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Study sheds new light on roles of women and men on RTB farms

Husband and wife harvest potato. Photo credit J. Okonya/CIP


Results from a household survey of farmers in Rwanda and Burundi challenge our stereotypes about how women and men engage in growing roots, tubers and bananas. In male-headed households, decision-making and labor-provision were most of the time joint efforts by men and women, while in female-headed households, men made most of the decisions and supplied most of the labor.

“It is truly surprising,” said Joshua Okonya, lead author on the study. Okonya, a research associate with the International Potato Center (CIP) and CGIAR Research Program on Roots, Tubers and Bananas (RTB) based in Kampala, Uganda, says that one of the key messages of the study is that gender is a complex subject that requires a deeper understanding of the community.

The survey looked at 811 farming households in two watersheds, Rusizi in Burundi and Ruhengiri in Rwanda. Each farmer grew at least two of four RTB crops; bananas and potatoes, primarily as cash crops to be sold at market, and sweetpotato and cassava as food crops to be eaten by the family. (Previous results from the survey looked at understanding farmers’ concerns in pest and disease management and the safer use of pesticides.)

Most of the households (80% in Burundi and 84% in Rwanda) were headed by men, usually a father or husband. In Rwanda, female-headed households had a combined on-farm and off-farm income less than half that of male-headed households. In Burundi, by contrast, female- and male-headed households had similar incomes. In general, lower farm incomes were observed where men participated less. This may be because men were able to earn more by working off the farm. Households with lower total income, especially those far from markets, showed increased joint decision-making.

Two factors may explain this, Okonya suggests. “Men can walk or ride a bike further than women, and when markets are far from home the women, who are in charge of most household chores and childcare, cannot spend long hours away from home.”

Woman in potato store selecting seed for planting. Photo credit J. Okonya/CIP

Whose crops?

Traditionally, cash crops are controlled by men while women control food crops, but the survey tried to uncover the details by asking who made the decisions about 10 different activities, from preparing the land to weeding and pest control, through to finally selling the crop. Separately, surveyors asked who actually carried out those activities.

For food crops and cash crops alike, men and women jointly took decisions and provided labor in almost half the male-headed households. Surprisingly, perhaps, in female-headed households men made most of the decisions and provided most of the labor. Fewer than one in five female-headed houses reported joint decision-making and labor. The proportion was slightly higher for cash crops (banana and potato, 17%) than for food crops (cassava and sweetpotato, 13%).

“Most female-headed households have an adult male around; an adult son, a father, a friend or a hired worker,” Okonya explains. “The female head consults and can delegate some duties to these men.”

Social norms rule

Social norms do still govern many activities. In Burundi, for example, girls are not permitted to prepare the land for bananas or plant bananas, because they do not own the land. Men show little interest in sweetpotato as a crop, because the roots are not usually sold. Violence is also a factor, with women telling the surveyors that they avoid asking men how they spent cash from crop sales.

This makes it imperative, the study says, for men to be continually sensitized and enlightened, to stop using violence against their wives and to increase the involvement of women in all aspects of farming. Where women do have their own plots, they decide what to grow and how to spend the proceeds, usually on school fees for their children and taking care of the home.

“Once men appreciate the role and significance of women making decisions and handling the cash from crop sales, then cultural norms as a gender-based constraint may gradually dissipate,” the study concludes.

Achieving equity

A surprise result is that women do not provide 60-80% of the agricultural labor, as was previously thought. At least for Burundi and Rwanda, this is simply a myth, for the four RTB crops in the study. It is not possible to say how much labor the women in this study do provide, because the researchers did not look at time budgets. However, even for weeding, the task to which women contribute the most, in only about 15% of households did women do all of the work.

“This finding absolutely changes the way we previously imagined women’s participation in banana production,” said Okonya. “The reason could be strong cultural norms, where girls are raised from childhood being told that banana is a man’s crop.”

The survey’s results will provide additional impetus for RTB research to deliver improved varieties that farmers like and that are resistant to various stresses. Work to improve links to markets and value chains will also continue. With specific regard to gender, Okonya sees a large contribution to future changes.

“Results will inform policymakers and development partners to design gender transformative approaches to women’s empowerment,” he said.

Traditional gender norms recognize men as the main decision-makers at household and community levels. That perception is already changing. According to this study, women and men perceive their contributions differently. Women tend to say that decisions are mostly made by men, while men say that decisions are mostly made jointly.

“This is a good thing,” Okonya said, “and shows that cultural norms can change and equity can be achieved.”

Scientists show which genetic loci is associated with bunch weight in highland banana

Scientists have, for the first time, located the position of major quantitative trait loci associated with bunch weight and its component traits in Matooke, the East African Highland cooking banana. This is an important breakthrough in efforts to speed up the breeding of improved high-yielding varieties for both food security and improved household incomes in the region.

Increasing banana bunch weight is a major objective in banana improvement since it determines yield. Little was known about the genetic factors regulating it.

Scientists, therefore, sought to understand the genetics underlying bunch weight and its component traits in banana. The components of bunch weight include several traits such as the number of hands and fruits, fruit length and circumference, and the diameter of both fruit and pulp.

Through a genome-wide association study (GWAS), researchers found that chromosome 3 was most associated with bunch weight in banana. This breakthrough has been published in a paper entitled “Association Genetics of Bunch Weight and its Component Traits in East African Highland Banana” in the Theoretical and Applied Genetics journal.

