Report 1 Impact of the loss of all azoles Issued by ADAS UK Ltd. Date 30 Sep 2011

Transcription

1 Evaluation of the benefits provided by the azole class of compounds in wheat, and the effect of losing all azoles on wheat and potato production in Denmark, France and the UK. Report 1 Impact of the loss of all azoles Issued by ADAS UK Ltd Date 30 Sep 2011 Submitted to: Euros Jones European Crop Protection Association ECPA aisbl 6 Avenue E Van Nieuwenhuyse B-1160 Brussels Belgium Report Authors : Jonathan Blake 1, Sarah Wynn 1, Claude Maumene 2, and Lise Nistrup Jørgensen 3 1 ADAS UK Limited, Woodthorne, Wergs Road, Wolverhampton, WV6 8TQ 2 ARVALIS - Institut du végétal, 3 rue Joseph et Marie Hackin F Paris FRANCE 3 Dept. of Integrated Pest Management, Faculty of Agricultural Sciences, Aarhus University, Forsøgsvej 1, DK-4200 Slagelse ADAS

2 ACKNOWLEDGEMENTS In the preparation and provision of data we would like to thank Sarah Cook and Steve Ellis at ADAS, Gilles Couleaud and Denis Gaucher at ARVALIS, and the team at Aarhus University, that provided supporting information for this study Verification Report reviewed and authorised by Name: Neil Paveley Job Title: ADAS Principal Research Scientist Date: AUTHENTICATION I declare that this report represents a true and accurate account of the work carried out. Signed: Date: 2 of 23

3 CONTENTS Acknowledgements...2 Verification...2 Authentication Executive Summary Introduction Methodology Objective A Evaluate the benefits of azole compounds Objective B Determine agronomic impact of active ingredient loss in wheat and potatoes Results Objective A Evaluate the benefits of azole compounds Objective B Determine agronomic impact of azole loss in wheat and potatoes Discussion and conclusions...18 Appendix 1 Active Ingredients approved in each Crop of 23

4 1 Executive Summary The azole fungicides (comprising the triazoles and imidazoles) are widely used to control economically important diseases in cereals and other crops. Following the introduction of Regulation 1107/2009, this study evaluated the impact of the potential loss of these substances on wheat and potato production, using the UK, France and Denmark as case studies. The two objectives were to: A. Evaluate the benefits from use of the azoles for disease control. B. Determine the potential agronomic impact of losing use of the azole active substances. The effects of azole use on potatoes were small relative to those on wheat, so this summary focuses on the latter. The methods used for the analysis were as follows: Objective A: This retrospective analysis estimated the benefit to yield that the azoles have provided over the last 10 years. The yield benefit varies in each country, in each season, depending on: (i) crop area, (ii) crop value, (iii) the proportion of disease susceptible varieties sown, (iv) disease pressure, (v) yield response to disease, and (vi) use of different plant protection products (PPPs). To account for these variables, for each main variety, in each year, in each country, the yield response attributed to the control of each of the major diseases was determined. Using expert knowledge and trials data, a calculation was made to estimate the proportion of control of each disease that was due to azoles. These yield benefits were then multiplied by the total wheat area to give a total yield benefit in tonnes from the use of azoles. This yield benefit was then multiplied by the average price of the crop (in euro) for that year, to give the value of azoles to the wheat industry in each country in each of the last 10 years. Objective B: The analysis estimated the consequences which would result from future withdrawal from use of all azole fungicides (scenario 3). Although this might be a somewhat extreme scenario, the current uncertainty surrounding endocrine disruption, in particular, means that such a scenario is conceivable. Withdrawal of all azoles (scenario 3) was compared with two reference scenarios in which all fungicides remain available (scenario 1) or all classes of fungicides are withdrawn from use (scenario 2). Hence, scenarios 1 and 2 set the outer boundaries between which the estimated impact of scenario 3 must lie. The analysis of scenario 3 accounted for the extent to which control might be maintained by the use of alternative active substances (assuming that all other relevant fungicides remain available for use). The key results were as follows: Objective A: The mean economic value from azole use in wheat across the last decade for the three countries studied, was estimated at 1,071 million euro per annum. This estimate excludes the economic value of the fungicide products used, which are an input cost to the grower and a source of revenue to the manufacturers and distributors. Objective B: The estimated future reduction in wheat production which would be caused by loss of azoles (scenario 3) was estimated at 5.0% (252,258 t p.a.), 6.8% (1,006,808 t p.a.) and 8.7 % (2,753,285 t p.a.) in Denmark, the UK, and France respectively. These represent loss of production with values to growers of 34 million euro, 157 million euro and 408 million euro in Denmark, the UK and France, respectively. The projected losses were primarily attributed to the loss of control of the foliar disease septoria tritici blotch (STB, caused by Mycosphaerella graminicola). The loss of azoles was also considered to have adverse effects on the sustainability of disease management in wheat, through increasing the selection pressure for fungicide resistance. The extent to which losses might be ameliorated by non-chemical control is discussed. 4 of 23

