Structural change in the international horticultural industry: Some implications for plant health

The horticultural sector has seen much structural change both nationally and internationally over the last decades, but the implications for plant health have been neglected. We review in the context of the risk of emerging plant diseases recent developments including the movement towards a global horticultural market, the rise of the horticultural industry of many developing countries, and the economic integration of the European Union. North America is typically well ahead of other regions in economic developments, and in horticulture this is shown for example by the growing importance of Mexican growers. Asia is rapidly catching up also in horticulture, with China and India becoming key producers. Australia and New Zealand show the impact of change in horticulture extension services. The Eastern enlargement of the EU is having profound influences on fruit and vegetable growers both in the new and in the old member countries. Similar developments are taking place in South America and Africa. In all continents, there is a general trend towards fewer and larger horticultural growers, an increasing role of supermarkets and a concentration of the retail pathways. These developments have consequences for the control of plant pathogens and invasive species. Technical issues seem to be of lesser consequence in terms of structural change compared with labour and trade aspects. However, examples can be found where technical innovations have opened up new opportunities or provided solutions to pressing problems, as can be seen in the hardy nursery stock and ornamental industry in the UK. Future technical, economic and social impacts on the sector are likely to play a key role for securing a diverse and reliable food supply for the still expanding world's population. Recent advances in modelling disease spread in complex networks representing trade pathways should be used to target control of introductions of new plant pathogens. There is a need for more long-term research on how structural change in the horticultural sector will affect and be affected by climate change.