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PARTIAL REGULATORY IMPACT ASSESSMENT

CONSULTATION ON THE FUTURE MANAGEMENT OF RISKS FROM PHYTOPHTHORA RAMORUM AND PHYTOPHTHORA KERNOVIAE

Purpose and intended effect

1. To achieve the best overall outcome for society in the management of these diseases, considering their current geographic spread in the wider environment and within the commercial plant trade, and balancing support for rural and horticultural businesses with the risks to woodland and heathland. The desirability of adopting a consistent approach across Great Britain ( GB) will also be evaluated.

Background

History of the diseases in GB

2. In 2000, Forestry Commission scientists highlighted the similarity between a pathogen which had been causing leaf blotches and dieback of rhododendron nursery stock in the Netherlands and Germany since the early 1990s, and a pathogen which had been causing sudden death of oak trees on the Pacific west coast of the USA (California and subsequently Oregon) over the same period. An early assessment suggested a potential risk to European trees, but with a significant margin of uncertainty. Although the pathogen was found to be of the same species, Phytophthora ramorum ( P. ramorum), there are differences between the European and North American populations, and between the plant communities and climates of the Pacific west coast and GB. However, GB and EU plant health services were alerted to the threat, and surveys began in GB in summer 2001 and in other Member States the following year.

3. P. ramorum was first found in GB in April 2002, on nursery stock in England, and on nursery stock in Scotland in May 2002. In light of the potential risk to woodlands and other habitats, emergency control measures were put in place in GB, followed by the EU in November 2002. These measures aim to ensure that plants moving in trade are free of the pathogen, and require action to be taken to eradicate the disease where it is found in nurseries and to contain other outbreaks.

4. Following the initial findings in nurseries, P. ramorum was identified in the wider environment in England and Wales, in gardens, parks and woodlands, with findings concentrated in Cornwall and the south-west. The first outbreak of P. ramorum in an established garden in Scotland was confirmed in September 2007. Several further outbreaks have since been found here, mainly on the west coast.

5. In late 2003, a new pathogen was found on rhododendrons and beech trees at a site in Cornwall. This pathogen, now named Phytophthora kernoviae ( P. kernoviae), is quite distinct from P. ramorum, but seems to behave in a similar fashion and to pose similar risks. GB plant health authorities therefore decided to implement the same measures to control its spread. P. kernoviae was first found in Scotland in January 2008, in a privately-owned garden open to the public.

6. An interdepartmental Programme Board was established in 2003 to co-ordinate action against P. ramorum and P. kernoviae across GB. The Programme Board includes representatives from Scottish Government, Defra and the Forestry Commission, and is advised by a number of sub-committees, including a science sub-group and Industry Liaison Group. (Defra acts on behalf of the Welsh Assembly Government on this topic.)

Outbreaks

7. From 2002 until January 2008 there were 35 outbreaks of P. ramorum on 24 different Scottish nursery or garden centre sites. Controls are still in place at one of these. There were also 7 findings in the wider environment. Three were recently landscaped sites which were cleared following eradication action. The other four were established gardens found infected since September 2007; action is still ongoing at these sites, and at the garden where P. kernoviae was found in January 2008.

8. In England and Wales, by the end of January 2008 P. ramorum had been identified 576 times on 488 different nursery or garden centre sites. At some sites there have been repeated outbreaks. 464 of these outbreaks have been eradicated and controls are still in place at 112 sites. In gardens and woodland there had been 217 outbreaks at 198 sites, of which 65 had been eradicated leaving 152 ongoing cases .

9. There have been three nursery outbreaks of P. kernoviae in England, of which one was rapidly eradicated, and 52 woodland or garden outbreaks in England and Wales, one of which has been found completely clear of infection, and good progress has been made towards eradication at a number of other sites.

10. To date, despite the containment and eradication activity 86 trees in England and Wales have been infected, 26 with P. ramorum and 60 with P. kernoviae. The great majority of these have been beech trees. On some unmanaged sites tree infection has occurred very quickly with up to 24% of beech trees in one particular wood becoming infected with P. kernoviae prior to rhododendron clearance.

11. In December 2007 P. kernoviae was confirmed on bilberry / blaeberry ( Vaccinium myrtillus) at a woodland site in Cornwall.

