Report from the Sub-committee on Agriculture

Summary

On 15 May 1997 the Folketing (the Danish Parliament) unanimously passed a parliamentary resolution urging the government to appoint a committee with independent expertise to analyse all the consequences of totally or partially phasing out the use of pesticides in agriculture and to examine alternative methods of preventing and controlling plant diseases, pests and weeds.

Mandate

The mandate for the Sub-committee on Agriculture stipulated that the committee evaluate scenarios for total and partial phasing-out of pesticides and consider the consequences of restructuring for organic farming. In particular, the Sub-committee on Agriculture was to:

	illuminate alternative, non-chemical methods of controlling plant diseases, pests and weeds
	propose cultivation systems for agriculture under a total or partial phase-out of pesticides
	evaluate the consequences of restructuring for organic farming
	consider the possibilities of maintaining production of cattle and pigs
	make the greatest possible use of experience from existing organic production in the agricultural sector
	identify any areas in which a phase-out would give rise to particular problems
	propose solutions to those problems – e.g. through research and development.

A description of restructuring for organic farming is provided in separate reports examining cultivation-related, economic, employment-related and environmental factors and will therefore not be dealt with in this report.

Choice of Scenarios

The sub-committee has specifically described agricultural production as it is today, compared with a total phase-out and 3 scenarios for partial phasing-out of pesticides. Intermediate scenarios were specified by the main committee:

	0-scenario with no use of pesticides
	0+scenario, in which pesticides are allowed to enable compliance with the present phytosanitary rules (almost total phase-out)
	+scenario, in which pesticides are used with a view to avoiding the biggest losses in yields (limited use)
	++scenario, in which pesticides are used so that economic losses caused by pests are generally avoided (optimised use).

The scenarios are based on a division of Danish farms into 12 types, each of which is assessed separately. Two of these farm types cover farms with less than 20 ha and have not been analysed in detail. In the case of market gardening and forestry, the principal forms of production have been analysed. Within farming, a short description is given of each scenario separately, while total phasing-out and partial phasing-out within market gardening and forestry are dealt with together.

Agronomic and optimized crop rotation

In the different scenarios the sub-committee has worked with "agronomic crop rotations" and "optimised crop rotations". The agronomic crop rotations come only from the Sub-committee on Agriculture's work, while the optimised crop rotations have been developed and used in the Sub-committee on Production, Economics and Employment's analyses. However, both these types of crop rotation contain agronomic and economic elements. The contribution margin has not been  optimised in the agronomic crop rotations, but has been in the optimised crop rotations, which, however, also contain a large number of constraints based on agronomic considerations. In the agronomic crop rotations, the production of special crops is retained, while this is not the case in the optimised crop rotations. In the optimised crop rotations it is permissible, where there is no animal husbandry, to have up to 30% set-aside, which is competitive with several other crops.

The Sub-committee on Agriculture has based its analysis of total and partial phasing-out of pesticides primarily on yields and production losses in the different crops and crop rotations. For the farm types, however, figures are presented for contribution margin II per ha as the average of 10 farm types. The economic consequences of production losses as a result of attack by pests have been analysed and calculated by the Sub-committee on Production, Economics and Employment.

The basis used for assessing the need for control, in both present-day production and the intermediate scenarios described, has been an evaluation of whether, from existing knowledge, it pays to treat the individual pests. This means that at least the cost of the treatment must be covered.

Present-day agricultural production

Crop Distribution

In Denmark, about 2.7m ha land are under cultivation. More than 50% is used for cereal production and about 35% for winter cereals. Grass and greenfeed account for about 20%, while special crops, beets, potatoes, rape and pulses together account for 13%. In the last few years, the total set-aside acreage has varied between 5% and 8%.

The crop rotations and choice of crops used at conventional farms today are largely a result of the fact that pesticides are available. Agricultural production and pesticide consumption generally depend on the relationship between treatment costs and crop prices.

Weed control

In conventional farming, dicotyledonous weeds in all crops are controlled with herbicides. In the parts of the country with the biggest production of winter cereals, both monocotyledonous and dicotyledonous weeds are controlled. Herbicides are used mainly for sugar beet and mangolds, which are sprayed 2-3 times. Couch grass is treated every 3-6 years in the crop rotation, typically every four years on the same acreage. Soil preparation (mechanical weed control) is rarely if ever used for controlling weeds in cereals. In the case of winter rape, a move has started towards sowing in widely spaced rows (5% of the acreage in 1998/99) and hoeing to remove weeds.

Disease control

At least 85% of cereal seed is treated with dressing agents to prevent seed-borne fungal diseases. Cereals are sprayed frequently to prevent leaf diseases. Wheat fields are sprayed about twice, while about half the acreage with spring barley is treated against leaf diseases, depending on the pressure of disease and the resistance of the varieties used. In peas and rape, control measures against fungal attack are only needed approximately every 10 years. In potatoes, intensive control of potato blight is practised – with approx. 5-6 applications. Potatoes are dressed against black scurf to ensure good establishment and avoid loss of yield.

Pest control

A number of crops are sprayed with pesticides. Rape is sprayed once or twice every year. On average, about one quarter to one half of the acreage with wheat and spring barley is sprayed against aphids. Peas are sprayed with pesticides approx. every 18 months, and fields with beets are sprayed twice a year against aphids and other pests or a combination of seed dressing and one spraying is used.

Growth regulation

Growth regulators are used on about 10% of winter cereal and in the production of certain varieties of grass seed. Growth regulation of winter wheat in conventional farming is believed to be on the way out because varieties with good stem strength are now being grown and less nitrogen is being used. There is still deemed to be a need for growth regulation in certain varieties of rye and grass-seed species.

In the case of both plant diseases and pests there is a very considerable variation in the need for control and in the percentage losses from year to year. For weeds there is a more uniform need for control to keep down the general pressure of weeds.

Assumptions for description of present production

The evaluation of present production is based on yields from 1993-96 and the treatment frequency index (TFI) from 1994. The farming scenarios are based on a breakdown of Danish agriculture into 12 dominant types of farm on the basis of 13,000 operating accounts from 1995-96. These 12 types of farm can be scaled up so that they are in accordance with current crop figures from Danmarks Statistik. The 12 farm types provide a generally comprehensive picture of the factors to be clarified but do not, of course, reflect all existing farm combinations.

Pattern of pesticid consumption

Herbicides account for around two thirds of all pesticide treatment, insecticides for 10-15%, fungicides for around 20%, and growth regulators for 2-5%. The proportion of sprayed land at the different types of farm varies between 60% at dairy farms and 90% at pig farms. The large proportion of unsprayed land at dairy farms is due to the large areas of grass.

Approximately 15% of all spraying is done in the autumn, while more than 65% is done in April, May and June. Owing to the large proportion of land used for cereals, around 65% of all spraying takes place in cereal crops. The intensity is generally greatest in special crops. Most spraying is done on clayey soil, where the greatest specialisation in arable farming is to be found. The sub-committee has thus found an average treatment frequency index of 3.3 in Storstrøm County, where there is a large proportion of sugar beet, compared with 1.9 in Ringkøbing County, where there is a large proportion of dairy farms. There is a bigger consumption of pesticides at the largest farms, due in part to the land use at these farms.