5 2 Introduction Plant protection products (PPPs) are fundamental to the way most crops are currently grown in Europe. They provide cost-effective options for controlling the major weeds, pests and diseases. The future availability of PPPs is uncertain currently. This is due to changes in European approvals legislation, with the replacement of EU Directive 91/414/EEC with Regulation (EC) No. 1107/2009. At present there are uncertainties about the effects of the implementation of the new regulation, especially with reference to products that might fail to meet hazard criteria, including endocrine disruption. This uncertainty affects the azole class of compounds, which are important for disease control in the major arable crops, and some herbicides and insecticides. Fungicides contribute substantially to the yield of wheat. Average responses to treatment usually range between 0.5t/ha (5Hkg/ha), and 2.5t/ha (25Hkg/ha), though where Septoria tritici blotch (STB) pressure is particularly high, yield responses of 5t/ha (50Hkg/ha) are sometimes seen. As STB is favoured by rainfall, the higher rainfall regions in the west of Europe, such as the UK and France usually have higher yield responses to disease control than Denmark and Sweden. (Figure 1) Figure 1: Average yield response (Hectokilogrammes/ha) to fungicide treatment in UK Denmark, France, Poland and Sweden between 2002 and 2009 (source Eurowheat: ). Azole fungicides have been widely used over the last 15 years to control economically important diseases in cereals and other crops. Despite some shifts in pathogen sensitivity, several of these compounds are still effective PPPs and are central to current disease management strategies in wheat. This study evaluated the impact of the potential loss of these substances on wheat production, in the UK, France and Denmark. This study was commissioned to: Provide a detailed economic evaluation of the importance of particular crop protection tools, using the UK, France and Denmark as case studies. 5 of 23

6 To meet this aim the work was divided into two objectives; C. Evaluate the benefits for agriculture in the UK, France and Denmark, of the azole class of compounds for disease control in wheat. The evaluation to consider the benefits, especially in terms of yields, that the azoles have provided over the last 10 years. D. Determine the potential agronomic impact of losing the azole active substances in wheat and potatoes for Denmark, France and the UK. This scenario was compared against losing all pesticides 3 Methodology 3.1 Objective A Evaluate the benefits of azole compounds The value of crop protection products varies in each country in each season, depending on: (i) crop area, (ii) crop value, (iii) the proportion of disease susceptible varieties sown, (iv) disease pressure, (v) yield response to disease, and (vi) relative activity and use of the different PPPs. To account for these variables the following information was collected from each country: 1. Wheat crop areas and crop values between 2000 and 2010, 2. The yield response to fungicides for each of the top ten varieties for each year was identified. 3. The proportion of yield response attributable to the control of each disease*. 4. The proportion of the control of each disease that was due to triazoles*. * as estimated by independent experts in crop pathology in each country The mean annual benefits that the azole class of compounds have provided to wheat production, were calculated over a period of 10 years, to ensure that both high and low disease pressure years were included. Hence, the first stage of the exercise was to identify the area of wheat grown in each country over the last 10 years, and the average price at which it was sold. In the UK the wheat price was based on the quantity and price of wheat sales each week between August and July following each harvest. The next step was to identify the 10 most widely grown varieties of wheat in each year, and the proportion of the crop that was grown from these varieties. For UK and Danish wheat varieties, seed production tonnages (NIAB and Plant directorat, unpublished data) were used as an approximation of the percentage area represented by each of the top 10 varieties. In the case of France, the percentage area attributable to each variety was estimated in a survey by FranceAgriMer/Arvalis. The remaining wheat area, i.e. that in varieties other than those in the top 10, was proportionally allocated to the top 10 varieties to ensure that the overall calculations covered the whole of the wheat crop in each country. The area adjusted to account for these other varieties therefore assumed that the yield response and disease profile of the 10 most grown varieties reflected the yield response and disease profile of all varieties grown. The key diseases that affected wheat crops in each country and the disease susceptibility of each variety were then determined. For UK varieties this information was provided by the HGCA recommended list trials ( which give a disease susceptibility score on a 1-9 scale with 9 being resistant and 1 being highly susceptible. In Denmark and France this was estimated by experts and based on variety trials information. 6 of 23

7 For each variety, in each year, in each country, the yield responses to fungicides were determined using trials data, by comparing untreated controls with those that had received standard fungicide regimes. In the UK this information was based on HGCA variety trials. These tested all varieties with and without fungicide treatment, at around 10 sites each year ( In Denmark data were similarly obtained from national field trials (Landsforsøgene) where yield responses from individual cultivars were summarized across a wide range of trials applying typically 2 fungicide treatments per season, using reduced dosages in line with the national average. More specific knowledge on disease management in Denmark has been described in Jørgensen et al (2008). The potential loss of yield from not using fungicides was based on the Bichel study. Conducted between 1997 and 1999, this tested a scenario where no pesticides were applied for a range of crops (Anon 1999). In this scenario a 9% yield loss was estimated if no chemical disease control was permitted in wheat. The switching to more resistant cultivars, and other ways of reducing disease pressure such as delayed sowing, were also considered in this report. In France the yield response to fungicides was determined through variety trials that tested treated and untreated yields between 2006 and 2010 (survey by France AgriMer/Arvalis). Data before 2006 are estimated from other variety trials in France. For each variety, in each year, in each country, the proportion of the yield response attributed to the control of each of the diseases was determined (referring back to the susceptibility scores for each disease x variety combination). Using expert knowledge and trials data, a calculation was then made to determine the proportion of control that was due to azoles. These yield benefits were then multiplied by the total wheat area to give a total yield benefit in tonnes from the use of azoles. This yield benefit was then multiplied by the average price of the crop (in Euros) for that year, to give the value of azoles to the wheat industry in each country, in each year. The areas, average yield and value of the wheat crop (in euro per tonne) in each year, for each country are shown in Table 1. Table 1. Area, yield and price values used in this assessment United Kingdom France Denmark Annual wheat Area (ha) Average annual wheat yield (t/ha) Average price ( /t) Annual wheat area (ha) Average annual wheat yield (t/ha) Average price ( /t) Annual wheat area (ha) Average annual wheat yield (t/ha) Average price ( /t) ,931, ,935, , ,775, ,733, , ,080, ,067, , ,830, ,783, , ,836, ,810, , ,867, ,867, , ,990, ,829, , ,836, ,551, , ,996, ,894, , ,635, ,462, , Mean 1,877, ,793, , Objective B Determine agronomic impact of active ingredient loss in wheat and potatoes A number of scenarios of pesticide loss were assessed by a methodology used previously (Clarke and Green 2008) to assess the impacts of active ingredient losses on crops. This 7 of 23

