*figures from recently commenced trials at DIAS
**figures from economic analyses at farm level for organic producers
*** sprayed with sulphur

Reduced self-sufficiency

Owing to the heavy losses in a 0-scenario, it is believed that a pesticide ban would result in a considerable reduction of fruit and berry production in Denmark and thus to reduced self-sufficiency and increased imports of foreign products. It would probably be impossible to obtain Danish apples after Christmas owing to impaired keeping qualities. The consumers would thus increasingly have to buy foreign fruit, which is treated with more pesticides than Danish fruit (Anon., 1995). Since cultivation security would be significantly reduced, one would have to expect a reduction in new plant of cultures and fewer newcomers to the industry.

Long restructuring period for pomes

With the varieties of apple grown today, it would take a long time to restructure the acreage in question for cultivation with a minimum of pesticides. At the same time, it must be stressed that cultivation of the present varieties, which are produced with a view to storage, could not continue without use of pesticides. Without substantial premiums, most of the production of fruit for sale to consumers (apples, pears and strawberries) would be discontinued. A very reduced production of industrial fruit (sour cherries and strawberries) might be maintained if a considerable premium were achieved (Lindhard et al., 1998).

Evaluation of existing quality requirements

If production of apples and pears was to be maintained without use of pesticides, a reduction of the quality requirements might improve the possibility of selling the fruit. However, the sub-committee does not consider that the present quality requirements should be reduced very much. The consumers can be expected to choose fruit that does not have a lot of deformities and surface defects. However, this theory should be tested by means of consumer surveys before any changes are made to the present quality requirements.

If agents for controlling the pests listed in table 11.4 were available, a production of a substantial size could be maintained.

Table 11.4
The most serious pests, in order of priority. It is for these pests that fruit and berry producers could least do without control methods.

Alternative methods

Extensive research is needed to identify alternative, non-chemical control methods. However, with the present level of knowledge, it is already considered possible to achieve some reduction in the present use of pesticides. Weeds in fruit and berry cultures can be controlled without herbicides, but only at considerably greater cost. In some of the cultures there is a possibility of cultivating more resistant varieties, but a change in the assortment would in many cases – apples, for example, take 10-15 years. There are various cultural practices that can reduce disease and pest attacks, but many of them are rather costly (removing old foliage, cutting out infected shoots, etc.) and would add considerably to the cost of production.

Problems with common scab

If pomes are to be produced organically/without pesticides, it is important to get a product approved for combating scab on apples and pears overwintering on the bough. Scab has been a growing problem since 1995, when the use of agents containing copper was banned in Denmark. Organic producers in many other EU countries are allowed to use cuprous agents.

IP; production is practised today

A large part of the Danish production of apples and pears is carried out in accordance with IPM rules. The main purpose of IPM production is to promote good cultivation practice and reduce significantly the use of pesticides and fertilisers. The system has been used in Denmark since the beginning of the 1990s, and producers are inspected by the Danish Plant Directorate. A list of pesticides for IPM-production is issued each year. The pesticides listed are those that are least harmful to the environment and useful animals (IPM working group for pomes, 1997).

11.3  Greenhouse production

Generally speaking, very little is actually known about the consequences of a 0-scenario. Everything is therefore in the nature of estimates that can only give an indication of what the consequences could be.

Greenhouse vegetables

A very rapid phase-out of pesticides would result in a considerable fall in the production value of vegetables, although the fall could gradually be reduced. There is a great deal that can go wrong in vegetables, and for this and other reasons, it is estimated that there would be a greater need for replanting of cultures (cucumber, for example). However, if one gets towards late summer, it becomes impossible to achieve a new planting with a reasonable yield. There would therefore be a big spread in the yield losses, both at the individual market gardens and between years at the individual market garden. A loss of up to 50% is not unrealistic, while the average yield would probably be reduced by 5-15%. There are examples of organic production of tomatoes and cucumber, but the yield is lower. In the case of edible products it would be difficult to meet the quality standards for fruit and vegetables in the EU's market scheme, one of the requirements of which is no pests or damage from pests.