12. These outbreak figures are taken up to the end of January 2008. Since then, further outbreaks of the diseases have been confirmed in established gardens in Scotland.

Biology and potential spread

13. Science summaries for each pathogen are provided at Annexes A and B. More detailed information can be found in the data sheet for P. ramorum and the Pest Risk Analysis for P. kernoviae, available on the Defra website at www.defra.gov.uk/planth/pra/sudd.pdf ( P. ramorum) and www.defra.gov.uk/planth/pra/forest.pdf ( P. kernoviae).

14. Both pathogens cause bleeding bark cankers on certain tree hosts, especially in the family Fagaceae ( e.g. beech and oak); as they grow larger these cankers can kill affected trees. Both pathogens also cause leaf blights or dieback on a wide range of shrub hosts and also some trees; these foliar hosts are responsible for producing the spores which spread the infection.

15. Spores produced on foliar hosts are principally dispersed over short distances by rain-splash. Both pathogens may also be transferred in soil or debris attached to footwear or vehicles; they can also be found in water-courses or ponds at outbreak sites, though it is not known how significant this is for transmitting the disease to plants or trees. The main means of long-distance spread is by the movement of infected plants. Both pathogens can persist for significant periods of time (years) in soil and plant debris.

16. The most significant sporulating host in GB, for both pathogens, is rhododendron, particularly Rhododendron ponticum ( R. ponticum), an invasive non-native weed species which is widespread in many areas. To date, all trees in GB with bleeding bark cankers have been in close proximity to infected rhododendron. There have also been very heavy levels of infection on understorey R. ponticum in woodlands where trees have fallen victim to P. kernoviae. This may explain why P. kernoviae appears to be more aggressive towards trees than P. ramorum, or it may be due to the speed with which the symptoms of each disease become apparent in trees. Tree infection has been managed at both P. ramorum and P. kernoviae sites by removal of infected rhododendron. Uninfected rhododendron may also be cleared as a preventive measure. The Forestry Commission's research agency, Forest Research, has indicated that tree infection would continue on sites where infected rhododendron is not cleared.

17. Vaccinium myrtillus (bilberry / blaeberry) was found infected with P. kernoviae in woodland in Cornwall in December 2007 and in open heathland in February 2008. Other heathland species, including heather ( Calluna vulgaris), have been identified in laboratory experiments as susceptible to these diseases. The UK has 20% of the world's lowland heath and approximately 75% of the total resource of upland heath, the majority of which is in Scotland. Whilst the potential for the spread of P. kernoviae and P. ramorum in open heathland in Scotland is not currently known, if significant areas become infected or need to be destroyed as part of control measures this could have an impact on the condition of these important habitats.

18. In addition to host factors, disease development and spread for both pathogens is favoured by mild and wet climates. Areas most at risk are in the west of the country. Computer models have been used to identify areas where the climate is most similar to those parts of California and Oregon where tree mortality caused by P. ramorum occurs, and to prioritise areas of GB for surveillance and testing.

19. Diseases left uncontrolled normally follow a pattern of lag phase (little noticeable spread as they establish and spread locally), followed by exponential growth and then a plateau or reduction once host material diminishes or environmental conditions become unfavourable for the pathogen. It is difficult to try to predict the exact spread of any particular disease, however evidence and expert knowledge suggests that both P. ramorum and P. kernoviae are currently in the lag phase in GB, but are likely to move into the exponential phase in the near future, at least in certain areas.

20. P. ramorum has been reported throughout much of Europe and third countries within the nursery trade. This indicates that, even if it is controlled within GB, there is a threat of re-introduction of the disease. In contrast, P. kernoviae is found only in GB, mainly in the south and west, and in New Zealand, suggesting that it may be more easily contained and potentially eradicated.

Current control measures

21. EU measures are in place aiming to eradicate P. ramorum from commercial ornamental plant production and to at least contain outbreaks in the wider environment. EU legislation requires that:

• Host plants may only be imported into or moved within the EU if they are free of the pathogen;
• Nurseries growing host plants must be inspected at least twice a year;
• If any infected material is found at a nursery or garden centre, it must be treated by:
• Destruction of the infected plants and all susceptible plants within 2m;
• Holding all susceptible plants within 10m for 3 months of growth with at least two inspections in that time;
• Inspection of all other susceptible plants on the premises for signs of disease.
• Member States must undertake surveys of cultivated and uncultivated plants for evidence of the disease;
• If the pathogen is found at sites other than nurseries, measures must be taken at least to contain it.