Denmark contra EU

Pesticide consumption is low in Denmark compared with many other EU countries. Sweden and Finland, however, use even less than Denmark. The need to use pesticides varies considerably from country to country. The variation is due to differences in the crops grown, crop rotations, climatic conditions and a considerable variation in the pressure of diseases and pests. The consumption of active ingredients in different countries varies widely, from less than one kg/ha in Finland and Sweden to more than 10 kg/ha in the Netherlands and Belgium. Only limited information is available on the precise pattern of pesticide consumption in different crops and only Denmark calculates the consumption in terms of treatment frequency indices.

0-scenario in agriculture

Farm evaluations

In the 0-scenario, crop rotations have been set up for 10 different types of farm. The direct production loss in the crop rotations compared with present production would typically be between 10 and 25%. For dairy farms on sandy soil, restructuring would cause only limited losses, while the biggest losses would be suffered by specialised arable farms, which have a substantial production of, for example, seed, potatoes and sugar beet. It would presumably be impossible to maintain these special productions in the event of a total ban on pesticides.

Restructuring of farms

A 0-pesticide scenario would require considerable restructuring of farms compared with present production. For example, it would be necessary to use crop rotations with a substantially smaller proportion of winter cereals (max. 40% of the crop rotation) to reduce grass weed problems. Clover grass and wholecrop would replace mangolds and maize. To maintain the requirements concerning 65% green crops, second crops have been inserted in the scenario in connection with the cultivation of spring-sown cereals. The scenario also includes a large number of cultural practices that would be needed to minimise pest problems.

It is estimated that there would be losses on all crops as a consequence of cultivation without pesticides. The losses have been estimated assuming the use of alternative methods to minimise losses caused by pests. The annual production losses caused by pests are expected to vary considerably, thereby reducing the existing stability of cultivation. It must be expected that some productions with big requirements concerning purity and freedom from disease would have to be abandoned.

There is generally considerable uncertainty in the estimation of percentages in a 0-pesticide scenario due to significant differences in the epidemiology and population dynamics of the pests. At the present time, there is thus only very limited research documentation on which to base an evaluation of a 0-scenario.

Yield losses due to pests in individual crops

The losses for the individual crops have been broken down between different pests. The total average production losses for different crops would vary between 3% and 50%. For potatoes, the loss as a consequence of potato blight, for example, would be around 38%, while for seed grass, it is estimated that the net yield would be halved owing to weed problems and problems with removing weed seed. For wheat, the total loss is estimated at 27-29% as a result of a loss of 7-9% from leaf diseases, 14% because of weeds and damage to the crop during harrowing, and around 3% from pests, while other factors, such as postponing the sowing time and use of resistant species, give a 7-8% loss. It is estimated that grass and winter rape, which would only be very slightly affected, would have the smallest losses. For the individual crops a maximum loss has also been calculated, based on a pest causing particularly heavy losses, which happens in some years.

If seed-dressing products for controlling seed-borne diseases were phased out, the risk could arise of an uncontrollable and unforeseeable proliferation of seed-borne diseases and great concomitant losses. In fields with severe attacks of stinking bunt, the crop would be worthless as either animal feed or human food. Owing to the uncertainty concerning these losses, the sub-committee suggests that dispensation be granted for control of seed-borne diseases in the early generations of seed. The calculated yields in the 0-scenario are based on an assumption of dispensation. If seed-dressing of the first generations were retained up to and including C1, followed by a need assessment of C2, the dressed area could presumably be reduced to less than 10% of the present consumption.

Economic consequences in agronomic crop rotations

Contribution margin II per hectare, which includes yield losses/yield gains and changed costs, has been used to assess the success of the farms. Assuming that the present proportion of special crops is maintained, contribution margin II at the farm types shows a total reduction of 4-8% for dairy farms on sandy soil, 31% and 48%, respectively, for arable farms on sandy and clayey soil, and 50% and 93%, respectively, for arable farms with seed production and sugar beet, while the reduction for arable farms with a big potato production would be 66% (table 2).

Besides the crop rotations proposed with a view to reducing the level of pests and maintaining the present acreage with special crops, an economic optimisation model has been used to arrive at some agronomically and economically optimised types of farm. In a 0-scenario, these farms would almost totally phase out special crops. This accords well with the loss levels described in these crops, where one can expect high costs for weed control and losses as a consequence of, for example, mould, mildew and blight attacks. In a 0-scenario, special crops would thus naturally be out-competed by other crops. Because of the substantial losses in many crops, the economy of the farms would be so impaired that set-aside would become advantageous. The proportion of set-aside acreage has been put at a maximum of 30% at pure arable farms, which do not have to consider handling of liquid manure and harmonisation rules. In the agronomic 0-scenario, it is proposed that some rape and peas be included in many crop rotations. These crops would not be found competitive where economic optimisation was practised, but would be replaced by rotation set-aside, which is also assigned a previous-crop value. Spring-sown cereals would be favoured at the cost of winter cereals. Economic analyses of contribution margin II for these optimised farms, where there are largely no special crops, show a total reduction of 21-24% for dairy farms on sandy soil, 26 and 34%, respectively, for arable farms on sandy and clayey soil, and 35% and 39%, respectively, for arable farms with seed production and sugar beet, while the reduction for arable farms with a large production of potatoes would be 51%. In the case of potatoes, only a small production of Danish ware potatoes would be retained. It is assumed that some consumers prefer Danish potatoes and would be willing to pay a higher price for them.

The success of a 0-pesticide scenario would depend greatly on whether the current quality requirements concerning, for example, seed, seed potatoes, starch potatoes, and similar crops, could still be met. For crops grown in rows, manual weeding would be necessary until new methods had been developed. Whether it would be possible to procure sufficient manpower for such seasonal work is another open question and one of the factors that would determine whether sugar beet production could be maintained. The lower yields and, in some cases, larger additional costs for e.g. weeding and drying, must be judged in relation to the possibility of achieving a higher price for crops that have not been treated with pesticides.

The stated percentages in the 0-scenario are deemed to be relatively optimistic for the following reasons:

	The expected losses due to weeds have been put at half those observed at organic farms today. On the other hand, a larger loss has been added as a consequence of crop damage in connection with mechanical control.
	It is not known whether disease epidemics would develop more quickly and be more widespread without control measures.
	Adjustment has not been made for those situations in which the assumptions made do not hold. This applies, for example, to certain species of weed on organic soil, which are difficult to control.
	Allowance has not been made to any great extent for the fact that production management would not be optimal in all situations.
	Mechanical weed control generally requires a big machine capacity and dry weather. Problems might therefore arise with getting fields harrowed at the times when the crop is least affected and the weeds are mostly easily controlled.
	Account has not been taken of the fact that the latest fungicides (strobilurines) make it possible to harvest a bigger yield than those traditionally used for the past 15 years.