Cultivation in soil instead of a growth medium, which is practised by organic producers today, sometimes causes serious problems with fungal infections. Cultivation in soil would require greater use of disinfectants, which are no longer available on the market, and would give rise to problems with leaching of nutrients.

Pot-plants cultures

Pot-plant production covers about 400 different cultures, which makes it extremely difficult to estimate the overall consequences for all areas. For each culture there are a number of diseases and pests that can impede or damage the production. The tolerance level in greenhouse cultures is very low due partly to the current plant health rules, which include a 0-tolerance rule for certain pests, and partly to the fact that the consumers demand pot-plants of very high quality.

The fall in production of ornamental plants would be between 0 and 100%, depending on the culture and the season (Ottosen et al., 1998). The reason for this large variation is to be found in the legislation, which permits not more than 2% common pests (aphids and thrips). It might be possible to ensure this percentage in periods of the year using biological agents. It is estimated that there would be 5-10 cultures (certain bulb cultures) that would rarely have problems with these so-called dangerous common pests.

Biological control methods are an obvious option for spring cultures, but a massive invasion by thrips, for example, after the grain harvest would prevent effective biological control. This is a factor that could impair the quality of the plants and make it difficult to sell them.

Problems with 0-tolerance pests

The visual quality of ornamental plants is of great importance to their saleability. For example, compact and uniform ornamental plants, which are major quality requirements in the export market, would be difficult to achieve without the use of growth regulators. The existence of pests could also mean direct rejection of plants and make it impossible to export them. This would happen particularly in the case of pests covered by 0-tolerance rules.

11.3.2  Intermediate scenarios for greenhouse production

IPM production of greeenhouse vegetables

Vegetables: Basically, in a scenario with the partial phase-out of pesticides, it would be possible to use many of the methods used in integrated production, the rules for which include rules for vegetables (Ottosen et al., 1998). The conditions for approved integrated production of greenhouse vegetables, covering all cultures, are as follows:

	The greenhouses must be cleaned before the culture is started.
	The varieties grown must be chosen from among the varieties that are best able to resist plant diseases.
	The climatic control must meet the needs of the culture and limit the risk of plant diseases.
	Plant health must be based on biological plant protection measures and cultural practices.
	The pesticides used must be those that are least harmful to useful organisms in the biological plant protection system.

Biological control of pests

In a partial pesticide phase-out scenario, the sub-committee considers that there would be good prospects for continuing the production of vegetables. This is not least because biological methods of control are already widespread. Biological control can keep pests down in most situations, but a market garden is not static. Biological control sometimes fails due to changes in the surroundings that allow the pest to gain the upper hand. In such situations it is necessary to control the pest chemically in order to reestablish the balance between pest and useful animal.

With a partial phase-out there would also be a need for pesticides for combating disease. In market gardening that means particularly pythium in propagation plants, powdery mildew in cucumber and grey mould in tomatoes. The last-mentioned can often be dealt with by swabbing sore faces and removing leaves. Problems with diseases could probably be reduced through improved hygiene, although this would mean increased use of disinfectants, which are also in the nature of control agents even though they do not figure as plant protection agents.

The current situation in Denmark is that most vegetable production is carried out in accordance with the IPM rules. According to the industry, this, together with the fact that producers in Denmark have very few plant protection agents at their disposal compared with other EU countries, means that the present situation can already be regarded as critical with respect to maintaining the production.

Increased potential for biological control

Ornamental plants: The sub-committee considers that there is a big potential for expanding the use of biological control to ornamental plants. That means that chemical agents could in time mainly be reserved for compliance with 0-tolerance and the 2% rule for pests. However, it is estimated that growth regulators and certain fungicides would still be needed for up to 10 years to ensure stable production.

For the production of ornamental plants to be maintained it is crucial that the producers be allowed to continue using agents that enable them to meet the requirements concerning 0-pests and the quality requirements concerning maximum 2% of common pests.

