P1812281: Monitoring the development of resistance in wheat and barley pathogens to foliar fungicides

P1812281: Monitoring the development of resistance in wheat and barley pathogens to foliar fungicides


Since the mid 1970s, fungicides for the control of foliar diseases have become a vital part of economically sustainable cereal production in the UK. In their absence, significant yield losses and declines in quality occur. Fungicide manufacturers have introduced several different fungicide modes of action (MoA), but a number of key cereal pathogens have developed resistance to one or more of these. Current foliar disease control in wheat and barley relies principally on three fungicide MoA, triazoles, quinolin outside inhibitors (QoIs) and succinate dehydrogenase inhibitors (SDHIs), but at least one cereal pathogen has developed resistance to all these MoA. In some pathogen/MoA combinations the resistance is functionally complete, in others it is partial and stable, and others partial but evolving. There are an additional range of so-called multi-site fungicides which are robust against the development of resistance, but all are under threat from legislation and have a limited disease spectrum. As new fungicide MoA are introduced, pathogens are likely to evolve resistance to these and while the risk of resistance development can be predicted to an extent, the timing, severity and speed of development cannot be predicted.

In order for levy payers and their advisors to design fungicide programmes that provide adequate disease control and minimise the risk of resistance development, up to date information on the resistance status of key pathogens to the main fungicide MoA used to control them is required.


The project will include the following components.

Monitoring of the spread of known mutations (including target site and non target site) to SDHI and triazole fungicide groups, alongside the testing of fungal isolates for new mutations to these fungicide groups and the implications of new mutations for fungicide sensitivity with either invitro and/or in planta testing.

  1. Development of highly sensitive DNA-based genotyping assays for the detection of resistance conferring mutations (including target site and non target site) to any new fungicide MoA introduced to the UK cereal market targeting the key diseases of wheat and barley during the duration of the project.
  2. Monitoring to detect the evolution and spread of mutations (including target site and non target site) conferring resistance to any new fungicide MoA introduced to the UK market targeting the key diseases of wheat and barley during the duration of the project and the implications of new mutations for fungicide sensitivity.

The key disease requiring annual monitoring and sensitivity testing is septoria leaf blotch in wheat (Zymoseptoria tritici). Net blotch (Pyrenophora teres), rhynchosporium leaf scald (Rhynchosporium commune) and ramularia leaf spot (Ramularia collo-cygni) in barley may require monitoring and sensitivity testing on an ad-hoc basis in response to changes in field performance of fungicides.

The development of assays for monitoring sensitivity of septoria leaf blotch and the annual testing of septoria to new fungicide MoA will be included in the project budget. It is anticipated that at least one new fungicide MoA will be authorised for use in the UK during the duration of the project.

Monitoring and sensitivity testing of net blotch, rhynchosporium and ramularia will be funded separately on an ad-hoc basis as required, but the expertise and capacity to undertake this, in addition to the annual testing of septoria, must be available.

Fungal isolates for testing will be obtained from AHDB fungicide performance trials, commercial crops or other suitable sources. Leaf samples will be collected and delivered to the successful bidder and no allowance for collection of plant material should be made within the project proposal, beyond the writing and annual updating of a suitable collection protocol.

Required testing

AHDB conducts six trials targeting control of septoria. Annual testing must include these trials, with five treatments tested as listed below. The testing must include phenotyping to establish the sensitivity profile of the population and genotyping to test for mutations in the target gene.

1 – Untreated (pre and post treatment)

2 – Two azole treatments (post treatment)

3 – Two SDHI treatments (post treatment)

The specific azoles and SDHIs tested may vary, depending on those being marketed and considered most appropriate to farm decision making. If new fungicide MoAs are introduced to the UK cereals market, testing of these would replace one of the five treatments above, rather than being in addition to these.

Each treatment is replicated three times and it is anticipated that replicates will be pooled for phenotyping and genotyping, giving a total of 5 samples for each trial and 30 samples in total per year. For each sample, a minimum of 30 isolates per population should be phenotyped. Genotyping should be carried out on the least sensitive strains to characterise the resistance mechanisms involved.

Additional testing

Testing of the six AHDB trials should be considered the minimum required, not the maximum. Proposals that include additional testing within the allotted budget or contain co-funding, either as cash or in-kind, allowing additional testing would be favoured.


Results from annual testing must be reported to AHDB by the end of November in the year of sampling.

Budget & Duration

The Project will commence April 2019 until 31 March 2022, with an annual budget of £30,000 (total budget £90,000).

Application Procedure

Applicants should complete an AHDB Research and KE Application Form – Full Proposal Large, referring to the guidance notes to aid completion. 

Applications are made on the basis of the AHDB Research Funding Agreement and any organisation receiving funding shall comply with the terms and conditions specified in the RFA. AHDB will not be held responsible for any expenses or losses incurred by applicants in the preparation of an application(s).

Completed application forms should be submitted to research@ahdb.org.uk no later than 18:00 on the 4 February 2019.

Proposed timings for application and project delivery

Stage of Process


Call published

18 December 2018

Full proposal submission deadline

4 February 2019

Applicants informed of outcome

22 February 2019

Project commencement

1 April 2019

Project completion

Three years (ending 31 March 2022)


If you have a specific question related to this call please email research@ahdb.org.uk. As part of the open tender process AHDB cannot discuss specific project details prior to submission of a proposal. All Questions and Answers are published.

Assessment criteria

The standard assessment criteria will be used.