Category Archives: News

Triple S method secures sweetpotato planting material for farmers

“Next season I will fill my farm, and my father’s farm, with sweetpotato,” says Bezabih Hamamo, who is using Triple S technology on his farm in southern Ethiopia to produce his own quality sweetpotato planting material. Triple S, which stands for ‘Storing in Sand and Sprouting’, involves storing sweetpotato roots in sand through the dry season, only allowing them to sprout and produce planting material when the farming season begins again with the rains. This method ensures a consistent supply of seed for farmers while reducing costs and is particularly beneficial in areas with long dry seasons and unpredictable seasons – an increasing challenge under climate change.

Hamamo is from Hawassa Zuria, approximately 40km from Hawassa town, and it is in this area that the Triple S technology is being scaled through the CGIAR Research Program on Roots, Tubers and Bananas (RTB) Scaling Fund portfolio.

Sweetpotato farmers watch a demonstration of how to set up a Triple S container, storing roots in dry sand. Photo: CIP

Hamamo and his wife, Worke Kuchuta, are enthusiastic orange-fleshed sweetpotato (OFSP) farmers and, as part of efforts to scale the technology, have been identified as a Triple S ‘champion household’ tasked with disseminating knowledge on the technology for conservation and multiplication of planting material to farmers in their kebele (village).

Although the next planting season not for another five months, the pair are not worried about where they will find vines to replant their fields. Following the Triple S process, they will store roots in sand in a cool dry place over the dry season. Six weeks before rains are expected, the sprouted roots are taken out of storage and planted in an irrigated seed bed, to produce planting material which will be ready at the beginning of the wet season.

Hamamo was introduced to this technology through the SASHA II project with 20 roots as starter material in 2016 and was trained on how to use the method by Mihiretu Cherinet, a scientist from the International Potato Center (CIP).

Hamamo and Worke produce planting material both for their farm and for sale to other farmers. They attest to the nutritious benefits and income gained from OFSP cultivation. Recently, Hamamo sold roots from a small section of their farm to traders in Hawassa for ETH Birr 7,000 (USD255) and says there is a high demand for the roots. “My six children enjoy OFSP very much, eating it on its own and mixing it with other staples such as kocho and maize,” says Worke. Kocho is a starch extracted from the enset plant, fermented and then used to prepare different local foods.

It is currently the harvesting season and the couple have already identified the section of the farm that they will select roots to use for their Triple S system. The plants in this section look healthy, vigorous and have the medium sized roots ideal for this technology. As they prepare to harvest, Hamamo and Worke are also taking the time to train other farmers on this technology using their farm as a good demonstration that it works. Hamamo emphasizes that with this technology, farmers will not need to depend on projects to distribute vines or spend money to buy vines, instead they are assured of their own quality planting material.

Bezabih Hamamo and Worke Kuchuta on their farm in southern Ethiopia. Photo: CIP

 Hamamo and Worke are not the only ones teaching farmers about this new technology; extension agricultural officers from the Bureau of Agriculture and Natural Resource Development have partnered with CIP to train other champion households in target villages. They identify four champion households who are trained in a classroom setting, as well as participating in a physical demonstration on how to select healthy roots and set up the Triple S container. In turn, the champion households train other farmers in their respective communities increasing the opportunities of this technology going to scale.

Cherinet highlights the advantages of Triple S, explaining that in the three years that this technology has been in use there has been no observable reduction in yield and no weevils observed, unlike when traditional methods of conserving planting material are used. Traditional conservation methods include preservation under the shade of enset trees during the dry season.

With 48 Triple S champion households in three different districts (Hawassa Zuria, East Badiwacho and Mirab Abaya) cascading knowledge to other households in their communities, the use of Triple S has great potential to positively impact food security, nutrition and income in the region. 

With support from RTB, CIP is implementing the Triple S PLUS initiative with different scaling partners and is also testing effective methods for the dissemination of the Triple S technology by using gender-responsive communication materials in the form of step-down trainings, video-based trainings and radio programs. In partnership with People In Need, a nongovernmental organization working on nutrition projects that include sweetpotato, the Triple S PLUS initiative aims to reach 25,000 households in six districts of Ethiopia. 