22. These requirements are implemented in Scotland through the Plant Health ( Phytophthora ramorum) (Scotland) Order 2004 and the Plant Health (Forestry) ( P. ramorum) (Great Britain) Order 2004, both as amended. EU Member States cannot unilaterally relax these measures, but they are due for review in 2008, after the report of an EU research project which is producing a European Pest Risk Analysis for the pathogen. The review of measures will be considered by the EC's Standing Committee on Plant Health, and the UK's line in those discussions will be informed by responses to this consultation and that being conducted in parallel by Defra.

23. In relation to P. kernoviae there is no specific EU legislation, but as with any new disease problem, we are required to prevent its spread to other countries. GB plant health authorities have agreed to apply the same measures to P. kernoviae as for P. ramorum, using powers under the Plant Health (Scotland) Order 2005 and its equivalents in other administrations .

24. An EU Food and Veterinary Office ( FVO) mission visited the UK in April 2008 to evaluate the controls on P. kernoviae, and some aspects of controls on P. ramorum. The report of the mission may make recommendations which might impact on future disease management policy. The European Commission may also, if it deems it necessary for the purpose of protecting the rest of the Community, seek to introduce regulatory provisions by proposing measures on P. kernoviae to the Standing Committee on Plant Health.

25. The approach agreed across GB to contain outbreaks of these diseases at sites other than nurseries is to destroy infected plants and other susceptible plants within 2m, and to carry out regular monitoring of the site for any further signs of disease. Where appropriate, surveillance is carried out in a 3km zone around the outbreak to check for any other infected plants. In England and Wales, clearance of infected and uninfected R. ponticum has been found effective in reducing the spread of the disease. This has not been necessary for any outbreaks in Scotland to date, but could be used in future.

26. As an invasive non-native species, clearance of R. ponticum can have significant benefits for biodiversity and wildlife, in addition to removing a vector for P. ramorum and P. kernoviae infection. Where this activity can be shown to meet the necessary criteria, grants may be available through the Scotland Rural Development Programme Rural Priorities scheme.

27. In 2007 the Scottish Government carried out a public consultation on proposals to amend the Wildlife and Countryside Act in respect of various non-native species (see http://www.scotland.gov.uk/Topics/Environment/Wildlife-Habitats/InvasiveSpecies/legislation). The proposals would make it an offence to plant or cause R. ponticum to grow in the wild, and would prohibit its sale. If approved, this decision could influence the impact and costs to the nursery trade of applying any of the options proposed for control of P. ramorum and P. kernoviae.

28. This table shows some of the main differences between P. ramorum and P. kernoviae.

Policy on cost and responsibility sharing

29. For many years the general policy for statutory action against serious plant pests and diseases has been that government pays for risk analysis, research, surveys and monitoring inspections. The costs of measures at outbreak sites, including destruction of affected plants, fall to the grower, landowner or occupier. Statutory powers are available under the Plant Health Act 1967 to require landowners and occupiers to carry out eradication work at their own expense or, in default of that, for government officials to undertake the work and recover the costs. Scottish Ministers appreciate the efforts which have been made by the nursery stock industry, and the costs which have been incurred by individual growers, to bring these pathogens under control and to avoid further spread.

Rationale for Government intervention

30. A degree of Government intervention is required by EU legislation, to prevent plant diseases being spread to other Member States through trade. Additional measures are currently taken with the aim of eradicating P. ramorum and P. kernoviae within Scotland, both in traded plants and in the wider environment. This consultation considers whether those additional measures should continue, taking into account the financial and environmental implications of different options.

Consultation

31. This paper and its supporting documents have been prepared in discussion with Forestry Commission, Defra and industry representatives.

Options

32. The Scottish Government is now considering how to manage P. ramorum and P. kernoviae in the future, in parallel with similar consideration in England and Wales. Although only a small number of outbreaks have so far been identified in Scotland, research suggests these diseases could have the potential to spread from these areas to affect large parts of Scotland. We are consulting to seek views on three options. The options under consideration are:

Option 1: Meet EU minimum requirements on control of P. ramorum and remove all controls against P. kernoviae, other than maintaining a ban on the movement of infected plants to other countries. This option recognises that the minimum EU control levels of P. ramorum are under review and invites comments on where that level should be set, noting that the cost benefit analysis can only include the impact of current requirements.

