Blight Forum Pesticide Review European Fungicide Table Update Variety resistance LINK project. Ruairidh Bain, SAC

Transcription

1 Blight Forum 2010 Pesticide Review European Fungicide Table Update Variety resistance LINK project Ruairidh Bain, SAC

2 Pesticide Review Ruairidh Bain, SAC

3 Threat to fungicide availability Due to changes in European legislation (revision of directive 91/414/EEC) Implementation of the Water Framework Directive Market factors Size of market Market acceptability, e.g. residues in food

4 Fungicide actives under threat Mancozeb and maneb (dithiocarbamates) Revision of 91/414/EEC Chlorothalonil - Water Framework Directive

5 Possible consequences of loss of these fungicides Mancozeb/maneb Increased cost of fungicide programmes due to alternative partner fungicides being more expensive Poorer control of Alternaria blight Increased risk of insensitivity in Phytophthora blight(?) Chlorothalonil Poorer control of Alternaria blight Increased risk of insensitivity in Phytophthora blight(?)

6 Risk of insensitivity Has the risk increased? What determines risk? Inherent risk for the pathogen (P. infestans generally medium risk but classed as high for phenylamides) Mode of action of active ingredient (a.i.) Single site inhibitor, e.g. phenylamides (synthesis of ribosomal RNA) Multi-site inhibitor, e.g. dithiocarbamates

7 Risk of insensitivity What determines risk? Mode of action of partner a.i. Relative mobilities of a.i.s in/on the plant e.g. Fubol compared with Consento

8 Effect of partner a.i. on risk of insensitivity a.i. Fubol partner metalaxyl mancozeb Consento partner fenamidone propamocarb Risk for a.i. high low high low/med. Mobility systemic contact translaminar systemic Concentration in/on new growth > < Risk for metalaxyl in Fubol > fenamidone in Consento

9 Available modes of action in 2008 compared with 1992 FRAC code M3 M5 43 Risk H H MH LM LM LM LM LM L L L? PA QoI QiI ZOXA FENT PROP CAA CYM FLUA DITH CHLO FLUO

10 Risk categories for products High + low/medium High + low/medium + low High + low Medium/high Low/medium Low/medium + low/medium Low/med + low Low Low + low? + low/medium Consento, Tanos Trustan Epok, Fubol, Intro Plus Ranman, Shinkon Du-ter, Revus Proxanil Curzate M, Electis, Farmatin, Merlin, Tattoo, Valbon, Invader, Cyclops Dithane, Shirlan, Bravo Adagio Infinito

11 Has the risk increased? Percentage area treated with different risk categories % ware area treated in Scotland Consento, Tanos Trustan Epok, Fubol Ranman, Shinkon Duter, Revus Proxanil Various Bravo, Dithane, Shirlan Adagio "Infinito"

12 Has the risk increased or decreased in 2008 compared with 1992? Decreased Phenylamide use from 30% to 1% The number of a.i. insensitivity groups is now 11 compared with 5. All but one of the 11 groups have only one or two different a.i.s Increased But QoI and QiI fungicide use increased from 0% to 29% Use of dithiocarbamates and chlorothalonil have declined from c. 90% to c. 35%

13 Dithiocarbamate and chlorothalonil usage in Scotland from Ware Seed Ware (chlorothalonil only) Seed (chlorothalonil only) % of sprayed hectares treated with products containing dithiocarbamates or chlorothalonil

14 Has the risk increased or decreased in 2008? Although the number of different mode of action groups more than doubled between 1992 and 2008, the average number of foliar blight sprays in Scotland increased by approximately the same number. Number of groups Average number of sprays (ware) Average number of sprays (seed) ? 12?

15 Has the risk increased or decreased in 2008? Decreased Insensitivity in P. infestans in the field only reported for phenylamides Increased Insensitivity to QoIs in various fungal species Insensitivity of Botrytis to fluazinam claimed in Japan Insensitivity to CAA a.i.s in Plasmopara viticola Insensitivity to cymoxanil claimed

16 Has the risk increased or decreased in 2008? There is no clear evidence one way or the other Up to now the impact of sexual reproduction in the GB P. infestans population on the risk of insensitivity development has been minimal. Will this continue to be the case? One weapon against insensitivity is the diversity of modes of action of the currently available fungicides. This begs two questions : how diverse and numerous are the modes of action in the host resistance of the GB crop and how large has the recent decline in diversity been because of genetic changes in the pathogen population, e.g. the complex virulence of genotype 13_A2?