This research was supported by CGIAR Trust Fund contributors.

Refining the use of innovation platforms to support scaling

Guidelines are helping the agricultural research for development sector to rethink how and when to use ‘innovation platforms’ to most effectively develop and scale technologies.

Innovation platforms are increasingly used in agricultural research for development initiatives to help researchers, farmers, food processors, government officials and other actors design effective innovations. An innovation platform is a group of individuals and organizations with different backgrounds, expertise and interests who come together to diagnose problems, identify opportunities, and find ways to achieve their goals. They may design and implement activities together or as individual members.

Based on early successes, innovation platforms are now being used widely in agricultural research for development to test local innovations and take them to scale at the national level by increasing the collaboration, exchange of knowledge and influence mediation among stakeholders. However, these cases often involved highly motivated people in well-supported initiatives.

“Innovation platforms are fast becoming part of the mantra of agricultural research for development projects and programs. However, innovation platforms run the risk of being promoted as a panacea for all problems in the agricultural sector. Recent studies have shown that there are some practical limitations that must be considered, which led us to develop a set of guidelines on how to best use innovation platforms,” said Marc Schut, social scientist at the International Institute of Tropical Agriculture and Wageningen University, and the leader of RTB’s Flagship Project 5.

Continue reading the story in the RTB 2017 Annual Report: From science to scaling

Decision-support tools remove the guesswork from agronomic innovation

Decision-support tools being piloted in Nigeria and Tanzania can help cassava growers decide if agronomic recommendations will be profitable under their local conditions.  

Crop yields in Africa are often limited because farmers and extension agents lack reliable agronomic recommendations that are tailored for their local conditions. For example, judging the most effective quantity of fertilizer depends on knowing fertilizer and labor costs, expected weather, soil type, cropping history and past soil management. Crops in different locations may respond to fertilizer in different ways. Or, the market may reward farmers with high crop prices in one area, but not in another. As a result, farmers may not be able to judge if an investment is worthwhile before trying it. 

Since 2016, the African Cassava Agronomy Initiative (ACAI), a project managed by the International Institute of Tropical Agriculture (IITA) in partnership with national and international research institutes, universities, development organizations and the private sector, has developed tools to support cassava growers and extension agents in Nigeria and Tanzania to make decisions by tailoring investments in agronomic practices to farmers’ local conditions, maximizing profits. 

Continue reading the story in the RTB 2017 Annual Report: From science to scaling

Toolbox to understand and enhance root, tuber and banana seed systems

A suite of tools for understanding root, tuber and banana seed systems are helping document and guide the implementation of on-going seed interventions.

Root, tuber and banana crops are clonally propagated, meaning they are grown by planting tubers, suckers, stalks, or vine cuttings, referred to as ‘seed’. This presents several challenges for farmers, including low seed multiplication rates, bulky and perishable planting material and rapid seed degeneration leading to low crop yields.

RTB centers have collaborated to develop tools that allow practitioners to understand and systemically diagnose seed systems and determine how to effectively intervene in them. In 2017, experts from Wageningen University and the RTB centers met to incorporate and describe these tools in a single toolbox using a standard format.

“This toolbox is a much-needed guide, a collection of 14 tools that enables researchers to come to grips with the seed systems of vegetatively propagated crops, and to overcome social, economic and market constraints,” said Jorge Andrade-Piedra, seed expert and plant pathologist at the International Potato Center (CIP). The toolbox is being validated in 14 projects in Asia, Africa, and South America across all major RTB crops.

One of the tools, a ‘multi-stakeholder framework for intervening in root, tuber and banana seed systems’ will be used in all locations to allow the designers of new seed projects to identify the major stakeholders, their roles, and critical bottlenecks of vegetatively propagated seed systems. So far, the framework is being used in ongoing interventions in Nigeria for cassava, in India for potato, in Ethiopia for sweetpotato, and in Uganda for banana. It has allowed researchers to organize multi-stakeholder workshops to analyze the seed system, identify appropriate interventions and to guide the design of household questionnaires to probe deeper into key constraints to seed use.

Continue reading the story in the RTB 2017 Annual Report: From science to scaling

Making storable orange-fleshed sweetpotato purée a commercial reality

Orange-fleshed sweetpotato purée is a profitable and nutritious commercial product to meet urban consumers’ needs in Kenya.