The team studied a banana population of 307 genotypes of the East African Highland banana in the IITA breeding program of the International Institute of Tropical Agriculture (IITA) under three different environmental conditions.

“The findings of the study will facilitate marker-assisted breeding which allows breeders to identify early in the breeding cycle hybrids with poor fruit-filling characteristics and hence low bunch weight, thus saving time and money,” says Rony Swennen, head of IITA’s banana breeding program and corresponding author of the paper.

Cooking banana is an important food and income crop for over 80 million people in the East African Great Lakes countries of Burundi, the Democratic Republic of Congo, Kenya, Rwanda, Tanzania, and Uganda.

The study was carried out by a team of researchers at IITA in Tanzania and Uganda in collaboration with researchers from the Department of Plant Breeding, Swedish University of Agricultural Sciences; Institute of Experimental Botany, Centre of the Region Haná for Biotechnological and Agricultural Research from Czech Republic; and Laboratory of Tropical Crop Improvement, Division of Crop Biotechnics, Katholieke Universiteit Leuven, Belgium.

It was supported with funding from the Bill & Melinda Gates Foundation and the European Regional Development Fund project, “Plants as a tool for sustainable global development” and contributions from the CGIAR Research Program on Roots, Tubers and Bananas (RTB).

The blog was first published on the IITA website

Scaling up the use of Orange Fleshed Puree for Baked and Fried Products

OFSP puree Photo credit: J.Maru/CIP

In late May the International Potato Centre (CIP) organized a stakeholder engagement and launch meeting in Nairobi, Kenya bringing together over 20 organizations involved in sweetpotato value chain in Kenya. The launch involved representatives at the national level from the Ministry of Agriculture (MOA), Ministry of Health and the Kenya Bureau of Standards (KEBS). The new project titled “Scaling up the use of Orange Fleshed Puree for Baked and Fried Products” will be implemented in Kenya, Uganda, and Malawi. The stakeholders worked together on the modalities of creating synergy and layering, mapping them to who is doing what, where and possible linkages, a key ingredient that most projects overlook limiting the efforts to go to scale.

Speaking through the launch Tawanda Muzhingi, CIP regional food scientist explained the potential of orange-fleshed sweetpotato (OFSP) as a highly nutritious biofortified crop, that is short maturing (3-4 months), high yielding with low production costs which makes it a suitable to addresses vitamin A deficiency, food insecurity and  low incomes among households in rural sub-Saharan Africa. He explained that extensive scientific evidence had shown that OFSP when consumed regularly reduced vitamin A deficiency in women, young children and the whole family.

John Waithaka, the principal agriculture officer for the Ministry of Agriculture, Livestock, and Fisheries emphasized the need for increased agro-processing which fits in in the government “Big 4” agenda for Kenya. He noted that increased investment in the OFSP puree processing and OFSP value chain by the private and public sectors in Kenya will create employment and income opportunities for men, women, and youth, which the government is committed to delivering.

Project launch Photo credit N.Ronoh/CIP

Previous efforts to reach both rural and urban dwellers and commercialize OFSP have been hindered by inconsistent production and seasonality. OFSP puree processing and utilization are avenues to address this challenge. It was revealed that technology advancements have led to the development of a vacuum-packaged OFSP puree that can be stored without refrigeration for 12 months, creating the potential for widespread use by bakeries and food vendors.

In the baking industry, it has been shown that OFSP puree can be used as a substitute for up to 30-50% of wheat flour in a range of baked or fried products, reducing production costs by 12% and increasing nutritional content. Some of the largest supermarkets in Kenya, Tuskys, and Naivas, who have baked and sold OFSP products have shown that they are widely accepted and liked by consumers.

Benjamin Kivuva, assistant director of agriculture from Kenya Agricultural and Livestock Extension Organization (KALRO) questioned why there were so few investments and yet the technology is simple and products nutritious. “One of the things that limits small and medium investors to get into processing is standardization and food safety,” said Agnes Nzomo of the KEBS and assured the potential investors on the willingness of KEBS to support.

The low production costs of OFSP makes it an ideal crop for youth and women. The OFSP varieties are open access to public goods, so anyone can multiply seed without a license.  This means that people with limited money can get involved in vine multiplication, transportation as well as root aggregation. “Until people learn and get the knowledge of how to run a business, we will keep relying on donor funding and not growing our own business,” said Antonio Magnaghi, a food processing specialist. It was recognized that identifying entrepreneurial youth and linking them to business skills development will be a key entry point for this project.

The CGIAR Research Program on Roots, Tubers and Bananas funded CIP with a scaling grant to accelerate the use of OFSP puree in Kenya, Malawi and Uganda.  The two-year (2019-2021) project targets both formal (processors) and informal (street vendors) sectors with OFSP puree as a major ingredient to reduce the use of wheat flour and to enrich products with vitamin A. 

Unlike previous efforts to promote the use of OFSP in Kenya, this initiative will employ the scaling readiness approach to identify and address bottlenecks along the OFSP value chain to enable it to go to scale. By addressing the bottlenecks such as farmer organization, seasonal production, limited extension service, food safety, access to credit among others, farmers will benefit from a ready market for their roots, and as a result, increasing incomes.

Increased OFSP root and puree production will lead to expanded markets, attracting investment, creating jobs and income opportunities along the value chain. Making OFSP enriched products more widely available and affordable will improve the nutrition of women and children.

The blog is written and photos provided by Rose Chesoli. 

