Knowledge for Development

Related developments

Cassava – exploring its leaves

Cassava leaves are available throughout the year and should be given as much attention as the roots. They are one of the most valuable parts of the cassava plant containing high amounts of protein, and are also a rich source of vitamins, B1, B2 and C, as well as carotenoids and minerals. In fact, the total amount of essential amino acids in cassava leaf protein is said to be similar to that of a hen’s egg and greater than that of spinach leaf, soybean, oat or rice. Toxicity and antinutrients limit the consumption of cassava leaves as food. These toxic and antinutritional aspects must be addressed properly during processing and before consumption. Research at Hohenheim University is examining the optimal way to treat the cassava leaves in order to transform them into an economical and sustainable source of protein and micro-nutrients. Various cassava leaf processing methods have been developed.   (Rural21, 08/09/2014)


Morphological, physiological and molecular characterisation of drought tolerance in cassava

In this study multi­seasonal and locational field based trials were conducted in Kenya to identify drought-tolerant and drought-susceptible cassava genotypes. Cassava (Manihot esculenta Crantz) is inherently drought tolerant. Nevertheless, substantial genotypic variation exists for this characteristic. Field drought stress generally reduced cassava vegetative growth and productivity. In addition to other phenotypic parameters, storage root fresh weight was used as a primary criterion to discriminate between drought-tolerant and drought-susceptible genotypes. Charles Ochieng' Orek, researcher at ETH­Zurich, Switzerland, subsequently subjected the cassava gentoypes to further physiological and molecular categorisation under controlled water deficit assays. Categorisation of these morphological, physiological and molecular differences will establish an essential foundation for future development of drought-associated molecular markers for cassava.   (Dr.Sc. thesis, ETH-Zurich, 2014)


Pan-African Cassava Surveillance Network – PACSUN

Scientists from agricultural research centres in Africa met at a workshop in Saint-Pierre, Reunion, from 10 to 13 June 2014 to contribute to the war against pests and diseases of cassava. The workshop resulted in the establishment of a pan-African network for surveillance of cassava diseases (PacSun) that will provide expertise in understanding the viruses and bacterial diseases that attack cassava in Africa; pool data via a website; develop applications with simple diagnostic fields on mobile phones for the benefit of African producers; and propose measures appropriate to each country to control the spread of pandemics such as cassava brown streak disease. The workshop participants also called for the establishment of an international transit cassava centre that would exchange of cassava cuttings between African countries, which is currently prohibited because of the risk of spreading cassava mosaic disease and brown streak disease.   (Institut de Recherche pour le Développement, 2.07.2014)


Curing cassava of deadly virus infections

Maruthi Gowda and his team from the Natural Resources Institute of the University of Greenwich have developed a procedure for eliminating virus infections from cassava. They built a 'virus-indexing' procedure for cleaning cassava lines, which involves a combination of protocols for accurate identification and elimination of viruses. The procedure involves growing disease-infected cassava stem cuttings and identifying at a later stage plants free of disease symptoms. Plants free of viruses are then grown in tissue culture media, certified to be virus-free after several disinfection protocols and shipped to African partners for further multiplication and subsequent distribution to farmers.   (NRI, 11/10/2013)


Cassava database becomes open access

Cassavabase is a database of phenotypic and genotypic data generated by cassava breeding programmes within the Next Generation Cassava Breeding (NEXTGEN Cassava) project. The database makes available breeding data immediately available. Data can be accessed through the web interface and various tools are available to explore and extract the datasets. Cassavabase will be hosted at IITA-Nigeria. As well as offering the latest data on cassava, the on-line database provides access to tools for genomic selection, a new technique that dramatically accelerates the breeding cycle, as well as social networking pathways for the cassava community.  (Cassavabase and NEXTGEN Cassava via AIMS FAO, 07/05/2013)


Understanding cassava to feed Africa

This blog post is a detailed overview of the cassava economy in Africa and the agricultural research efforts made to improve the crop. It presents a new paper in AoB PLANTS on the germplasm being integrated into the breeding programme at the National Crops Resources Research Institute in Uganda. Given the inherent challenges with cassava breeding, an understanding of the molecular basis of cassava drought responses and tolerance can help greatly in the development of appropriate varieties. Conventional breeding has been hindered by cassava’s high heterozygosity, genotype by environment interaction, long life cycle and limited seed production, while molecular breeding is hindered by limited information on genomic regions and genes associated with drought tolerance in cassava. Blog, 11/04/2013)


Understanding cassava to feed Africa

This blog post is a detailed overview of the cassava economy in Africa and the agricultural research efforts madfe to improve the crop. It presents a new paper in AoB PLANTS on the germplasm being integrated into the breeding programme at the National Crops Resources Research Institute in Uganda. Blog, 11/04/2013)