Unused method

There are several unused alternatives to chemical control that could improve the cultivation conditions in a 0-pesticide scenario. The most obvious of them are better utilisation of disease resistance and broader distribution and further development of methods of mechanical weed control. Adjustments to crop rotations would have a powerful effect when pest prevention becomes more important than direct pest control. It could thus prove necessary to change the choice of crops considerably to cope with weed problems. The sub-committee believes that the demand for alternative methods would, in itself, promote and stimulate the development of alternative methods.

The total production figures in a 0-scenario have been assessed by the Sub-committee on Production, Economics and Employment on the basis of a socioeconomic model. With respect to the production of sufficient feed units to maintain Denmark's present livestock production, the 0-scenario is based on sufficient arable farming at dairy farms to maintain the necessary production of feed units. Account has not been taken of whether arable farmers could receive liquid manure from livestock producers in a 0-scenario when the proportion of set-aside acreage would rise and cereal production fall. Nor has consideration been given to the question of whether sufficient straw could be harvested to fulfil present requirements. Total cereal production would fall by about 30% in both the agronomic and the optimised 0-scenario, which would make it necessary to import cereals to maintain the present pig production (table 3). In the agronomic scenario, production of both potatoes and seeds would be approximately halved, while production of both rape and peas would rise by around 30%. This rise would reduce the need for bought-in supplementary fodder. In the economically optimised scenario, this production would be largely replaced by set-aside and both potato production and sugar beet production would be reduced by more than 90% and seed production by 60%.

Intermediate scenarios in agriculture

The Sub-committee on Agriculture has considered three specific intermediate scenarios: a 0+scenario (almost total phase-out), a +scenario (limited use) and a ++scenario (optimised use). The effects have again been evaluated for 10 different types of farm. In addition, the sub-committee has provided input for calculations of economically optimised farms carried out by the Sub-Committee on Production, Economics and Employment for the + and ++scenarios. The main figures for the 0 and intermediate scenarios are given in tables 1-3.

The 0+-scenario

The 0+scenario (almost total phase-out) is a scenario in which the only aim is to comply with current quality requirements concerning plant health (phytosanitary legislation). This means seed-dressing of cereals for all early generations (to and including C1) and where a need analysis shows that seed-dressing is necessary in the C2 generation (60,000-100,000 ha), spraying of about 70,000 ha with seed production and seed potatoes, together with areas infected with wild oat. Spraying with pesticides would also be permitted in greenhouse and nursery cultures in order to comply with rules for export and home sale. The treatment frequency index would be very low in a 0+scenario. For most farm types it would be almost 0, while at farms producing potatoes and seed it would still be less than 5% of the present level. Since the scenario lies very close to the 0-scenario, its economic consequences have not been analysed.

Table 1  Look here!
Treatment frequency for pesticides in 3 scenarios, shown for 10 different farm types on sandy and clayey soil

The +-scenario

The +scenario (limited use) is a scenario in which continued use of pesticides is permitted for control of pests of critical economic importance. Altogether, the treatment frequency index in this scenario would be below 0.5, which is a reduction of at least 80% compared with present consumption. The treatment frequency index would vary between 0.2 for dairy farms on sandy soil to 1.1 for potato production on sandy soil (table 1).

This reduction depends on largely the same restructuring of production as described in the 0-scenario. The chosen input is deemed sufficient to maintain the present production of sugar beet, seed crops and potatoes. The scenario allows the use of pesticides where pests cause an average yield loss of more than 15%. The scenario thus does not calculate the consequences that could occur in a crop in individual localities and farms in some years because, for the vast majority of crops, it is not possible to predict how often such a situation would arise. The scenario also permits sufficient use of pesticides in outdoor vegetables, fruit and berries and ornamental greenery to maintain production (approx. 20,000 ha with horticultural crops; 35,000 ha with ornamental greenery).

Economic analyses of contribution margin II for the different types of farm in a +scenario show a total reduction of 0% for dairy farms on sandy soil, 15% and 36%, respectively, for arable farms on sandy and clayey soil, and 13% and 22%, respectively, for arable farms with seed production and sugar beet, while the reduction for potato producers would be 36% (table 2). For dairy farms, the losses in the ++scenario would be large compared with the +scenario, because mangolds and maize are retained in this scenario, but are not included in the 0 and +scenarios.

Table 2  Look here!
Contribution margin II in DKK/ha for 10 different types of farm with and without economic optimisation of the 0-scenario and the intermediate scenarios + and ++. The percentage reduction in contribution margin is shown for the 6 different scenarios.

Table 3 Look here!
Principal productions in 1000 hkg (crop units) for present production. For the scenarios, the change in production is given in %. The figures are based on figures from the economic analyses at farm level.

In the economically optimised +scenario, the treatment frequency indices would generally be of the same order of magnitude as in the agronomic scenarios, but the reduction in contribution margin for some of the farms would probably be smaller. The reduction would 14-15% for dairy farms on sandy soil, 8% and 19%, respectively, for arable farms on sandy and clayey soil, and 15% and 23%, respectively, for arable farms with seed production and sugar beet, while the reduction for potato producers would be 15%. Only in the case of potato producers would there be a significant difference between the treatment frequency index at farms based on agronomic considerations and economically optimised farms. This is because starch potatoes are only included in the agronomic scenario.

The ++-scenario

The ++scenario (optimised use) allows sufficient continued use of pesticides to avoid serious financial losses. The scenario assumes the use of all available damage thresholds and use of harrowing and other forms of mechanical control where these methods can compete with chemical methods. Crop rotations corresponding to present-day rotations are expected to be used. Economic optimisation would have to be practised but also optimisation with respect to minimising the use of pesticides. More hours would have to be spent than in present production on monitoring pests and using decision-support tools (about 1 hour/ha per year). If the present pattern of acreage were maintained, the total treatment frequency index in this scenario would be around 1.7, corresponding to a reduction of 31% compared with the treatment frequency index in 1997 and 36% compared with the treatment frequency index in the reference period 1981-85. In the ++scenario, which is economically optimised, the treatment frequency index would vary between 0.3 at dairy farms and 2.6 at arable farms with a substantial production of potatoes. Nationally, a treatment frequency index of 1.45 is assumed in the optimised ++scenario. It is assumed in the ++scenario that CMII remains at the present production level for all farms. The economically optimised scenarios show that there is a potential for improvement of several of the farm types' present contribution margins.

The intermediate scenarios, taken overall, would definitely help to reduce the losses in the 0-scenario. In the +scenario the yield losses would typically be reduced by 25-50%, while in the ++scenario they would be almost eliminated. To reduce the losses it would be necessary, particularly for diseases and pests, to continue using existing damage thresholds and warning systems and to develop additional damage thresholds and further develop some of the existing warning systems. Since we do not have reliable damage thresholds for all areas at present, and since many of the evaluations require long-term weather forecasts in order to provide a reliable prediction of the size of the yield loss, it is very difficult to indicate the treatments that can be relied on to reduce the losses significantly (>15%). To avoid attack by diseases, a considerable breeding effort would also be needed as "resistance" became ineffective.