Vitamin A deficiency is a serious problem in East Africa. Through the efforts of the International Potato Center (CIP) and its partners, many vitamin A-rich, orange-fleshed sweetpotato (OFSP) varieties have been made available to rural households. As Africa is rapidly urbanizing, more people want to buy food that is ready to eat or easy to prepare.

Earlier research in Rwanda demonstrated that OFSP purée (steamed, mashed roots) was an economically viable ingredient in baked products when the purée was produced and used in the same bakery. Between 2010 and 2014, CIP and the Rwanda Agricultural Board worked with a bakery, Urwibutso Enterprises, to make biscuits and donuts from sweetpotato purée. The bakery made its own purée and used the waste for animal feed at their piggery. However, most bakeries do not want to make purée or deal with the waste.

“The challenge for us as researchers was to develop a more complex market chain that could take orange-fleshed sweetpotatoes all the way from the field, through processing and baking, to reach consumers with bread that was rich in vitamin A,” noted Dr. Tawanda Muzhingi a food scientist at CIP. In 2014, the Center began to work with a wider range of value chain actors in Kenya to develop baked goods made with OFSP. During product development, the food technology specialist at Euro Ingredients Ltd. created improved OFSP bread, buns and cake recipes.

Continue reading the story in the RTB 2017 Annual Report: From science to scaling

Disease-resistant potato and banana give hope to farmers

Late blight remains one of the most devastating diseases for potato worldwide, costing farmers an estimated USD3 – 10 billion per year globally. Traditional breeding for resistant varieties takes years, and resistance can break down as the pathogen mutates when it encounters resistance genes, leaving farmers no options than using fungicides up to 15 times per season. Similarly, banana Xanthomonas wilt (BXW) is a growing threat to the livelihoods of small-scale farmers. Since its appearance in Uganda in the early 2000s, BXW has spread rapidly in the region, causing food insecurity and income loss. No resistant cultivars have been identified, and it can only be controlled through on-farm management practices.

In the face of these serious and persistent challenges to food security and livelihoods, RTB centers and national research partners have developed a biotech late blight-resistant potato with multi-gene resistance, and a BXW-resistant cooking banana variety for East Africa. Confined field trials have shown the crops to be very disease resistant, and otherwise identical to the original varieties.

In 2017, a RTB cross-crop initiative began to ensure the responsible management and regulation of biotech crops. Stewardship in plant biotechnology is the responsible management of a product from its inception through its ultimate use (learn more: In addition, biotech crops need to be assessed for their safety to humans and animal health prior to release to the public for commercialization. Environmental risk assessments are also an essential part of regulatory decision-making for biotech crops. Consequently, stewardship plans along with risk assessments and experimental evidence are required to gain regulatory approval and for the responsible cultivation of these crops.

Continue reading the story in the RTB 2017 Annual Report: From science to scaling

Breeding improved cassava varieties that women and men want

Understanding gender differences in trait preferences for cassava can accelerate adoption as this knowledge is incorporated into breeding programs.

Cassava is the daily bread of Nigeria, but it is hardly ever simply boiled and eaten. Nigerian cassava is processed into products like gari (toasted cassava starch granules), which are made in villages and trucked to cities across the country. Processing usually involves several different steps and quite a lot of work. While women do grow cassava, they also provide most of the labor for cassava processing, both for food products to eat at home and in many cases, to make a living from small-scale enterprises. Men grow larger cassava farms than women and prefer to sell cassava as fresh roots, instead of processing it. Because of these varying roles, women and men’s perception of the most critical traits needed in cassava may differ. 

The Next Generation Cassava Breeding (NextGen) project aims to take these traits into account to improve targeting of cassava varieties for end users.  Nextgen uses a new approach to accelerate breeding called genomic selection that relies on statistical modeling to predict cassava performance before field-testing.

Hale Ann Tufan of Cornell University leads the survey component of Nextgen. She explains, “We need to think like a company. Companies have to build consumer profiles of their users and then develop typologies around these to inform the breeding program.” Likewise, plant breeders need to understand how important a trait is for farmers, as not all the traits that farmers list are equally important.

