Background to the study
Cassava was introduced into Central Africa from South America in the 16th century by the early Portuguese Explorers (Ohadike, 2007). It was probably the incapacitated slaves who introduced the cassava crop into southern Nigeria as they returned to the country from South America. Cassava however, did not gain importance in the country until the end of the nineteenth century when processing techniques were introduced as many slaves returned home (Odoemenem and Otanwa, 2011). In Nigeria, cassava is grown in all the ecological zones; the crop is planted all year round depending on the availability of moisture (Odoemenem and Otanwa, 2011).
Cassava is an important staple food in several tropical African countries, especially in Nigeria where it plays a principal role in the food economy (Agwu and Anyaeche, 2009). Cassava has the ability to grow on marginal lands, especially in drought-prone conditions and in low-fertility acid soils, where cereals and other crops do not thrive (Gobeze et al., 2005 as cited in Obayelu, et al., 2013). Cassava roots can also be stored in the ground (while still intact on the growing plant) for up to 24 months or more, so harvest may be delayed until market, processing or other conditions are favorable (International Institute for Tropical Agriculture, 2009). This comparative advantage over other staples serves to encourage its cultivation especially by resource-poor farmers. According to the Food and Agricultural Organization Statistics (FAOSTAT, 2011), Nigeria is the world’s largest producer of cassava with about 37 million metric tonnes and it ranks second after yam in extent of production among the root and tuber crops of economic value in Nigeria.