OPENING ADDRESS

As President of the Commission for Protected Cultivation of the International Society for Horticultural Science, I have the honor and the great pleasure to open this symposium concerning the Protected cultivation of flowers and vegetables. However I must say that I feel a little as if I were robbing my predecessor, Professor Lecrenier of this privilege, for it was during his presidency that the idea for this symposium was born and took form. Therefore I wish to express the appreciation of all of us present here to Professor Lecrenier for making it possible for us to meet here today.

Also let us not forget his many years of productive efforts as president of this commission. We pay him hommage for his professional competence, his magnificent leadership and his unfailing good judgement.

What better occasion could we choose to deal with problems concerning the protected cultivation of flowers and vegetables than the 75th anniversary of the founding of the research stations at Aalsmeer and Naaldwijk? The fact that those two stations are well known throughout the world shows the high quality and great importance of the work being done there.

Mr. Stadhouders, Inspector of Horticulture of the Ministry of Agriculture and Fisheries, has kindly agreed to address us. He will trace historically the research which has been done at those two stations. I express now my heartfelt appreciation for his coming and talking to us today. What he shall tell us will make our later visits to Aalsmeer and Naaldwijk more meaningful.

We also thank Messrs. van Doesburg and Kooistra for opening their doors to us and I wish to express our sincere appreciation for the work of all those who have been involved in the preparation of our visits.

The organisation and preparation of a symposium such as this one is indeed a heavy responsability and a difficult task and it is Dr. van Koot who has carried the burden with his usual efficiency, sound judgement and dedication. I know that I express the deep gratitude of all present for his valuable contribution to the success of this endeavour. We also thank Dr. de Bakker, Secretary General of the International Society for Horticultural Science and his associates for their valuable assistance.

Dear friends of Holland, we must take this opportunity to express our admiration for the high standards of professional competence that you have achieved in your country. Although everyone knows this, we cannot say it too often. Further we must acknowledge the excellent day to day close cooperation between your scientists and growers which has resulted in perfect confidence and mutual understanding. The scientist working in his laboratory and the grower in his hothouse are constantly stimulated to greater efficiency and production. This has contributed to your admirable progress in horticulture. Thus working together your scientists and growers have acquired an enviable international reputation.

This fact should be emphasized. Enduring benefits cannot be had without our continuing cooperation afterwards.

This is the most important point for me to make now.

Whishing for complete success of this symposium and for our continuing productive cooperation after we have finished here, I hereby declare this symposium on the Protected Cultivation of Flowers and Vegetables open.

Mme D. Blanc
President of the Commision
for Protected Cultivation
Antibes - France


INTRODUCTORY ADDRESS - 75 YEARS RESEARCH OF PROTECTED CULTIVATION

Mr.Chairman, Ladies and gentlemen,

It gives me great pleasure that I have got the opportunity to speak a few words to you at the beginning of this Symposium and to welcome you here in this country on behalf of the Ministry of Agriculture and Fisheries in The Hague. We appreciate it that the International Society for Horticultural Science has organized this Symposium in the Netherlands to commemorate the 75th anniversary of the Research Station for Floriculture at Aalsmeer, and also the 75th anniversary of the Research Station for Fruit and Vegetable Growing under Glass at Naaldwijk.

Seventy-five is quite a respectable age for a research station, though age itself is not a merit to be proud of.

The merit of these two research institutes, however, consists of their work for the development of horticulture and especially the initiatives and the dash they have been dealing with the present-day problems.

We can say that both research stations have played a role of importance in the many changes which have been introduced in Dutch horticulture during this century. Many new developments - successfully used in practice - were originally introduced by these research stations. They have solved the practical problems by invention and good research and knew how to utilize the new possibilities, created by technique and science, and how to use these for horticulture under glass.

I express the wish and confidence that both research stations will proceed in this way and that they will complete the first century of their existence successfully.

The title of my lecture suggests that I shall primarily give a historical survey. But besides, I prefer to talk about our topical needs and requirements in present-day horticulture.

The cultivation of horticulture crops has a history of ages. This history tells us that, again and again, man has been captivated by what nature has bestowed upon him and by the possibilities to make this nature servicable upon him.

Man became more familiar with the qualities of the plants (crops) and learned how to get the growing process better under control. Horticultural crops, however, have for centuries, only been grown in the open and the climate of some areas offers greater possibilities than others.

With the introduction of glasshouse cultivation, the possibilities to grow horticultural crops in areas with a moderate climate considerably enlarged, both where the crops and the growing periods are concerned.

It was Frederic the Great who, on his estate "Sans Souci", in 1782, first built glasshouses against walls. These glasshouses had quite another function than the orangeries used centuries before. However it would take nearly another century, before horticulture under glass would become of importance for commercial purposes.