More equitable crop improvement

Ensuring plant breeders can take women into account

M9 is the code name of a new banana variety developed for the smallholder banana farmers of Uganda, where banana is a very important staple. Yields can be 60% higher and, because the variety is resistant to pests and diseases, it does not need to be replanted as often. When it came to trials, however, men and women differed in their appraisal of M9. Men rejected it, largely because the bigger bunches failed to get a higher price at market. Women, however, who cook bananas every day for their families, appreciated the new variety’s food value. As a result, M9 was the only one of 18 new varieties to be released, women’s preferences being the deciding factor.

M9 is noteworthy precisely because women’s preferences do not often carry much weight. Plant breeders sometimes assess gender differences in attitudes to new varieties, but not in any great depth. Many would like to have the tools to carry out a more profound analysis, and a new approach from the CGIAR Gender and Breeding Initiative (GBI) offers just that.

The implications of gender relations for modern approaches to crop improvement and plant breeding, by Jacqueline A. Ashby and Vivian Polar, is a chapter in “Gender, Agriculture and Agrarian Transformations,” a new book from Earthscan. In it, Ashby and Polar address a crucial step in the process of plant breeding and offer ways for plant breeders to ensure that the needs of women are fully taken into account.

Gender-based preferences

Polar is a Gender, Monitoring and Evaluation Specialist for the CGIAR Research Program on Roots, Tubers and Bananas (RTB) and GBI. She says that in the past, public-sector breeding, to benefit the poor, paid little attention to gender differences in deciding what traits to incorporate in new varieties. “That,” Polar says, “is changing.”

Driving the change, at least in part, is evidence gathered by a CGIAR research looking at gender-based trait preferences. That investigation found only 39 studies that document the preferences of women and men, or women only, for specific traits and offered reasons for the differences. While there are differences across crops and localities, some commonalities emerge.

In some cases, only women may, for example, value ease of threshing, or the storage life of the produce, or the time needed to cook it. In other cases, only men may talk about pest resistance or yield per hectare. Other traits can be mentioned by women and men alike, but there are still many that represent the preferences of either women or men.

A better measure of successful breeding

Plant breeding goes through several stages at which stringent selection is applied to ensure that only varieties likely to be successful pass to the next stage. Success, in this case, is judged by how closely the candidates match something breeders draw up called the Product Profile, a set of heritable traits that is biologically feasible and that will meet demand from a well-identified set of customers.

“That’s where we need breeders to consider women,” says Polar.

Women’s preferences often clearly reflect the work they do. Ease of threshing may be of little interest to men because when they are not responsible for threshing the harvest. But there are also important differences between different crops and places. In lowland rice production in West Africa, for example, women are responsible for weeding, and unsurprisingly prefer varieties that are better able to suppress weeds. With upland rice in Ghana, men do the weeding, and it is they who value weed suppression. Even this difference is not static, as men migrate for off-farm labor and women take on new tasks.

To cope with these complexities, which their chapter examines in detail, Ashby and Polar suggest a framework that breeders, working with social scientists, apply to each trait in the proposed Product Profile.

Do no harm

“The first objective is to minimize the risk of releasing a variety that could exacerbate existing gender inequities,” explains Ashby, who has worked in CGIAR senior management on the application of social and gender analysis to plant breeding, most recently as Senior Adviser for Gender in Research to the CGIAR System Office and to GBI. This she calls “do no harm” analysis. A second analysis asks whether a trait is uniquely advantageous to women, which could give that trait a higher positive rating. Of course, traits can be gender-neutral, with no general differential between women and men.

“A final product profile may end up with all gender-neutral traits,” says Ashby. “Gender screening should ensure that the profile has not overlooked the possibility of a harmful outcome for women. It also lets a breeding project discuss how important the traits beneficial for women should be in the final set of priorities.”

The sort of analysis proposed could help to avoid some of the problems that have beset recently released varieties. In Ethiopia, for example, women objected to modern short-strawed sorghum varieties because they lost income from the sale of the stalks as cooking fuel, while in East Africa women objected to productive maize varieties that had harder kernels, making grinding — women’s work — more time consuming and more difficult.

Sometimes, counterintuitively, women may prefer varieties that need more processing. In central Malawi, poorer women, unlike men, prefer bitter types of cassava, even though they need more post-harvest processing. Bitter cassava is less likely to be stolen.

“Niche traits,” such as specific qualities required for food processing, can be a real benefit for women by relieving their drudgery or giving them the chance to improve their income. Women in Nigeria, who process small amounts of cassava when they need extra income, prefer varieties that can be left in the ground until needed.

Closing the adoption gap

The framework for gender screening, set out in more detail in the book chapter, has been reviewed by breeders and social scientists from the Gender and Breeding Initiative. The analysis generated an informative discussion of gender implications of individual traits that will now inform breeding work in RTB and beyond.

Vivian Polar says “we know that women producers often have lower adoption rates of modern varieties than men, but plant breeding has had difficulty taking gender differences into account, in part because of the complexity of the picture. Gender screening makes it more likely that breeding will include important traits that are better aligned with women’s needs and priorities.”

Guiding farmers to safer use of pesticides in Rwanda and Burundi

Farming spraying a field of potatoes. Photo credit Joshua Okonya, CIP

It’s hard to overstate the importance of root, tuber, and banana (RTB crops) for smallholder farmers in the Great Lakes region of Central Africa. Thousands of farming households here depend on orange-fleshed sweetpotato, cassava, east African cooking banana and table potato for their daily meals. These families also rely on the cash generated from the sale of surplus RTB crops to cover home expenses, often including school fees and medical care.  

