Abstract:
Carbon dioxide is a key factor for photosynthesis and plant growth.
Without CO2 there will be no growth.
Most greenhouse plants which mainly are C3 or CAM plants, strongly respond to about 3 times higher CO2 concentration than normal CO2 concentration of about 330 μl 1-1 (vpm)2 in the atmosphere.
In tight greenhouses it is easy to maintain a higher CO2 concentration, and the overall effect of CO2 is enhanced growth rate and improved plant quality.
The interest for CO2 enrichment of greenhouse crops has passed several waves this century.
The first started more than 50 years ago.
The last one was initiated a few years ago.
The main factors for the great interest of CO2 application to greenhouse crops, especially in Scandinavia, may be:
- Increasing information about the effect of CO2 enrichment on various crops,
- More knowledgeable growers,
- Tighter greenhouses,
- Surprisingly good effects of CO2 enrichment at low light intensity,
- Reduced CO2 flux from microbiological decomposition due to less use of organic material in the greenhouses,
- Improved equipment for CO2 application and for measurement of CO2 concentration in the greenhouse atmosphere and
- The development of computerized control of the total environment in the greenhouse including CO2.
The last meeting about CO2 was held in Berlin in the middle of 1960's.
Therefore, it was in time to discuss several aspects as biological, technical and economical factors concerning CO2 enrichment.
It was decided during the 21. International Congress in Hamburg in 1982 to arrange an ISHS symposium or seminar on CO2 enrichment in Norway.
The organizing committee wants to thank ISHS for the confidence shown by giving us the task to arrange this symposium.
It is organized by the CO2 working group of the commission for protected cultivation.
The organization committee wants to thank the chairman of the CO2 working group, Ir.
Niels van Berkel, for valuable suggestions and ideas about the arrangement.
Twentythree papers and 11 posters will be presented and a whole day excursion to greenhouses and Gjennestad Horticultural School in Vestfold and an afternoon visit to the Department of Floriculture and Greenhouse Crops is included in the program.
I'm sure the symposium will initiate more research and development work which can lead to progress for the greenhouse crop production.
It is also a great interest for CO2 by companies and organizations, and their financial support is highly appreciated.
Roar Moe
KEYNOTE ADDRESS
Norwegian Horticulture
Geographically large areas in Norway are so far north that horticulture would not normally be possible.
Regions equally far north in Canada, the United States/Alaska and Russia are almost entirely barren.
However, Norway has the life-giving Gulf Stream, whose warm waters wash along our coast so that plants can grow and be cultivated much farther north than in any other country.
Thanks to the mild climate resulting from the Gulf Stream, coastal areas in southern and south-western parts of Norway have almost the same temperatures as in Holland and Denmark, in spite of being so much farther north.
Consequently most of Norway's horticultural activities are concentrated in these southern regions.
A particularly typical feature is that tomatoes sufficient to meet the needs of the entire country are grown in greenhouses in Rogaland.
Fruit growing takes place mostly along the deep fjord in south-western Norway, where the mild sea climate penetrates far inland between mountains 1000 meters high.
These regions are heated by the sun so that land along e.g. the Hardanger and Bogne fjords has a "greenhouse climate" providing good conditions for growing fruit.
A large amount of fruit is also grown in the south-eastern region, as here in Lier, where the relatively low hills ensure a satisfactory climate.
I have mentioned that most of the greenhouses for tomatoes are situated in Rogaland in the south-western part of the country.
However, the region where we now is also an important centre for greenhouse vegetables, cucumbers and salad crops mostly being grown here.
Greenhouse floriculture takes place mostly in the areas along the deep Oslo fjord, with Oslo, the capital, as a large and naturals market.
Otherwise growers are spread all over the country and many of the nurseries are designed to meet the demand in their local market.
The most northerly nursery in Norway - and in the world - is in Alta.
Norway's southernmost nursery is in Lista and a distance of almost 3000 kilometers separated the two.
This distance describes in a nut-shell the length of our country.
To illustrate this by an example more familiar to those of your who come from central Europe, this is the same as the distance from Hamburg to Sicily in Italy.
Perhaps this gives you an impression of the transport and communication problems we have to deal with.
A glance at the map will tell you that apart from the long distances, the country is divided up by long, deep fjords and mountain ranges.
Travelling westward or northward from Oslo, the roads cross mountains 1000 meters high.
It goes without saying that this makes all transport problematic and expensive, particularly in winter when it is not uncommon to have snow 1 – 2 meters deep and temperatures down to minus 20 – 30 degrees Celcius.
This makes it even more difficult and expensive to distribute horticultural products that are unable to withstand frost or long periods in transport.
Area and value
Measured by European standards Norwegian horticulture covers a small area and the value it represents is low.
Norway has only 4 million inhabitants and it has been our policy to be selfsupporting to the greatest possible extent.
Our activities are not designed to grow for export and only occasional exports take place.
Young flower plants are an exception in this respect, as owing to professional skill and our climate these are regularly exported to the other Nordic countries every year.
We have about 900 floriculture nurseries that annually grow roughly 25 million potted plants.
Potted plants are absolutely the most important branch of floriculture.