8 methodology was based on a gross margin calculation using, in the case of the UK, standard published figures for input costs (J. Nix, ). Similar information was made available through independent experts in France and Denmark. Gross margins were calculated on a per hectare basis and then multiplied up to the whole country area using national statistics for crop area (Table 2). This provided a baseline gross margin from which to calculate the impacts of reduced pesticide availability. Two baseline scenarios were then assessed, the first where all currently registered PPPs were available, and a second where no PPPs were available (fully untreated). This provided an upper and lower limit to the impacts that could occur from losses of particular active ingredients or classes of PPPs. Table 2. Wheat gross margin details, all countries UK France Denmark Area of crop grown (5 year average) Ha 1,890,400 4,865, ,400 Average harvested yield (5 year average) t/ha Average price ex farm (5 year average) /t Total production t 14,782,928 34,591,010 5,045,178 Average Total crop value M euro 2,306 4, Average crop output /ha Seed /ha Fertiliser /ha All sprays (fungicides) /ha 175 (79) 135 (61) 90 (45) Cultivations /ha Total crop costs /ha Gross Margin /ha For all assessments the percentage area of the crop affected by the disease was multiplied by the percentage reduction in yield that was expected to occur as a result of the reduced pesticide availability in that scenario. In the UK this was calculated from seed production tonnages for each variety (NIAB, unpublished data), and variety trials indicating susceptibility or otherwise to disease ( 2011). This gave an area weighted reduction in yield and therefore importance of the impact. This reduction in yield, plus any additional costs associated with mitigation on the affected areas were then combined to calculate the potential cost of the pesticide losses to the industry in each country. A loss could have a large impact on a per hectare basis, but if the weed, pest or disease was not widespread then the overall impact on the crop might be small. However another weed, pest or disease might only have a relatively small impact per hectare, but if it is widespread the overall impact on production might be high. In order to see both of these, impacts are shown both as a cost to the industry and as a cost per affected hectare. The following scenarios were assessed; Scenario 1 All fungicides available As standard gross margin calculations are based on treated crops, this provided a base line, against which the effects of the loss of azoles could be benchmarked. A list of the active ingredients currently approved for use on each crop in each country is included in Appendix 1. 8 of 23

9 3.2.2 Scenario 2 No fungicides available (untreated) The second scenario considered the impact of diseases, if crops were left completely untreated. This information was based, where possible, on untreated control plots from trials, as well as expert knowledge from each country. It is possible that if entire regions were not fungicide treated, the losses could be greater than for isolated untreated plots surrounded by treated crops. However, this effect could not be estimated, so was not accounted for the in the analysis. In the UK, for example, information was collected on fungicide treated and untreated yields within the HGCA recommended list trials. This was then allocated to each disease, based on disease prevalence and varietal susceptibility. The calculation for this scenario was based on the area affected by the disease multiplied by the % reduction in yield expected to occur in an average year (based on a 3+ year average). If there were quality implications as a result of disease damage, the value of the crop affected was reduced to reflect the decreased quality. This calculation produced a percentage reduction in overall production that would form the outer limit for other scenarios Scenario 3 No azoles available This scenario was assessed based on no azole fungicides remaining available for the control of disease in wheat and potatoes. The active ingredients that remained available and those that were assessed as unavailable, for each country are listed in detail in appendix 1. Trials data, where available, and expert knowledge were used to determine the impact of disease, in terms of yield and quality, on wheat and potatoes in the absence of these actives. Current usage of azoles in each country, was considered as part of the evaluation. 4 Results 4.1 Objective A Evaluate the benefits of azole compounds in wheat United Kingdom In the UK, the average annual impact (over the ten years studied) of disease control by fungicides was 387 M, of which 274 M (70.8% or 145 /ha) was attributable to azoles. The dominance of STB and the efficacy of azoles on this pathogen meant that it accounted for around 69% of the overall yield benefit attributable to azoles. Azoles were also valued in the control of yellow rust with this pathogen accounting for 16% of the yield benefit attributable to azoles. Brown rust accounted for 10%, and mildew, eyespot and fusarium ear blight (FEB) accounted for the remaining 4% - reflecting the smaller impact of mildew on yield, and the lower levels of control of eyespot and FEB provided by fungicides. In recent seasons the importance of azoles in the control of yellow rust has increased, due the development of a new race of yellow rust virulent on several of the more widely grown current varieties (incl. Oakley and Solstice). In 2010, 110M, was attributable to azoles due to the control of yellow rust alone. On average azoles provided a financial benefit of 145 /ha/year, based on a wheat price of 133 /t (the UK average price over the 10 year period). Assuming an average fungicide spend in UK wheat crops of 79 /ha (Nix 2010), and that 52% (41 /ha) was spent on azoles (Amis global data 2009), the net benefit for UK growers from azoles was 104 /ha/year. 9 of 23