Option 2: Increased activity, aimed at eradicating the diseases or reducing the level of inoculum to epidemiologically insignificant levels, by removal of infected sporulating hosts in woodlands and the wider environment, combined with enhanced containment and eradication measures in infected gardens and nursery sites, and increased surveillance to identify and control any new outbreaks.

Option 3: Holding option; a further two years of the current level of containment and eradication activity whilst more evidence is gathered, after which a decision on long-term action would be taken.

Costs and benefits

33. For each option, where possible, an attempt has been made to identify the impacts and to quantify the costs and benefits. The quantification is informed by scientific research to date and data available from experience in managing the diseases within GB and, for P. ramorum, in other countries. Information on the sources of data used and the assumptions made is provided in Annex C, and we welcome comments on these as well as on the options themselves.

34. The outbreak figures used in this Partial Regulatory Impact Assessment to calculate the impact of the different options are taken up to the end of January 2008. It is acknowledged that several further outbreaks of the diseases have been confirmed in established gardens in Scotland since that date. Higher incidence of infection is likely to increase the costs of any course of action to control the diseases, but it is not possible at this stage to assess how the increased number of outbreaks in Scotland since February 2008 would alter the impact of the different options.

35. The analysis and comparison of options shows costs for the first year and total costs calculated over a 20 year period, using a discount rate to convert these into equivalent present values ( PVs). This technique makes it possible to compare future streams of benefits and costs with different profiles over time. A discount rate of 3.5 per cent was used in accordance with the guidance in the 'Green Book, Appraisal and Evaluation in Central Government'.

36. A period of 20 years was chosen because Option 2 considers increased activity to be taken over a period of 5 years to reduce the spread of the diseases and finally eradicate them with the aim of reducing costs in the future. Therefore, the length of time had to be considerably longer than 5 years to capture the expected benefits of government intervention. The lifespan of trees is significantly beyond twenty years, but the possibilities of continued impacts of disease on trees beyond the 20 year period are not accounted for in this impact assessment.

37. The full calculations used to quantify the impacts of each option are available on request from Jean Waddie, Scottish Government Rural Directorate, email jean.waddie@scotland.gsi.gov.uk or telephone 0131 244 4895.

Impacts

38. The key impacts which have been identified are:

i. Government inspection staff costs: under each option some level of official inspection and control will be required. The costs of official inspection will vary depending on the option chosen and on the level of disease present.

ii. Diagnostic testing costs: whenever an infection is suspected, laboratory tests are required to confirm the presence of the pathogen. The number of tests required will vary with the level of inspection activity and the amount of disease present.

iii. Costs to nursery and garden centre industry: these will be affected by the need for staff to spend time dealing with inspections, the destruction of infected plants and quarantine of others when infection is found, and possible loss of export markets if non- EU countries lose confidence in GB measures to control the diseases. There is also an administrative burden associated with the existing requirements to ensure that susceptible plants moved in trade are accompanied by the necessary documentation

iv. Costs to historic and public gardens: the removal of infected plants and susceptible host plants nearby can mean the loss of significant specimen plants or displays, such as spring flowers, which are central to the character of a garden. Clearance work may leave unsightly gaps and may require closure of part or all of the garden for a time. Visitors may also be concerned about the risk of carrying disease away with them. All of these issues may reduce visitor numbers and may ultimately affect the viability of some gardens. However, it is unclear how visitor numbers would change with each option. Only the actual cost of clearance has therefore been quantified under this heading.

v. Rhododendron clearance costs: this heading covers the costs to landowners of removing infected and uninfected wild R. ponticum, which has been shown to reduce disease spread.

vi. Loss of social and environmental benefits of woodland: woodlands provide various benefits including recreation, landscape, biodiversity and carbon sequestration. If significant numbers of trees become infected, these benefits will be reduced. There may also be costs for felling diseased trees for safety reasons.

vii. Loss of ecosystems services of heathland: as with woodlands, heathland provides a range of social and environmental benefits which could be reduced as a result of any significant Phytophthora infections.

viii. Biodiversity benefits of rhododendron clearance: removal of invasive R. ponticum is funded in some parts of the country because it can be shown to improve biodiversity. Although this is an incidental benefit, it would be a consequence of a policy of clearing R. ponticum to reduce Phytophthora infections, and has therefore been included in the cost benefit analysis.

