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Researching African Indigenous Fruits and Vegetables – Why?
Mary Oyiela Abukutsa-Onyango
Department of Horticulture, Jomo Kenyatta University of Agriculture & Technology, Nairobi, Kenya
Introduction
Traditionally, Africans made use of edible fruits and leaves of plant species growing wild as weeds. These edible plants were well-known to the rural communities and were often collected from the wild or planted in home gardens as intercrops with staples. For some indigenous fruits and vegetables, wild collection is still practiced, especially in southern Africa and parts of eastern and western Africa. Recent surveys reveal that indigenous fruits and vegetables were consumed by the rural populations for nutrition and food security. The hidden potential of indigenous fruits and vegetables needs to be exploited to play a pivotal role in solving malnutrition, food insecurity and poverty challenges facing Africa.
Advantages
Nutritive Value: With particular reference to food security and nutrition, indigenous fruits and vegetables are rich in vitamins, minerals, proteins and anti-oxidants. They improve palatability and add variety to diets, especially those of the poor. They are particularly valuable sources of food during emergency periods such as occur during flood, famine, drought and war.
Health Benefits: African indigenous fruits and vegetables have medicinal properties and health benefits. Spiderplant (Cleome gynandra), for example, has been reported to relieve constipation and facilitate child birth (van den Heever and Venter, 2007), while African nightshade (Solanum scabrum) has been documented to cure stomach ache (Adesina and Gbile, 1984). They are also known to contain substantial amounts of antioxidants that scavenge for and bind to harmful radicals, which have been linked to ailments such as cancer, diabetes and cardiovascular diseases.
Agronomic advantages: Indigenous fruits and vegetables are well-adapted to harsh climatic conditions and disease infestation and are easier to grow in comparison to their exotic counterparts. They produce seed under tropical conditions, whereas exotic species often fail to do so. Indigenous vegetables generally have a short growth period, with most of them being ready for harvesting within 3-4 weeks. They can also do well under intercropping. Furthermore, because most of them have not been intensively selected, they have a wide genetic base.
Income generation: Socio-economic surveys in various parts of Africa have revealed that indigenous fruits and vegetables provide employment opportunities and generate income for the rural population.
Constraints
Despite their advantages, indigenous fruits and vegetables have not been fully exploited in Africa. The introduction of exotic fruits and vegetables on the continent had some negative impact on the consumption, domestication and cultivation of indigenous fruits and vegetables. For a long time, agricultural policies in many states advocated the use of exotic species at the expense of indigenous ones. Recently, indigenous fruits and vegetables have won some recognition through crop research at international, regional and national institutions.
The marketing system has remained informal, with economic inefficiencies. Neglect and stigmatization, non-availability of high-quality seed and planting material, inadequate awareness of value and potential of indigenous fruits and vegetables, lack of agronomic and processing technical packages, short shelf life, inadequate research, knowledge-sharing and training and a lack of transparency about intellectual property rights to guide their use, especially those collected in the wild are additional constraints.
Consequences of not addressing these constraints include low production and distribution, leading to low consumption, utilization, loss of biodiversity, malnutrition and poor health (eIFL, 2010).
Research
Increasing population, a relative decline in agricultural productivity, accelerated food insecurity and high dependence by rural farming households in SSA have raised interest in indigenous fruits and vegetables. This needs to be supported by a strong research agenda. Research on the biology and ecology of relevant species can enhance conservation, domestication and cultivation.
Improved production technologies will lead to increased yields and improved nutrition and economic empowerment of rural communities. Appropriate management, preservation and processing protocols for the priority species are needed and should be driven by research (Abukutsa, 2010).
Priority indigenous fruits with nutritional and economic potential include: jackfruit (Artocarpus heterophyllus), sumac (Rhus natalensis), guava (Psidium guajava), tamarind (Tamarindus indica), bush mango (Irvingia gabonensis), African plum (Dacryodes edulis), bitter cola (Garcinia kola) and white star apple (Chrysophyllum albidum). Market surveys in Kenya and Zimbabwe revealed that there was substantial trading of indigenous species in both rural and urban areas; however, the system was still underdeveloped. Identified priority indigenous vegetables include cowpea (Vigna unguiculata), nightshade (Solanum scabrum), amaranth (Amaranthus blitum), spiderplant (Cleome gynandra), jute mallow (Corchorus olitorius), eru (Gnetum africanum) and bitter leaf (Vernonia amygdalina) (Abukutsa, 2007a, Kaloki, 2009).
Germplasm collection of priority indigenous fruit and vegetable species has been carried out to enable selection and improvement in the domestication process. Additionally, evaluation, characterization and multiplication have been done for several indigenous fruits and vegetables such as African nightshade, spiderplant and amaranths, resulting in high-quality planting materials.