10 Table 3. UK: Summary of the yield benefit attributable to azoles over the last 10 years (values in M unless otherwise stated). STB Y. rust B. rust Mildew Eyespot FEB Total Annual average M Average /ha France The impact of diseases in France was very variable between seasons. Overall, the average annual benefit to production from the control of disease was 1,011M, of which 751 M (or 74%) was attributable to azoles. The main benefit was from the control of STB, accounting for 63% of the yield attributable to azoles. 18% of the benefit attributable to azoles was through the control of brown rust; a disease prevalent mainly in the south of France. Eyespot and mildew accounted for a small proportion of the yield benefit attributable to azoles. Little importance as been given to yellow rust which has, until now been well controlled with resistant varieties. A new pathotype is now present in France, which might change this situation. Azoles contributed an average financial benefit of 154 /ha, based on a wheat price of 118 /t (the average price in France over the 10 year period) (Table 4). Assuming an average fungicide spend on azoles in France wheat crops of 70 /ha, and that 60% (42 /ha) was spent on azoles (Amis global data 2009), the net benefit for French growers from azoles was 112 /ha/year. Table 4. France: Summary of the yield benefit attributable to azoles over the last 10 years. (values in M unless otherwise stated). STB Y. rust B. rust Mildew Eyespot FEB Total , , Annual average M Average /ha of 23

11 Denmark In Denmark, disease pressure is comparatively low, and yield responses to disease control by fungicides are around a half of those seen in the UK and France. The average annual impact of disease control in wheat was 71 M and the proportion of this attributable to azoles was lower than France and the UK at 60.6% (or 43 M ), due partly to the lower availability of azoles in the last 10 years (Denmark approved epoxiconazole in 2003, but have not approved the use of prochloraz, cyproconazole, and fluquinconazole). However since the resistance to strobilurins developed in 2003/2004 the proportional benefit from azoles has increased. Mildew is of importance in Denmark accounting for 4 M per year (or just over 9%) of the total benefit from disease control, and the control of mildew is less attributable to azoles. The smaller benefits from disease control in Denmark are reflected in the lower benefit attributable to azoles of 62.6 /ha. Assuming an average total spend on fungicides in Denmark of 45 /ha, 50.1% of which (23 /ha) (Amis Global data 2009) is attributable to azoles, the net benefit in Denmark was 39.6 /ha/year Table 5. Denmark: Summary of the yield benefit attributable to azoles over the last 10 years (values in M unless otherwise stated). STB Y. rust B. rust Mildew Eyespot FEB Total Annual average M Average /ha of 23

12 4.2 Objective B Determine agronomic impact of azole loss in wheat and potatoes Wheat United Kingdom The azole class of compounds accounted for 50.2% of fungicide active ingredient usage in UK cereal production in 2009 ( 2010). This figure was similar in 2008 with azoles representing 49.8% of actives used in cereals, based on field areas sprayed. It is reasonable to assume this value is representative for wheat, given the dominance of this crop (around 70% of UK cereal production), and the similar diversity of product usage across cereal species. If azole compounds were no longer permitted, the total financial loss in the UK, would amount to 157 M / year, based on a 5 year average wheat price of 157 / t. The greatest immediate affect would be seen though a reduction in STB control. This would amount to a total financial loss of around 5% or 115 M /year. Yellow and brown rust control would also be affected. Other products such as rust active strobilurins and spiroxamine would provide some control of these pathogens, however HGCA fungicide performance studies (Lockley et al. 2008, Lockley and Clark 2005) between 2003 and 2008 indicate, that these would not be as effective as the use of triazoles, especially where yellow rust is the target pathogen. It is expected this would amount to a further financial loss of 36.9 M /year. The control of FEB with fungicide would be reduced and would rely only on one active ingredient: thiophanate-methyl against which some resistant strains already exist. It is expected the lack of azoles for FEB control in the UK would lead to a further financial loss of 3.7 M /year, due to loss of yield, effects on quality were considered to be negligible due to the continued availability of thiophanate methyl. Mildew and eyespot control would not be significantly affected by the loss of azoles due to the availability of other modes of action to control these pathogens. Table 6. Impact of three scenarios of future fungicide availability on wheat - UK STB All fungicides available (Scenario 1) Total area of crop (ha) 1,890,400 Total production (t pa) 14,782,928 Total value of crop ( M pa) 2,306 Area affected (ha) 1,890,400 1,285,472 1,304, , ,544 37,808 1,739, ,600 % area affected 100% 68% 69% 43% 36% 2% 92% 25% Yellow rust Brown rust Powdery mildew Eyespot Sharp eyespot FEB Take all Total No fungicides available (Scenario 2) Area affected (ha) 1,890,400 1,285,472 1,304, , ,544 37,808 1,739, ,600 1,890,400 Production loss (t pa) 1,906, , , ,524 42,575 7,391 32,641 14,783 2,890,661 Cost of production loss ( M pa) Percentage reduction in production (% pa) % 3.1% 2.2% 0.7% 0.3% 0.1% 0.2% 0.1% 19.6% No azoles available (Scenario 3) Area affected (ha) 1,890,400 1,285,472 1,304, , ,544 37,808 1,739, ,600 1,890,400 Production loss (t pa) 739, ,648 73, , , ,006,808 Cost of production loss ( M pa) Percentage reduction in production (% pa) 1 5.0% 1.1% 0.5% 0.0% 0.1% 0.0% 0.2% 0.0% 6.8% 1 Based on loss of crop value ( ) due to reductions in yield and/or quality 12 of 23