Despite the prominent role RTB crops play in the livelihoods of farmers in the region, their production is constrained by numerous pests and diseases that can hamper yields and cause significant postharvest losses. The African sweetpotato weevil and diseases such as potato late blight, cassava mosaic disease, and banana Xanthomonas wilt place high pressure on crop health and yields and are spreading to new areas with changing climatic condition.

“Quantifying crop losses from pests and diseases with high accuracy is difficult,” explains Joshua Okonya, Research Associate – Crop Protection, at the International Potato Center (CIP). “Official statistics don’t exist, and farmers rarely keep records.” Okonya estimates that losses would be in the average range of 10-30% depending on crop type, pathogen, weather conditions, and crop management. Crop losses significantly affect smallholder farmers’ livelihoods and food security.

In a bid to control these threats, farmers in Rwanda and Burundi are increasingly using pesticides to reduce yield- and postharvest losses. Yet information on pesticide use practices in RTB crops in these two countries is lacking, and there are few studies on farmers’ use of personal protective equipment (PPE), exposure symptoms, handling, and pesticide misuse.

Knowledge gaps in safe pesticide handling, the importance of PPE and a lack of working application equipment and safe storage pose significant hazards to farmers and their families. Neither Rwanda nor Burundi had or enforced regulations on safe pesticide use and handling, essentially leaving it to commercial sellers—many of them untrained—to advise farmers on how to store, package, label, transport, and handle these hazardous and often unlabeled chemicals.

“If nothing is done, cases of pesticide poisoning will continue to rise leading to ill-health among those who apply pesticides, hence reducing productivity and increasing expenditure on medical care,” says Okonya, a co-author of the paper published in 2019 in the International Journal of Environmental Research and Public Health. However before potential interventions can be designed, a clearer picture is needed to capture farmers’ knowledge, attitudes, and practices about the role of pesticides in managing RTB pests and diseases. 

Farmer spraying without any PPE. Photo credit Joshua Okonya, CIP

What the survey revealed

In 2014 a team of researchers from the International Potato Center (CIP), the International Institute of Tropical Agriculture (IITA), Bioversity International, the Rwanda Agricultural Board, and the Institut des Sciences Agronomique du Burundi surveyed 811 RTB crop farming households in two watersheds, Ruhengeri in Rwanda and Rusizi in Burundi.

The survey gathered data on existing pest and disease control methods, toxicity levels of pesticides and frequency of application, protective measures against exposure, cases of acute poisoning while handling pesticides and descriptions of farmers’ level of knowledge regarding pesticide handling and use of PPE.

Results of the household survey paint a detailed picture of how farmers are managing the main pests and diseases of each of their RTB crops through the use of pesticides, cultural control methods such as single stem removal, crop rotation, and early harvesting, or a combination of different practices.

More than half of surveyed farmers applied pesticides with damaged knapsack sprayers, meanwhile use of PPE such as eye protection, face, and nose masks, gloves, and waterproof jackets were low. Farmers typically wore face-covering such as handkerchiefs, which provide poor protection. Farmers were reluctant to use PPEs while applying pesticides, citing cost and lack of availability as barriers.

As a result, all surveyed farmers reported some type of symptoms (e.g. itchy skin, irritated eyes, headaches, and nausea) following field application of pesticides, and in both countries, they knew of cases where some farmers have died from accidental poisoning.

Where future efforts should go from here

The household survey offers insights and information that can be used when designing vector control programs, intervention programs, and integrated pest management (IPM) approaches, including the safe use and handling of pesticides.  

The results can be of great value to other stakeholders in the pesticides value chain and can feed into efforts to raise awareness of the need to enforce pesticide legislation and alternative control methods.

Given the high risk of pesticide poisoning, it’s imperative that farmers and agrochemical retailers of pesticides alike be trained on how to use and handle pesticides safely, and that IPM approaches that are more sustainable and environmentally friendly be prioritized and promoted through increased policy and institutional support.

On farm: exploring the genetic diversity of RTB hotspots

Project sites and crops included in the RTB on farm diversity! project.
Photo credits: Stef De Haan/CIP, Erik Delaquis/CIAT, Gabriel Sachter-Smith/consultant, Bioversity International

This June, scientists from all over the world convened in the south of France for a unique conference. Held every ten years or so since 1997, the Harlan Symposium showcases research on the origins of agriculture, crop domestication & evolution, and the diversity and utilization of genetic resources. Named after Jack Harlan, professor of plant genetics, a passionate advocate of agrobiodiversity, and early crop diversity collector, this year’s edition explored diverse topics ranging from the domestication of the Asian elephant to using citizen science to document banana diversity.

Attending the symposium was a group of CGIAR and CIRAD scientists who took the opportunity to launch a three-year initiative in the spirit of Harlan’s legacy: to document and understand the genetic diversity of RTB crops in three continents.

Building on several years of previous work in the CGIAR-RTB research program, the project ‘On farm: Exploring the genetic diversity of RTB hotspots’ (or ‘RTB on farm diversity!’ for short) takes on the challenge of evaluating and documenting genetic diversity in hotspots of some of the world’s most important staple crops.

Farming communities continue to shape and maintain the diversity of crops the world over. It is through the interaction of farmers and crops that functional diversity in each species is shaped and maintained in an ever-evolving process of adaptation, selection, breeding, and maintenance. In this way, farming communities are the stewards of crop-variety diversity.

