Research in Rwanda aims for a good harvest of sweet potatoes

Crop production

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For nearly a century, Rwandans have grown and eaten sweet potatoes. Over time, this crop has gained popularity. Almost all Rwandan farmers grow sweet potatoes, but they are mostly eaten by women and children. Families usually eat the sweet potatoes they grow, because the crop fetches a low price in the market.

Government agricultural workers in Rwanda, including extensionists, do not generally focus on sweet potato for a number of reasons, including: 1) Sweet potatoes are only for consumption, not for export; 2) they deteriorate quickly, so are difficult to store; 3) they are mainly grown by small-scale farmers; and 4) they may not be profitable. However, the National Agricultural Research Institute of Rwanda (ISAR) is a government agency that does focus on the crop, by conducting research to improve the quality and quantity of sweet potatoes in Rwanda.

Extending research findings to farmers is not easy. Sometimes, research findings conflict with the agricultural practices of Rwandans because farmers want to continue practising their traditional methods. The following script will help Rwandan farmers and other Rwandans learn what is being done in the field of research on sweet potatoes in Rwanda. This knowledge will help Rwandan farmers to improve their agricultural techniques for better harvests of sweet potatoes.

This script is based on actual interviews, conducted with a researcher and farmers in Rwanda. To produce this script on your station, you might choose to use voice actors to represent the interview participants, and change the wording in the script to make it suitable for your local situation. If so, please make sure to tell your audience at the beginning of the program that the voices are those of actors, not the original people involved in the interview, and that the program has been adapted for your local audience, but is based on real interviews.


Theme music to introduce program, then fade under host after 15 seconds

Dear friends and listeners of Radio Salus, hello and welcome to the show. Today, we will talk about agriculture, as usual at this time. The theme of the show is “Research in Rwanda aims for a good harvest of sweet potatoes.” In this program, we will talk about research work that the National Agricultural Research Institute of Rwanda or ISAR is conducting to improve the quantity and quality of sweet potato production in Rwanda. This show is prepared and presented by Jean Paul Ntezimana. Please stay tuned for more!

Ten second musical break and then fade under host

Dear listeners, as you know, 95% of Rwandans are farmers. Farmers grow staple crops and cash crops. Among the staple crops grown throughout the country are sweet potatoes. Since today’s show will focus on the work of ISAR to increase the production of sweet potatoes in Rwanda, we invited Ndirigwe Jean, a researcher at the Institute, to speak with us. Mr. Ndirigwe, hello and welcome to the studios of Radio Salus!

Hello, Jean Paul, and thank you for inviting me!

Mr. Ndirigwe, you are an experienced researcher in the production of sweet potatoes, and you are head of the research programme on sweet potatoes at the National Agricultural Research Institute of Rwanda. What can you tell us briefly about the history of sweet potatoes in Rwanda?

(The tone of his voice is low and he speaks slowly) The history of sweet potatoes in Rwanda is short. Sweet potatoes were first introduced to Rwanda by the warriors of Kigeri iv Rwabugiri during the war in Rwanda against Nkole around 1880. Later, sweet potatoes were grown by missionaries in the parishes of the Catholic Church. With the creation of the National Agricultural Research Institute of Rwanda (ISAR) in 1930, the research programme on sweet potatoes began.

Different varieties were introduced and quickly distributed to farmers. Sweet potatoes became popular in Rwanda because they are tolerant to drought, especially in regions of low and medium altitude. Today, Rwandans are the number one consumers of sweet potatoes in Africa. Rwanda is also the third largest producer of sweet potatoes in Africa. According to the Ministry of Agriculture, the average Rwandan produces 300 kilograms of sweet potatoes per year. In Rwanda, sweet potato production is second only to bananas in the area of farmland used for production.

Mr. Ndirigwe, you say that sweet potatoes are grown throughout the country. At the beginning of this month, we went to Gasharu in South Province, in the centre of the country. Jeannette Uwizeye is a farmer. She grows sweet potatoes, but, since it is the beginning of summer, she has finished the harvest work and is at home. I asked her what she thought of the production of sweet potatoes.

I have lived here in Gashauru since my marriage, and today I have a few children. My husband’s family grows sweet potatoes. My husband and I also grow them. We have different varieties – Nsasagatebo, Mugande, Ndamirabana, and Rukubinkondo – there are many. It is true that we do not lack sweet potatoes throughout the year. But our yield of sweet potatoes in Gasharu is not good. Maybe the varieties we use are old.

