Origins, production, and utilization of cassava in Burkina Faso, a contribution of a neglected crop to household food security

Abstract Cassava (Manihot esculenta Crantz) is a food plant introduced in Africa from America by the Portuguese in 1558. The objective of this study is to establish cassava origins, production, and utilization in Burkina Faso. The investigation was carried out in the regions of Center West, Cascades, Boucle du Mouhoun, Hauts Bassins, South West, and Center East of Burkina Faso. Eighteen cassava processing units and 226 farmers in 57 communities from the selected regions have been involved in the survey. The investigation showed that cassava was introduced to Burkina Faso, former Upper Volta from the costal countries, Gold Coast (now Ghana), by both local traders and the Roman Catholic White missionaries. This happened between the second half of the 19th century and the beginning of the 20th century. The main variety introduced was Banfti. Some improved varieties like V5 (94/0270), Banké (V2), 68.61, 30572, KTMA developed by research are now available and used by farmers along with the traditional varieties like manchien, santidougou, tchinda yaar, léo. The cases of intoxication evoked by some farmers are evidence that some of those varieties may have a high level of cyanohydric acid content. Cassava is available all the year throughout the country. But the top of cassava production is reached in July. Most of the small‐scale farmers (98%) grow cassava both for household use and as income generator. About 83.92% of cassava farmers have less than 10 tons as annual production and only 1.72% of them can produce more than 100 tons. The main food products based on cassava found in communities are raw roots, boiled roots, roasted roots, tô, attiéké, tapioca, ragout, beignets, boiled leaves, soup (with leaves), cassava juice, etc. And the main cassava‐processed products in the processing units are attiéké, gari, tapioca, and flour. Cassava contributes greatly to household food security during food shortage period. It sustains families for weeks as food and is also exchanged with other foods or sold to buy food or meet household needs.


| INTRODUCTION
Cassava (Manihot esculenta Crantz) is a food plant brought from the New World to the Tropical Africa where it does now establish (Roger, 2014). The utilization of cassava as food for America's societies began around the 18th century before Christ (Charrier & Lefrèvre, 1994). It is a woody plant with about 1-3 m height belonging to Manihot gender and Euphorbiaceous family (Bombily, 1995). There are hundreds of cassava varieties spread around the world (Favier, 1977;Laure, Pinton, & Sécond, 1998). Approximatively the half of the world's cassava current production comes from Africa where it is cultivated in around 40 countries.
In Burkina Faso, cassava has been introduced some decades ago.
It used to be an adequate solution to household food security during food shortage period in some regions. The fermentation technology incorporated in the population's food habits is increasing cassava production and its utilization as food. This contributes to the development of cassava processing units. Cassava is now cultivated both during rainy season and dry season under irrigation. Several improved varieties are available and adapted to the national agroecological conditions and the processing technology. Attiéké is the most widely consumed cassava-based product in Burkina Faso. Its production contributes in generating incomes especially for women (Diacoumba, 2008). The aim of this study is to establish the origins of cassava varieties grown in Burkina Faso, to evaluate cassava variety knowledge and use, the state of its processing, and its contribution to household food security.

| MATERIALS AND METHODS
An investigation was carried out in the main cassava production areas of Burkina Faso. The targeted regions were Center West, Cascades, Boucle du Mouhoun, Hauts Bassins, South West, and Center East.
Cassava processing units and cassava producers were both the target of the investigation. About 226 farmers from 57 communities in the selected regions were involved in this investigation for cassava production and use of cassava by the households. The data were collected using a questionnaire by SphinxV5demo software. The questions included knowledge of cassava origin in the locality, cassava varieties used or known, the production level, cassava production challenges and opportunities, it family use, and the knowledge about cassava toxicity. For the industrial uses and cassava processing, another questionnaire was used. Eighteen processing units using cassava roots as raw material and located in Léo, Dédougou, Gaoua, Kampti, Orodara, and Bobo Dioulasso were surveyed. The required questions focused on the processing level and cassava-based products. The collected data were then analyzed with R statistical software for average determination variance and linear regression. The graphics are made with Excel (2010).
Food security definition here used is base on the FAO (2012) recommendation of 2300 kcal per adult per day to evaluate the contribution of cassava to household food security. Food security status of households can then be expressed nationally as follows: where F secn = food security status of household n; X n = per capita calorie consumption of household n; Z n = recommended daily minimum energy requirement of 2,300 kcal.
The contribution of cassava to family need is evaluated based on equation (3) of household needs:

