The future of African bananas

The use of genetic engineering has transformed agriculture, and food production and development by providing options and solutions where none existed before—to the benefit of billions of the world’s inhabitants.

Tripathi discusses work with staff at Namuloge, IITA-Uganda. Photo by IITA

IITA and its partners have been using genetic transformation as a crop improvement tool to help produce more and better food staples. The Institute—with partners such as the National Agricultural Research Organization (NARO) of Uganda, Academia Sinica (Taiwan), and the African Agricultural Technology Foundation (AATF) in Kenya—is at the forefront of research “designing” a genetically modified banana that is resistant to the worst bacterial disease so far—Banana Xanthomonas Wilt (BXW). Entire banana fields can be destroyed, especially those planted to Pisang awak, a susceptible exotic variety widely grown to make banana beer.

Bananas are a major staple in East Africa produced mostly by smallholder subsistence farmers. Uganda is the world’s second leading grower with a total annual production of about 10.5 million tons. It is Africa’s biggest producer and consumer of bananas and plantains.

Most growers cannot afford costly chemicals to control the many pests and diseases that affect banana cultivation. As diseases continue to spread, demand grows for new improved varieties.

Bacterial wilt caused by Xanthomonas campestris pv. musacearum is threatening banana production and the livelihoods of these smallholder growers, and solutions have to be found fast before it could destabilize food security in the region.

Work on developing a GMO banana has been ongoing since BXW was first reported in 2001. The disease has been identified in the Eastern Democratic Republic of Congo, Rwanda, Kenya, and Tanzania, and is widespread in Uganda. It attacks almost all varieties of bananas, causing these countries an annual loss of over US$500 million. These can be reduced bunch weights or absolute yield loss or clean planting material is unobtainable for new plantations.

Banana Xanthomonas wilt-infected plants. Photo by IITA

“Developing resistant varieties is a long-term but more sustainable way to control pests and diseases. Improving the plant’s defense mechanism against BXW through genetic engineering is still the best line of defense because of its many advantages,” commented molecular geneticist Leena Tripathi based in IITA-Uganda, Kampala. “Farmers are reluctant to employ labor-intensive disease control measures.”

“Genetic engineering offers many opportunities for improving existing elite varieties not amenable to conventional cross-breeding, such as bananas. It allows breeders to develop new varieties quickly through the introduction of cloned genes into commercial varieties.”

Transgenic bananas possess a gene or genes that have been transferred from another plant species. The term “transgenic plants” refers to plants created in a laboratory using recombinant DNA technology.
Tripathi said that the development of stable and reproducible transformation and regeneration technologies has opened new horizons in banana and plantain breeding. The development of transgenic banana and plantain has been reported by several groups, but a commercial transgenic banana variety is yet to be released.

There are no cross-fertile wild relatives in many banana-producing areas. Most edible bananas and plantains are male and female sterile. The clonal mode of propagation makes the risk of gene flow from banana to another crop species not an issue.

IITA’s in vitro screening method for early evaluation of resistance to BXW uses small tissue culture-grown plantlets. This method can be used by breeders for screening Musa germplasm with larger numbers of cultivars for resistance to BXW and other bacterial diseases.

Currently, most transformation protocols for banana use cell suspensions, Tripathi said. Establishing cell suspensions is a lengthy process and cultivar dependent. At present, the major barrier in transforming East African Highland Bananas (EAHB), a cooking banana from Uganda, is the limited success in producing embryogenic cell suspension cultures from a wide range of cultivars. IITA scientists in collaboration with NARO have developed a rapid and efficient protocol using a cultivar-independent transformation system for improving Musa species including EAHB. This new technique has paved the way for the development of a transgenic banana using transgenes from sweet pepper that confer resistance against BXW.

Tripathi explains how the technology works: the ferredoxin-like amphipathic protein (pflp) and hypersensitive response-assisting protein (hrap), were isolated from the sweet pepper, Capsicum annuum. These are novel plant proteins that intensify the harpinPSS-mediated hypersensitive response (HR). These proteins have a dual function: iron depletion antibiotic action and harpin-triggered HR enhancement. The transgenes were shown to delay the hypersensitive response induced by various pathogens in nonhost plants through the release of the proteinaceous elicitor, harpinPss in various crops including dicots such as tobacco, potato, tomato, broccoli, orchids and monocots such as rice. Elicitor-induced resistance is not specific against particular pathogens, hence it is a very useful strategy.