13 France In France, the azole class of compounds accounted for 48.7% of active ingredient usage in cereal production in 2009 ( 2010). The total financial loss in France, if the azole class of compounds were no longer permitted would amount to 408 M / year, based on a 5 year average wheat price of 136 / t. The largest affect would be from a reduction in STB control, amounting to an annual loss of production of around 6.0% (or 282 M / year). Both yellow and brown rust control would also be affected, amounting to a financial loss of a further 61.4 M / year. The control of FEB with fungicide would be compromised in the absence of azoles. Thiophanate methyl would still be available, however resistance already exists to Microdochium spp. and resistance is likely to develop for F.graminearum. Reduced control of FEB would amount to a total financial loss of 64.7 M / year, due to a reduction in both yield and wheat quality that would affect the price. This value assumes thiophanate methyl remains effective. Mildew and eyespot would be considered as controllable by other non azoles, so loss of control of these pathogens would not affect production. Table 7. Impact of three scenarios of future fungicide availability on wheat France. STB All fungicides available (Scenario 1) Total area of crop (ha) 4,865,600 Total production (t pa) 34,591,010 Total value of crop ( M pa) 4,703 Area affected (ha) 3,892, , , , , ,120 % area affected 80% 15% 20% 10% 10% 20% Yellow rust Brown rust Powdery mildew Eyespot FEB Total No fungicides available (Scenario 2) Area affected (ha) 3,892, , , , , ,120 4,865,600 Production loss (t pa) 6,328, , , , , ,683 8,684,246 Cost of production loss ( M pa) ,215 Percentage reduction in production (% pa) % 2.0% 2.6% 0.5% 0.4% 2.0% 25.8% No azoles available (Scenario 3) Area affected (ha) 3,892, , , , , ,120 4,865,600 Production loss (t pa) 2,077, , , ,842 2,753,285 Cost of production loss ( M pa) Percentage reduction in production (% pa) 1 6% 0.7% 0.7% 0.0% 0.0% 1.4% 8.7% 1 Based on loss of crop value ( ) due to reductions in yield and/or quality 13 of 23

14 Denmark The azole class of compounds in Denmark accounted for just over 52.8% of active ingredient usage in Denmark cereal production in 2009 ( 2010). The total financial loss in Denmark if the azole class of compounds were no longer permitted would amount to 41 M / year, based on a 5 year average wheat price of 133 /t. The greatest effect would be seen though a reduction in STB control, amounting to a financial loss of around 4.5% or 30 M / year. Yellow and brown rust control has generally been less problematic in Denmark for the years which have been investigated, and it was considered these would be adequately controlled by other non-azole products, particularly strobilurins which have been seen to provide sufficient control. Mildew control in Denmark (unlike France and the UK), would be partially affected by the loss of azoles, due to other active substances with alternative modes of action, such as proquinazid and cyflufenamid, not being registered for use. Both fenpropidin and metrafenone are available and can provide good control, however it is considered a reduction in control would be expected in the absence of azoles. This effect would be relatively small, amounting to 1.34 M / year. Eyespot and FEB are minor diseases in Denmark and although the loss azoles would affect their control, overall this would have negligible effect on production. Table 8. Impact of three scenarios of future fungicide availability on wheat Denmark STB All fungicides available (Scenario 1) Total area of crop (ha) 693,400 Total production (t pa) 5,045,178 Total value of crop ( M pa) 671 Area affected (ha) 693, , , ,700 69,340 34, ,700 % area affected 100% 25% 25% 50% 10% 5% 50% Yellow rust Brown rust Powdery mildew Eyespot FEB Take all Total No fungicides available (Scenario 2) Area affected (ha) 693,400 69, , ,700 69,340 34, , ,400 Production loss (t pa) 277,485 15,136 10,090 50,452 10,090 5, ,298.0 Cost of production loss ( M pa) Percentage reduction in production (% pa) 1 5.5% 0.3% 0.2% 1.0% 0.2% 0.1% 0.0% 7.3% No azoles available (Scenario 3) Area affected (ha) 693,400 69,340 69, ,700 69,340 34, , ,400 Production loss (t pa) 227, ,090 10,090 5, ,258.9 Cost of production loss ( M pa) Percentage reduction in production (% pa) 1 4.5% 0.0% 0.0% 0.2% 0.2% 0.1% 0.0% 5.0% 1 Based on loss of crop value ( ) due to reductions in yield and/or quality 14 of 23

