PREFACE

The idea of a joint syposium was initiated by the Commission for Horticultural Engineering and approved by the Commission for Protected Cultivation, Commission for Horticultural Economicies, Section for Ornamentals and Section for Vegetables. The technical part of the symposium was well prepared by a working Party in Karlsruhe, Germany, in September 1976, organized by professor Christian von Zabeltitz.

The call for papers was made under the following headings:

1. Localization of the production in relation to energy,
2. Tecnical and physical aspects,
3. Production programs adjusted to high energy costs and technical development,
4. Biological, economical and technical aspects of realized programs,
5. Protected cultivation in the future.

The call resulted in as many as 63 papers which reflected the great interest for this symposium.

Invited papers were presented by dr H. Z. Enoch, dr G. H. Germing, professor H. Storck and professor J. N. Walker. The participants were much obliged for the thorough and intelligent intruduction they offered and for the great many details which were penetrated.

More than 125 scientists representing 22 countries attended the scientific meetings. Summaries of all the papers were at hand at the opening of the symposium. This was valuable since parallel sessions had to be arranged, but for the invited lectures. After each session discussions in groups of 5–6 persons took place. In this way more time could be devoted to interdisiplinary, fruitful discussions. Each group presented the main conclussions from the group study in plenary meetings. The closing session with panel discussion of the protected cultivation in the future was very stimulating and promissing. Hotel Sparta in Lund seemed to be well suited for this layout of a symposium.

The protected cultivation has been very badly hit by the energy crises. Unfortunately the glasshouses as they have been designed are thermally rather inefficient. As long as the oil was cheap, this was not crucial for the commercial production. Consideration of light availability formerly dominated the design. Greater attention needs, however, to be payed to energy consumption in the future.

The biological uncertainties of protected production are less than for field production, since a wide range of environmental control and growing methods are technically possible. The biological and physical research has, however, not always been balanced by a comparable effort on the economic side. It was experienced at this symposium that it might be advantageous that biologists, economists, and engineers exchange experience and ideas, to justify different research programs and try to arrive at some definite conclusions about the construction of tomorrows greenhouses and to improve and to form a long term stable basis for economy in protected cultivation.

The flow of information at this symposium seemed to justify the need for similar symposia every few years as long as we have to deal with complicated interdiciplinary problems where a great many details in different production lines ought to be analysed.

Sincere appreciation and cordial thanks are extended to all those who contributed to the success of this symposium, those who presented papers and the participating scientists. Particular thanks go to Ann-Britt Sörensen, Rolf Larsen and Bengt Landgren for careful preparation of the program.

Financial support for this symposium was given by the Swedish National Board for Technical Developments and Department of Agriculture, which is gratefully acknowledged.

Tryge Kristoffersen
Convenor

The Swedish University of
Agricultural Sciences

Alnarp, Sweden