The pflp genes encode for ferrodoxin, which exists in all organisms, and is therefore common in human diets. This protein is safe for human consumption and the environment. The pflp and hrap genes are owned by Taiwan’s Academia Sinica, the patent holder. IITA has negotiated a royalty free license through the AATF for access to the pflp and hrap genes for use in the production of BXW-resistant varieties in sub-Saharan Africa.

Hundreds of transformed lines of various banana cultivars have already been generated, and are under screening for disease resistance under laboratory conditions. The most promising will be evaluated for efficacy against BXW in confined field trials under different farming systems by national partners with IITA. The transgenic lines will be tested for environmental and food safety, in compliance with target country biosafety regulations, risk assessment and management, and seed registration and release procedures. The project will also study public perceptions, consumer preferences, and the acceptability of transgenic banana in Africa to guide commercialization and wide use.

“Wide-scale deployment of genetically modified, farmer-preferred banana varieties in African countries would succeed only with effective interinstitutional partnerships, particularly with advanced research institutions, AATF, national committees on biosafety, nongovernmental organizations, and private tissue culture companies,” explained Tripathi. “This project will enhance the capacity of partners from the national agricultural research and extension systems in genetic transformation of banana, molecular biology, and biosafety. High-yielding BXW-resistant banana will bring greater productivity for smallholder farmers in East Africa and improved food security.”


Alliance for a Green Revolution in Africa (AGRA) Vice President for Policy and Partnerships Akin Adesina, was at IITA recently to talk about how agriculture could transform Nigeria from a food-deficit to a food-exporting country again.

“The answer to Nigeria’s development problems lies in using agriculture to transform the country into ‘cohesive production system’,” he said. “Agriculture has changed from a way of life to a business. Market intelligence is required to make agriculture work. Hence, national governments in Africa have to change their mind sets and think of agriculture as a business.”

Sub-Saharan Africa has a population of 781 million people, with 306 million or 39% living on less than US$1 a day. Of this number, 131 million live in Nigeria. Of the 131 million Nigerians, 101 million, equivalent to 77%, are poor. “Africa is not a basket case,” Adesina said. “With a distinctly African Green Revolution, we can turn the situation around. We can do this by building our competitive advantage in agriculture through research and infrastructure. Government support is crucial; political will is important. Africa cannot afford not to act.”

“A new, efficient, dynamic, and competitive agricultural sector will unlock hope for millions of children, and will provide a better, more secure future for everyone,” he concluded. Adesina was formerly a socioeconomist at IITA.

Irish Aid

Peter Power, image by DFA
Peter Power, image by DFA

IITA was among eight CGIAR centers that will receive over €4 million in funding from Irish Aid.

Peter Power, Irish Minister of State for Overseas Development, said that the €4.4 million funding is a “central component” of Irish Aid’s response to the global food crisis. “More than 850 million people across the world today are hungry, while high food prices risk pushing 100 million additional people over the edge into hunger and poverty. Top quality agricultural research plays a crucial role in improving the performance and sustainability of agriculture. It will also help the poorest and most vulnerable farmers cope with the effects of climate change.”

IITA will receive €640,000 in funding. Other research centers selected include Biodiversity International, International Livestock Research Institute (ILRI), and the World Potato Centre (CIP). Ireland has provided more than €20 million to support the UN’s World Food Programme (WFP) this year, which includes €3 million to help mitigate the effects of price rises on the WFP’s existing food relief programs.

Cassava research

The United Nations Food and Agriculture Organization (FAO) has called for more research on the tropical root crop cassava to help poor countries cope with rising food and oil prices. Cassava is a staple food for millions of poor people in sub-Saharan Africa, Latin America, and Asia, providing as much as a third of daily calories.

African cassava mosaic virus. Photo by IITA

Members of the Global Cassava Partnership for Genetic Improvement (GCP21) such as IITA reviewed the current state of cassava production worldwide and future prospects at a conference held in Belgium in July. Current average cassava yields are barely 20 percent of those obtained under optimum conditions. Despite growing demand and its production potential, the crop is grown mainly in areas that have little or no access to improved varieties, fertilizer and other production inputs, by small-scale farmers with no access to marketing channels and agroprocessing industries.