Detailed analysis of options

Option 1: Meet EU minimum requirements on control of P. ramorum and remove all controls against P. kernoviae, other than maintaining a ban on the movement of infected plants to other countries.

39. Under this option, containment rather than eradication measures would be taken in relation to any garden and wider environment outbreaks. No clearance of uninfected R. ponticum would take place. Containment and eradication measures would continue at all infected commercial nurseries in accordance with current EU requirements. There would be a ban on the movement of infected plants to other countries, and surveys of both nurseries and garden or woodland sites would be carried out at the minimum level required by the EU.

40. It is anticipated that this option would lead to increasing levels of disease both in nurseries and garden centres and in the wider environment, spreading to heathland. New controls on P. kernoviae could also be imposed by the EU.

41. The costs of this option have been calculated using the current EU minimum levels of control. Should the EU Minimum levels change as a result of discussions at the European Commission this year then the costs may vary appropriately. When considering this option consultees are asked to comment on the minimum level of controls describe above.

Impacts of option 1

i. Government inspections: Inspection levels would be cut back to those prescribed under EU law, at an estimated cost of £28k in the first year increasing by 5% each year as disease levels increase. The PV of these costs over 20 years would be £631k.

ii. Diagnostic tests: diagnostic costs would be £16.5k in the first year, increasing by 5% each year leading to a PV of £376k.

iii. Cost to nursery and garden centre industry: Infected plants are currently found as a result of 1.7% of surveys at nurseries and garden centres leading to around 4 outbreaks identified per year. For this option it is likely that the number of outbreaks will rise over time as the diseases become more widespread. Costs to nurseries in the first year are estimated at £14.5k for lost plants, £3.5k for dealing with inspections, and £5.5k in lost export trade. The total impact on nurseries and garden centres over 20 years would be £694.5k.

iv. Cost to Historic and Public Gardens: This option is likely to have the largest impact on historic and public gardens. Continued spread of both diseases in the wider environment is likely to increase the number of infected gardens across Scotland. The cost of clearance of infected and susceptible plants over 20 years would increase from £105k per year to £642k per year, leading to a PV of £3.9m

v. Rhododendron clearance: no clearance would be required.

vi. Loss of social and environmental benefits of woodlands: Although no woodlands in Scotland have yet been found to be infected, it would be unrealistic to assume that this situation will continue. A current infected area of 5ha has therefore been used to facilitate calculations of disease spread. After 20 years it is estimated that 846ha of woodland may be infected, with an annual reduction in benefits of £16k. This equates to a PV of £29.6k over the 20 years.

vii. Loss of ecosystems services of heathland: As with woodland, it is assumed that heathland in Scotland may become infected over time, this is likely to take longer than for woodland. A current infected area of 1ha has therefore been used, leading to an estimate of 169ha infected after 20 years. The loss of benefits over that time gives a PV of £20k.

viii. Biodiversity benefit of rhododendron clearance: Since no clearance would be carried out under this option, there would be no biodiversity benefit.

Option 2: Increased activity, aimed at eradicating the diseases or reducing the level of inoculum to epidemiologically insignificant levels, by removal of infected sporulating hosts in woodlands and the wider environment, combined with enhanced containment and eradication measures in infected gardens and nursery sites, and increased surveillance to identify and control any new outbreaks.

42. This option would involve more frequent inspections of nurseries and a increased programme of surveillance of gardens and woodlands. Where infection is found, all infected or susceptible host material will require to be cleared. This could have significant impacts in the short term, but over time this activity is expected to result in falling numbers of outbreaks.

43. P. kernoviae has only been found in gardens and semi-wild environments in limited areas of south west England, South Wales, and the west of Scotland, there have been only 2 or 3 outbreaks in nurseries. As a result it is estimated that a 2 - 3 year campaign of increased activity may be able to eradicate the disease from known outbreak sites in woodland and the wider environment, and stop the potential future spread to other countries.