Experience from trials and farmers’ groups (on plant protection) with intensive input from agricultural advisers shows that a treatment frequency index of about 1.3 for ordinary arable farming is realistic. There is no similar experience from research or practice with a treatment frequency index of around 0.5. This makes it difficult to judge how realistic it would be in practice to indicate precisely those treatments that avoid considerable losses - of 15-20% of the yield.

Present production and total and partial phasing out of pesticides in market gardening

Production within this segment is very varied and comprises many different cultures. The requirements concerning plant health within horticultural cultures are generally high and are governed by the EU's plant health directives, which determine which pests and levels of pests can be accepted. Today, there is a considerable degree of self-sufficiency in vegetables (60-90%), while the degree of self-sufficiency in fruit and berries varies between 25% for apples and 95% for cherries.

The supply of pesticides within the market gardening sector is already relatively limited because some pesticides are no longer marketed and/or have been removed in connection with a review. There are no reliable investigations that indicate pesticide consumption within market gardening. There is therefore considerable uncertainty concerning the exact consumption, which makes it difficult to analyse the scenarios.

Outdoor vegetables and garden seed

Present production

In 1997, 6,200 ha of land were used in Denmark for production of outdoor vegetables, plus 3,700 ha for production of green peas for freezing. Most of the Danish production of vegetables takes place at specialised farms, where vegetables account for most of the farms’ turnover. Outdoor vegetables are a very intensive production, requiring a big investment. At harvest, the vegetables have a value of DKK 30-100,000/ha. According to the garden seed industry, about 3,000 ha are used for vegetable seed and about 200 ha for flower seed. The area has been increasing in the last years, particularly for spinach. Around 80% of the garden seed produced is contract production for foreign firms, which make requirements concerning both supply security and quality. The production of garden seed is a production that is part of ordinary arable farming because a large number of years have to pass between the seed-producing crops. A high contribution margin depends on a high-quality crop.

Generally speaking, more pesticides are used in the production of vegetables and garden seed than in most ordinary crops. The treatment frequency index is typically between 4 and 12, depending on the culture.

Yield losses in 0-scenario

The yield losses in a 0-scenario have been estimated on the basis of estimates from organic growers because there is no usable trial material on which to base a calculation of loss magnitudes. The reduction in yield in relation to conventional cultivation is approx. 30% for onions, 25% for cabbage, 15% for carrots and 35% for peas. Production of such vegetables as cauliflower and broccoli is expected to be very uncertain, which is reflected by the fact that there is only a very small organic production of these vegetables today. Bigger fluctuations in the production than today must be expected because of severe pest attacks in some years. The sub-committee thus judges 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 would so large that a very substantial premium would have to be obtained to maintain unchanged contribution margins. In organic production today, a premium of 30-100% is obtained, depending on the crop. Similar premiums are deemed necessary for products in a 0-pesticide scenario. For some crops, e.g. seed onions and carrots, weed control is of great importance to the size of the yield. Both mechanical and manual control can be used, but the costs are high and it is very uncertain whether sufficient manpower could be procured for weeding.

Partial phase-out in outdoor vegetables

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

For garden seed in particular, increased costs for weed control are expected to affect production. It is estimated that cultivation security would be considerably reduced as a consequence of a greater risk of pollution with weeds and fungal attack on the seed. Most of the production is exported and it is thought that it would be difficult to keep this market if the quality could not be maintained.

Production of fruit and berries

Present production

In 1997, 7,300 ha were used for production of fruit and berries. The area used for this production has been decreasing for a number of years. Production of pomes typically takes place at specialised farms, whereas blackcurrants, redcurrants, strawberries and sour cherries are grown to some extent by ordinary arable farmers. The total Danish production gives approximately 50% self-sufficiency. Fruit and berries are quality products and are covered by common EU quality rules. Production of fruit and berries requires substantial investments. The cost of establishment is around DKK 100,000/ha for pomes and DKK 10-15,000/ha for berries. The labour input is greatest for apples, strawberries and pears, mainly because these cultures are picked by hand. Most of the production goes to direct consumption. Sour cherries and blackcurrants are industrial products that are harvested by machine.

A considerable quantity of pesticides is used in the present production of fruit and berries. In particular, there is a large consumption of fungicides to keep fungal diseases down. Apples, for example, are sprayed with fungicides about 18 times during a growing season, mainly to keep down mildew, scab and storage diseases. These diseases affect the quality of the fruit. Danish apples are generally sprayed less than foreign fruit. They are not sprayed after harvesting and are not waxed or lacquered.

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 usable trial material on which to base a calculation of the magnitude of losses. Assessed on the basis of interviews with organic growers, with the current quality requirements, the losses in apple production would be around 80% of the yield. The yield in unsprayed pears would be reduced by 40-80%, depending on the variety. For sour cherries, the losses, compared with the traditional production, are estimated to be about 30% (based on 3-year trials), for blackcurrants around 50% and for strawberries around 40%. It is thus estimated that production would fall considerably. With our present choice of varieties it would not be possible to produce apples that would keep until after Christmas. All else being equal, that would have major consequences for the quantity of fruit produced in Denmark. The consumers would increasingly have to buy foreign fruit. A big reduction would have to be expected in new plantings and in new players in the sector because cultivation security would be significantly reduced. Without substantial premiums, most of the fruit and berry production would not be profitable without the use of pesticides.

Partial phase-out

In a scenario with partial phase-out, there would be some pests for which there are not deemed to be alternative methods that could directly replace the chemical methods of controlling diseases and pests. The sub-committee believes that production could be maintained to a large extent if there were agents for controlling the pests in question. It would in particular be important to have agents for controlling scab in apples overwintering on the bough. Since the ban on agents containing copper in Denmark, organic producers have had increasing problems with this form of scab.

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 varieties that are resistant to diseases, but in the case of apples, for example, it often takes 10-15 years to change the assortment. There are various cultural practices that reduce attacks by diseases and pests, but many of them are rather costly (removal of old foliage, cutting off infected shoots, etc.) and would considerably increase production costs.

There would be an urgent need for rational and effective alternative methods to be developed for controlling pests and weeds if pesticides were to be phased out, and it could become necessary to change the quality rules for the goods produced.

Greenhouse production

Present production

The production of both vegetables and pot plants is very intensive and highly specialised. The production is spread over 780 production units with a total greenhouse area of about 500 ha. Production in greenhouses comprises a very large number of cultures – both edible cultures and ornamental plants. The main edible cultures are tomatoes, cucumbers and lettuce. The assortment of ornamental plants comprises more than 400 different cultures. In greenhouse vegetables there is very widespread use of biological methods of controlling pests. The chemical agents used in these cultures are mainly for controlling diseases, (grey mould, mildew, etc.). Slightly less than 20% of the producers use only biological methods of control, while about 50% use combined chemical and biological control, and the remainder only chemical control.

Biological control

In ornamental plant cultures there is some use today of biological control of pests. However, the chemical methods are still used against pests in cases in which biological methods are not available or are not deemed to be sufficiently effective or competitive. Chemical agents are also used when invasion from outside makes biological control impossible and at the pre-marketing stage in order to meet the current rules on plant health, which make requirements concerning 0-tolerance pests and pests that affect quality. Fungicides are used to control soil-borne diseases, which can be very destructive in the establishment phase of pot plants, but also to control mildew, grey mould, etc. Growth regulators are used several times during the production of most pot plants to get the desired size and flowering structure.