However, the FAO 2019 state of the world’s biodiversity for food and agriculture report highlights alarming declines in biodiversity at both species and genetic levels – and increases in the threats responsible for this erosion. Though it is on farms where crop wild relatives continue to breed with landraces, introducing new genes into breeding pools, over 95% of such species are still inadequately represented in gene banks. In this perilous context, understanding on farm diversity management is more critical than ever to safeguard the future of our food supply.

Three sites were chosen for the RTB on farm diversity! project:

  • Peru, where the Andean topography generates an array of microclimates from tropical forests to glacial peaks, accompanied by primary centers of diversity for staple crops including cassava in the steamy lowlands, and the bewildering diversity of potato on high altitude plateaus.
  • Papua New Guinea, the planet’s most linguistically diverse country, with a stunning array of bananas to match. Here there is undocumented diversity of many globally important RTB crops – included for evaluation in this project are banana, yam, and sweetpotato.
  • Benin, a long, club-shaped country in West Africa’s center of crop diversity, where the yam represents more than just food. Over 95% of the world’s yam production remains in Africa; particularly in the Western continent where the crop takes a paramount role in nutrition and markets, but also in ritual beliefs and social customs. Africa is also a secondary center of diversity for cassava, the result of centuries of crossing and selection by farmers following the crop’s introduction from South America.

Representatives from Bioversity International, CIAT, CIP and CIRAD (IITA participated virtually) gathered in Montpellier to launch the project ‘On farm: Exploring the genetic diversity of RTB hotspots.

Despite their differences, these three sites are reservoirs of crop diversity, each facing the transformative pressures of a world undergoing rapid environmental and social change. The research in this project is vital, not only to understand how the human-crop relationship continues to shape both parties but also to identify gaps in existing ex-situ gene bank collections, bringing to the fore what we risk losing without concerted efforts to protect and manage crop diversity.

In this project, Bioversity International, CIAT, CIP, CIRAD, and IITA join a wide array of national partners; integral project members who make it possible to document the genetic resources in these hotspots. Together the group will share each other’s strengths, expertise, and methods, shedding new light on global RTB crop diversity.

Major partners include Grupo Yanapai and Universidad Nacional Daniel Alcides Carrion in Peru, Laboratory of Biotechnology, Genetic Resources and Plant and Animal Breeding (BIORAVE) at the University of Abomey in Benin, and the National Agricultural Research Institute in Papua New Guinea.

Climate change and rising population put pressure on essential crops in low-income regions

Crops such as bananas, potatoes, and cassava are essential to food security in the world’s poorest regions. By 2050, their importance will increase, but climate change and population growth will put unprecedented pressure on production. 

Climate change and population growth are increasing concerns for global food security. Modeling future agricultural trends that account for these seismic shifts is essential to understanding food supply and income generation, especially in low-income countries. Research often focuses on widely consumed cereal crops, which form a substantial portion of the global diet. But roots, tubers, and bananas (RTB crops) are the mainstay of diets in many of the world’s poorest regions, and a new analysis shows these crops have great potential for reducing malnutrition and poverty through 2050, as long as they are on the receiving end of appropriately targeted investments.

Known as RTB crops, these crops include plantains, cassava, potatoes, sweet potatoes, yams, and tropical and Andean roots and tubers. They are some of the most valuable crops in the world’s poorest regions. Rich in nutrients, vitamin A and carbohydrates, RTB crops often outperform cereals in terms of energy per cultivated hectare and can produce high yields under harsh conditions – including extreme climate events that go hand-in-hand with climate change.

These traits make RTB crops particularly important for undernourished populations such as in sub-Saharan countries, where they contribute up to 50 percent of the daily calorie intake. What is more, they have a significant role in income generation and are frequently grown and marketed by women.

“RTB crops are the mainstay of diets and rural livelihoods in many poor regions,” said Guy Hareau, a researcher at the International Potato Center (CIP) in Peru and co-author of the analysis published in Global Food Security. “However, overcoming the productivity and market challenges are constrained by underinvestment.”

RTB crops only receive a fraction of the attention given to other food commodities. The number of researchers dedicated to RTB crops in Africa, Asia, and Latin America during 2010-2014 was only one third the number of those dedicated to cereals and livestock, according to the analysis. This underinvestment is also mirrored in the gap in the literature on RTB crops, which is needed to inform food security interventions and policy.

Increased attention is warranted not just because of food security and nutrition. Some RTB crops are being grown for industrial purposes, including cassava for starch, and potatoes for biofuels. Growth in these industries could increase demand even further than projected.

“One understudied issue is the extent to which industry will increase demand on these staple crops to produce biofuels and starch,” said Steven Prager, a co-author from the International Center for Tropical Agriculture (CIAT) and co-leader of the CGIAR’s Global Futures & Strategic Foresight initiative. “We need to take a serious look at how these humble crops are hooked into global markets and how policy decisions around the world can affect the markets for these crops, today and well into the future.”

Enoch Kikulwe, a co-author from Bioversity International echoes the sentiment: “A rising demand for biofuel or industrial starch is likely to exert pressure on RTB crops, especially cassava, which can result in an increase in prices, depriving poor people from accessing their staples as predicted in this research.”

RTB crops, today and tomorrow

The analysis was conducted by researchers at five CGIAR research centers – CIP, CIAT, Bioversity International, the International Food Policy Research Institute (IFPRI) and the International Institute for Tropical Agriculture (IITA) – within the framework of the CGIAR Research Program on Roots, Tubers and Bananas (RTB).