15 4.2.2 Potatoes United Kingdom Azole compounds are not widely used in potato production in the UK (or any of the countries under investigation here). One azole, imazalil is used to control tuber diseases in the UK, predominately those affecting stored tubers. Its loss would leave thiabendazole to control tuber diseases, however resistance to this active has been reported in silver scurf, skin spot and dry rot. It is usually only available in formulation, or applied in conjunction with imazalil, which has had no resistance problems reported to date. Table 9. Impact of three scenarios of future fungicide availability on potatoes - UK Blight (Phytophthera infestans ) Rhizoctonia solani Black dot (Colletoctrichum coccodes ) Silver scurf (Helminthosporium solani ) Skin spot (Polyscytalum pustulans) dry rot (Fusarium spp.) Powdery scab (Spongospora subterranea) All fungicides available (Scenario 1) Total area of crop (ha) 128,960 Total production (t pa) 5,741,944 Total value of crop ( M pa) 868 Area affected (ha) 105,747 47,715 61,901 81,245 42,557 87,693 83,824 % area affected 82% 37% 48% 63% 33% 68% 65% No fungicides available (Scenario 2) Area affected (ha) 105,747 47,715 61,901 81,245 42,557 87,693 83,824 Production loss (t pa) 1,883, ,471 82, ,523 47,371 97,613 18,661 Cost of production loss ( M pa) Percentage reduction in production (% pa) 1 33% 2% 1% 2% 1% 2% 0% No azoles available (Scenario 3) Area affected (ha) 105,747 47,715 61,901 81,245 42,557 87,693 83,824 Production loss (t pa) , Cost of production loss ( M pa) Percentage reduction in production (% pa) 1 0% 0% 0% 0% 0% 0% 0% 1 Based on loss of crop value ( ) due to reductions in yield and/or quality 15 of 23

16 France The azole class of compounds is not widely used in potato production in France. One azole, Imazalil has recently (2011) been registered however it is not clear how widely it will be used. So the loss of imazalil here is assumed to have no adverse affect on potato production. Table 10. Impact of three scenarios of future fungicide availability on potatoes - France Blight (Phytophthera infestans ) Rhizoctonia solani Black dot (Colletoctrichum coccodes ) Silver scurf (Helminthosporium solani ) All fungicides available (Scenario 1) Total area of crop (ha) 136,800 Total production (t pa) 5,997,312 Total value of crop ( M pa) 1,024 Area affected (ha) 123,120 34,200 17,100 34,200 % area affected 90% 25% 13% 25% No fungicides available (Scenario 2) Area affected (ha) 123,120 34,200 17,100 34,200 Production loss (t pa) 1,349,395 74, Cost of production loss ( M pa) Percentage reduction in production (% pa) % 8.6% 3.7% 7.4% No azoles available (Scenario 3) Area affected (ha) 123,120 34,200 17,100 34,200 Production loss (t pa) Cost of production loss ( M pa) Percentage reduction in production (% pa) 1 0% 0% 0% 0% 1 Based on loss of crop value ( ) due to reductions in yield and/or quality Denmark Potato disease control in Denmark is important, as diseases such as late blight can cause yield losses of over 30%, as well as affects on quality. The loss of azoles (imazalil) would have a significant impact on potato production in Denmark. Imazalil is the only product used for the control of tuber diseases in DK and the main use is in the production of seed tubers for export. It is very important for this production to have access to an effective seed treatment such as Imazalil and its loss would have great impact on the potato export industry. 16 of 23

17 Table 11. Impact of three scenarios of future fungicide availability on potatoes - Denmark Blight (Phytophthera infestans) Rhizoctonia solani Black dot (Colletoctrichum coccodes ) Silver scurf (Helminthosporium solani ) Skin spot (Polyscytalum pustulans ) dry rot (Fusarium spp.) Powdery scab (Spongospora subterranea ) All fungicides available (Scenario 1) Total area of crop (ha) 39,800 Total production (t pa) 1,544,240 Total value of crop ( M pa) 235 Area affected (ha) 33,830 13,134 7,960 5,174 7,960 7,960 7,960 % area affected 85% 33% 20% 13% 20% 20% 20% No fungicides available (Scenario 2) Area affected (ha) 33,830 13,134 5,970 5,174 5,970 5,970 5,970 Production loss (t pa) 459,411 25,480 5,791 52,195 5,791 5,791 0 Cost of production loss ( M pa) Percentage reduction in production (% pa) 1 30% 2% 0% 3.4% 0% 0% 0% No azoles available (Scenario 3) Area affected (ha) Production loss (t pa) , Cost of production loss ( M pa) Percentage reduction in production (% pa) 1 0.0% 0.0% 0.0% 3.4% 0.0% 0.0% 0.0% 1 Based on loss of crop value ( ) due to reductions in yield and/or quality 17 of 23