11.4  Nursery cultures

Problems in connection with propagation of cultures

It is estimated that, in a 0-scenario, large parts of the production would be closed down because the cultures would be ruined or become so expensive that they would be unable to compete with other countries’ products. The experts’ cautious estimate indicates that 30-50% of the production would stop because of competition problems and problems in supplying plants without pests (Brander et al., 1998). Nursery cultures are extremely sensitive in the propagation phase, whether propagated from seed or from cutting. For this reason, there is today only a very limited organic production of nursery cultures.

The sub-committee considers that, where insecticides and fungicides are concerned, the 0-scenario would have a devastating effect on the production of many cultures. Particular problems are predicted for fruit trees and ornamental trees, fruit bushes, roses and many other ornamental plants if alternative methods are not available.

In the case of herbicides, a 0-scenario here and now would have a ruinous effect on production, particularly in the propagation phase, because the additional cost of mechanical control, including manual weeding, would make it difficult for Danish producers to compete with foreign producers.

Problem with 0-tolerance pests

The quality rules for all productions would have to be changed if pesticides were no longer available because producers would have difficulty in complying with the phytosanitary rules for pests (Order No. 128, 1997). There are 0-tolerance values for certain pests, while for others, a small number is acceptable.

It is difficult to analyse the consequences of a partial phase-out for the cultivation of nursery-garden cultures.

For some cultures ; roses, fruit trees and ornamental trees, fruit bushes and some ornamental plants - big problems could be expected, particularly with scab and various mites.

It would be almost impossible to do without control agents in the propagation phase, which often takes 1-2 years. Once this phase is over, there are fewer pest attacks and the plants are more resistant. After planting out in forest, park or garden, there is rarely any need for control measures, except for fruit trees and fruit bushes.

Alternative methods

The sub-committee considers that technical changes could to some extent be implemented to cope with weed control. This means different cultural practices that facilitate mechanical control and the use of cover crops or organic materials such as wood chips to help keep weeds down. Many of these alternative methods are still at the development stage. Another alternative method is to use steam to control root rot and weed seed, but with present-day methods and technology, the method is very energy-intensive.

It is estimated that some nursery production could be maintained even if pesticide consumption were reduced, but agents would have to be available for combating acute, severe attacks of pests (Brander, 1998).

11.5  Conclusions concerning total and partial phasing out of pesticides in market gardening

Outdoor vegetables and garden seed

The yield losses in a 0-scenario have been estimated on the basis of estimates from organic growers. This has been done because there is no usable material from trials on which to base a calculation of loss sizes. The yield losses have only been estimated for the main crops. The reduction in yield would be about 30% for onions, 25% for cabbage, 15% for carrots and 35% for peas. The production of such vegetables as cauliflower and broccoli would become very unreliable. This is obvious from the fact that there is only very limited organic production of these vegetables today. Production of Chinese cabbage for winter sale would also be impossible. The production would probably suffer even more than it does today from large annual fluctuations owing to severe attacks of pests in some years. The sub-committee therefore estimates that a 0-pesticide scenario would have very serious consequences for the production of outdoor vegetables and garden seed and that most of the production would be abandoned because the estimated yield losses and/or additional costs are so great that a very substantial premium would be needed to keep contribution margins at their present level. In organic production today, a premium of 30-100% is obtained, depending on the crop. It is considered that similar premiums would be needed for products in a 0-scenario. For some crops, e.g. seeded onions and carrots, weed control is of great importance to the size of the yield. Mechanical and manual weeding could be used, but the costs might be high and it is very uncertain whether sufficient manpower could be procured for the work.

In a scenario with a partial phase-out of pesticides, some areas are indicated where there are not deemed to be alternative methods that could replace the chemical methods for combating diseases and pests. Within weed control, the possibility of band spraying is pointed out, which could reduce consumption by 60-70%. There would be a big need to develop rational and effective methods for controlling weeds in rows by mechanical means or by means of cover material.

In the case of garden seed, it is estimated that increased costs for weed control would affect the production and that cultivation security would be considerably reduced as a consequence of a greater risk of pollution with weeds and fungal attack on the seeds. Most of the production is exported, and it is estimated that it would be difficult to maintain this market if the quality could not be maintained.