Similarly, the RTBfoods project led by Dominique Dufour, Food Scientist at CIRAD is also working to understand gender differences in trait preferences for important food and income-generating root and tuber products, with the aim to develop new varieties that meet the needs of men and women producers, processors and consumers. “Creating an evidence base for crop and product preferences by gender and other factors of social difference is a new and innovative approach that we are excited about. Importantly, this will further the contributions of breeders to improving food security and income generation in sub-Saharan Africa,” explains Lora Forsythe of the Natural Resources Institute, who leads Work Package 1 on preferences for the RTBfoods project.

Continue reading the story in the RTB 2017 Annual Report: From science to scaling

Pest distribution and risk atlas for Africa includes potato and sweetpotato pests

Insect pests cause major yield losses in agricultural crops. Climate change is expected to exacerbate this impact, with warming temperatures affecting insect populations, range expansion and outbreaks. To inform the development of integrated pest management strategies, the International Potato Center (CIP) launched an online Pest Distribution and Risk Atlas for Africa in early 2017.

This open-access, mobile-accessible resource combines up-to-date information on major insect threats to potato, sweetpotato, vegetable and maize production with current risk maps for each pest and predictions for future climate scenarios. Researchers, agricultural ministry officials and extensionists can use that information to plan efforts that help farmers better manage crop pests now and prepare for future threats. The maps were generated using insect life cycle modelling software (

“Any increase in temperature caused by climate change will have drastic effects on pest invasions and outbreaks that will affect pest management, crop production and food security,” said Jürgen Kroschel, CIP Agroecology and Integrated Pest Management science leader, who started the Pest Risk Atlas project.

Continue reading the story in the RTB 2017 Annual Report: From science to scaling

Competition calls for innovative packaging of cassava stems to increase sales

A new competition is calling for innovative packaging designs to sell bundles of high quality cassava stems in Nigeria.

The competition has been launched by the ‘Building an Economically Sustainable, Integrated Seed System for Cassava in Nigeria’ (BASICS) project, which aims to develop a sustainable cassava seed value chain in Nigeria, based on the commercial production and dissemination of improved cassava planting material.


A farmer carries a bunch of cassava stems in Nigeria. Photo IITA

This seed value chain will serve as a vehicle to deliver better quality and more productive cassava varieties in order to improve productivity and food security, increase incomes of cassava growers, processors and village seed entrepreneurs, and enhance gender equity in Nigeria.

Currently, most cassava farmers use the stems from their own farm for planting or buy stems of dubious quality from the local market. To sustainably and significantly change farmers’ behavior to buy improved and quality certified stems, at least two things need to happen:

  1. The improved variety stems need to result in the farmers getting higher cassava production and ultimately translate that into higher net incomes, consistently, meaning that the variety needs to meet the contextual market demand. (Substance)
  2. The improved stems need to be presented well, packaged well and they need to result in a visibly improved crop stand in the farmers’ fields. (Style)

While the ‘substance’ is of greater importance in long term success, the ‘style’ is important to get the attention of the market to influence the initial buying behavior and hence is a vital part of marketing of any new product or service.

This competition invites innovative ideas for the ‘style’ or presentation of the cassava stems. Participants should submit their proposal in maximum of three pages on how to make a bundle of improved/certified cassava stems more marketable to farmers on a large scale.

Entries must include the following:

  1. Your contact details and a brief profile
  2. Cassava stem bundle treatment, packaging, labeling and handling proposal
  3. Overall additional cost per bundle of 50 one-meter stem cuttings (you can make explicit assumptions to get reasonable economies of scale)
  4. What attributes brought about through your proposal do think will entice the farmers to pay the higher price to buy your bundle of stems and come back as a repeat buyer or become an advocate for it?

Any individual or a group of individuals or an institute who has the ability to demonstrate the proposal in Nigeria is eligible to participate.


  1. $1,000 cash prize for the best proposal
  2. A Certificate Of Appreciation for the TOP THREE proposals signed by the Program Director, CGIAR Research Program on Roots, Tubers and Bananas (RTB) and Deputy Director General for Research, IITA
  3. $5,000 award for implementing a pilot project of the proposal as a part of the BASICS project. (only if the committee feels the technology/proposal is mature enough to be piloted)

Judging criteria
Entries will be judged based on attractiveness of the proposed presentation of the stems in the eyes of various stakeholders, practicality of the proposal, on ease of availability of additional inputs being suggested, ease of handling of the bundle, tamper proof certification tagging of the bundle, overall cost and value for money considerations.

