Chief Plant Protection Service and Senior Plant Pathologist, FAO, Rome, Italy

World food production has over the last 40 years grown faster then the population. In 1961 the average per caput food supply was 2290 ca/day (DES) while in 1988/1990 the average was 2700. The world population during that period increased from 3.1 billion to 5.2 million. Estimates put the DES for 2010 at 2900 with 3390 for developing countries and 2770 for developing countries. The number of undernourished people has decreased from 920 in 1969-1971 (35% of world population) to 840 in 1990-1992 (20%) and is estimated to decrease further to 680 (12%) in 2010. Although the overall situation is improving, in particular due to the green revolution in Asia, large localized problems remain in countries in Asia and in particular in Africa where per caput food production has declined. Overall food security is not only an issue of the ability to produce sufficient food on a world scale; the problem is also accessibility: people who need food do not have the resources to obtain such. Thus, (the problem cannot be solved through trade only, instead a major factor, in particular for developing countries, will be lout local food self-sufficiency. The world population will continue to grow and most of the growth will occur in developing countries. Growth in food production will have to continue to increase substantially in particularly in Africa, there, rates of growth will have to be realized that have not been seen before to meet the requirements of the population projected for 2030>

The green revolution has resulted in a very high increase in cereal production in Asia. Successes in other crops and in other developing countries have been less obvious. The adagium of the green revolution was to create optimal conditions for improved varieties of rice and wheat for realising the genetic potential of the crop. These conditions included large scale use of pesticides. Only later, issues on sustainability and concerns for human health and the environment have influenced the introduction and the use of IPM. Cultural control was the traditional way of disease control and still plays a major role. Technology changes in Agriculture in relation to plant pathology have nearly always relied as a first line of defence on the use of disease resistance. Advances in biotechnology may make this strategy even more widely applicable and may hold promise for crops in which there are less possibilities on making advances through traditional breeding programmes like clonal crops. In relation to fungi, the use of fungicides has continually increased since the second world war. In pesticide reduction programmes, the reduction of fungicide use (except for soil treatment) has shown to be difficult. Participatory IPM methodologies and biological control are in most cases only in an embryonic stage and their wide scale application needs very careful thinking. Very substantial yield increases could be made in clonal root and tuber and fruit crops through regulatory schemes to guarantee disease freedom of the planting material. Root and tuber crops are in particular grown and used in countries where food security is low. It is however doubtful if such countries can indeed maintain the infrastructure required for certification schemes and therefore further investment is also necessary in improving resistance to such diseases.

New introductions of plant pathogens are both a source of substantial crop losses and increased pesticide use, and an impediment to trade. Some examples of disease with major economic impact are the "black sigatoka" of bananas and plantains in central and south America, the epidemic of citrus tristeza virus that is gradually moving through central America, citrus greening in Asia and downy mildew of maize in Africa. An example of a disease with major trade concerns is Karnal bunt of wheat. The new international trade regime makes it likely that countries will have to invest more in proving disease freedom of their export products.

In conclusion much remains to be done to safe guard food production from existing and from 'new' diseases. Important choices are to be made concerning control strategies and subsequent research and extension. This requires close interactions between researcher, extension and farmer to be able to solve problems. Unfortunately publicity funded research budgets have been decreasing substantially and innovative, problem solving, research in relation to many diseases does not exist anymore. Furthermore, for many small crops the choice of inst resort, fungicides are both too expensive to register and too expensive for resource-poor farmers. In the longer term, the inability to make strategic choices and built research programmes around these will seriously damage....