The ecology and biology of Uapaca kirkiana, Strychnos cocculoides and Sclerocarya birrea have been studied in Southern Africa and provenance testing of the three species has identified some superior clones, using participatory selection in Zambia and Malawi (Chirwa and Akinnifesi, 2007). However, more strategic research tailored to consumer preferences is also required.
Agronomic studies reveal that most indigenous fruits and vegetables are grown as intercrops in home gardens, most of which are poorly maintained and intercropping has several advantages that need to be exploited. The inclusion of fruit trees in production systems reduces the risks such as those from pest and disease outbreaks. Topping, the removal of the apical stem, could be used to delay flowering in some of the indigenous vegetables that flower early, such as spiderplant, and increases productivity (Abukutsa et al., 2003).
A nutritional evaluation of indigenous vegetables in two sites in Kenya considered that the nutritional contribution of cooked and uncooked vegetables was enormous (Habwe et al., 2009, 2010, Abukutsa et al., 2010). Nightshade and cowpea contained iron levels that would provide 100% of the recommended daily allowance and 50% for protein. Indigenous vegetables cooked with lye (traditional salt) had higher iron content than cooked ones
Visioning the Future
Developing information systems and dissemination materials such as leaflets and DVDs would greatly contribute to advocacy, promotion and popularization of any commodity (Box 1. Dissemination Materials, Nierenberg, 2010).
University students from agricultural faculties normally form the major human resource in research and extension services. It is therefore important to build capacity in human resources that will undertake research and effectively disseminate information on the indigenous species. (Box 2. Restructured Programmes).
Establishing sustainable quality seed supply systems is a key step in the promotion of any crop (Box 3. Quality seed supply system, Abukutsa, 2007b).
Conservation of African indigenous fruits and vegetables would minimize loss of biodiversity (Box 4. Maseno University Botanic Garden, Abukutsa and Onyango, 2005).
The involvement of consumers is critical in determining and identifying products which have a greater chance of being accepted by rural, peri-urban and urban communities. Consumer assessment of some of the fruit and vegetable products and recipes has been undertaken in Malawi, Tanzania and Kenya (Habwe et al., 2008).
Favourable policy design is central to sustainable agricultural production, land tenure, management of natural resources and poverty alleviation. Research on indigenous fruits and vegetables will only be successful when national priorities are sensitized to the needs of local communities, industries and consumers.
Over 75% of producers in many African states processed indigenous fruits and vegetables, where most of the processed products were consumed at a household level, while only a small percentage was traded. People employ traditional processing techniques, methods and equipment to make dried products, oil, powder, juice, jams and wines (Abukutsa, 2009).
Conclusion
It would be beneficial to extend the production season to provide a supply of indigenous fruits and vegetables outside the peak period. Governments of African countries should set up institutional frameworks that will reduce risk and uncertainty for traders marketing indigenous species.
Research to facilitate their introduction to formal markets should be conducted. There is need to compile information on the existing marketing systems and the factors that influence the performance in the Southern African states. The shelf life could be improved by further research on ways of introducing small-scale enterprises for traders (Habwe et al., 2008).
Other approaches include the following:
· Commercial production, value-addition processing and product development for domestic and export markets and validation and standardization of processing methods used by farmers should be considered;
· Research into commercial seed production and efficient seed delivery systems for indigenous fruits and vegetables should be instituted;
· Exploring the nutraceutical development potential of indigenous fruits and vegetables should be exploited;
· Engaging the private sector and other partners in developing seed production, processing, packaging and distribution by seed distribution agents and community-based organizations;
· Developing product prototypes into business ventures;
· Mainstreaming African indigenous fruits and vegetables in the curricula of agricultural programmes
African indigenous fruits and vegetables are high-profile commodities with nutritional and health benefits. They have a role to play in food security, nutrition, income and sustainable development in Africa and beyond; they are a ‘gold mine’ to be harvested and research will accelerate this process.
