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.
The primary production of crops and animals forms the first step in the chain from the soil to the ultimate consumed product. Much of the produced food is lost in post-harvest processes. This may be one of the major loss factors for food production in Africa. Although post-harvest losses are acknowledged broadly, it is difficult to estimate the actual damage. Amleson (2004) reports losses in African countries ranging from 10 to 100 percent. The FAO (1989) estimates the post-harvest losses of food grains in the developing world at 25 percent. Fruit, vegetables and root crops are much less hardy and can quickly perish. Consequently, they are much more vulnerable to decay than grains. Even moderate decay may render them unsuitable for human consumption, or at least reduce their commercial or nutritional value. Some authorities put losses of sweet potatoes, plantain, tomatoes, bananas and citrus fruit up to, at times, 50 percent, and some crops can even be destroyed completely. Reduction in this wastage, particularly if it can economically be avoided, would be of great significance to growers and consumers alike.
Various factors, differing from region to region, from system to system and from commodity to commodity may affect post-harvest losses. Losses will be less in typical subsistence agriculture than in commercial farming. The latter requires higher standards since more handling is needed and the product must meet higher quality standards. The most important factors in post-harvest loss are harvesting and field handling, on-farm storage, packaging, transport and market handling. Major reasons for the losses are decay, especially in the case of fresh fruits and vegetables, insect and rodent damage, and fungal infection.
There is much to gain from reducing post-harvest losses. Interventions are appropriate at many different levels. Local processing may be one of the most promising interventions. Local agro-processing engineering not only restricts post-harvest losses, but also increases the economic value of harvested agricultural products. Although Africa produces numerous crops that are needed in industrialized countries, most processing does not take place in Africa. It is easy to appreciate that to alleviate poverty African countries must cease to be mere producers of bulk agricultural commodities. Rather, the agricultural products must first be processed into finished products for domestic consumption and for export. The latter movement of value adding along the production-market chain is now virtually absent in Africa and requires more knowledge, expertise and experience of other steps in the production-market chain. That knowledge and expertise is currently only available at a limited number of places. A policy oriented towards such development would promote much more food processing, food technology and non-food technological innovations in Africa.