Kenya: Orange-fleshed sweet potato

The Rome-based Global Crop Diversity Trust and the International Potato Center (CIP) in Peru are finalizing a US$1 million five-year renewable grant to support, maintain, conserve and make available sweet potato varieties. CIP describes the sweet potato as a crop that grows in marginal conditions, requiring little labor and chemical fertilizers. It is a cheap, nutritious solution for developing countries needing to grow more food on less area for rapidly multiplying populations. It also provides inexpensive, high-protein fodder for animals. Sweet potatoes, particularly varieties with purple-fleshed roots are a rich source of compounds called Anthocyanins, which have medicinal value as Anti-oxidants and Cancer Preventing agents. More research is being done about it. But even if it is a major food security crop and can be a commercial crop, it has had little funding for research and development compared to other major staples. However, its contribution to food and nutrition security in the developing world is increasingly being recognized.

“Conserving available farmers’ varieties is urgent for exploitation for traits such as drought tolerance in the face of climate change,” Dr. Robert Mwanga a sweet potato breeder for sub-Saharan Africa at CIP. The orange-fleshed sweet potatoes particularly, are an important source of beta-carotene, carbohydrates, fiber and a cheaper source of vitamin A for children and breast-feeding mothers. Research shows that just about 250 grammes of the orange-fleshed sweet potatoes can provide the recommended daily requirement for vitamin A. This is particularly important in sub-Saharan Africa and Asia where Vitamin A deficiency is a leading cause of blindness and premature death among children under five and pregnant women. With its cocktail of benefits, especially for women and children, who are most vulnerable to malnutrition, disease and hunger, ASARECA initiated a project to enhance farmers’ uptake and adoption of orange fleshed sweet potato technologies.

Nutrition ProjectThree years on, ASARECA and CIP have developed 11 varieties and a number of technologies that range from those, which are appropriate and preferred for processing or value addition such as Jewel and Carrot-Dar and some which are suitable for normal cooking for home consumption such as Ejumula, Kabode and Kakamega. “We are also testing a technology that will preserve the vines during the dry season and conservation of the root in the sand and rapid multiplication,” said Dr. Lydia Kimenye, the program manager, knowledge management up scaling with the Association for Strengthening Agricultural Research in Eastern and Central Africa (ASARECA).

Variety and health benefits

The varieties exist with a wide range of skin and flesh color, from white to yellow-orange to deep purple-fleshed roots, which are a rich source of compounds called Anthocyanins, which have medicinal value as Anti-oxidants and Cancer Preventing Agents. Cancer research is ongoing about these. “It is desirable for countries to promote high yielding varieties for instance in terms of nutrition; Vitamin A, diseases and drought tolerance,” said Mwanga. Ultimately, improved varieties in terms of nutrition and yields can lead to self-sufficiency for food and sell of excess leading to improved nutrition and income. The CIP project will address constraints such as perish ability, conservation of farmers’ varieties and wild relatives of the cultivated sweet potato.

Patrick Makoha, the Secretary for Siwongo Drainage and Irrigation Self-help Group, Busia, Kenya started multiplying orange fleshed sweet potato vines from less than a quarter an acre, that have expanded to seven acres in three years. He earns US$ 293.5 a month from the sale of the potatoes and US$ 195.7 monthly from the sale of vines. Multiplication and distribution of clean planting materials or vines is at all levels; individual farmers, farmer groups that manage secondary multiplication sites and national agricultural research institutes and supply-side partners such as extension and non-governmental organization staff that do the backstopping and monitoring. So far, about 10,000 farmers across the five countries- Ethiopia, Kenya, Tanzania, Rwanda and Uganda- have been reached by the project with planting materials and training on the technologies.

In Rwanda and Ethiopia, cleaning of selected varieties to make them virus free using tissue culture and positive selection are progressive. Two popular varieties - Cacearpedo and 97-062 led to 360,000 cuttings are being produced from 1.6 hectares (ha) of primary multiplication stages and a million cuttings from 4.7 ha of secondary multiplication stages. Motivated by improving linkages, high demand and income generation, farmers in western Kenya have expanded the acreage of land under orange-fleshed sweet potatoes from an average of 0.125 acres per farmer to 0.25 per farmers. This in turn has occasioned increased production and sale of vines by about 30 percent Kimenye resonating that ultimately, ASARECA is building capacity of farmers to become vine multipliers for the local communities.

Ugandan school snacks

Increased acreage is in tandem with demand for orange-fleshed sweet potato flour in Kenya, which has increased from 500 kg per month in 2008 to now 2 metric tonnes per month, according to ASARECA records. It has also impelled the number of farmers engaged in growing orange-fleshed sweet potato while primary handling and enterprises have increased from 30 farmers to more than 250, improving the scale of household incomes by about 20 percent. In Rwanda, the nutritional values of the orange-fleshed sweet potato have attracted non-governmental organizations working with people living with HIV/AIDS that urge their clients to grow and consume them. Uganda, second largest producer of sweet potato after China in the world continues to feed its children on the flour’s confectionaries for breakfast, as a school snack and as chips.

CIP works with national programs to improve the farmers’ varieties in different countries. The national sweet potato programs can access sweet potato varieties from CIP/Lima or the regional Sub-Saharan Africa offices. The national programs can use those varieties directly or use them in their breeding programs to improve their local varieties to produce improved varieties better suited for the market and home consumption or for livestock feed or processing. Improved varieties in terms of nutrition -high Beta-carotene or Vitamin A-, and yield can lead to self-sufficiency for food and sell of excess leading to improved nutrition and income.

Source: onislam.net