Since production in greenhouses 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, the sub-committee believes that a 0-pesticide scenario introduced over a short time horizon would have a serious impact on the present greenhouse production, which would, for example, be unable to meet the international requirements concerning pest control in connection with exports. The visual quality of ornamental plants is of great importance for their saleability. Compactness and uniformity are major quality requirements in the export markets and would be difficult to achieve without growth regulators. In addition, the presence of pests could mean direct rejection of plants – particularly in the case of pests covered by 0-tolerance rules.

The reduction in the production of ornamental plants would be between 0 and 100%, depending on the culture and the season. This big variation must be seen in the light of legislation that permits no more than 2% common pests. In some periods of the year that is impossible to achieve using only biological agents. For all main cultures, a ban on pesticides would have far-reaching consequences. 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.

In a scenario with a partial phase-out of pesticides, it is estimated that there would be a good possibility of continued production of vegetables because extensive use is already made of biological methods of control. Biological control can cope with pests most of the time, but a market garden is not static. Biological control regularly fails. Owing to changes in the surroundings the pest gains the upper hand, and in such cases it is necessary to control it chemically 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. Here, it is particularly pythium in propagation plants, mildew on cucumbers and grey mould on tomatoes that cause problems. The last-mentioned can often be dealt with by swabbing sore faces and removing leaves. It is thought that problems with diseases could be reduced by better hygiene etc. However, that would imply increased use of disinfectants, which must also be regarded as a kind of control agent, even though they are not included among pesticides.

IPM-production

The current situation in Denmark is that most vegetables are produced in accordance with the IPM rules. In our opinion, this, together with the fact that few plant protection agents are available in Denmark compared with other EU countries, means that the present situation is already critical for stable production.

There is thought to be a big potential for expanding biological control of pests in ornamental plants. This means that chemical agents could in time mainly be reserved for situations in which biological control does not work and for meeting 0-tolerance and the 2% rule for pests. There would, however, probably be a need for growth regulators and fungicides for a 10-year period to ensure stable production.

Present production

Nurseries produce plants for fruit growing, hedgerows, forests, landscape care, gardens, parks and plantations. The plants are propagated from seed or cutting or by grafting and are grown to a size regarded as suitable for planting out. There is a very large number of species. About 300 species are normally cultivated and there is a very large number of varieties of each of them. Only limited information is available about the sector's production of individual cultures. There are more than 300 companies producing nursery cultures. The units are typically around 10 ha and 2,300 people are employed in the production. Turnover is in the region of DKK 480 million.

It is not possible to give precise figures for pesticide consumption in nurseries because the consumption varies greatly from culture to culture and year to year and from one company to another. However, pesticide consumption is high in all cultures. It is relatively low in avenue trees, evergreen plants for gardens and conifers for forestry (TFI = 4-7), at intermediate level in deciduous trees for forestry, and high in roses, fruit trees and fruit bushes and some ornamental plants (TFI = 10-14).

0-scenario

In a 0-scenario, the sub-committee estimates that large parts of the production would cease because the cultures would be destroyed or become so expensive that it would not be possible to compete with other countries. It is estimated that 30-50% of the production would disappear because of competition problems and problems with supplying plants without pests. Nursery-garden cultures are particularly delicate in the propagation phase. This applies to propagation from both seed and 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 could be expected for fruit and ornamental trees, fruit bushes, roses and many other ornamental plants because, with our present level of knowledge, there are no alternatives to the present control agents. It would therefore be difficult to produce healthy plants from, for example, blackcurrants (blackcurrant bud gall mite) and apples (apple canker), which could mean an increased need for pesticides later in the process. In the case of herbicides, a 0-scenario would have a devastating effect on production, particularly in the propagation phase, because the additional costs for mechanical control, including hand-weeding, would be so considerable that it would be difficult to compete with other countries. Different quality rules would be required for all productions if pesticides were no longer used because the phytosanitary rules make specific requirements for 0-tolerance and 2% for different pests.

Partial phase-out

It is difficult to analyse the consequences of a partial phase-out for the cultivation of nursery cultures. The sub-committee considers that part of the nursery production could be sustained, even if pesticide consumption were to be 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 certain ornamental plants, serious problems must be expected, particularly with scab and spider mite. It is in the propagation phase, which often lasts 1-2 years, that it would be most difficult to do without control agents. The sub-committee considers that a change in cultural practices would to some extent help producers cope with weed control – for example, changing to cultural practices that facilitate mechanical weed control and using cover crops or organic materials, such as chipwood, to alleviate the weed problem. Many of these alternative methods are still at the development stage.

Present production and total and partial phase-out of pesticides in forestry

In all, approx. 11% of Denmark is forested. The ratio between private and state-owned forests is about 3:1. It has been agreed that the forested area must be doubled within one tree generation, and afforestation of around 3-4,000 ha a year is therefore planned. Pesticide consumption in forestry accounts for approx. 1% of the total consumption. The pesticides are mainly used for weed control in connection with the establishment of cultures, afforestation and production of ornamental greenery.

Wood-producing forestry: A ban on the use of pesticides would mean a considerably longer culture phase, incomplete cultures and increased costs for replanting, resulting in poorer economy and a different composition of forests. The sub-committee thinks that one consequence of phasing out pesticides would be that the assemblage of tree species in forests would change towards less deciduous forest. In the case of conifers, there would be problems with weevils during reestablishment on sandy soil, and in the case of deciduous trees, there would be problems with grass, and they would lead to problems with frost and mice. This would all increase the cost of reestablishment and result in a slower growth rate in the first years of growth.

Afforestation: In contrast to reestablishment in forests, afforestation offers good prospects for mechanical weed control and prevention. Considerable development work is going on in mechanical control, and a number of practicable machines have been designed for use on easy, flat land. However, only slow progress is being made on the development of machines for use on difficult, undulating land. If herbicides were prohibited in good localities for deciduous trees, one would have to expect the already slow afforestation to be further impeded. In the case of afforestation near existing coniferous forests, problems could arise with weevils. If afforestation took place far from old forests, there would only exceptionally be damage due to pests.

Ornamental greenery: The quality requirements for production of Christmas trees are high. Even small injuries, caused by either pests or weeds, can affect the saleability of trees and greenery. A total ban on pesticides would thus have a devastating effect on the present production of ornamental greenery. Alternative weed control in the form of mowing would add to the cost of production and reduce quality.

Pests, particularly spruce aphid in Norman fir, are a serious problem in some parts of the country and make it uncertain whether the desired quality could be achieved. The uncertainty in connection with the production of Norman fir Christmas trees is considered to be so great that large parts of the production would end. Just a few, small insect attacks can destroy a whole culture with Christmas trees, so the financial yield would fall considerably. Production of ornamental greenery extends over a lengthy period of years, so an attack by pests in a culture that is 7-8 years old would have a far more serious effect, financially, than in the case of an annual farm crop. We would expect it to be possible to produce abies nobilis greenery without pesticides, although there would be a considerable reduction in the yield, mainly due to problems in controlling weeds in the establishment phase.

