GEOGRAPHIC RELEVANCE

Food crops are produced in greenhouses over a surprisingly wide geo graphical range. The commercial industry, however, has been concentrated in the developed nations, principally in Europe. Within these areas, production has typically been located in the colder temperate regions. Some greenhouses are found in developing nations, generally those with a temperate, Mediter ranean, or arid climate. Only a few commercial operations are located in trop ical or semitropical regions.

While this report, therefore, might at first seem to be of principal concern to the developed nations, there are reasons why it might be of interest to a wider range of countries:

— Greenhouses are, or are becoming, important commercial realities in several developing nations: Greece, Turkey, Lebanon, Kuwait, Abu Dhabi, Mainland China, and South Korea.

— Developing nations exporting winter produce, or planning to do so, to North America or Europe will be competing with greenhouse crops. Regions presently in this category include North Africa, Central America (including Mexico), the West Indies, and the northern part of South America. Some North African countries, moreover, make use of simple forms of environmental con trol to reach an early market.

— In some tropical regions with very heavy rainfall, simple greenhouses or plastic covers may provide a way of producing tender and high value crops during the wet season. This practice has been utilized to a limited extent in the Philippines.

— If desalinized water is ever to be used for irrigation, it may be necessary to use greenhouses to reduce moisture loss. This is already the case in Kuwait and Abu Dhabi on the Persian Gulf.

— Some of the environmental control concepts or techniques utilized in greenhouses may ultimately have some applicability to field culture.

— At the very least, interested developing countries should be aware of the forms and merits of environmental control before investing scarce capital.

Socially, intensive food production under controlled environmental condi tions will probably never be a direct way of providing inexpensive food to low income groups in developed or developing nations. But it could have desirable economic benefits by serving as a source of import substitution, export expan sion, increased farm income, and expanded employment. It is hoped that this report will help suggest where these goals are possible and will contribute to their more efficient realization.

REFERENCES AND NOTES

1. J. J. Ochse, et al., Tropical and Subtropical Agriculture, Macmillan, New York, Vol. 1, 1961, p. 2.

2. A comprehensive review of traditional practices is provided by Gene C. Wilken in "Microclimate Management by Traditional Farmers," Geographic Review, October 1972,

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