From the second part of the previous century, horticulture under glass has developed regularly and continuously. It originally and especially developed in Western Europe where - with the climatic conditions in that part of the world - the need to grow protected crops was greatest and the demand for horticultural products continously increased.

Horticulture under glass greatly developed in the years after the Second World War, not only in places where horticulture under glass had been customary for many years, but also in those countries and areas where horticulture under glass had previously still been unknown.

During the last ten years, this great development of horticulture under glass has even been exceeded by that of cultivation under plastic foil.

Thanks to the application of plastic foil and adapted building techniques, an enormous area under protected crops has developed, especially in the Mediterranean area. This area is still being enlarged because experiences have taught that the cultivation of protected crops has great advantages.

These advantages are:

1. greater crop security
2. higher yields per ha
3. better quality of the products

In spite of these evident advantages there are also problems. Besides the economic problems which are the result of the high investments needed for the protected cultivations, there are problems connected with the greatly altered growing method. Many of these difficulties are due to lack of experience with this growing method. which, in fact, may greatly differ from the traditional growing method.

The great change in environmental factors, for instance, may have unexpected consequences and cause plant diseases.

With more experience we shall certainly learn how to solve some of these problems. Many, however, should be solved by research.

In view of the new developments to be expected, we shall continously be confronted with new questions. The development of protected horticulture can only permanently be maintained on places where a good and well directed research apparatus will continue to give sufficient support. This has, both now and in the future, become all the more essential, as protected cultivation is being confronted with the consequences of a number of economic and social developments which are clearly the bottlenecks for this intensive branch of horticulture.

Ir.Jacobs will go further into this in his lecture.

Priorities in research

I shall now briefly elucidate a few research problems and fields of research to which, I think, high priority should be given, because this is necessary from the social-economic and from the research point of view.

Climactic research and glasshouse culture

An important point is, that in principle, the environmental factors of protected cultivation can be far better influenced than those of outdoor-grown crops. It is therefore obvious that these advantages should be used as optimally as possible. The most important of these environmental factors are: the soil and air temperature, the quantity of light, the air humidity, the air circulation in the glasshouse, and the CO₂ concentration.

It will first of all be necessary to study the glasshouse climate to know more about the way in which certain environmental factors influence each other and in what way the glasshouses climate is influenced by the outer climate.

Secondly, we should gradually get more insight into the environment needed for the different crops in the successive stages of their development so as to come to optimal yields both where physical yields and quality are concerned. Though this means a complicated long-term research, the research in this field is already beginning to bear fruits.

This integrating ecological research will have to be supported by more specialized physiological research in the field of photosynthesis, evaporation, plant nutrition etc. for which well-equipped phytotrons are almost indispensable.

In the third place I should like to mention the technical research (engineering). This research has to supply the measuring and registration apparatus, and also the regulating apparatus to regulate (on the basis of what has been measured) the glasshouse climate as well as possible. Important provisions are now being made in the Netherlands - also at the research stations at Naaldwijk and Aalsmeer - for climate research in glasshouses.

Besides, a few working groups have been formed in which the research workers of these research stations, together with research workers of some institutes at Wageningen, cooperate to coordinate all the research on the optimalization of the glasshouse climate (so the research in the field of ecology, physiology, climate and technique) as well as possible.

Energy-saving research

The great rise in fuel prices has made it necessary for research workers to pay far more attention to the saving of energy and to more efficient use of it. Besides technical adaptations, which, to some extent, can be made in heating installations and glasshouse constructions, attention will also have to be paid to those changes in cultivation which give a saving of energy. The climate research which I have mentioned just now, can in this respect be of great importance. Energy supply in glasshouses is primarily used to maintain the right room temperature and also to reduce the air humidity and to promote evaporation. By studying the influence of the environmental factors, - especially that of day and night temperature - upon the production level, we can investigate how high the energy supply should be for the economic optimum in the production. The quality aspects will, of course, also closely have to be considered.

Another aspect to which attention should be given in energy research is a separation of air and soil heating.

Bringing a sufficiently high soil temperature on the desired level and maintaining this level by heating the air in the glasshouse, will sometimes lead to waste of energy.

I would further mention the measures to decrease heat emission, such as the isolation of gutters and glasshouse rods and making plastic screens in the glasshouse which can be closed. The latter, however, will again influence the climate in the glasshouse.

Finally I want to draw your attention to the research into the cultivation in substrates in containers. This may give a better regulation of soil and root temperature. The plant spaces in the glasshouse can gradually be adapted, and owing to this, the heated glasshouse can be utilized more economically.

Quality improvement and product renewal

The products of protected cultivation are generally sold in prosperous countries where the consumers are very exacting. Much attention will therefore have to be paid to new or better products which encourage and stimulate the demand. The introduction of new crops can stimulate the demand for our products.