To help develop the crop’s potential in addressing the global food and energy crisis, GCP21 will launch new projects such as establishing a cassava chain delivery system to channel technical advances to poor farmers, improving soil fertility, enhancing basic scientific knowledge of the crop, including genomics, and training the next generation of cassava researchers in developing countries.

Detailed information about the Ghent meeting also on the AGRA website

R4D Review launched

For more than four decades, IITA and partners have been developing award-winning solutions to the severe and complex problems that plague agricultural systems in Africa. Our science is based on cutting-edge, authoritative thinking anchored on development needs of the hungry and poor. We focus on research for development (R4D) that reduces producer and consumer risks, improves productivity and production, and generates wealth.

Bustling market. Photo IITA

Many promising solutions remain on shelves because participation in their development and access to such knowledge have been limited. We launch this 6-monthly R4D Review in print and interactive online versions based upon open source principles. The free flow of information and participation in knowledge development with partners, investors, beneficiaries, and others help to accelerate the development, dissemination, and continuous improvement of innovative solutions.

We encourage you to visit and participate in the online R4D Review at, which provides the essential interactive and collaborative environment to share views, ideas, and innovations. The print version does not help with dialogue as the online version does, but it provides access to some of the solutions which otherwise may be impossible to obtain online. We would like to encourage you to share your copy of the print version with others and try to give us feedback through other means, such as a letter to the editor or email

Each R4D Review will have general information and a more particular focus. This maiden issue focuses on bananas, highlighting the important work done by our scientists and partners to address problems in banana growing and development. We also forward a perspective on how the current food crisis provides Africa with opportunities to turn agriculture around, and achieve food security and economic development. We present insider and outsider views about our R4D work and partnerships, and emphasize the breadth and depth of R4D work in developing solutions and its impact on natural resource management and sustainability, producer communities, and markets.

The R4D Review is looking for new sources of solid, useful ideas that can improve research-for-development practice. Please submit your contributions or participate in the R4D Review interactive site at The general guidelines for contributions are also available at this site. Prospective authors can also send submissions, communications, comments, and suggestions to: The Editor, R4D Review. The quickest is to email

Banana and Plantain Systems

Bananas drawg
Grown by smallholder farmers, bananas and plantains are major food staples and two of the leading cash crops, both in the East African Great Lakes zone and the West African humid lowlands. Diverse banana cultivars are grown for a number of uses, including brewing (juice bananas), cooking and roasting, as well as sweet dessert bananas. Banana starch, flour, and chips are processed banana products whose markets are yet to be fully developed. Because of its cash crop status, farmers are more likely to adopt high-level management technologies in order to intensify production and yet sustain the natural resource base in the systems. Clearly, much progress can be realized with more profitable and sustainable banana systems.

Since the 1970s, reports of low and declining banana yields have been widespread. Some have attributed this phenomenon to constraints such as soil degradation, pests, poor crop husbandry, and drought. In this project, the hypothesis is that these constraints are, to a large extent, interlinked. Although each constraint can, on its own, potentially cause serious yield decline, the complex interactions between a number of them compound yield losses.

The overall purpose of the banana and plantain project is to enhance the performance of banana and plantain systems within smallholder farms in sub-Saharan Africa.

The main project objectives are:

  • To increase knowledge on ecosystems, social systems, and commodity chains related to banana and plantain production in
  • To research ways to improve profitability of banana and plantain systems in Africa
  • To improve the quality of banana- and plantain-based food products

Erostus Njuki Nsubuga: Lessons on partnership

AGT CEO and Managing Director Erostus Nsubuga
AGT CEO and Managing Director Erostus Nsubuga

R4D Review interviewed Erostus Njuki Nsubuga, the chief executive officer and managing director of Agro-Genetic Technologies Ltd (AGT), to get his insights on the IITA-AGT partnership. AGT is the first and only private commercial tissue culture (TC) laboratory in Uganda and so far the biggest single supplier of banana TC planting material in East and Central Africa. It produces up to 8 million tissue culture plantlets per year, of which 1 million are banana plants.

Nsubuga wants to see AGT become well established and profitable by increasing its capacity to provide the region with quality TC planting material at affordable prices and introducing other services such as plant and soil analysis, and produce organic fertilizers. His dream is for AGT to become a one- stop shop that provides total solutions to farmers.