18 5 Discussion and conclusions Wheat In the last 10 years, the azole fungicides have had a major impact on wheat disease control in Denmark, France and the UK. This impact is likely to be broadly representative of their impact elsewhere in Europe, although we have shown that the scale of the benefit from fungicide use varies between countries, depending on their wheat area, the severity of different diseases, and the degree of reliance on particular active substances. The broad spectrum of azole activity has contributed substantially to the control of STB, rusts, mildew, eyespot, and FEB. The retrospective analysis reported here (Objective A), quantified the proportion of the increase in yield from fungicides which could be attributed to use of the azole fungicides, and multiplied that yield increase by the grain price per tonne for the country and year under consideration. The mean economic value from azoles across the last decade for the three countries studied, was estimated at 1,068 million euro per annum. This estimate excludes the economic value of the fungicides used, which are an input cost to the grower and a source of revenue to the manufacturers and distributors. The analysis in Objective B estimated the consequences which would result from future withdrawal from use of all azole fungicides (scenario 3). Although this might be a somewhat extreme scenario, the current uncertainty surrounding endocrine disruption, in particular, means that such a scenario is conceivable. Withdrawal of all azoles (scenario 3) was compared with two reference scenarios in which all fungicides remain available (scenario 1) or all classes of fungicides are withdrawn from use (scenario 2). Hence, scenarios 1 and 2 set the outer boundaries within which the estimated impact of scenario 3 must lie. The analysis of scenario 3 accounted for the extent to which control could be maintained by the use of alternative active substances (assuming that all other relevant fungicides remain available for use). The estimated future reduction in production which would be caused by loss of azoles was estimated at 5.0% (252,258 t p.a.), 6.8% (1,006,808 t p.a.) and 8.7% (2,753,285 t p.a.) in Denmark, the UK, and France respectively. These values represent a financial loss to growers of 34 million euro, 157 million euro and 408 million euro in Denmark, the UK and France, respectively. The extent to which these losses might be ameliorated by non-chemical control is discussed later in this section. The economic loss to growers through reduction in gross margin may differ to some extent from the figures given above, if the input costs for alternative fungicides differ from the input costs for programmes including azoles. If fungicide programmes became substantially cheaper under scenario 3, this would ameliorate a small proportion of the total economic loss to growers, but decrease revenue to manufacturers and distributors. This may happen if many alternative active substances were also removed from use, either by regulation or by market forces (i.e. if the remaining products were not cost-effective to apply to most crops in most years). The analysis used past commodity prices, because future prices are impossible to predict with any reasonable certainty. However, it is likely that if the reduction in production estimated for scenario 3 occurred across Europe, there would be a rise in grain value and/or greater price volatility. To some unpredictable extent, this would compensate the grower for the lower production, but result in higher food prices. 18 of 23

19 The impact of withdrawal of azoles would vary between the major wheat diseases. The prospects for alternative methods of control of each disease, and the implications for the vulnerability to future loss of control due to fungicide resistance, are considered below. STB control In all three countries investigated, the control of STB was highlighted as the single most important disease controlled by foliar applied fungicides, and the greatest cause for concern. Although other plant protection products such as chlorothalonil have useful protectant activity against STB, it was calculated that the effect of removing azoles from the UK, France and Denmark, would result in a financial loss totalling 428 million euro. In all countries, the analysis included the use of alternative products that are currently available (chlorothalonil is not available in Denmark). The loss of azoles would increase the use of chlorothalonil, a protectant multi-site inhibitor that has been used for over 20 years in wheat. Although classed as at low risk of resistance development, resistance has previously been shown to develop to multisite inhibitors. A recent review of the literature on fungicide resistance in Europe found that five such cases have been described in a range of pathosystems, with resistance occurring from 18 up to 57 years after fungicide introduction (Paveley et al. 2010). The increased use of chlorothalonil would increase the probabilility of resistance occurring. There is also uncertainty about the continued availability of chlorothalonil under the Water Framework Directive (WFD) in the UK. Discussions are still ongoing regarding a possible reduction of the use of chlorothalonil in France. Prior to the spring 2011 season, two new active substances both succinate dehydrogenase inhibitors (SDHI s), were registered for use in the UK. These are currently only available in formulated mixtures with triazoles in the products Aviator Xpro (bixafen + prothioconazole) and Seguris (isopyrazam + epoxiconazole). One other SDHI, boscalid was registered in 2003 for use in wheat and this is also only available in formulated mixture with epoxiconazole. As these are only currently available in mixture with azoles and are only registered in the UK, they were not considered as being available as substitutes in this analysis. However, their potential role is considered below. The SDHI actives in these mixtures have been shown to add both curative and protectant activity on STB, so could be seen as a potential alternatives for azoles, assuming products could be re-registered as solo s or in mixture with other remaining active substances. However this would be a high risk, and probably a short term solution. The SDHIs have a single-site mode of action and are considered medium to high risk of resistance development. Their use alone or with actives with no curative activity against STB would probably accelerate the development of resistance against this group. Rust control Control of yellow and brown rust would be affected in the UK and France by loss of azoles as the strobilurins provide useful control, but are not as effective as azoles or azole + strobilurin mixtures under high disease pressure. To date the strobilurins have maintained efficacy on rust control and the rust fungi are generally considered to be at lower risk of resistance development than some other pathogens. However, strobilurins have a single-site mode of action, and resistance has developed in STB, and powdery mildew in wheat and powdery mildew and ramularia in barley. An increased dependence on strobilurins for rust control would increase the probability that resistance will develop in Puccinia striifomis and P. triticina. The presence of an intron in the rust genome is thought to confer a strong/lethal fitness cost to the G143A strobilurin resistance mutation seen in other pathogens, but this does not preclude a resistance mutation occurring elsewhere in the rust genome. 19 of 23