| Origin and spread of cassava in Burkina Faso
The investigation shows different routes of cassava introduction in Burkina Faso. It varies according to region. In Center West region, all interviewed person recognize two ways of cassava introduction. (1) F secn = 0 for X n < Z (2) F secn = 1 for X n > Z In the Center East region, cassava was introduced by local traders (from Ghana) and also by farmers from other localities. In South West region, cassava was introduced from Côte d'Ivoire. The main factors that increased cassava production in a larger scale in this region were due to a German-based Agriculture Development Program (PDA) and the government actions at the early beginning of the 21th century.

| Cassava production and available varieties in Burkina Faso
Till date, cassava in not registered as national food plant by agricultural statistic division of the government. The evolution of its annual production is still unknown. The production of cassava throughout the country was 60,000 tons in 2013 as estimated by the PDA technicians.
In general, cassava is cultivated in a small scale for family consumption and sold or exchanged with other items during food shortage period.
The proportion of cassava producers according to the level of their production is as shown in Figure 1. Importantly, it appears that cassava farmers have less than 10 tons as annual production. Only 1.72% of them have more than 100 tons as annual production. Cassava is then produced in small scale essentially for family use.
The availability of cassava in Burkina Faso varies from one region to another according to the variety used and the possibility to produce it during the dry season ( Fig. 2 and 3). Improved cassava varieties are in full diffusion from South West region to Center East region where it has been tested first. But farmers are still attached to their traditional varieties for family use. Improved cassava varieties are better for processing, but not ready to be eaten. The availability of cassava in Burkina Faso is as shown in Figure 2. The cassava production is high in July and more than 40% of its farmers have the availability from June to October.

Figure 3 highlights the fact that the availability of cassava in
Burkina Faso depends on the period of the year, the main period of production is ranged between June and October. The dry season is characterized by a small quantity of cassava root available. According to the region, there is a variation in cassava availability. In Center East region, cassava is available only during the rainy season. In the Hauts Bassins, Cascades, and Boucle du Mouhoun regions, cassava is available all the year (Fig. 3).
The characteristics of cassava varieties found during the survey are as shown in Table 1 Households use drying and soaking as processes to eliminate cassava toxicity. The cassava varieties identified in this study are shown in

| Cassava utilizations at household level in Burkina Faso
Cassava cultivated in Burkina is used essentially for human food.
Animals are fed only with cassava leaves and cassava root peels and sometime mixed with salt. In the communities, cassava is mainly pro-   The final products of cassava are sold in local markets and also exported to Mali republic and even to Senegal.

| Utilization of cassava in processing units in Burkina Faso
Cassava leaves are sometime used as medicine, mixed in cereals to produce various meals. Many processes are used to prepare cassavabased food. The interrelationship of cassava-based products found in all the investigated communities is shown in Figure 6.  (Rouch, 1956). They used to sell cotton strips, livestock, and slaves in Gold Coast (Ghana). And they brought their salt and cola to be sold in their homeland. During the beginning of the 20th century, the European's occupation secured the roads and then increased this trade to a great extent (Rouch, 1956 during the foundation of their mission agency there (Hououdié, 2008;Appolinaire, 2012). The general district of this mission agency was established in Tamale in Ghana where cassava was already promoted (Tiendrebeogo, 2008). It is from Tamale that the missionaries bring cassava to Burkina Faso. Réo and the surrounding villages began to experiment this new crop which was very profitable. In the last half of the 20th century, Sanguié was the most producing area of cassava in the country. during dry season to overcome food insecurity also associated cassava as profitable food plant. And it contributes in cassava spreading.