Production of fruit and berries

The yield losses in a 0-scenario have mainly been estimated on the basis of estimates from organic growers because there is only a limited amount of material from trials on which to base a calculation of loss sizes. The yield losses have only been estimated for the main crops. With the current quality requirements, the losses in apple production would be more than 86% of the harvest yield. The yield in unsprayed pears would be reduced by 40-80%, depending on the variety. It is estimated that the losses in sour cherries would be approx. 30%, in blackcurrants approx. 50%, and in strawberries 40% of the traditional production. It is thus estimated that there would be a very big fall in production. It is hardly likely that apples that keep until after Christmas could be produced. The sub-committee believes that this would have serious consequences for the amount of fruit produced in Denmark. The consumers would thereafter increasingly have to buy foreign fruit, which is treated with more pesticides than Danish fruit. A big reduction would have to be expected in new plantings and in new players in the sector because cultivation security would be greatly reduced. With significant price increases, by far the greater part of fruit and berry production would become unprofitable if the fruit were to be produced without the use of pesticides.

In a scenario for a partial phase-out of pesticides, some pests have been indicated for which it is not estimated that there are alternative methods that could directly replace the chemical methods of combating diseases and pests. Much of the production could be expected to be maintained if there were means of combating these pests. In particular, it is regarded as important to have agents for combating scab on apples left on the bough over the winter. Support for this view is provided by the fact that organic producers have experienced growing problems with fruit on the bough since the use of cuprous agents was banned in Denmark.

Weed control without herbicides is possible in fruit and berry cultures, but the solutions are considerably more costly. In some of the cultures it is possible to cultivate more disease-resistant varieties, but a change in the assortment – in the case of apples, for example – often takes 10-15 years. There are various cultural practices that can reduce attacks of disease and pests, but many of them are rather costly (removal of old foliage, cutting off infected shoots, etc.) and would add considerably to the cost of production.

There would be a great need to develop rational and effective alternative methods of controlling pests and weeds if pesticides were phased out. It might also be necessary to consider whether the quality rules for the products should be changed.

Greenhouse production

Since greenhouse production comprises a very large number of cultures – both edible cultures and ornamental plants – it is very difficult to generalise about the consequences of a 0-scenario. However, it is estimated that a 0-pesticide scenario introduced over a short time horizon would have a very negative impact on present greenhouse production, with producers unable, for example, to meet the international requirements concerning prevention and control of pests in connection with exports. The visual quality of ornamental plants is of great importance to their saleability. For example, compactness and uniformity are major quality requirements for ornamental plants on the export markets – and would be difficult to achieve without the use of growth regulators. The presence of pests can also mean direct rejection of plants. This applies particularly to pests covered by 0-tolerance rules.

The reduction in the production of ornamental plants would be between 0 and 100%, depending on culture and season. The reason for this large variation is to be found in the legislation, which permits max. 2% common pests such as aphids and thrips. It might be impossible to achieve this percentage with biological agents in some periods of the year. A pesticide ban would be unfortunate for all the main cultures. The reason for putting the loss at between 0 and 100% is that there are very big variations from one season, culture and year to another. Biological control is an obvious option for spring cultures, but a massive invasion by thrips, for example, after the grain harvest often makes effective biological control impossible. This is a factor that could impair the quality of the plants and the possibility of selling them.

In a partial pesticide phase-out scenario, we consider that there would be good prospects for continued production of vegetables. This is due particularly to the fact that biological control methods are already widely used for pests. Biological control can keep pests down in most situations, but a market garden is not static. Biological control sometimes fails due to changes in the surroundings that allow the pest to gain the upper hand. In such situations it is necessary to control the pest chemically in order to reestablish the balance between pest and useful animal.

With a partial phase-out there would also be a need for pesticides for combating disease. In market gardening that means particularly pythium in propagation plants, cucumber mildew and grey mould in tomatoes. The last-mentioned can often be dealt with by swabbing sore faces and removing leaves. Problems with diseases could probably be reduced through improved hygiene, although this would mean increased use of disinfectants, which are also in the nature of control agents even though they do not figure as plant protection agents.