20 FEB control Some Fusarium species in wheat cause a loss of grain quality through the accumulation of mycotoxins such as deoxynivalenol (DON) and zearalenone (ZON). They can also have a small direct effect on yield. A key risk factor in the disease pressure in a given crop has been linked to previous cropping. In wheat following maize as the previous crop, levels of DON and ZON more frequently exceed limits for human consumption. This can lead to rejections at mills and the downgrading of milling wheat to feed wheat. Currently the percentage of French wheat above the limit of 1250 ppb of DON (human food) varies from 0 to 10% between years. In Denmark the wheat area regarded to be at risk for attack of FEB is small, fungicides are rarely used specifically to control FEB. In the UK, azoles are used to reduce FEB, although the risk of rejection due to mycotoxins is relatively low. The most effective fungicides available to control Fusarium spp are azoles. Of the three countries investigated, withdrawal of azoles was predicted to have the largest effect in France, in part due to the widespread inclusion of maize as a break crop in the rotation. Some good agricultural practices (already widely used) may reduce the risk, such as burial of maize stubble, before the crop establishment. During the season, controlling Fusarium species with fungicide is still the most efficient way to prevent the risk of contamination. Thiophanate Methyl is the next most effective FEB product and provides about 70% of the control usually obtained from azoles. However it is considered likely that if it was used more widely on FEB, resistance would rapidly develop. Non-chemical disease control There is limited scope to control the major diseases of wheat by cultural practices. Analysis of disease survey data in the UK shows that changing sowing date has a relatively small effect on the severity of STB and the rusts, unless sowing is delayed until the spring (thus avoiding much of the ascospore/uredospore dispersal that initiates crop infection). Spring cropping would substantially reduce yield, compared with the predominant current practice of sowing in September/October. Hence, if azoles were withdrawn from use under scenario 3, the most effective non-chemical recourse would be for growers to switch to more disease resistant varieties. In the long-term, improvements in breeding techniques (such as marker assisted selection) may substantially improve the disease resistance of wheat varieties, and there are some early indications of progress in that direction. For the foreseeable future, variety resistance against STB will remain partial, but increasingly effective. The position with variety resistance against the rusts is likely to remain volatile, with almost complete rust resistance in some varieties being overcome by new virulent pathogen races. More effective partial resistance is likely to reduce the severity of these boom and bust cycles, but progress through plant breeding will take time. The cost to the industry of the loss of azoles would be only partially offset by a movement to more resistant varieties: firstly because of the limitations described above, and secondly because disease resistant varieties are generally lower yielding (due to direct and indirect effects from selection for resistance genes). Potatoes The only azole used in potato production currently is imazalil in the UK. Withdrawal from use in the UK would probably result in a reduction in silver scurf control, as the only remaining the key active substance for use against silver scurf is thiabendazole; against which resistance has already been detected. Reduced silver scurf control would have little effect on yield, but would be predicted to reduce potato prices due to a reduction in quality. Withdrawal of imazalil 20 of 23

21 is recognized to cause the similar problems in Denmark, where imazalil currently is the only product available. It has recently been registered for use in France (in 2011). 21 of 23

22 APPENDIX 1 ACTIVE INGREDIENTS APPROVED IN EACH CROP 5.1 Wheat Scenario 3 No azoles available Table 13 Active ingredients lost in scenario 3 and countries affected wheat Countries these products are currently approved in Active ingredients lost in scenario 3 UK France Denmark Bromuconazole Yes No No Cyproconazole Yes Yes No Difenoconazole Yes Yes Yes Epoxiconazole Yes Yes Yes Fluquinconazole Yes No No Flusilazole Yes Yes No Flutriafol Yes Yes Mo fuberidazole Yes No Yes Ipconazole Yes No No Metconazole Yes Yes Yes Prochloraz Yes Yes No Propiconazole Yes Yes Yes Prothioconazole Yes Yes Yes tebuconazole Yes Yes Yes Tetraconazole No Yes No Triticonazole Yes Yes Table 14 Active ingredients remaining in scenario 3 and countries they are available in wheat Active ingredients remaining Countries these products are currently approved in available in scenario 3 UK France Denmark Azoxystrobin Yes Yes Yes boscalid Yes Yes Yes Carbendazim Yes No No Carboxin Yes Yes No Chlorothalonil Yes Yes No clothianidin Yes? no Cyflufenamid Yes Yes No Cyprodinil Yes Yes Yes dimoxystrobin Yes Yes No famoxadone Yes No No Fenpropidin Yes Yes Yes Fenpropimorph Yes Yes No Fludioxonil Yes Yes Yes fluoxastrobin Yes Yes No Guazatine Yes Yes No imidacloprid Yes Yes Yes Kresoxim-methyl Yes Yes Yes Mancozeb Yes Yes Yes Maneb No Yes No Metrafenone Yes Yes Yes Picoxystrobin Yes Yes Yes Proquinazid Yes Yes No Pyraclostrobin Yes Yes Yes Quinoxyfen Yes Yes No 22 of 23