Ghana: Turning cassava peel into animal feed

Students from the Kwadaso Agricultural College in Ghana have set up a company to recycle waste cassava peels into animal feed that has the potential to replace maize. About Feed, 15/04/2013)


East African cassava research gets major funding boost

Three projects targeting the deadly viral cassava diseases, cassava brown streak disease (CBSD) and cassava mosaic disease (CMD), have received a financial boost for research and development focused on developing resistant varieties in Eastern Africa. The multimillion dollar funding for cassava research aims to boost sharing of disease-resistant seed. The advanced technologies to be developed will help accelerate and increase the accuracy of breeding programmes. Read SciDevNet’s report:, 18/12/2012)See also: Cassava varieties developed by IITA show promise of tackling famine in the Horn of Africa 


New sweet potato variety triples yields in Gakenke, Rwanda

A new variety of potatoes introduced in the Gakenke District in Rwanda has increased output from 4 tonnes to 12 tonnes per hectare. The new variety of orange-fleshed sweet potatoes was introduced by Sweet Potato Action for Security and Health in Africa (SASHA), in conjunction with Rwanda Agriculture Board (RAB) which multiplied 875800 sweet potato vine cuttings and distributed them among farmers. Besides cultivation of the sweet potatoes, SASHA has been training farmers to bake sweet potato doughnuts from their produce as a form of value addition.AllAfrica has the story (15/10/2012).


IITA opening offices in Congo-Kinshasa

The international Institute for Tropical Agriculture (IITA) opened new offices early August 2012 in Kinshasa, along with a large research laboratory in South-Kivu. It appears research efforts will focus on cassava.


New project ‘Gratitude’: Gains from Losses of Roots and Tuber Crops

Private and public sector organisations from Thailand, Vietnam, Ghana, Nigeria, the Netherlands, Portugal and the UK came together at the Natural Resources Institute, University of Greenwich, UK, in April 2012 to launch the new European Union Framework 7 funded project ‘Gratitude’ (Gains from Losses of Roots and Tuber Crops), and to begin the planning phase. The project aims to help small-holder farmers and small-medium enterprises to find and disseminate solutions that will reduce waste from postharvest losses of root and tuber crops and turn typically discarded by-products into something of increased value. By addressing food security, creating demand for root and tuber crops and improving efficiency at all stages along the value chain; this unique and innovative project will greatly improve the livelihoods of people with low incomes. (NRI via AlpĥaGalileo; 18/4/2012)


Giant swamp taro: untapped potential in the Pacific

World Watch Institute's 'Nourishing the Planet' project describes another little known food crop with an untapped potential for securing food security. Giant swamp taro (Cyrtosperma chamissonis) is more abundant on Pacific atolls than its cousin, the taro (Colocasia esculenta), but it is much less commercially available. Its traditional cultivation is labour intensive and dependent upon a consistently saturated environment, which makes it practical to grow only in small, marshy plots. Swamp taro is a native plant of the Philippines that has dozens of varieties thriving on most of the tropical islands in the Pacific. Giant swamp taro is grown and harvested in small patches for its underground tubers, called corms. Atoll farmers often grow giant swamp taro as part of complex polycultures, in the shade of larger trees. Researchers consider the potential of giant swamp taro to be largely untapped, partly because it is not often studied by researchers and techniques for improving the plant's cultivation have not been developed. (Nourishing the Planet, 27/02/2012)


PNG’s NARI releases two blight resistant potato varieties

Papua New Guinea’s potato industry suffers from the potato late blight (PLB, Phytophthora infestans). The Sequoia, PNG’s most common potato variety, is highly susceptible to PLB. After a devastating outbreak in 2003, only commercial farmers who could afford fungicides, portable sprayers and potato seeds did continue to grow the crop. However, smallholders farmers on the islands could not afford to buy the standard remedial to the blight. Especially for the farmers living at higher altitude, potato was an important cash and subsistence crop. In May 2011, PNG’s National Agricultural Research Institute released two late blight resistant potato varieties, the product of a large-scale project that start started in 2003 with the assistance of the Australian Centre for International Agricultural Research (ACIAR). Blight resistant potato seeds are now distributed to farmers, who are also offered training on integrated late blight management for existing and new potato cultivars. (Malum Nalu, 31/5/2011)