Nsubuga was born in Uganda and spent his early years there. Because of the war, he and his family had to move to other countries in Africa and Europe. He started living on his own at 16, studying in Europe and USA for 24 years to obtain an MSc (Agriculture) and MBA (International Marketing). He worked in international companies and managerial positions for over 20 years but his dream was always to come back, to help his mother who had survived all the wars, to sustain himself and his family, and to contribute to the development of his people and country.

What made you establish AGT?
I had completed one contract and was about to start a new job when I decided to start a TC laboratory at my house. I employed and trained two people to produce TC plants out of my kitchen while I was traveling. At that time (2001–02) banana and coffee wilt diseases were spreading like wildfire in Uganda. It was easy to start with these two crops as there was great demand for disease-free planting material to reduce the spread of diseases and restore healthy plantations. Over time, using my own finances, AGT built a state-of-the-art TC facility and we grew significantly. Our technical team now includes five university graduates and a retired professor. Degree students from Makerere University have been doing their internships at AGT’s laboratory with their programs embedded in our production line.

How did the AGT and IITA partnership come about?
It started when Dr. Thomas Dubois called me out of the blue. IITA was looking for a commercial enterprise to start testing and producing its endophyte-enhanced plants. Under a mutual agreement, AGT and IITA have worked on fine-tuning the enhancement of TC plants with endophytes. We identified and established on-farm trials together, using the same farmers. In the short run, IITA assisted us with laboratory chemicals and AGT also benefited from publicity. In the longer run, production of endophyte-enhanced TC material would be greatly beneficial to AGT and other commercial producers in the region. Now that the original project has expired, we are trying to get this unique product commercialized to supply farmers facing high pest and disease pressure.

Please give some insights on public-private collaboration.
Collaboration can be very important in developing and disseminating research products. For IITA, it has forced them to think commercially from the onset. A good example has been the experimental protocol for endophyte inoculation. After piloting it in my lab, IITA quickly abandoned the use of a nutrient solution in favor of fertilizer-amended soil along the lines of the system used in commercial nurseries. Such partnerships should be developed as early as possible, especially for a technology such as this. This would help AGT to build up its technical, human, and financial capacity to take on the research products once they reach commercialization. Also a very clear agreement has to be drafted and this is sometimes a balancing act.

How could IITA improve its relationship with the private sector?
AGT indicated to IITA that it was open to other research products but wanted to be involved at an early stage. This is what we call a demand-driven research agenda where the consumer is sure of getting research products through private sector involvement. We are now backstopping a socioeconomic study looking at full commercialization of our nurseries in Uganda and Rwanda. At present AGT sells mainly through NGOs and institutions. Direct marketing to farmers would be better.

What lessons have you learned from the partnership with IITA and others?
It is great that research organizations such as IITA have realized the role of private sector involvement in agricultural research and in the product value chain. Such partnerships are relatively new and we still have much to accomplish. Personally, I feel many governments and international research institutions, even IITA, are working too much for the donors, not the farmers. We should tell the donors what needs to be funded. More impact assessment is needed on some research products.

Any suggestions for future collaboration or collaborators?
I hope IITA can do more demand-driven research by including the private sector in the development of research products as early as possible with specific roles for each partner clearly defined.

What do you think makes AGT successful?
I have a professional approach and commitment, with many years of experience in agriculture and entrepreneurship and good relationships, local and international. AGT started when diseases such as banana bacterial wilt and coffee were at their peak, so I was in the right place at the right time.

How else could development organizations and private entities such as AGT help farmers and consumers?
AGT is getting farmers involved in production, distribution, and training by establishing banana nurseries and demonstration gardens owned by local farmers. The farmer then becomes the AGT distributor for that community and the nursery the focal point for training others in modern agricultural practices.

What is your dream for Uganda?
Uganda is the second largest producer but seventy-fifth in banana exports. The Government and all development partners should industrialize this crop and thus lift many out of poverty.

Any thoughts about the world food crisis, food security, GMOs, or development in general?
African countries are the poorest in the world today with many problems. We urgently need biotechnology tools, including GMOs, to address problems. We should not waste time blaming others for creating poverty and hunger but make efforts ourselves to get out of the rut. I still have far to go but I am contributing to the well being of farmers in Uganda and the whole region.