Disease research for cereals and oilseeds

AHDB research examines the sensitivity of crop pathogens to fungicides and monitors resistance in the UK. We also invest in integrated pest management (IPM), which includes the publication of varietal disease resistance ratings in the Recommended Lists (RL).

Many economically important diseases of cereals and oilseed rape are caused by pathogenic fungi. Although fungicides are available to treat crop diseases, product efficacy levels vary, with some pathogens exhibiting degrees of resistance to some mode of action (MoA) groups. As a result, management requires the use of non-chemical interventions, as part of IPM, alongside well-designed fungicide programmes.

AHDB research focuses on:

• Production of resistance ratings for major diseases, as part of the RL
• Delivery of independent information on the efficacy of fungicide active ingredients
• Monitoring resistance to fungicides in cereal pathogens
• Development of IPM approaches to reduce reliance on chemistry

Some viruses are also economically significant. These include Barley yellow dwarf virus (BYDV) in cereals and Turnip yellows virus (TuYV) in oilseed rape. Transmitted (vectored) by aphids, related projects are described on our pest research pages.

Knowledge of the potential power of an active ingredient (or product) is essential in disease management. First and foremost, it will help you gauge the potential return on your spray investments. Critically, it can be used to develop effective fungicide programmes that balance the need to control disease with the need to protect chemistry from fungicide resistance. The current fungicide performance project phase is part of a strategic investment in trials – with the wheat, barley and oilseed rape trial series going back to 1994, 2002, and 2006, respectively. The researchers test new and established products, with latest information released at AHDB’s Agronomists’ Conference (in December) or as soon as new fungicides hit the market.

Fungicide resistance monitoring

In theory, any pathogen can develop resistance to fungicides. However, the risk is not the same in all pathogens. In wheat, septoria tritici is currently of greatest concern. AHDB-supported work monitors changes in pathogen sensitivities to key fungicide mode of action (MoA) groups and studies the genetic basis of resistance.

Case study: DMI (azole) resistance in septoria tritici

Septoria populations gradually started to become less sensitive to DMIs (azoles) in 2001. The loss of sensitivity is due to various mutations, which are highly variable across the UK. There is a relatively large variation in performance of active ingredients in this group.

Case study: SDHI resistance in septoria tritici

Monitoring of septoria populations started to detect significant shifts in sensitivity to SDHIs in 2017. As SDHIs show cross-resistance with other SDHIs, the efficacy data provides a warning for all users of SDHI chemistry. Like azoles, there appears to be year-on-year and site-to-site variability in control.

AHDB Recommended Lists (RL)

Varietal disease resistance is the foundation of control. Our RL trials produce disease resistance ratings for wheat, barley, oat and oilseed rape varieties. Varieties that are more resistant allow greater flexibility in fungicide programmes – including the omission of sprays and the use of reduced doses, especially where disease pressure is low.

UK Cereal Pathogen Virulence Survey (UKCPVS)

The UKCPVS continually monitors cereal rusts and mildews in UK varieties. When a change in virulence (ability to cause disease) is detected, the project determines the significance for resistance in RL varieties, in addition to varieties in trials and breeding programmes.

*A report is submitted at the end of each project. After review (which can take several weeks), the final project report is published on the corresponding project page. At this stage, the project is official complete.

Information on all disease research projects is available in our research archive:

• In the ‘Sector’ drop-down box, select ‘Cereals & Oilseeds’
• In the ‘Topic’ drop-down box, select ‘Disease management’