44. For P. ramorum, which has wider geographical spread within GB, is more widely present in the nursery trade, and is reported in other Member States, possible eradication in woodland and wider environment sites across GB might be achieved over a longer time period. The exact timeframe is difficult to predict. However, the assumption is that it may take decades rather than years.

45. To facilitate this option it may be necessary to re assess the use of Disease Management Zones ( DMZ). There is currently a DMZ in part of Cornwall which controls the movement of susceptible plants out of the zone. Depending on the progress of infection in Scotland the Scottish Government may consider whether DMZs could be helpful.

46. A review of progress would be built in after 5 years to measure whether the increased activity was having the desired impact.

47. If eradication is successful this option also introduces the possibility of establishing within Great Britain a 'Protected Zone' against P. ramorum under EU law. 'Protected Zone' status allows Member States in which a disease which is established within the Community but is not endemic within that Member State to impose certain restrictions on trade from other Member States. Protected Zone status is agreed at EU level through the Standing Committee on Plant Health and can be applied to individual Regions, such as Scotland, as well as to complete Member States.

48. The assessments outlined below are based on current knowledge of the disease, which suggests that these measures could be effective in eradicating the disease. However, there is some risk that the measures may fail and disease continues to spread, either because the disease spread estimates are poor, disease outbreaks occur in new geographic areas or control measures are ineffective. If this is the case further more costly intervention may be required over a longer period combined with a manifestation of the impacts identified in option 1.

Impacts of Option 2

i. Government inspections: increased activity would cost £70.5k annually for the first five years, after which it is assumed that the staffing requirement will reduce as disease levels fall. From year 10 onwards costs would be equivalent to the initial annual cost of the EU minimum option (£28k). Using these assumptions the PV would be £620k over 20 years.

ii. Diagnostic tests: in line with the estimated profile of inspections, the cost of diagnostic tests would be £37.5k per year for the first five years, falling to £16.5k from year 10 onwards, giving a PV of £343k over 20 years.

iii. Cost to nursery and garden centre industry: the value of plants lost would be £14.5k per year in year 1 diminishing to £7k from year 11 onwards. Additional inspections would mean that staff costs rise to £9k in the first year, but then diminish to £3.5k from year ten onwards as the number of outbreaks falls. Control of the diseases will avoid any impact on exports under this option. The total impact on nurseries and garden centres over 20 years would be £121k.

iv. Cost to Historic and Public Gardens: it has been assumed that costs to historic and public gardens will be high, £121k per year, in years 1 - 5, then diminish to zero in year nine once infections have been cleared in gardens and significantly reduced in the wider environment. The PV cost to historic and public gardens is estimated to be £1.2m.

v. Rhododendron clearance: For this option all known infected R. ponticum in woodlands would be cleared as it is identified. While to date only one woodland infection has been identified in Scotland, the wide distribution of P. ramorum in Great Britain, and in nursery stock, suggests that infection is likely to occur at a low level, with continuing re-infection from new sources. An area of 5ha to be cleared each year has therefore been calculated, giving a cost over 20 years of £582k.

vi. Loss of social and environmental benefits of woodlands: Because of the control measures introduced as part of this option it is assumed that there will be minimal loss of social and environmental benefits of woodlands.

vii. Loss of ecosystems services of heathland: This option assumes negligible impact on native heathland in Scotland.

viii. Biodiversity benefit of rhododendron clearance: The consequential biodiversity benefit from rhododendron clearance over 20 years is estimated at £408k PV.

Option 3: Holding option; a further two years of the current level of containment and eradication activity whilst more evidence is gathered, after which a decision on long-term action would be taken.

49. This option would provide a further two years of the current level of activity, aimed at eradicating the disease at infected sites but without clearance of uninfected ponticum. Current controls on commercial trade would continue, together with targeted monitoring of other sites.

50. Under this regime, outbreaks of P. ramorum in nurseries and garden centres in Scotland declined from 18 in 2002 to none in 2006. However, 2007 saw 4 outbreaks in commercial premises and 6 in established gardens, and P. kernoviae was found for the first time in Scotland in January 2008. There is therefore a degree of uncertainty over the progress of these two diseases in Scotland.