Flowers for cutting are grown on about 400.000 m2 of land, roses and carnations being the most important.
Thanks to the fact that imports are controlled in Norway, we have been able to maintain better conditions for carnation growers than other European countries.
In 1980 floriculture represented a value of 651 million kroner.
We have been able to ascertain that sales of cut flowers, potted plants and young plants for planting out, are increasing steadily.
In spite of the stagnating economy, we have not noticed any stagnation or decline in flower sales.
However, like the rest of Europe we have noticed a change in the composition of the demand, for example the demand for bulbs is declining, while the demand for roses, dianthus, gerbers and other cut flowers has increased.
We also have "top of the pops" in potted plants too, and in recent years these have been the African Violet and Elatior Begonia.
Greenhouse vegetables are grown at about 650 nurseries, concentrating mainly on tomatoes and cucumbers.
Salad crops such as the different types of lettuce, cucumbers, chinese cabbage etc. have made great progress in recent years.
Greenhouse vegetables were calculated to represent a value of 108 million kroner in 1980.
In the past few years tomato growing has been in the grips of a financial crisis, since oil prices increased so greatly and it was impossible to recoup these expenses through higher prices.
However, this is a common problem throughout Europe, not only in Norway.
Outdoor cultivation of vegetables takes place all over the country, but mostly in the more southerly regions.
Early vegetables are extensively grown along our southern coasts.
An area of about 4800 hectares is used for outdoor vegetable growing, and these vegetables represented a value of 294 million kroner in 1980.
Berries too are grown all over the country from north to south.
Naturally enough strawberries are the most important.
The greater part of the berries are grown for the fresh fruit market, but we also have a well-established system so that berries for jam-factories etc. can be delivered to freezing plant.
Norwegian berry production is sufficient to meet national demand for fresh berries and for the jam industry.
Only occasional imports are necessary.
Plant-breeding nurseries satisfy a very special need in Norway.
As a result of our particular climate, with very long, light summer days and extremely low winter temperatures, we have very great need of special types of trees and bushes.
Norwegian nursery output covers about 75% of the demand, the remainder is imported.
Many of the imported species and types are unsuitable for the Norwegian climate, often causing the buyers disappointment.
With the help of grants-in-aid, work is being done to develop plants suitable for our special climate.
Import protection
As I have already mentioned several times, the climate in Norway differs from that in any other part of the world and topographical conditions are difficult in our country.
Therefore there is little cultivable land, farms are small and often the fields are on steep slopes.
The official policy in Norway is that it shall be possible for people to live anywhere in the country.
To facilitate this, conditions must be made suitable for agricultural production, including horticulture.
It is undeniable that owing to our climate it costs more to grow vegetables, fruit, berries, flowers and other agricultural products in Norway than in any other European country.
If domestic agricultural production is to be maintained, we must have protection against imports that depress prices.
Norway has this protection in the form of an agreement with the EEC countries.
As you will know, Norway is not a member of the Community, but agreements have been concluded.
The agricultural agreement with the EEC gives Norwegian producers protection against price-depressing and damaging imports in parts of the year when it is natural that the demand for products is met by Norwegian producers.
By this agreement Norway and the EEC have acknowledged the fact that growing agricultural products costs more and is more difficult in Norway than in the EEC countries.
In other words, the prices of most of our agricultural products are higher than any found elsewhere in Europe.
Agricultural wage agreement
Norwegian agriculture holds a position that is unique in Europe, as our parliament has decreed that those engaged in agriculture shall be ensured an income equivalent to earnings in industry.
In recent years this has led to relative prosperity among the agricultural population, compared with other countries.
A further result is that working on the land and producing vegetables, fruit, flowers and ordinary agricultural products is no longer regarded as a low status occupation.
On the other hand the system has also had the effect of making agricultural products more expensive in Norway than in other countries.
Earnings are ensured through the agricultural agreement, but another effect is that natural formation of prices no longer exists for products other than flowers and breeding nursery products.
This is because under the system, if the prices of vegetables exceed an agreed limit and there is a shortage of products on the market, unrestricted imports are allowed.
The agreement also provides other benefits for agricultural workers, such as a holiday scheme.
It also includes schemes for promoting agriculture.
For example, a sum of 20 million kroner has been made available for 1982 for energy-saving measures for greenhouses.
Other schemes have also been taken up through the agricultural agreement, such as funds for building common warehouses for vegetables, fruit and flowers in order to regulate the market.
By degrees the agricultural wage agreement has become extremely comprehensive and important for Norwegian agricultural production.
The future
In Norway today there is a very good balance between production and consumption of horticultural products.
The country's own production of grain is too small and for milk products it is a little too high, but this is not really a serious problem.
Norway will continue to follow its own agricultural and import policies in the coming years.
At present it is entirely unthinkable that Norway should enter the EEC and join the free market there.
Agricultural structure and development, as well as imports, will be determined by Norway itself in the future too, in the same was as at present.
Countries with a high output in Europe will still not be able to market their surplus products in Norway for the first few decades at least.
Terje Askvig
Chairman of the Norwegian Professional
Horticultural Organization
|