1.3.4 Marketing Strategy
Tropical roots and tubers produced for off-farm markets can vary considerably in their transportation, storage facilities, processing techniques, consumption patterns, economics, etc. These differences need to be taken into account when various opportunities are assessed for improving trade. In fact, some individual root and tuber crops are presently experiencing a segmentation of markets that will undoubtedly require substantially different types of cultivars to meet divergent market needs (www.fao.org).
The true potential of tropical roots and tubers may be unlocked through various value-adding activities. Their processing level needs to be divided into two levels, the primary level and the secondary level. Therefore, various facilities need to be provided at each level to enhance their potential. Processing of tropical roots and tubers into different products will enhance options to the consumers. This diversity may create a large market space within which food processors can make long-term development plans supported by various growth prospects for investments in the processing of tropical roots and tubers.
1.3.5 The Properties of the Product and Constituents
The selection of raw material and products is mainly dependent on the physicochemical, microbiological and sensory properties of the product itself and its constituents. For example, in the case of snacks (chips), the level of carbohydrate (reducing sugars) is regulated in the product, therefore monitoring the level of this parameter becomes very important for industry along with the other physico-chemical and sensory parameters of that product. Recently, there has been a great deal of research into the area of characterization of tropical roots and tubers. However, the methods required to evaluate the quality characteristics and the product potential are to be identified for different roots and tubers. The relevant characteristics of tropical roots and tubers based upon their optical, physicochemical and mechanical properties need to be recorded in the field to ascertain their quality. In addition, the required processing technologies and the properties of the products thereof need also to be established and disseminated globally for roots and tubers. This information gap represents a whole new area of research that needs to be addressed if post-harvest technology of tropical root and tuber crops is to become a reality.
1.4 World Production and Consumption
Roots and tubers can be grown under diverse environmental conditions and in different forms of farming systems. The choice of food by rural consumers is generally determined by the agricultural production in their area, whereas the choice of urban consumers, who have developed a preference for more convenience foods, is partly determined by the availability and convenience of low-cost imports and most significantly by their improved purchasing power (Aidoo, 2009).
In South America and the Caribbean, overall per capita consumption of roots and tubers has declined by 2.5 % per annum since 1970, while a growth of 1 % is recorded in consumption of cereals (FAO, 1987). This reflects the lower preference of urban populations in towns and cities towards the consumption of roots and tubers. The major tropical roots and tubers are cassava (Manihot esculenta), sweet potato (Ipo-moea batatas L.), yam (Dioscorea spp.), edible aroids (Colocasia esculenta and Xan-thosoma sagittifolium) and elephant foot yam (Amorphophallus paeoniifolius). These are widely cultivated and consumed in many parts of Latin America, Africa, the Pacific Islands and Asia.
It is estimated that more than 600 million people depend on cassava in Africa, Asia and Latin America (www.fao.org). Global output is forecast to reach new records in the near future, driven by population expansion in Africa and Asia. World cassava output in 2013 showed the expected marginal increase from 2012 and is expected to continue to show an approximate 7 % annual rise in succession. The expansion is possibly being fuelled by the rising demand for food and increasing industrial applications of cassava, especially for producing ethanol and starch.
Cassava remains a strategic crop in Africa, for both food security and poverty alleviation (Howeler, 2008). The world cassava areas, yield and production from 1995–2011 is presented in Table 1.3. Cassava production increased from 162.48 million tons in 1995 to 252.20 million tons in 2011, whereas an increase in area from 16.46 million ha in 1995 to 19.64 million ha in 2011 has been observed. The world average cassava yield, 9.87 ton/ha in 1995 increased to 12.84 ton/ha in 2011 (Table 1.3).
Table 1.3 World cassava areas, yield and production from 1995-2011
Year | Areas (million ha) | Yield(ton/ha) | Production (million tons)
1995 | 16.46 | 9.87 | 162.48
2000 | 17.00 | 10.38 | 176.53
2005 | 18.42 | 11.18 | 205.89
2006 | 18.56 | 12.06 | 223.85
2007 | 18.42 | 12.28 | 226.30
2008 | 18.39 | 12.62 | 232.14
2009 | 18.76 | 12.51 | 234.55
2010 | 18.46 | 12.43 | 229.54
2011 | 19.64 | 12.84 | 252.20
Source: FAO (2013)
The world leading producers for different tropical roots and tubers in 2012 are given in Table 1.4. Nigeria is the top producer for cassava, yam and taro, whereas China is the top producer for sweet potato (Table 1.4).
Sweet potato is considered a solution for the emergent challenges being faced by the developing world, such as climate change, disease, migration and civil disorder (Beddington, 2009). Yams are ranked as the fourth major crop in the world after cassava, potatoes and sweet potatoes (Adeleke and Odedeji, 2010). Yams are recognized by their high moisture content, which makes them more susceptible to microbial attack and brings out their high perishability, with an annual production of more than 28 million metric tonnes (FOS, 2011). Production of yams in Africa is largely concentrated in the area popularly known as the “yam zone”, comprised of areas such as Cameroon, Nigeria, Benin, Togo, Ghana and Cote d’Ivoire, where approximately 90 % of the world’s production takes place (Hamon et al, 2001). Ghana is the leading exporter of yam, accounting for over 94 % of total yam exports in West Africa. Total yam production in Ghana has increased from 877 000 to 5 960490 tonnes from 1990 to 2010, mainly due to efforts by smallholder farmers. However, the highest yam production in 2012 was reported in Nigeria (38 000 000 MT), followed by Ghana (6 638 867 MT) (Table 1.4).
Taro is currently grown in nearly every tropical region of the world. Taro has been a staple crop for the inhabitants of the Pacific Islands for many years and is considered an integral part of the farming systems and diet of many people living in the Pacific Islands. Nigeria stands on top, with a production of 3 450 000 MT for taro in the year 2012 (Table 1.4).
Table 1.4 World leading tropical roots and tubers producers in 2012
Cassava
S. no | Country | Production (MT)
1 | Nigeria | 54 000 000
2 | Indonesia | 24177 372
3 | Thailand | 29 848 000