Important note
Please note that this is not a research proposal. It is expected that you would have experimented and come up with something that is now ready to be tested on a commercial pilot level. Or it could be a proven native knowledge that has been lost to the world and is waiting to be rediscovered. There could be ideas that improve the packaging of the stems and improve ease of handling, there could be methods for improving the look and feel through some low cost dyeing of the stems or some nutrient/fungicide dips to improve the crop establishment in the field. Your proposal could address just one or multiple issues at the same time and the most commercially viable proposal will be picked.

The entries should be submitted in the format mentioned above and should not be more than three pages long. The committee may seek more information at an appropriate time, if required.

Entries should be emailed to by July 25, 2016.

Download the full competition details

Understanding potato seed degeneration to increase yields in Ecuador

The resilience of potato production systems in Andean countries heavily depends on seed quality. Under local conditions in Ecuador, the variation in seed quality has been estimated to account for 30% of variation in attainable potato yield. This is critical for the country’s estimated 85,000 potato farmers, of which around 75% are small-scale producers. Farmers’ seed quality is usually poor because of degeneration, which is the increase in incidence of pests or pathogens in the seed tuber leading to yield loss and a decline in seed quality over successive cycles of vegetative propagation.

One of the pathogens causing seed degeneration is Rhizoctonia solani which is disseminated by the seed tuber (black scurf) or the soil. Yield losses caused by R. solani in potato in Bolivia, Ecuador and Peru have been reported to be up to 20%, indicating the importance of the pathogen for the Andean region. Despite this, the influence that the sources of infection and the density of the pathogen have on potato seed degeneration and on fungal soil colonization has been poorly quantified and understood.

To understand the role of inoculum sources and inoculum densities on the potato seed degeneration caused by R. solani, researchers from the International Potato Center, the Centre for Crop System Analysis and the Laboratory of Phytopathology of Wageningen University set up a glasshouse experiment at Wageningen University with different levels of R. solani on the seed tuber and in the soil. To explore how these factors influence the extent to which the pathogen infects the surrounding soil, DNA was extracted from soil samples taken from the pots at 30, and 60 days after planting and one day before harvesting. Then, the absolute amount of DNA of R. solani was quantified using real-time PCR.

Assessing sources of infection and the density of the pathogen on potato plants

“Our results found that the disease delays the emergence of the potato plants and consequently causes problems in the management of the crop. This means that we need to be careful with the tubers that we are planting because these may affect the development of our crop,” explains MSc student Israel Navarrete from Wageningen University, whose research scholarship for the project was funded by the McKnight foundation.

fgfg“Additionally, our results show that the pathogen can disseminate aggressively on the tubers and in the soil and that IPMs need to take into account not only the health of the seed, but also the health of the soils. The results also found that we can monitor the disease either in the soil or in the tuber, making it possible to integrate this in Integrated Pest Management strategies,” he says.

Effects of R.solani on emergence and amount of R.solani DNA on tubers

The researchers concluded that both inoculum sources are relevant to reduced seed quality regardless of the inoculum density, and that soil colonization by R. solani is similar after 30 days after planting.


“These findings will eventually be translated into better pest management strategies in order to improve the quality of the seed produced by smallholder farmers, and improve the health of the Ecuadorian soils for the benefit of the same farmers. Monitoring strategies can be designed to understand the variation of the pathogen on Ecuadorian farms, and reduce the impact of the pathogen on farmer fields,” explains Israel.

Better management of critical pests and diseases is an essential step towards helping boost Ecuador’s potato production (9 ton per hectare), which continues to be much lower compared to its neighbours, Colombia (19 ton per hectare) and Peru (14 ton per hectare). This will bring much needed income and food security for the country’s small-scale producers.

This research was conducted as part of the ‘Seed degeneration of roots, tubers and bananas’ project funded by the CGIAR Research Program on Roots, Tubers and Bananas.