(Interrupting) No, I think the sweet potatoes that we produce here in Gasharu are good. As you know, sweet potatoes are grown to feed women and children. But beware. A family with children that does not produce a lot of sweet potatoes is a family that will have no peace.

The voice you have just heard is that of Mr Théogène Sindikubwabo, Jeannette Uwizeye’s neighbour. Both are residents of Gasharu, in the district of Muhanga. As you can hear, sweet potatoes are a very important crop for families.

Ten second musical break, and then fade under host

Mr. Ndirigwe, you have just heard the views of farmers from Gasharu about the production of sweet potatoes. What is your reaction to this news?

Jeannette is right. The varieties that we have today in our country are old. Sweet potato varieties, like humans, can become old. This is why we are looking for new varieties that can provide a better yield of sweet potatoes in Rwanda. Through this research, we have found that white sweet potato varieties can produce higher yields than the older varieties. As was mentioned by Mr. Sindikubwabo Théogène, in Rwanda, sweet potatoes are mostly consumed by children and women. Some older varieties are either yellow or orange-fleshed. We found that the orange sweet potato varieties are rich in vitamin A. Unfortunately, they do not produce a good yield, but they are very nutritious. Research on the new varieties is focused on finding varieties of sweet potatoes that are rich in vitamin A.

I think that you have chosen to visit the right area for your interview with the farmers, because Gasharu is where we are doing our socio-economic research. We have been involving Gasharu farmers in our research and have plots of land in Gasharu to research sweet potatoes.

Apart from the fact that the old varieties are aging, poor yields of sweet potatoes are also due to the way in which our farmers grow them. They use traditional methods. In a square metre, the farmer plants ten cuttings of more than six varieties. This makes it impossible to have a good yield. We show them that a better method is to plant three cuttings of a single variety.

Ten second musical break and then fade under host

Thank you Mr. Ndirigwe, would you like to add anything before we close?

What I would like to add is that there are other problems preventing our farmers from obtaining good yields of sweet potatoes. For example, there are virus attacks and other problems that farmers can eliminate if they have the help of local agronomists.

However, the word “agronomist” reminds me that the government’s agricultural program has not always promoted sweet potatoes. They are not a top priority crop like cereals, cassava or cash crops. It’s really a problem!
Host: Taking into account the problems and solutions that you have outlined, what are your expectations for the future?

We will continue our research, especially our programs which involve farmers. We will soon increase our research on the storage of sweet potatoes. Sweet potatoes rot quickly in storage because they contain large amounts of glucose, a kind of sugar. ISAR has also started research on sweet potato processing to expand the number of ways in which they can be consumed. We are trying to find sweet potato flour that can be used in the preparation of cakes, pasta and other foods. All this research may change the perception in Rwanda that sweet potato is a food that is only for women and children.

Dear listeners and dear farmers, we hope that you have learned what researchers are doing to increase the quantity and quality of sweet potato production in Rwanda. We hope that some of the techniques raised during this program will be useful to you.

Thank you, Mr. Jean Ndirigwe, for explaining your research on sweet potatoes! I would like to remind our listeners that you are a researcher and program manager on sweet potatoes at the National Agricultural Research Institute of Rwanda. Thank you, dear listeners, for following this program with your host Jean Paul Ntezimana! Goodbye until we meet again on our next program.


Contributed by: Jean Paul Ntezimana, a journalist with Radio Salus.

Reviewed by: Robert Mwanga, Head, Sweetpotato Research, National Agricultural Research Organisation, National Crops Resources Research Institute, Kampala, Uganda.

Thanks also to Ndikubwayezu Gilbert, journalist with Radio Salus.

Information sources

Jean Ndirigwe, 2006. Adaptability and acceptability of orange and yellow-fleshed sweet potato Genotypes in Rwanda, MSc Thesis, Makerere University, Kampala.

Ruben L. Villareal and T. D. Griggs, editors, 1982. Sweet Potato: Proceedings of the First International Symposium. Asian Vegetable Research and Development Shanhua, Tainan, Taiwan, China, 1982.

ISAR Rubona, Rwanda, 2008. Botany, origin, spread and distribution of sweet potato.