| Cassava origins and spread in Burkina
The improved cassava varieties distributed increased the production considerably (Sidwaya, 2014). But the most important movement of cassava varieties is between farmers of the same locality and across regions. Nowadays cassava is found in many localities in Burkina Faso, from the southern to the northern and from the western to the eastern part of Burkina Faso. Cassava is cultivated mostly by poor farmers (96%) in their gardens to be used during food shortage period and also to increase their income. The money they got is usually used for school fees.

| Cassava production and available varieties in Burkina Faso
Cassava name varies according to the language. It sometime takes a designation of it derivate food's name. Cassava alternative names are mandioka (Portuguese, from Tupian), rogo (Hausa), mbay (Fulfulde), ege (Yoruba area), and banakun in Mande and Dogon area (Roger, 2014). The first cassava variety introduced in Burkina is Bantfi (Roger, 2014). are stomach aches, distending, insomnias, vomiting, dizziness, jolts, diarrhea, constipation, tiredness, headaches, and paralysis. Some of these symptoms are clinically proved as cassava intoxication (Délange & Ahluwalia, 1982;Hovette et al.,1992;Hugon, 1998;Bennito & Silvana, 2010). Drying and soaking are the main processes used by household to eliminate cassava toxicity. The criteria of adoption of cassava depend on its sweetness as food and its ability to be sold in the market. Cassava is a promoting crop, but the greatest challenges of its production are the domestic animal that devastate the plant (60.4%), the insufficiency of water (43.6%) during the dry season, and the lack of specific fertilizer for cassava. The main factors limiting its long-time use is its perishability.
Burkina Faso is among the countries where cassava production is not important (Okibgo; 1980) cited by Felix (2004). In 1998, the production of cassava in the country was estimated to be 2,000 tons by FAO (Hillocks, 2002). The production increased during this decade to reach to 60,000 tons (in South West and Center West) in 2013 according to PDA technicians interviewed. Burkina Faso is not considered as cassava production country in West Africa. The annual production of cassava in all African countries is estimated to be 153 million tons in 2012 and the production in Nigeria, the leader in African cassava production, is estimated to be 57 million tons in the same year (FAO, 2012). The main crop produces in Burkina Faso is sorghum and the research on cassava for industrial use is still not significant comparatively to other countries (Johanna, 1998;Rusika, Mahun, Jumbo, Sandifolo, & Malindi, 2010;Ademola, Ogugua, & Parayil, 2012;Eke-Okoro & Njoku, 2012;Michael et al., 2013). Research on cassava is still insufficient to provide significant number of improved cassava varieties for different uses (Oluwole, Onabolu, & Mtunda, 2007;Eke-Okoro & Njoku, 2012). In coastal countries there are many recipes made from cassava than in Burkina Faso (Andrew, 2002;FAO and IFAD (2005) (Felix, 2004;IITA and FAO 2005).

| Contribution of cassava to household security
Since 1970, food insecurity used to be recurrent in Burkina Faso every year. It occurred early in the rainy season and last until the next crop harvest period. It usually happened from March to October (Janin, 2003;Thombiano, Natacha, Lamien, & Didier, 2012). It is a critical time when farmers sale their properties to acquire food. Many strategies like nonwood forest products consumption, diversification of agricultural production, etc., were undertaken to overcome food insecurity in this period. Cassava production is one of these alternatives. But its production and consumption is lower (0.3%) compared to costal countries like Cote d'Ivoire, Togo, Ghana, and Nigeria. Cassava is mainly cultivated by households to reduce food shortage period. At this time, cassava contributes to food availability, its stability, and accessibility.
In equation (1) According to equation (3), cassava contributes to household needs by increasing household production and stocks and by reducing food purchase level during shortage time. Cassava is also given to other families as local food aid. This contributes to secure some household food security for a short time. In addition to family use, cassava is also exchanged with other food supplies. The exchange increases the accessibility of households to other food for their daily food balance. Cassava processing and cassava sell generate an important income for households. But this income is not only used to buy food, but also help to cover the household other needs. More than 40% of cassava farmers use the money they got from cassava selling to pay school fees for their children.
In some regions, cassava processing creates jobs for hundreds of people which generate income for household. During food shortage period, the income is mainly used for food need. This indirect contribution of cassava to household food security is also significant for families.

| CONCLUSION
This study establishes proofs of cassava introduction in Burkina