17 Acknowledgements Gillian Reay, Pesticide Usage Survey Manager (SASA) ADAS authors of the Potato Council Research Report Pesticide availability for potatoes following revision of Directive 91/414.EEC: Impact assessments and identification of research priorities. FRAC (Fungicide Resistance Action Committee)

18 European Fungicide Table Update Ruairidh Bain, SAC

19 Protocol : Effectiveness against leaf blight Products applied from beginning to end of growing season Spray intervals: 7 days +/- 1 day

20 Protocol : Effectiveness against leaf blight Doses standardised at the highest recommended European rate The rates different from the maximum UK label rate were Dithane 2.25 kg/ha Merlin 2.7 L/ha Valbon (Dutch formulation) 2.0 kg/ha Invader (Acrobat) 2.0 kg/ha

21 Protocol : Effectiveness against leaf blight Foliar blight assessed weekly AUDPC values calculated Ratings calculated using results of at least six trials

22 Location of the 13 leaf blight trials 2006 : NL, DK & UK 2007 : NL, DK, UK & D 2008 : NL, UK & D 2009 : NL, UK & D

23 Revised trial ratings (leaf blight) and change from previous ones Change Dithane NT Shirlan Consento Electis Invader (Acrobat) Valbon (NL) Merlin Ranman TP Infinito Revus

24 Euroblight 2009 UK Ranman TP Electis Untreated Shirlan Revus Laminator Flo

25 Tuber blight ratings 13 treatments tested in UK in 2009 Similar trials in NL and DK also Blanket sprays of Curzate M until foliar blight reaches c. 0.5% Test fungicides then applied at short intervals to maintain the same foliar blight control Tuber blight assessed pre- and post-storage (1600 tubers per treatment) Six trials over 2 years are required for a rating

26 Acknowledgements Funding from BASF, Bayer CropScience, Belchim Crop Protection, Certis, Dow, Gowan, Nissan, NuFarm, ProCam, Syngenta Huub Schepers & Bert Evenhuis, Applied Plant Research, Lelystad Bent Nielsen, University of Aarhus Hans Hausladen, Technical University of Munich

27 Variety Resistance LINK project Sustainable and effective control of potato blight : matching fungicide inputs to cultivar resistance SAC ADAS SCRI DEFRA RERAD Potato Council Bayer CropScience Branston Greenvale AP Higgins Syngenta Crop Protection

28 Objective To provide robust data to support the widespread use of integrated blight control management without compromising the control of blight April 2009 to September 2012

29 Evaluate integrated control Up to date cultivar ratings Effective integrated control Integrated control knowledge Model cultivar resistance and fungicide Up to date fungicide ratings

30 Up to date cultivar resistance ratings Robust information on cultivar resistance is a pre-requisite requisite for successful integrated control. Early warning of any deterioration on in cultivar resistance is essential. Monitor P. infestans population Test appropriate cultivars for resistance using contemporary P. infestans genotypes

31 Up to date cultivar resistance ratings Test appropriate cultivars for resistance using contemporary P. infestans genotypes Foliar and tuber resistance Cultivars selected on the basis of the top 20 (planted area) with h a published foliar blight resistance of 5 or greater Six P. infestans genotypes dominant in the period 2003 to 2008 selected. Isolate Genotype 07/39 13_A2 2008_6090A 6_A1 2008_6066A 7_A1 2008_6070E 8_A1 2008_6262A 10_A2 2008_6850D 2_A1

32 Model cultivar resistance and fungicide It s s only possible to test experimentally a small fraction of the possible combinations of treatments Modelling the interaction of host resistance with the efficacy of o fungicide treatments demonstrates how fungicide efficacy and spray interval should be adapted to exploit resistant cultivars Controlled experiments will examine the impact of cultivar resistance on the persistence of fungicide protection and curative activity

33 Evaluate integrated control Evaluate the performance of different levels of integrated blight t control 2009, 2010 and 2011 seasons 2 trial sites (Scotland & Wales) separate trials for rapid canopy (Revus) and stable canopy (Infinito, nito, Revus and Shirlan) five fungicide doses and two spray intervals (7 & 10 days) integrated control is a combination of a more resistant cultivar r (Cara or Markies) treated with less fungicide input than the susceptible King Edward

34 Integrated control knowledge Develop a web-based based tool that allows agronomists and others to analyse the protection afforded by different fungicide inputs in relation to cultivar resistance, fungicide ratings and the timing g of fungicide applications in relation to high-risk weather Technical article explaining integrated control of potato blight Summary of results from fungicide positioning trials demonstrating ng the concept of critical sprays Summary of results from previous and current integrated control trials, in appropriate format Experiences of integrated control in commercial crops

35 Benefits from the research Reduced cost of control where appropriate Reduced environmental impact of blight fungicide programmes Optimise the use of nitrogen and irrigation water Comply with the EU Thematic strategy integrated control Facilitating substantial use of integrated crop management by providing the potato industry with the robust information required The project output should have enduring practical value because it will relate required fungicide inputs (product, interval and dose) to categories of host resistance and fungicide efficacy ratings