Growth in RTB crop production has increased steadily in the last 50 years, most rapidly in Africa, albeit slower than cereals. Asia has now become the largest RTB crop-producing region, with much of growth concentrated on potato and sweet potato production in China. In Latin America, RTB crops are important staples and cash crops throughout the region.

Their key role in providing calories and nutrition makes it crucial to examine long-term trends in RTB crop supply and demand to better understand how focused investments can bolster their production. The existing studies, however, consist of primarily inadequate projections (limited in terms of geographic coverage, time horizon, and range of crops) that do not capture the impacts of socioeconomic drivers and climate change.

The study builds on research by IFPRI and other CGIAR centers that explores future trends for crops. The IFPRI study provided a baseline projection for 2050, including an assessment of the different agricultural investments to understand future changes in matters of food security. The projection takes into account socioeconomic and climate change pathways – namely the Shared Socioeconomic Pathway 2 and the Representative Concentration Pathway 8.5, developed by the Intergovernmental Panel for Climate Change – which follow a business-as-usual scenario of fairly rapid change in the population, economic growth and climate change.

“In this research, we were happy to join with CGIAR colleagues to look at the prospective role of RTB crops under a future in which we face challenges not only from increasing total demands and shifting diets but also potentially adverse effects of climate change on production systems,” said Tim Sulser, a co-author from IFPRI. “Investments in research and development for RTB crops are important for addressing the imminent challenges we will be facing in the coming decades.”

Using the study’s baseline scenario and the assessment related to RTB crops, the new study examines how RTB crop agriculture will look like in 2050. Climate change and water availability will be key factors for crop productivity: whereas banana and potato are sensitive to water stress, cassava, yam, and sweet potato are drought tolerant. Agro-ecological conditions and poverty will cause the consumption of RTB crops to increase, especially in Africa, indicating their growing importance for food security. While potato stands out as the crop most affected by changing preferences, especially in China, the banana will exhibit the highest growth in supply and demand across all regions.

The analysis also reveals that targeted, localized investments can strengthen the role of RTB crops as food security crops. Specifically, investments that aim at increasing productivity offer greater benefits than investments in marketing improvements.

This blog was first published on the CIAT’s website.

How RTB researchers try to develop the potential of RTB seed systems

Roots, tubers and bananas share one characteristic that unites them in the CGIAR Research Program on Roots, Tuber and Bananas (RTB): farmers multiply them vegetatively, rather than as true seeds produced by sexual reproduction. Of course, they are also extremely important for the food security, nutrition and livelihoods of the most resource-poor farmers on Earth. And that makes a recent paper in the journal Food Security, which asks why interventions in RTB seed systems do not reach their full potential, important to policy-makers and farmers alike.

Together with RTB colleagues, Conny Almekinders, of Wageningen University in the Netherlands, examined 13 previous efforts to improve seed systems for potato, sweetpotato, cassava, yam and banana. “We began to look at these cases in 2014,” Almekinders said, “as it became clear that an increasing number of RTB projects were introducing new varieties and improved multiplication practices, especially in Africa.”

“The case study documents did not show us evidence of many efforts to understand target seed systems,” Almekinders added.

Too often, the projects did not consider the fact that they were intervening in an existing local seed system or farmers who were known to be local seed experts. Many projects simply assumed that some farmers would specialize and become seed-supply entrepreneurs to fill the gap where the public sector could not reach, and the private sector was absent or uninterested. Such projects were often founded on the idea of a central source of high-quality foundation stock, usually produced with advanced technology, such as aeroponic micro-potatoes, yam mini-setts, and tissue culture bananas. These would then be passed to “decentralized multipliers” who would create further generations for distribution.

This approach succeeded sometimes, as with sweetpotatoes in Rwanda, where there was a good link to market for the products. In other cases, Almekinders says, “without project support and subsidies, the technical and economic viability of these decentralized multipliers is not clear.”

One problem, especially in sub-Saharan Africa, is that many farmer cultures consider it inappropriate to pay or to ask for payment for planting material. This reticence may be partially overcome in the case of new varieties, but otherwise is likely to limit the opportunities for business-based informal RTB seed systems.

Some projects, such as the introduction of orange-fleshed sweetpotato in Mozambique, focused on health and nutrition and barely considered the seed system. Despite this, adoption and spread, via the informal seed system, have been impressive. “Orange-fleshed sweetpotatoes are now being grown by thousands of women on small plots of land,” Almekinders said. Varieties will spread and be adopted if farmers see a benefit.

RTB community of practice on one of their learning journeys, a joint visit of KEPHIS laboratories in Nairobi, Kenya

Pros and cons

Vegetative reproduction means that the variety keeps its genetic characteristics, unlike sexually produced seeds. This is a boon when getting new material into the hands of farmers, because it means they can share the improved material in their communities. The flip side, however, is that viruses and other diseases can accumulate in the planting material, reducing its performance.

Farmer-to-farmer diffusion remains the primary route for adoption, as farmers with good experiences multiply the improved material and share it with others. For banana, cassava and potato, the cases show that farmers often share new material with five or more others.

Unfortunately, diseases often spread along with the crops, as they have recently for viruses of cassava in eastern Africa and banana bunchy top virus in the Congo basin. Such degeneration is perhaps the most common reason for farmers to seek RTB planting material off their farm. Although this suggests an additional motivation for decentralized multipliers, there is little evidence that farmers will pay for clean planting material of varieties they already have.

