From yam production and postharvest constraints to opportunities

D.B. Mignouna, d.mignouna@cgiar.org, T. Abdoulaye, A. Akinola, and A. Alene

Food insecurity remains a huge concern in West Africa. Agriculture, without doubt remains the main source of food and livelihood. Over the past two decades, agricultural yields have stayed the same or declined. Although there has been a recent rise in agricultural productivity, it derived more from expanded planting areas for staple crops than from yield increases. Thus, increasing and sustaining agricultural productivity should be a critical component of programs that seek to reduce poverty and attain food security in the region.

Yam (Dioscorea spp.), a vegetatively propagated crop cultivated for its underground edible tubers, is the mainstay for about 300 million people in West Africa. It is a very important food and income source for millions of producers, processors, and consumers in the region. About 48 million tons are produced annually in this subregion on 4 million ha. The five major yam-producing countries (Bénin, Côte d’Ivoire, Ghana, Nigeria, and Togo) account for 93% of the world’s production, with Nigeria alone accounting for 68% of global production (36 million t on 3 million ha) with 31.8% of the population depending on yam for food and income security. The crop contributes substantially to the amount of protein in the diet, ranking as the third most important source, much more than the more widely grown cassava, and even higher than some sources of animal protein. Hence, yam is important for food security and income generation with a domestic retail price of US $0.49/kg. Yam is also integral to the sociocultural life in the subregion.

In present-day Nigeria, yam is still culturally significant because it plays an important role in betrothal ceremonies or traditional marriages. It is one of the significant items a suitor presents to his in-laws to obtain their approval to marry their daughter. Some grooms are compelled to present as many as 40 pieces of long and fat yam tubers, aside from gallons of palm oil, baskets of kola nuts, bags of salt, and other sundry items, the nonprovision of which could invalidate the union. The cultural importance of yam is higher in some regions in Nigeria as it is a crop celebrated annually during the New Yam Festival, with rituals to thank the god of agriculture, to seek its blessings for a bumper harvest in the forthcoming years. Yam is produced more in the middle belt zone of Nigeria and is consumed more in the South, but those making commercial gains from its sales are core northerners from the North West, the North Central, and the North East.

Despite its importance in the economy and lives of many people, the crop faces several constraints that significantly reduce its potential to support rural development and meet consumers’ needs for improved food security and enhanced livelihood. Constraints limiting yam production and postharvest handling need to be identified to provide a basis for appropriate interventions. This was the reason behind the interventions through the Yam Improvement for Income and Food Security in West Africa (YIIFSWA) project. YIIFSWA was initiated to work with other stakeholders in West Africa to identify the opportunities of interventions that could potentially help to increase productivity in the region. This report documents production and postharvest constraints and opportunities in yam.

Using Nigeria and Ghana as cases, important worldwide yam-producing countries, a study was carried out using a multistage, random sampling procedure in selecting a total of 800 and 600 households, respectively. All surveyed households were interviewed using a structured questionnaire.

Survey results indicated that a range of factors limited yam production and storage. These include insect pests, diseases, water-logging, drought, rodents, low soil fertility, shortage of staking material, inadequate input supply and storage facility, land shortage, high cost of labor, lack of improved varieties, and others such as theft (Fig. 1).

High cost of labor stands out as the most pressing problem in all the surveyed zones, both in Nigeria and Ghana. For instance, mounding as a seedbed preparation method, is laborious, and hence expensive. But apart from mound making all yam production operations are labor intensive because they are performed with hand hoes, machetes, and digging sticks without any form of a labor-saving technology.

Another main constraint are insect pests and diseases. The unavailability and high cost of good quality disease-free seed yam had been on one hand a result of pests and diseases and on the other hand a serious hidden constraint due to the fact that farmers do not purchase seed yam. Other important constraints mentioned were the inadequate input supply that was very pronounced in Ghana, low soil fertility more reported in Nigeria, rodents and drought (Ghana), water-logging (Nigeria), lack of improved varieties more prominent in Ghana, shortage of land and staking material (Ghana), and others such as theft that were not negligible in both countries.

It is clear that there are shared priority constraints in the two countries, indicating no specificity of problems by country. The YIIFSWA research agenda needs to be informed by the constraints facing yam farmers and based on these the following interventions were identified: (i) Key investments for lowering farmers’ production cost using agricultural research (breeding, agronomy) and extension (improved agronomic and management practices; and (ii) Managing pests and diseases.

As regards opportunities, yam could be be a formidable force in the fight against poverty, hunger, and deadly diseases if research and development measures are implemented to develop and disseminate technologies that can bring the crop into central focus in national food policies. This will enable it to benefit from policy programs that can drive down production costs. Yam is a preferred food in the region; some varieties, especially yellow varieties, are sources of betacarotene. The crop is produced mostly for sale, and it is increasingly becoming a major source of foreign exchange in the region as an export crop.

Therefore, YIIFSWA, through its initiatives, should ensure that all constraints are turned into opportunities for all the yam value chain players in general and farmers in particular.