References
Abukutsa, M.O.O. 2007a. The diversity of cultivated African leafy vegetables in three communities in western Kenya. African Journal of Food, Agriculture, Nutrition and Development 7 (3).
http://www.ajfand.net/Volume7/No3/Abukutsa-IPGRI1-3.pdf
Abukutsa, M.O.O. 2007b. Seed production and support systems for African leafy vegetables in three communities in western Kenya. African Journal of Food, Agriculture, Nutrition and Development 7 (3).
http://www.ajfand.net/Volume7/No3/Abukutsa-IPGRI1-2.pdf
Abukutsa, M.O.O. 2009. Development and promotion of technologies for sustainable production and utilization of indigenous vegetables for nutrition security and wealth creation in Kenya. In: Urama, K., Francis, J., Momanyi, M., Ochugboju, S., Ominde, A., Ozor, N. and Manners, G. (Eds). Agricultural Innovations for Sustainable Development. Contributions from the Finalists of the African Women Professionals in Science Competition. Volume 2 Issue 1. African Technology Policy Studies Network, Nairobi, Kenya, pp. 100-108.
http://www.atpsnet.org/Files/agri_innovations_v2.pdf
Abukutsa, M.O.O. 2010. African Indigenous Vegetables in Kenya: Strategic Repositioning in the Horticultural Sector. Inaugural Lecture, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya. 30 April.
http://www.jkuat.ac.ke/article.php?id=177
Abukutsa, M.O.O. and Onyango, J.C. 2005. Conservation and seed production of African leafy vegetables at Maseno University botanic garden, Kenya. African Crop Science Conference Proceedings 7: 1201-1204.
http://www.acss.ws/Upload/XML/Research/726.pdf
Abukutsa, M.O.O., Muriithi, A.N., Anjichi, V.E., Ngamau, K., Agong, S.G., Fricke, A., Hau, B. and Stützel, H. 2003. Proceedings of Third Workshop on Sustainable Horticultural Production in the Tropics. Maseno University, Maseno, Kenya, Horticultural Association of Kenya and Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya; University of Hannover, Hannover, Germany and German Academic Exchange Service, Nairobi, Kenya.
http://www.gem.uni-hannover.de/fileadmin/institut/gemuesebau/pdf/SVepit/PROCEEDINGS_2003.pdf
Abukutsa, M.O.O., Kavagi, P., Amoke, P. and Habwe, F.O. 2010. Iron and protein content of priority African indigenous vegetables in the Lake Victoria Basin. Journal of Agricultural Science and Technology 2(1): 67-69.
http://www.ceps.com.tw/ec/ecjnlissuelist.aspx?jnlcattype=1&jnlptype=5&jnltype=43&newIssueIID=99822&jnliid=4117
Adesina, S.K. and Gbile, Z.O. 1984. Steroidal constituents of Solanum scabrum subsp. nigericum. Fitoterapia 55 (6): 362-363.
Chirwa, P.W. and Akinnifesi, F.K. 2007. Ecology and biology of Uapaca kirkiana, Strychnos cocculoides and Sclerocarya birrea in Southern Africa. In: Akinnifesi, F.K., Leakey, R.R.B., Ajaui, O.C., Sileshi, G., Tchoundjeu, Z., Matakala, P. and Kwesiga, F.R. (Eds). Indigenous fruit trees in the tropics: domestication, utilization and commercialization. CAB International, Wallingford, Oxon, UK, pp. 322-340.
eIFL. 2010. Prof. Mary Abukutsa-Onyango discusses the importance of Open Access for research from Kenya and other African countries. eIFL 24 March.
http://www.eifl.net:8080/cps/sections/services/eifl-oa/oa-news/2010_03_24_prof-mary-abukutsa
Habwe, F.O., Walingo, K.M. and Abukutsa, M.O.O. 2008. Food processing and preparation technologies for sustainable utilization of African indigenous vegetables for nutrition security and wealth creation in Kenya. In: Robertson, G.L. and Lupien, J.R. (Eds). Using Food Science and Technology to Improve Nutrition and Promote National Development, International Union of Food Science & Technology, Oakville, Ontario, Canada.
http://www.iufost.org/publications/books/documents/HabweetalChapter13.pdf
Habwe, F.O., Walingo, M.K., Abukutsa, M.O.O. and Oluoch, M.O. 2009. Iron content of the formulated East African indigenous vegetable recipes. African Journal of Food Science 3(12): 393-397.
http://www.academicjournals.org/ajfs/PDF/Pdf2009/Dec/Habwe%20et%20al.pdf
Habwe, F., Walingo, M. and Abukutsa, M. 2010. Copper and ascorbic acid content of cooked African indigenous vegetables. Poster: International Research on Food Security, Natural Resource Management and Rural Development. Tropentag, Zurich, Switzerland. http://www.tropentag.de/2010/proceedings/node63.html
Heever, E. van den and Venter, S.L. 2007. Nutritional and medicinal properties of Cleome gynandra. Acta Horticulturae 752: 127-130.
Kaloki, M. 2009. Not just any old weed. Radio Netherlands Worldwide Earth Beat, 9-14 October.
http://www.rnw.nl/english/radioshow/not-just-any-old-weed