What farmers want

The lack of demand is not simply because farmers do not understand the benefits; in many cases they lack other essential resources to make use of better planting material, such as capital or knowledge. Researchers may insert ‘demand’ in their project proposals, but when the project fails to distribute the expected amount of material, they seldom analyze the reasons why predicted demand did not materialize.

“Improved assessment of farmers’ demand will contribute to improving seed system interventions,” said Almekinders.

Government policy represents another barrier to improved seed systems. Certification schemes that guarantee the quality of planting material may raise costs beyond the reach of most farmers. But the absence of such schemes leaves farmers open to the sale of poor-quality seed.

Potential delivered

A 1990 study of potato identified many of the same problems as this more complete and wide-ranging survey of RTB seed interventions. “Not much seems to have changed since,” said Almekinders. But change is now in the air. The International Potato Center is already applying a diagnosis of existing seed systems to all projects going forward. And the project has started to create change beyond RTB.

“Just last week I learned that our framework is being used in a PhD project in Eritrea,” Almekinders said. “The key to progress is to pay attention to what works where, and for whom, and how to scale up good practices. We have not been good at understanding RTB systems or listening to what farmers really need. If we want to improve RTB crops, we have to improve RTB seed systems too.”

Understanding farmer concerns to improve pest and disease management


Enumerators use photos to help farmers identify the exact pests and diseases of RTB crops.

Insect pests and diseases are high on the list of concerns for farmers of root, tuber, and banana (RTB) crops across much of sub-Saharan Africa. For every RTB crop grown, there are several pests and diseases that can reduce yield, lower the quality and profitability of the crop or even wipe out the entire harvest. In addition, farmers also face mounting crop losses due to a lack of clean planting material, soil infertility, infrequent rains, and drought. This not only contributes to food insecurity and reduced household incomes but also discourages investment.

In Rwanda and Burundi in particular, the popularity of RTB crops has been on the rise in recent years as rural households respond to acute food and nutrition needs caused by a mix of biotic and abiotic constraints affecting yields and production. Private sector investment in the processing industry has also spurred demand for RTB crops as a source ingredient for products like cassava flour and sweetpotato-derived confectionery and flour. But can crop yields keep up?

Little is known about the magnitude of yield and postharvest losses in East and Central Africa. “It is hard to quantify losses with high accuracy due to lack of official statistics,” explains Joshua Okonya, Research Associate Crop Protection, International Potato Center (CIP) and a coauthor of the paper published in 2019 in the International Journal of Environmental Research and Public Health.  What’s more, a changing climate is enabling pests to migrate to previously pest-free areas. “Increasing temperatures, linked to climate change, is resulting in more favorable conditions for virus vectors at higher elevations,” says coauthor James Legg, Plant Virologist for the International Institute of Tropical Agriculture (IITA) and leader of RTB’s Flagship Project 3 on Resilient Crops.

Before integrated pest management (IPM) packages can be developed, researchers need to better understand the science of climate impacts and how farmers of RTB crops perceive the relative severity of different biotic constraints, says Legg.

To do just that, a team of researchers from CIP, IITA, Bioversity International, the Rwanda Agricultural Board, and the Institut des Sciences Agronomique du Burundi conducted a household survey in 2014 to better understand farmers’ concerns about pests and diseases affecting RTB crops. The team surveyed 810 farming households in 54 villages, 27 each in Rwanda and Burundi. All surveyed households reported farming as their main source of income. Most farmers grew at least two of the four main RTB crops for both home consumption and as a cash crop. The survey asked farmers to report on four key dimensions: (1) RTB crop production constraints, (2) pests and diseases threatening their crops, (3) estimated crop loss due to pests and diseases, and (4) whether their household experienced any form of food insecurity due to pests and diseases in the previous cropping season.

Enumerator use photos to help farmers identify the exact pests and diseases of RTB crops.

The survey captured detailed perceptual differences for each crop. Despite some similarities between the two countries, overall productivity was slightly higher in Rwanda, whereas the prevalence of pests and diseases and reports of food insecurity were higher in Burundi. Additionally, farmers listed poor quality planting material due to seed degeneration and the lack of certified seed commercially available as major constraints.

The study highlighted the significance of pests and diseases such as potato late blight, Xanthomonas wilt of banana, cassava whitefly, and sweetpotato butterfly, and their devastating effects on the livelihoods of many of the farmers. The survey also found that more farmers in Burundi than Rwanda had stopped growing some of the RTB crops due to damage by pests and diseases. Okonya observed that “in the low altitude areas of Kabezi in Burundi, the majority of farmers no longer grew banana because it was wiped out by Xanthomonas wilt of banana.”

Banana bunchy top disease

The research team suggested that a package of interventions is needed to control the impacts of the reported pest and diseases, and thereby strengthen the food security of these farming communities. Such interventions would combine the supply of healthy planting material of varieties that are pest and disease resistant with appropriate cultural control measures. “Although affordable and effective control measures are already available for many of the most common diseases of RTB crops, more research still remains to be done in Rwanda and Burundi to develop and adapt comprehensive integrated pest and disease management packages that can tackle all of the major pests and diseases affecting these crops,” the study concluded.