The current situation in Denmark is that most vegetable production is carried out in accordance with the IPM rules. According to the industry, this, together with the fact that producers in Denmark have very few plant protection agents at their disposal compared with other EU countries, means that the present situation can already be regarded as a "partial phase-out" scenario.

The sub-committee considers that there is a big potential for expanding the use of biological control to ornamental plants. That means that chemical agents could in time mainly be reserved for situations in which biological control fails and for compliance with 0-tolerance and the 2% rule for pests. However, it is estimated that growth regulators and certain fungicides would still be needed for up to 10 years to ensure stable production.

Nursery cultures

It is estimated that, in a 0-scenario, large parts of the production would disappear because the cultures would be ruined or become so expensive that they would be unable to compete with other countries’ products. It is estimated that 30-50% of the production would disappear because of competition problems and problems in supplying plants without pests. Nursery cultures are extremely sensitive in the propagation phase, whether propagated from seed or from cutting. The sub-committee considers that, where insecticides and fungicides are concerned, the 0-scenario would have a devastating effect on the production of many cultures. Particular problems are predicted for fruit trees and ornamental trees, fruit bushes, roses and many other ornamental plants if alternative methods are not available. In the case of herbicides, a 0-scenario here and now would have a ruinous effect on production, particularly in the propagation phase, because the additional cost of mechanical control, including manual weeding, would make it difficult for Danish producers to compete with foreign producers.

The quality rules for all productions would have to be changed if pesticides were no longer available because producers would have difficulty in complying with the phytosanitary rules for pests. There are 0-tolerance values for certain pests, while for others, a small number is acceptable.

It is difficult to analyse the consequences of a partial phase-out for the cultivation of nursery cultures. We consider that some nursery production could be maintained even if pesticide consumption were reduced but that this would demand the availability of products for controlling acute, severe pest attacks. For some cultures &; roses, fruit trees and ornamental trees, fruit bushes and some ornamental plants - big problems can expected, particularly with scab and various mites. It is in the propagation phase, which often takes 1-2 years, that it would be most difficult to do without control agents. The sub-committee considers that technical changes could to some extent be implemented to cope with weed control. This means different cultural practices that facilitate mechanical control and the use of cover crops or organic materials such as wood chips to help keep weeds down. Many of these alternative methods are still at the development stage.

References

Brander, P.E., Noyé, G., Nøhr-Rasmussen, A., Leonhard, B., Sivertsen, H. (1998): Assistance to committee in evaluation of the overall consequences of phasing out pesticides. Description of relevant production factors in a 100% (= present production) and a 0-scenario within market-garden production of fruit and berries. Report prepared for the Pesticide Committee, 1998.

Friis, K., Melander, B., Sørensen, L., Korsgård, M. (1998): Assistance to committee in evaluation of the overall consequences of phasing out pesticides. Description of relevant production factors in a 100% (= present production) and a 0- scenario within market-garden production of outdoor vegetables and garden seed. Report prepared for the Pesticide Committee, 1998.

IPM Working Group for Pomes, Nov. 1997. Rules for integrated production of apples and pears. Manual for fruit and berry producers, 1998. Association of Danish Fruit Producers, p. 112.

Lindhard, H., Bach-Lauritsen, H., Nøhr Rasmussen, A., Korsgård, M., Thorup, J. (1998): Assistance to committee in evaluation of the overall consequences of phasing out pesticides. Description of relevant production factors in a 100% (= present production) and a 0-scenario within market-garden production of fruit and berries. Report prepared for the Pesticide Committee, 1998.

Ottosen, C.O., Nøhr Rasmussen, A., Lippert, T., Rosager, L., Kristensen, K. (1998): Assistance to committee in evaluation of the overall consequences of phasing out pesticides. Description of relevant production factors in a 100% (= present production) and a 0-scenario within market-garden greenhouse production. Report prepared for the Pesticide Committee, 1998.