such as rotations also help to reduce losses. Diverse traditional systems enhance natural enemy abundance and generally keep pest numbers at low levels. Pest management in traditional agriculture is a built-in component in the overall crop production system rather than a separate well-defined activity (Abate et al., 2000).

Modern agriculture has brought the use of herbicides and pesticides. Nevertheless, the majority of African farmers still rely on indigenous pest management approaches, although many government extension programs encourage the use of pesticides. Today, chemicals are mostly used in crops produced in monoculture systems such as bananas, cotton, palm oil, pineapple, rubber and sugar cane and on horticultural crops. The SSA countries importing the highest volumes of pesticides are those with a large, thriving and agrochemical input-intensive export industry, particularly of fresh horticultural produce. These countries include Kenya, South Africa, Zimbabwe and Ivory Coast (Williamson, 2003).

Pesticides have also been used to some extent for combating outbreaks of migratory pests such as locusts. For ages, SSA countries have repeatedly been plagued by locusts such as the African desert locust (Schistocerca gregaria). The worst locust plagues in recent times hit the Sahel countries in 1957, 1987, 1993 and 2004. The plague of locusts in 1987 caused particularly severe losses in Mauritania, reaching
60% on pasture lands, 70% on rain-fed crops and 50% on irrigated crops (FAD, 2003). According to initial estimates, in 2004 African desert locusts in the Sahel caused the loss of 2 million tonnes of crops, equivalent to 20% of the population’s food needs.

A wide range of regulatory options exists, including outright bans or severe restrictions on chemicals. Legislation and associated regulations comprise an important component of national chemicals management. Appropriate chemicals management requires setting priorities, cooperation and a desire to anticipate and prevent problems rather than simply react to them.

In the mid-1980s, developing countries accounted for about one-fifth of global consumption of pesticides, of which SSA countries accounted for only 4%. Economic and social constraints have kept pesticide use in Africa the lowest in the world. Africa’s share has remained around 2% in recent years, with annual pesticide imports fluctuating between US$486-580 million over the period 1995-2000 and with import values estimated at US$503 million in 2000 (FAOSTAT, 2005). The use of pesticides in Africa continues to be extremely low relative to the global pesticide market. With the more recent trends of globalization and trade liberalization, especially in agriculture, the use of these chemicals may be intensified. Although most farmers cannot afford
to use chemical pesticides, those who use them often apply wrong doses and use improper procedures. In general, farmers in SSA lack basic agricultural training and this is aggravated by illiteracy that makes it impossible to read or follow complex pesticide label instructions.

Chemicals can contribute to increased food production, as they prevent losses caused by pests, fungi and herbs. Despite their contributions, most chemical pesticides may have created more problems than they solved. The kinds of chemicals used in chemical-intensive agriculture systems have exerted a heavy price, particularly to the environment

and human health. Concerns over their harmful effects are of importance due to the fact that most farmers in developing countries are generally unaware of the short- and longterm hazards associated with exposure to many pesticide products (Goldman and Tran, 2002). Pesticide misuse is a big concern in most of SSA. Most sub-Saharan African farmers and farm workers do not use adequate, if any, protective clothing or equipment and their exposure to pesticides is therefore higher than in countries with sophisticated application equipment and strict regulations on pesticides handling (Williamson, 2003). As a result, improper or indiscriminate use of pesticides is a major cause of ill health and environmental damage as well as the source of unacceptably high levels of residues on food or cash crops.

Some of the most hazardous pesticides, as determined by the World Health Organization (WHO), are widely used in SSA. Sixteen such products were documented on the market in Benin in 1999, 25 in Ghana (PAN Africa, 2000) and 45 in Senegal (PAN Africa, 1999). The European Union decided in 1999 to ban imports of Nile perch from countries bordering Lake Victoria in East Africa, after reports of gross and widespread misuse of pesticide to catch fish in the lake (EC, 1999). Many cases of poisoning, including at least 70 deaths in the 2000 cotton-growing season and 24 in the 2001 season (Ton et al., 2000) were reported in Benin. Endosulfan, an organochlorine insecticide (WHO Class II, moderately hazardous), was identified as the cause of most of these cases. Some pesticides are so persistent that they move far and wide, remaining in the environment for decades, and accumulate in fish, animals and humans causing a range of ill effects (PAN Asia and the Pacific, 1999). They may destroy natural predators of pests and disrupt natural immunity in both animals and plants.

Another danger in African countries stems from outof-date pesticide stocks, in many cases left over from past anti-locust campaigns. Countries generally stockpiled pesticides in order to better prepare for a further invasion. At the end of the 2004 locust plague, for example, Mali was still holding 75,000 liters of pesticide in reserve (Kuiseu and Thiam, 2006), fearing the arrival of further locust plagues. Over 50,000 tonnes of obsolete stocks have accumulated in African countries as well as tens of thousands of tonnes of contaminated soils according to the Africa Stockpiles Programme (ASP). This program was set up to address stockpiled pesticides and Pesticide Action Network (PAN) Africa has played an active part since it began.

Small-scale farmers represent a large proportion of the farming population. Their crop protection strategies such as burning, use of crop diversity, intercropping, use of genetically resistant crop varieties and weed control practices, have recently drawn attention (Hussey, 1990; Kirkby, 1990) and it is now understood that any new research results must fit into a traditional agroecosystem in order to be adopted
by farmers (Neuenschwander, 1993). Integrated Pest Management (IPM) involves the integrated use of a range of pest (insect, weed or disease) control strategies in a way that not only reduces pest populations to satisfactory levels but also is sustainable and nonpolluting. Organic agriculture avoids the use of synthetic fertilizers and pesticides. In Ghana IPM was adopted as a major component of agricultural policy in the early 1990s via the Ghana National IPM Program.