“It is envisaged that the survey findings will be used by researchers in national agricultural research systems and national plant protection organizations, as well as by NGO and extension staff. Additionally, the results could also provide valuable insights for other countries in East and Central Africa with mid- to high-altitude production systems,” explains Guy Bloome, a coauthor of the study who works on integrated banana and seed systems at Bioversity International. Not only will the findings generated by the survey be important first steps to understanding farmers’ perceptions of pest and disease constraints, but the knowledge and insights gained will also be useful in guiding policy, development interventions, and research to design sustainable strategies for managing such threats to RTB crops productivity. “Once this happens,” says Legg, “the future for RTB farmers in the region should be bright.”

Understanding farmers’ willingness to pay for root, tuber and banana crop planting material

Experimental auctions reveal the true willingness of farmers to pay (WTP) for various farming inputs. This is one of the main findings of scientists with the CGIAR Research Programs on Policies, Institutions and Markets (PIM) and Roots, Tubers and Bananas (RTB) now working to strengthen seed systems. Using this method, which is on the rise for smallholders in low- and middle-income countries, farmers bid for quality farming inputs with real cash.

Understanding the supply and demand of quality seed for farmers would allow scientists to forecast the effects of policy changes on consumption, according to Marcel Gatto, Agricultural Economist with the International Potato Center (CIP).

Experimental auctions provide incentives for farmers to truthfully reveal values, Patrick Ward of Duke Kunshan University pointed out, explaining that they elicit people’s ‘homegrown values for goods’. Data from the auctions can be used to generate demand curves, estimate product market shares and relative WTP or price premiums for enhanced product quality.

With support from the PIM project, “Strengthening seed systems and markets”, a workshop on 21-22 March in Nairobi, Kenya explored the usefulness of experimental auctions and how to adapt them to local contexts. Scientists from various CGIAR centers, national agricultural and research organizations (NAROs) and local and international universities focused on understanding farmers’ willingness to pay for quality seed of vegetatively propagated crops such as potatoes, sweetpotatoes, and cassava.

The workshop included a mock auction in which participants bid for a bar of chocolate. After being presented the chocolate, they were asked to submit their individual bids on a form that included some survey questions. A price was then generated using a random price generator. The participants who submitted a bid equal to or above the randomly drawn price were able to purchase the bar at the random price.

Exploring farmers’ WTP for quality seed in root, tuber and banana crops

Eliciting demand for seed is an important research topic for the work of RTB. Farmers still do not invest in quality seed in RTB crops. Over 90% of RTB farmers access planting materials through informal channels (i.e. other farmers or traders) or use recycled planting materials from their own production. Formal options through extension services or private sector are limited. Furthermore, there is little awareness about quality planting material and regulatory bodies do not often have the capacity and enforcement ability to monitor seed production and distribution through the formal sector. In Nigeria, for example, it was noted that there are few inspectors trained to examine the quality of cassava seed.

Seed producing farmers/entrepreneurs also have limited access to early generation seed coupled with other issues, such as insufficient transport and storage facilities. The case is the same for Rwanda, where low yield persists due to the lack of access to quality planting material. Most farmers still rely on social networks to obtain sweetpotato vines.

CIP Agricultural Economist, Srinivasulu (Srini) Rajendran identified potential opportunities for the PIM team to collaborate with the RTB seed system team in conducting experimental auction studies on various RTB crops. For instance, follow up studies could be conducted with farmers who participated in the experimental auction studies to explore gender aspects through qualitative assessments.

For the two proposed studies—estimating demand for quality planting material of improved cassava varieties in Nigeria and WTP for sweetpotato planting material of OFSP in Rwanda—context matters. The availability of sweetpotato vines that are distributed for free is a problem and could become a substitute product. As free distribution is often done with high quality vines, it can be hard for farmers to attach a value to vines in an auction if substitute is equally good and available free of cost. Participants agreed that if a farmer’s WTP depends on the price of substitute goods, then freely available seeds will reduce demand.

Julius Okello, CIP Impact Assessment and Monitoring and Evaluation Specialist, affirmed that the auction must be held at a time when farmers need materials. “Just before the planting season would be a perfect time to conduct auctions. Considering that the shelf life of sweetpotato vines is short, the timing of the auction experiments is critical to elicit farmers’ true WTP,” he noted.

Gender considerations are important as the valuations made by men and women are different. “In Malawi women said they would rather buy poor quality seed that they can afford rather than their families go hungry,” Netsayi Mudege, Gender Research Specialist at CIP, pointed out. The research design must take into consideration the different valuations of quality seeds by men and women and how that can influence bidding, she emphasized.

Mywish Maredia of Michigan State University shares insights on studies about farmer willingness to pay for seeds.

Way forward

Drawing lessons from previous studies conducted by Mywish Maredia of Michigan State University on the role of quality signaling on WTP for potato planting material in Kenya and the theory of value elicitation provided by Patrick Ward, the workshop was successful in discussing and aligning methods across the two case studies identified. Local partners from Kenya including the University of Nairobi, Rwanda Agriculture and Animal Resources Development Board (RAB) and National Root Crops Research Institute (NRCRI) in Nigeria provided valuable contextual insights.

As a next step, the methodologies will be revised to take into consideration the various issues and challenges raised in the workshop. Jointly with NRCRI, Tesfamichael Wossen, Postdoctoral Fellow – Agricultural Economist with the International Institute of Tropical Agriculture (IITA) will carry out a study on cassava. In Rwanda, Julius Okello, Srini Rajendran and Kirimi Sindi from CIP will collaborate with RAB to look at factors that influence farmers’ WTP for quality sweetpotato vines. These studies will be co-funded by PIM and RTB, and will be implemented over the coming planting seasons in the respective countries.

This blog was first published on the CIP website