotato pathogen-tested (PT) planting material has been reported giving over 80 percent yield increase, especially in sweet potato virus disease (SPVD) susceptible variet...
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2019 SASHA Brief 11. Bridging the gap between pre-basic seed producers and decentralized multipliers for a sustainable sweetpotato seed system in Tanzania.A study was conducted to understand the economic sustainability of basic seed enterprises to bridge the gap between pre-basic seed producers and decentralized vine multipliers. Four commercial see...
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Sustainable Sweetpotato Early Generation Seed: a conceptual framework to assess technical, financial and institutional innovationsIn many sub-Saharan African countries, public sector institutions have been mandated to generate income from their research activities. National Agricultural Research Institutes (NARIs) and private...
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The dynamics of smallholder farmers’ acquisition and distribution of sweetpotato vines in the Lake Victoria Zone Region, TanzaniaThis paper offers new insights into smallholder farmer’s practices regarding acquisition and distribution of sweetpotato planting material in the Mwanza and Mara regions of Tanzania by examining th...Read More »
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Sweetpotato production: A simple guide to Good Agricultural Practices.A simple guide for sweetpotato production tuned to the West African & sub-Saharan setting to enable the rural farmer understand basic activities that are needed to produce quality roots.
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Specialised Sweetpotato Vine Multiplication in Lake Zone, Tanzania: What “Sticks” and What Changes?In Lake Zone, Tanzania, farmers were trained to multiply and distribute quality sweetpotato planting material. The objectives of this study were to assess changes in skills and practices among the ...
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BATATA DOCE material de plantio SISTEMA TRIPLO SThe following brochure illustrates how to use the Triple S system for conservation of sweetpotato planting material. It is written in Portuguese, but is also available in English.
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Farmer-led Seed Enterprise Initiatives to Access Certified Seed for Traditional African Vegetables and its Effect on Incomes in TanzaniaFarmers need access to certified seed stocks for efficient production of traditional African vegetable seed. However, access to quality certified seed is constrained by several factors. Primary dat...
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Sweetpotato Seed Systems in Uganda, Tanzania, and RwandaSurveys were made of the seed systems used in Uganda, Tanzania, and Rwanda and to investigate the reasons underlying them. Along the equator in Uganda, where rainy seasons are evenly spaced and occ...
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SPHI Brief 2015: Sweetpotato for Health and Wealth in Nigeria UnderwayThis flyer provides details about the objectives, activities, achievements and the future plans of the ‘Sweetpotato for Health and Wealth’ in Nigeria project. The project plans to establish committ...
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Sweetpotato Seed Systems in Uganda, Tanzania, and RwandaSurveys were made of the seed systems used in Uganda, Tanzania, and Rwanda and to investigate the reasons underlying them. Along the equator in Uganda, where rainy seasons are evenly spaced and occ...
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GOING-TO-SCALE WITH SWEETPOTATO VINES DISTRIBUTION IN TANZANIA: MARANDO BORA BASELINE STUDYMarando Bora (quality vines) is a sweetpotato seed system project based in the Lake region of Tanzania. The project’s purpose is to address the main problems associated with sweetpotato vine availa...
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Sweetpotato Seed Systems: A Farmer Trainers’ GuideBotanically sweetpotato or Spanish potato is called Ipomoea batatas (L.) Lam, belongs to the morning glory family (Convolvulaceae) and originated from Latin America. Sweetpotato ranks as the world’...
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Review of Sweetpotato Seed Systems in East and Southern AfricaThis working paper highlights the challenges and opportunities for producing sweetpotato planting material in Eastern and Southern Africa, where there is a huge potential for the crop to contribute...
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CHALLENGE THEME PAPER 2: SUSTAINABLE SEED SYSTEMSSustainable seed systems for vegetatively or clonally propagated crops such as sweetpotato fulfill a number of critical roles: The timely provision of planting material of appropriate quality for s...
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Farmers willingness to pay for quality sweetpotato vinesThese results of an innovative study amongst small farmers in Zambezia, Mozambique showed that the farmers were willing to pay for sweetpotato vines for plating if they were sure they were good qua...
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Sweet potato seed systems training manual for farmersThis manual was developed by putting together a comprehensive reference technical tool for training trainers of trainers (TOTS), trainers and trainees. Although a lot of technical relative informat...
- Size: 734.7 kB
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- Pages: 45