Partial phase-out in forestry

The possibilities of a partial phase-out have not been analysed separately by the sub-committee, but they depend on how quickly alternative methods of weed control are developed. There is a need for a major research effort covering many alternatives if a usable solution is to be arrived at. If spruce aphid is to be controlled without insecticides, alternatives, including biological methods, will have to be researched. The sub-committee does not consider that all the problems of alternative weed control can be solved within a 10-year period.

Alternative methods of controlling pests without pesticides in farming and market gardening

The sub-committee has assessed alternative, non-chemical methods of controlling pests. Our conclusions are as follows:

Adjustment of crop rotation

Possibilities of regulation through changes in crop rotations and cultivation of other crops: The crop rotation used and the crops grown are of great importance for the level of diseases, weeds and pests. Thus, the level of weeds, in particular, can generally be reduced by a varied, many-sided crop rotation that switches between spring and winter crops, monocotyledonous and dicotyledonous crops, and annual and perennial crops. The problem of pests is often smallest at dairy farms with a large proportion of grass, compared with farms that use a lot of land for specialised productions. When planning the crop rotation, it is important to take account of crop-rotation diseases and ensure a sufficient number of years between the same crop - potatoes, rape, beet, etc.

Having examined the possibilities of cultivating new crops or of cultivating multiple crops that are less affected by pests, the sub-committee has come to the conclusion that, with the present level of knowledge, there is little immediate possibility of cultivating alternative crops.

Variety resistance to diseases

Disease control: With complete and partial phasing out of pesticides, the use of varieties with good resistance to diseases will be an important means of reducing losses from attacks of leaf diseases. The biggest losses from diseases occur in potatoes, wheat and winter barley. There are not at present varieties with good resistance to all leaf diseases in these crops. The varieties of spring barley generally have good resistance to mildew, so the gain from disease prevention measures is seldom significantly certain. In rape, beets and peas, maintaining varied crop rotations generally results in fewer problems with diseases, serious losses occurring only at intervals of several years.

With the types of wheat grown at present (in the years 1995-97), a tendency has been found for varieties with the best resistance to disease to produce 4-5 hkg/ha less net yield than varieties chosen for a high yield potential, while the same is not seen in other crops. It is not clear whether this factor in wheat applies to other periods of time. There is a great need for continuous improvement of resistance since resistance becomes ineffective over the years. The sub-committee believes that there is a big potential for improving resistance properties, but it is difficult to achieve resistance to leaf diseases and seed-borne diseases at the same time as better weed competition, good stem strength, winter hardiness, a high yield and other quality characteristics. Similarly, there is a potential for further development of resistance-based control strategies. A considerable breeding, research and consultancy effort is needed for full utilisation of these properties.

Foreign plant breeding is of great general significance to the Danish range of varieties and production; there is also close collaboration between Danish and foreign breeders. The feasibility of changing Danish breeding priorities in favour of breeding for resistance would thus depend on the interests of foreign breeders.

Use of variety mixtures and cultural practices

There is a not insignificant potential for strategic use of resistance (e.g. use of variety mixtures) to reduce losses from fungal diseases. Several cultural practices could be adjusted in present cultivation systems, such as the sowing time, fertilisation and the quantities sown, which would improve the possibility of minimising the problem of pests. However, diseases can neither be prevented nor minimised solely by adjusting cultural practices. Several of these cultural practices would reduce the yield level.

Within market gardening there are also various practices that help reduce attacks by diseases - for example, good plant hygiene, which includes removal or good decomposition of old foliage, together with pruning, which results in open trees. Several of these methods require increased manpower input.

Present scope of seed-dressing

Prevention of seed-borne diseases: 85-90% of all cereal seed is dressed today, as is a large proportion of other crops in Denmark. Seed-dressing of infected consignments is absolutely essential. Seed-dressing of other consignments could be omitted, but with present-day technology and resources, it is only to a limited extent possible to decide which consignments need seed-dressing. If seed-dressing were generally omitted, the sub-committee believes that there would be a rapid proliferation of several of the seed-borne diseases that cause heavy losses. Continued seed-dressing of the first generations of cereals, followed by a need assessment of subsequent consignments of seed, should be examined more closely and tested. Such assessment would require fast, reliable methods of analysis, separation of seed consignments and probably rejection of substantial quantities of seed for breeding.

There could also be considerable losses in beets as a consequence of uncertain establishment if seed-dressing agents were prohibited. Here, however, the losses would be due to a combination of diseases and pests. In potatoes, there could be a problem with black scurf. The problem could be reduced by using healthy seed material and an interval of at least 4 years between potatoes in the crop rotation, but it cannot be eliminated.

Alternative control of seed borne diseases

Work is in progress on several alternative methods of controlling seed-borne diseases, including use of resistant varieties, use of biological agents, technical control methods with hot water/air or brushes. The methods in question all still need a lot of research and development work before it can be determined whether they can replace the chemical methods.

Problems in phasing out seed-dressing agents

The risk, particularly in cereals, of directly phasing out the use of seed-dressing agents is so great that the sub-committee suggests that treatment with seed-dressing agents be retained where alternatives have not been developed and more rapid methods of analysis in winter cereals have not been implemented. We know too little today to be able to say whether the alternative methods could replace treatment with chemical seed-dressings within a 10-year period.

Variety resistance to pests

Prevention and control of pests: Very little is known about the resistance of Danish varieties to insects because this has so far been a largely unexplored area. Simple screening for receptivity to pests could prove it to have unused potential.

Today, little use is made of biological control of pests in fields, so this method is not at present a realistic alternative to chemical control. It is a well-known fact that natural field fauna, e.g. ground beetles and spiders, affect the pest population. In some years they contribute significantly to keeping down the aphid population, for example, while in others, they are insufficient because of high proliferation rates. We lack specific knowledge of the effects in this area.

Big attacks at interval of years

The way pest attacks develop is greatly affected by the climate, and losses are caused at regular intervals by major attacks that cannot be prevented, typically in seasons with hot weather, when the proliferation rate is high.

Cultural practices, such as sowing time, fertilisation and soil preparation, can affect the population of certain pests, and as much use as possible should be made of such methods to reduce losses from pests.

Within market gardening there are several alternative methods of controlling some pests, including placing of crops in satisfactory crop rotations, adjustment of sowing times, use of netting and watering.

Weed control: To achieve sufficient control of weeds in the case of a total or partial phase-out of pesticides, it would be necessary to use a combination of cultural practices and mechanical methods. This would mean reducing the amount of winter cereal in the crop rotation. The sowing time in the autumn would also have to be postponed, and for some crops it might be necessary to sow in more widely spaced rows (rape and cereals with serious weed problems) to facilitate mechanical weed control. Applying fertiliser could also improve the crop's ability to compete with weeds. Trial results have shown that there is a potential for mechanical control in almost all crops. However, it has not been clarified what effect mechanical weed control would have in the longer term on the weed population and, particularly, on the soil's seed pool. Under most cultivation conditions, mechanical methods can already compete with chemical methods of controlling weeds in rape and potatoes.