World’s top cassava researchers meet to address the challenge of climate change

Co-Founders of the Global Cassava Partnership for the 21st Century Dr. Claude Fauquet, Principal investigator at the Danforth Plant Science Center and Director of International Laboratory for Tropical Agricultural Biotechnology (ILTAB, St. Louis, USA) and Dr. Joe Tohme of CIAT in Cali (Colombia) gathered 29 prominent agricultural researchers from 14 countries, representing 17 cassava research institutions in Africa, Asia, Latin America, Europe, and North America for a three day conference in Italy, to discuss the impact of climate changes on the security food crop cassava. Experts at the conference explained how climate changes are likely to increase cassava production. New reports suggest that increases in atmospheric CO2 levels could lead to gains in yield and significant increases in the total acres dedicated to planting cassava. In addition, more frequent drought throughout most of Africa will not negatively impact cassava production like maize. Consequently, the land area dedicated to growing cassava is expected to continue to expand in the 21st Century. On the other hand, elevated rainfall in some areas will result in more disease pressure, and increased temperatures will exacerbate insect and mite infestations as well as viral diseases that have a major impact on cassava yield. These critical issues confirm the need for further research and investment in the cassava. (Source: CIAT, 1 December 2010.)


Cassava: Rooting out hunger in Africa -- and making Darwin proud

Scientists in Nigeria and six other African nations are experimenting with a fast-yielding, disease-resistant species of cassava. The results so far are glowing: the new plants stand taller, and appear stronger and more vibrant. When their tubers are pulled from the ground, they resemble fat, oversized fingers. The cassava stems are not genetically-modified. They were obtained through a conventional process of breeding and selection over more than a decade. Researchers at IITA, Ibadan, Nigeria, are distributing the stems to local farmers free of charge. They hope to get the improved cassava into 75,000 farms by the end of the year to increase yields in seven selected Nigerian states. The first results have been promising, scientists and farmers say. The project is financed by USAID and targets about 400,000 farmers in seven African nations: Sierra Leone, Ghana, Tanzania, Malawi, the Democratic Republic of Congo, Mozambique and Nigeria. (Source: The East African (newspaper), 16 September 2010)


East Africa: Cassava comes in from the cold

A research programme led by the Alliance for a Green Revolution in Africa (AGRA), Farm Concern International (FCI), and various partners aims to improve the food security of small-scale farmers in Kenya, Uganda and Tanzania. The hope is also to capitalise on cassava's utility as a source of products such as animal feed, glue, bio-fuel, and glucose syrup. New varieties with higher yields, less cyanide and better resistance to drought and disease are part of the project. The project will benefit from the work of Joseph Kamau, who has developed more than a dozen improved varieties of cassava at the Kenya Agricultural Research Institute. His team is developing varieties that mature quicker and contain more proteins. (Source: All Africa, 8 June 2010)


Cassava mosaic still a threat

Cassava growing in Uganda and the entire region is facing a serious threat from the cassava brown streak disease. According to agriculture researchers who gathered at Entebbe, Uganda, for a three-day workshop, the prevalence of the disease has been widening by the day, ever since it was discovered in 2004. Cassava is one of the leading staple foods in Uganda. It is commonly grown in bulk in the areas of Lango, Acholi and West Nile, and Nakasongola in northern central region. Cassava brown streak disease and cassava mosaic disease affect the roots or tubers, the stem and the leaves. Reports indicate that the disease levels in farmers’ fields have also increased, from 17.5% to as high as 85.6% in 2005 and 2008. The population of whiteflies was correspondingly high in districts that were affected by the disease. (Source: The New Vision, 11 May 2010)


Cassava: improving sustainability of farming systems

Throughout Africa populations are growing fast and pressure on land is steadily increasing. To maintain productivity, farmers are constantly adapting their management of natural resources. Farming systems are thus changing from “slash and burn systems” to ”natural fallow” systems into ”continuous cropping” systems without external inputs and ultimately into more ”intensive” systems using agricultural inputs. Though fertilizer use may be the easiest way to improve cassava productivity and improve system sustainability, high prices limit the adoption of fertilizers, unless strong markets develop. (Source: IITA, 31 March 2010)


IPC project launched to beat malnutrition and hunger in Africa using sweetpotato

The International Potato Center has launched a major project to leverage the untapped potential of sweetpotato to significantly improve the nutrition, incomes, and food production of farming families in sub-Saharan Africa, especially among impoverished women and children. The project, titled Sweetpotato Action for Security and Health in Africa (SASHA), will be implemented in eight Sub-Saharan African countries, and is supported by a five-year, $21 million grant from the Bill & Melinda Gates Foundation. It is the largest of a group of grants presented by Bill Gates at the World Food Prize Symposium on October 15, 2009 in Des Moines, Iowa. The SASHA program will help set the groundwork for reducing malnutrition, combating vitamin A deficiency, and improving incomes for 10 million African households within 10 years. (Source: International Potato Center, 3 November 2009)