SOME TYPES OF PLASTIC GREENHOUSES USED IN VARIOUS PARTS OF THE NORTHERN HEMISPHERE

For this brief presentation I have chosen transparencies of plastic greenhouses from eleven different countries to illustrate the remarkable variety of crop protecting structures which have been or are being used in different parts of the world. The greenhouse supports can be made of timber, bambo, metal, wire, synthetic netting, fibre glass, concrete or a combination of two or more of any of these materials. There is also of course a wide variety of translucent plastic materials for covering greenhouses ranging from flexible sheeting like polythene film to rigid P.V.C. and glass fibre reinforced plastic materials.

A slide lecture of this kind cannot pretend to show the most satisfactory or most advanced types of plastic greenhouses in use in any country. Any individual horticulturist will have his own ideas on this subject which will be related to the constructional materials at his disposal, the type and value of the crop grown and local climatic factors.

There is still a tendency, in the United Kingdom at any rate, to regard plastics as alternatives to glass - the traditional material for crop protection, and to construct plastic greenhouses to conventional glasshouse design. By so doing we are not taking full advantage of the unique properties of the new plastic materials.

The slides I now wish to show you are offered in alphabetical order of the countries in which they were taken, for the simple reason that I am unable to find a more logical sequence of presentation.

( Follows the presentation of slides taken in Bulgaria, Canada, Canary Islands, France, Greece, Italy, Japan, Norway, U.S.S.R., United Kingdom and U.S.A.)