51. Continuing the current approach for another two years may give a clearer indication of how best to tackle these diseases in Scotland. Action from 2002 to 2006 shows that the current regime has the potential to eradicate the disease in commercial trade, but it has not yet been tested against outbreaks in the wider environment. The additional evidence which may become available during such a holding period has to be weighed against the potential for the disease to spread further in this time. In the worst case the disease could move into the exponential spread phase, reducing the choice by negating the eradication option.

52. On a GB basis, the interdepartmental Programme Board and its science subgroup have identified what further evidence may be gathered during an extended containment and eradication period of 2 years.

• Further information about those trees and heathlands which are potentially at risk could be gathered through better mapping of species distribution and their host associations. The current assumptions about susceptible host trees are based on the incidence of beech woodland, in high risk climatic areas and on acid soils; beech trees in mixed woodlands are not accounted for and should be considered. Acidic soils have also been used as a proxy for the presence of R. ponticum since the mapping of R. ponticum is not currently available at a satisfactory resolution. Other tree species are also at risk other than beech (especially other Fagaceae) and these might also be mapped in a risk-based way in relation to climate and rhododendron.
• There is also scope to better understand risks to Vaccinium myrtillus and other heathland species in the wider environment setting, through more comprehensive epidemiological studies, including field-based studies of any existing or further outbreaks; current data on heathland species is limited and based on laboratory tests alone.
• Further monitoring of infected, but untreated, woodlands may give a better indication of the number of trees that may eventually become infected and die in areas of differing disease pressure. However, two years may not be sufficient time for significant tree death to become fully apparent.

53. It is not possible to predict what control measures might be recommended at the end of the 2-year period, and therefore it is not possible to provide 20-year cost estimates for this option.

Comparison of options

54. The following tables show the annual costs of each option and the 20-year present values ( PVs) of options 1 and 2. It should be noted that apart from the incidental benefits of rhododendron clearance there are no absolute benefits to be gained from any of the options - for example, there are no new export markets to be won by eradicating the disease - there are only reduced costs. The policy options can influence where the main costs fall and the overall level of costs, but they cannot prevent some losses.

Annual values in the first year for each option (£,000)

PVs over 20 years for options 1 and 2 (£,000)

55. These tables show that option 1 is cheaper in the short term, but has significantly higher costs than option 2 in the long term. Over 20 years the costs of government inspections and diagnostic testing are similar for the two options; for option 1 the number of inspections and tests starts low and is expected to rise, for option 2 it starts high and is expected to drop. The main costs of either option fall on historic and public gardens and nurseries and garden centres, reflecting the impact of destroying infected plants. Option 1 would require less activity initially, but this is likely to lead to higher levels of infection, including impacts on woodland and heathland, and greater numbers of outbreaks in gardens and nurseries needing treatment.

Competition Assessment

56. It is thought unlikely that any of the options outlined above would directly limit the number or range of suppliers. There could possibly be indirect effects, through an increase in costs of some suppliers relative to others ( e.g. nurseries with outbreaks), but it is unlikely the effect would be significant. The Horticultural Trades Association, which represents over 2,500 garden centres and other garden retail businesses, landscapers, growers and suppliers to the garden trade, has commented that growers continue to have a problem in getting over to specifiers the implications of disease, and if a particular nursery opts out of supplying host material such as Viburnum tinus they are perceived as being unprofessional as it is available in other UK and EU catalogues.

Small and Micro Firms Impact Test

57. The Programme Board has been actively engaged in informal discussions with the Horticultural Trades Association, the National Farmers Union, the Royal Horticultural Society, the Confederation of Forest Industries ( UK) Ltd. and individual nurserymen through the Phytophthora Industry Liaison Group. No indication of any significant impact on small businesses was identified from any of the three options set out above. We will gather further detailed data about likely impacts on small businesses as part of the consultation process.

Legal Aid Impact Test

58. This policy has no implications for Legal Aid.

Test Run of Business Forms

59. No new business forms would be introduced under any of the options considered.

Enforcement, Sanctions and Monitoring

60. Whatever level of control is chosen, enforcement would continue to be carried out, and sanctions applied, by Scottish Government Inspectors under existing statutory powers. Outbreaks would continue to be recorded, and reported to the EU as necessary, to monitor the impact of the policy.

Scottish Government
Rural Directorate
June 2008

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