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.
Integrated pest management in rice cultivation was one of the first attempts to exploit the functional relations between organisms within an ecosystem. The need for integrated pest management arose because farmers in the 1960s received a package deal - improved seeds and pesticides - that encouraged them to protect their improved varieties. The need for protective measures remained high, resulting in excessive spraying of pesticides, which undermined the effectiveness of the ecological prey-predator system in the rice fields.
The emergence of integrated pest management and farmer education has led to success in reducing pesticide use, while maintaining high yields. At farmers' field schools pioneered by fao, farmers and scientists share their knowledge about the predator or pathogen, its lifecycle, its impacts etc., with the objective of improving the timely discovery of infestations and taking adequate measures. It is stressed that there is no ban on the use of biocides (environmentally friendly pesticides) under these systems. Integrated pest management now represents a means for efficient pest control and reduction of pesticide use. It is promoted by major agricultural and development institutions and was adopted by the United Nations conference on environment and development in 1992 (Agenda 21, Chapter 14, sustainable agriculture and rural development).
The upgrading and updating of such integrated pest management systems is always needed. Some preliminary examples in Africa are available, but need upscaling and continuous upgrading. The cab International Integrated Pest Management Facility, Consultative Group on International Agricultural Research (CGIAR), FAO, United Nations Development Program (UNDP), United National Environment Program (UNEP), World Bank, as well as nongovernmental organizations, many governments and other institutions in Africa have adopted integrated pest management as policy. Opportunities for integrated pest management among smallholder farmers in Africa are expanding because it is enabling resource-poor farmers to maintain and sustain high agricultural productivity. For example, the strategies to control the parasitic weed Striga are described in Box 4.9.
Suppression of weed infestation to reduce yield losses can also be achieved through agronomic measures. Consider, for example, minimum tillage, which in essence consists of planting a crop with minimal disruption of the soil (e.g., no plowing or groundbreaking). While it is primarily seen as a means of soil protection and fertility conservation, minimum tillage appears to be an effective way of controlling weeds as well because the non-disturbance prevents seed banks of weeds from being periodically incorporated into the soil. This ancient indigenous technique is thus making a comeback. No tillage is being used in at least 21 million hectares of cropping land in South America at a growing pace of 5 percent a year.