Africa is rich in both natural and human resources, yet nearly 200 million of its people are undernourished because of inadequate food supplies. Comprehensive strategies are needed across the continent to harness the power of science and technology (S&T) in ways that boost agricultural productivity, profitability, and sustainability -- ultimately ensuring that all Africans have access to enough safe and nutritious food to meet their dietary needs. This report addresses the question of how science and technology can be mobilized to make that promise a reality.
Both the quantity and the quality of food items must be addressed in resolving food insecurity. Conventional breeding and selection has increased the content of pro-vitamin A in orange-fleshed sweet potato and orange or yellow cassava. After only two cycles of selection and recombination, the concentration of beta-carotene in cassava increased from 4.2 milligrams per kilogram of fresh roots in a base population to 14 milligrams per kilogram (Graham et al., 1999). Similar techniques reduced the concentration of phytate in barley, maize, rice and wheat. Anti-nutritional factors such as phytic acid or tannins cause complexes with micronutrients, reducing their availability for human uptake in several cereals to only about 5 percent of the available micronutrients.
Germplasm improvement has also contributed to improved diets through Quality Protein Maize (QPM), containing more lysine and tryptophan, which is being disseminated in Africa, in particular in Ghana. Quality Protein Maize is used for weaning diets and in poultry and pig feed. Normal maize protein is deficient in these two essential amino acids, which can be supplemented by consuming milk, meat or beans. As the latter option is often not within the reach of poor families, Quality Protein Maize can improve the health of people and livestock. Consumer preference for relatively soft grain maize has contributed to the success of Quality Protein Maize in Ghana (CIMMYT, 2002). Quality improvement of grains with respect to specific characteristics should be balanced with the possible trade-offs in terms of yield, disease and pest resistance and consumer acceptability.
Various initiatives are underway to increase the nutritive value of food crops, including high-iron beans, high-betacarotene maize, high-iron rice, high-vitamin A or golden rice and orange-flesh sweet potato in the Biofortification Challenge Program of the cgiar (CGIAR, 2002).
Various agronomic measures can improve the nutritive value of some food crops. Application of zinc to the soil increases grain zinc content in cereal crops by a factor of two to three, depending on species and crop genotype. Application of zinc and phosphorus led to increased yield and also increased the amino acids methionine and lysine in wheat grains in Bangladesh (Graham et al.,1999).
Medicinal plants are emerging as medical aids for health maintenance all over the world. The global market for medicinal plants is expected to grow considerably in the coming decade. Europe accounts for the largest part of this market. So conservation and propagation of medicinal plants in farms and parks is required. Besides the impact on local health care and nutrition, cash crops of pharmaceutical and nutriceutical plants can have a positive impact on creation of jobs and local capacity building, such as it has happened in Brazil, Morocco and South Africa.