Especially in floriculture we know many striking examples of this, from the latest period, though also in vegetable growing there are examples of products which, until recently, have only been of little importance but are now finding a good market, such as paprika (pepper) and aubergine (eggplant).

Both, plant breeding and ecological research should contribute to the production of these new crops in an economically justified way, and should shift the supply period of the products to periods in which these products are relatively scarce and are in great demand.

The introduction of new products has another advantage, namely, that it somewhat relieves the supply of the main products, such as tomatoes, and cucumbers, for which the market is now saturated. Plant breeding and critical research of the useful value of the new varieties, will remain one of the main conditions for the improvement of the quality of our horticultural products.

I think that, both within a short and a long period, high priority should be given to this research. Other diciplines, too, contribute to this great urgency of research, such as ecological and plant physiological research, fertilization research and the climate research already referred to.

An important criterium for quality is the durability of our products. These products should reach the consumer in the freshest possible state and the buyer of flowers must be able to enjoy them for quite a long time.

Research in its different aspects will have to pay much attention to the question what varieties and what growing methods will influence the durability of the protected crops favourably. In addition to this, the technological research in the post-harvest phase, such as research into cooling, atmospheric conditions and packing, - will have to supply the right data so as to maintain the quality of the products during the marketing phase as optimally as possible.

Reduction of the cost of labour

Apart from the cost of energy, which we have already discussed, the cost of labour is by far the main factor in protected cultivation. The higher social level for everyone, which is the object of most countries, is also confronting horticulture with higher costs of labour. And this is even intensified by the continuously strong inflation. The introduction of mechanization and automation to save labour, is therefore a matter of the highest priority. It is often a question of technical problems, but horticulture - and especially horticultural research - will have to carry the bricks upon which engineering can build. Besides, the varieties and growing methods will in many cases have to be adapted to the possibilities of mechanization.

Apart from the technical research in the field of mechanization and automation, we must also mention the research into labour organization and working methods.

It has been found that this research can produce interesting results, both to alleviate certain activities and to improve labour efficiency.

Public health and environment

Society and the consumers of our products are becoming more and more aware of the environment and become more and more critical towards the use of chemicals. The horticultural industry will also have to adapt itself to reasonable desires and requirements. The problems mainly concentrate on the application of pesticides, and, to a less extent, to the use of fertilizers.

Stringent condition for the application of chemicals and severe conditions concerning residues in and on the products are applicable nearly everywhere and we expect that these conditions will be tightened even further.

This means that the traditional possibilities of disease control will be restricted. The chemical industry, however, is very active in finding pesticides which little or hardly harm the environment, though we cannot expect that the problems in this field can ever be fully solved.

Resistance breeding (breeding for resistance against plant diseases) and research into a more elaborate application of biological control methods, will have to be the answer of horticultural research to this. After the fine results, already achieved with resistance breeding against different fungi, the research was also started into the resistance improvement against certain insects and the red spider mite. Besides, the biological control of the red spider and the white fly gives hopeful prospects.

These are only some of the many problems with which horticultural research is being confronted nowadays. The growing need of horticultural research in the different countries has now to face the economically difficult situation in which many countries are now involved. On some places, horticultural research must even be stabilized or restricted.

This is all the more regrettable now that the progress in technique and science create the possibilities to carry out research ever better and ever more quickly, though high costs of investments are sometimes involved.

It is to be hoped that these restrictions will only be temporary. The restrictions imposed upon horticultural research in many countries compel us to think critically of the priorities given to different research projects.

The economic prospects which we expect from the solution of a problem are dicisive for this and also the possibility that the relative problem can be solved by research.

Such an evaluation of research projects is difficult, however.

I think it of importance that the horticultural industry in question should also be engaged when we have to make a more justified choice. In this way, we create the possibility for others to have a "say"in the matter while we are also helped with the choice to be made.

This consultation will create a better contact with the industry and, in some cases it will be possible to receive financial assistance.

In spite of trial and error, we still see a growing cooperation between many countries in the field of economy and culture. It is positively of great importance that we investigate whether we can come to a greater cooperation in horticultural research (and certainly in a more limited field as that of protected cultivation).

We would help each other considerably already if we could exchange our scientific knowledge, methods and publications. We are also doing this at meetings, such as this Symposium, where we exchange our experiences with colleagues from other countries.

But a cooperation, also involving a certain task division for complicated and long-term projects, would even be more useful.

Researches on how to save energy and how to make a more efficient use of energy, may perhaps be a suitable project.

Ladies and gentlemen, I will end my speech by wishing you a fruitful Symposium. I hope that, apart from this Symposium, you will also have the opportunity of seeing something of Dutch horticulture and that you will get a fine impression of Holland in "spring-array".

I wish you a pleasant stay in this country.

Ir.P.J. Stadhouders
Inspector of Horticulture
Ministry of Agriculture and Fisheries
The Hague, Netherlands