In some situations with special types of soil, unstable weather, poor crop establishment and dominance of certain types of weed, mechanical control could cause problems. Crop damage after harrowing and generally less control of weeds would result in increased losses, and adjusting the choice of crops and cultural practices for the sake of weed control would lead to increased costs.

Poisonous plants

With the present cultivation conditions, poisonous plants in Danish farm produce present no health problems for humans. There are occasional problems with mortalities in livestock caused by poisoning. In Denmark, spring groundsel and deadly nightshade are considered to be the two most significant poisonous species. It cannot be precluded that restructuring for pesticide-free farming would allow these species to proliferate. It is hardly likely that there would be an increased poisoning risk for humans, but there might be more cases of poisoning among livestock, which would cause some production loss in the form of reduced milk yields, reduced growth rates and suchlike.

Wild oat

Pursuant to the Act on Wild Oat, seed-bearing wild oat must not occur during the growing season. Wild oat is spread by seed and earth drift. Seeds can survive in the soil for many years and are thus difficult to eliminate. In cereal production without herbicides it would be necessary to replace chemical control of wild oat with manual weeding. This is a realistic method of control for relatively small populations of wild oat but not for large ones. In such cases, it would be necessary to change the crop rotation in favour of coarse-feed production in order to reduce the population.

Seed production

The production of grass and clover seed, as well as vegetable and flower seed, covers a broad range of cultures. Over 90% of our production is exported. In the case of all these cultures, the crop is destined for sowing and the primary price criteria are high purity and a high germination capacity. In addition, the seed must contain very little or no seed of other cultures or weeds. These criteria mean very high requirements concerning the cleanliness of the crops – requirements that, for the greater part of the production – would be difficult to meet without the use of herbicides, given our present level of expertise.

Control of couch grass

Couch grass can be controlled without pesticides on most land. Comparisons of the necessity of controlling couch grass by mechanical harrowing after harvesting or by spraying glyphosate in arable crop rotations have been assessed in several studies. Mechanical harrowing after harvesting (as a substitute for treatment with glyphosate every four years) is necessary every year in such crop rotations. We have reasonably good experience of controlling couch grass in organic dairy farming, but the crop rotations practised at organic dairy farms are very different from those practised at the various types of arable farm. Experience from organic farming shows that thistles can be a major problem. Variations in the quantities of root weeds from field to field would become greater without access to pesticides, as it can take several years to attain effective control of large stands of such weeds. There is deemed to be a big potential for improvement of the present mechanical methods, including methods to replace manual weeding. A change to non-chemical methods would require considerable retraining and supplementary training, and investments would have to be made in new machines.

Growth regulation in wheat

Growth regulation: Chemical regulation is used in about 10% of winter cereals, especially in rye. Growth regulation is also used in seed grass and ornamental plants. There are good prospects for applying alternative methods in winter wheat, to minimise the risk of lodging. The risk is thus small when cultivating varieties with good stem strength and reduced plant counts. If less strong-stemmed varieties were grown it might be necessary to reduce the amount of nitrogen applied by 10-30 kg/ha. There is a considerable risk of lodging in rye grown in the better soils, but a lower risk in sandy soils.

Growth regulation in rye

No rye varieties are free from the risk of lodging, although the risk is lower in some varieties. The risk can also be reduced by postponing sowing until the beginning of October and by reducing the quantities of seed sown and the amount of nitrogen applied. This would, however, reduce the yield by 6-7 hkg/ha (about 12%). The use of alternative methods of growth regulation in seed grass has only been clarified to a limited extent. Until more is known about the potential of alternative methods of growth regulation, a reduction of the stability cultivation must be expected in certain soils.

Growth regulation in pot plants

In pot-plant production, growth regulators are used primarily to promote the especially richly-blossoming and compact plants that have the best sales value. In practice, a combination of "negative dif" and chemical agents is used in many cultures. No methods that could replace chemical growth regulators are immediately available for pot plants. Research is in progress on alternative methods, including drought stress and reduction of phosphorus. A considerable research effort is needed to clarify whether there are alternative methods for the many different pot-plant cultures.

Biological control is effective in greenhouses

Biological control methods: These methods, which include both useful animals and microbiological agents, have a big potential for control of pests in greenhouse production. They are already widely used in vegetable production, whereas there is still an unexploited potential for their use in greenhouse production of ornamental plants. Effective methods of controlling diseases biologically in greenhouses are still limited. In field cultures, the sub-committee considers that biological methods of controlling pests have some potential within special crops, whereas, in the short term, biological disease control only appears to have a potential against seed-borne diseases and fungi that are harmful to germination. An approval scheme for microbiological organisms (MBOs) is being built up, and it is not known at the present time how many agents can be expected on the market.

Methods of assessing the need for spraying

Use of damage thresholds to reduce the need for control: In recent years, damage thresholds and decision-support systems have been developed for several of our main crops as support for the farmer in his assessment of the need for pesticides. The decision-support systems have contributed significantly to a reduction and adjustment of dosages, not only through direct use of the programs but also through advisory services and newsletters from the Danish Agricultural Advisory Centre. Decision-support systems are deemed to be an important tool for communication of the results of research in plant protection to both agricultural advisers and farmers. Although the systems have attained some popularity, it has not been possible to reach all farmers. More needs to be known about the significance of attacks by serious pests in some crops. Damage threshold systems are still lacking for a number of crops, and there is a big potential for improvement of several of the existing systems. In some crops, the sub-committee believes that it would be possible to achieve a 20-50% reduction, compared with what is feasible today, by combining decision-support systems and chemical and non-chemical methods.

Site-specific plant protection

In the last few years, research has commenced within site-specific plant protection, in which control measures are limited to those parts of the field where there is a need for control or regulation of pests. The sub-committee believes that the development of methods that can handle such a system would help to reduce consumption considerably. Trials and research have shown that targeted use of fertiliser, pesticides and other input factors can contribute to satisfying environmental requirements and simultaneously optimise production economically.

Reduction of spray drift

Spraying techniques: Compared with current spraying techniques, the introduction of new types of spraying equipment offers only limited possibilities of reducing pesticide consumption. Exceptions to this are techniques for site-specific treatment, which could in time offer the possibility of varied treatment patterns at field level with the aid of GPS (Global Positioning System) technology. There are good prospects for reducing the risk of spray drift through the use of new types of nozzles that minimise the proportion of small spray drops, which have a considerable risk of drifting. Some of the new types of nozzles increase the capacity compared with earlier sprayers, thereby also improving the possibility of getting spraying done in acceptable weather conditions. The sub-committee also considers that, in fruit growing, new, shielded sprayers (which collect spray residues) offer good prospects for reducing the impact on the surrounding environment.

Handling of pesticides

Relatively simple methods are available to farmers for minimising the risk of point-source contamination of ground water, their own wells and artesian wells, and watercourses, in connection with filling, washing and cleaning sprayers. These methods require only a limited financial investment.

Herbicide-resistant species

Genetically modified plants: Within genetically modified plants, Denmark is furthest ahead with the development of herbicide-resistant plants, which could be ready for marketing within a short period of years. The introduction of genetically modified, herbicide-tolerant species of beet is expected to result in a considerable reduction of herbicide consumption, i.e. a reduction of about 1-2 kg active ingredient/ha. In the case of herbicide-tolerant rape and maize, no great reduction is expected in herbicide consumption compared with present practice, and if mechanical control in rape gains ground, consumption might even increase.

Intensive research in GMO

With the present level of knowledge, the sub-committee does not consider it possible to predict the extent to which genetically modified plants will affect the consumption of pesticides at Danish farms over a forthcoming 10-year period.

All over the world, intensive research is taking place within molecular biology, which in time will undoubtedly change our culture plants significantly. Particular attention is being paid to improvement of genetically modified, disease-resistant plants, which must be expected to create a basis for reducing losses from attacks by diseases without the use of pesticides. Genetically modified maize that is resistant to pests is rapidly gaining ground in America and elsewhere. A similar trend could also occur in other crops. However, the sub-committee does not think it likely that major progress will be made in pest control in Denmark within a 10-year period.

The pesticides of the future: New pesticides are constantly being developed to replace the old products, and new products are also being developed that offer new control options, for instance, for take-all disease. These products are generally used in smaller quantities than has previously been the case, and there is a growing tendency to use certain insecticides as seed-dressing agents. The search for active ingredients from nature's own substances is intensifying, although these often need considerable modification to produce stable and suitable pesticides. It costs far more to develop new pesticides nowadays because of increasingly stringent environmental and health requirements. As resistance to many products is constantly increasing, continuous development of products that act through other mechanisms is vital if we are to continue ensuring effective pest control.

General conclusions from the Sub-committee on Agriculture

Present-day production at conventional farms is a result of having pesticides available. If production is to be made less dependent on pesticides or free of them, the present crop rotations and cultivation practice will have to be changed. It is possible to practise a form of cultivation that has a preventive and reducing effect on pests, whereby the risk of yield losses can be considerably reduced. The proposed crop rotations in a 0-scenario generally have a significantly lower yield level, with an average reduction in cereal yields, for example, of 23%.

0-scenario

The sub-committee suggests that the following measures be included in the crop rotations described in the 0-scenario:

The crop rotations must contain fewer winter cereal fields than today in order to reduce weed problems. The sub-committee suggests a maximum of 40%.

More rye and triticale must be grown since these crops compete well with weeds and are less attacked by diseases.

Winter wheat and winter barley must be sown later than they are today in order to reduce the pressure of weeds, which reduces the establishment reliability.

	Second crops must be included to meet the requirement of 65% winter-green fields.
	Extensive use must be made of mechanical weed control.

	Where available, disease-resistant varieties must be chosen, and in cereal crops, use can also be made of variety mixtures.
	It is a condition that dispensation be granted for seed-dressing up to and including C1 in order to avoid uncontrolled proliferation of seed-borne diseases.

In a 0-scenario we have identified crops in which there would be a risk of considerable losses from attacks by pests (e.g. potatoes and wheat). For some crops (e.g. sugar beet and outdoor vegetables), increased manual weeding would be needed, while in others (e.g. grass seed), there would be an increased risk of contamination with weed seed, which would make it difficult to sell the product.

Intermediate scenarios

In intermediate scenarios, in which a combination of alternative and chemical pest control methods would be used, there would be considerable possibilities of targeting and reducing pesticide consumption by means of concrete guidelines based on warning systems and damage threshold models.

The +scenario is based on very limited use of pesticides – less than 20% of present consumption. At farms with a large production of coarse feed, that could be practised without any serious fall in yield and contribution margin. For other farms, major changes would have to be made in the crop rotations and there would be a considerable drop in contribution margin – 13-36%.

There are no trials showing the possibilities in a +scenario. There is thus considerable uncertainty here since it is assumed in this scenario that those activities that produce substantial losses can be identified accurately. A considerable restructuring of crop rotations is also assumed, with all the uncertainty that implies.

The ++scenario is a scenario in which pesticide consumption is optimised. Depending on whether the present crop rotations are maintained or are economically optimised, an approx. 30-50% reduction of the treatment frequency index compared with present production would be possible. The sub-committee considers that this scenario could actually be practised with a limited reduction of yield and contribution margin. The reduction in treatment frequency index would vary considerably between the different types of farm and would also depend on the set-aside acreage. Trials and practical experience show that a treatment frequency index of 1.3 can be achieved for traditional arable farming with our present body of knowledge without radically changing the present crop distribution. This corresponds directly to the ++scenario described. In this scenario, too, it is important to be able to identify profitable activities. For some pests/crops, there is insufficient basis for such identification and assessments in decision-support systems. Farmers would also have to invest in single-row hoes and row-crop sprayers in order to achieve the reduction described.

Market-garden crops

It is estimated that a 0-scenario would have very serious consequences for the market gardening sector. It would be particularly difficult to meet the current quality codes. In a 0-scenario we would thus expect most greenhouse production, fruit and berry production, field vegetable production and nursery production to cease. To maintain a profitable production, prices would have to be raised in the same way as in organic production. There are several ways of reducing the use of pesticides, which are already practised in IPM production. With more research and development work on alternative methods, the need for pesticides could be reduced still further.

Forestry

In forestry, it would be very difficult to maintain the present production of Christmas trees, and alternative methods of weed control in connection with afforestation and re-afforestation could be extremely costly.

Need for research

Research is a continuous process, in which elements are clarified over time. Research and development work on alternative control methods is in progress in many fields. Completely developed methods are not at present available in all areas, but elements are available that could be put into practice now and help reduce the present level of pesticide consumption.

The sub-committee recommends more intensive action in continuation of existing research activities in the following fields:

	development of alternative methods of controlling seed-borne diseases
	development of varieties with good disease resistance, good stem strength, competitiveness with weeds, combined with high yield and quality
	development of models for estimating the long-term development of the weed population in different crop rotations
	further development of mechanical methods so that these become more effective, including development of autonomic cultivators, weeding robots, etc.
	development and further development of damage threshold models for diseases and pests that incorporate resistance-based control strategies, all relevant components of prevention and, besides economic factors, also environmental considerations; this applies to both arable crops and market gardening
	further development of biological methods of control
	development of cultivation systems in which great importance is attached to preventive methods.

Within spraying technology and handling of pesticides it is possible to include methods for reducing drift, and there are many ways of minimising or avoiding point-source contamination during handling, filling, emptying and cleaning of sprayers.

Advice and training

When presenting research results, it is vital that a co-ordinated effort be made to ensure that all available information reaches the farmers. It is important that advisory activities include:

	advice on strategic planning, with choice of varieties and crop rotation
	presentation of warnings of diseases and pests
	demonstration farms that illustrate different levels of protection
	training in the use of decision-making tools and accessibility, e.g., over the Internet
	establishment of experience groups focused on low pesticide consumption.

For a farmer to be receptive to this advice, he must be able to transfer the results to his own farm and practice.

In line with the supplementary training required for a spraying certificate, follow-up courses focused on the possibilities of minimising pesticide consumption must be developed.