A comprehensive review of ergot management evidence has strengthened AHDB's guidance to help UK farmers reduce disease pressure, limit crop infection and keep clean grain clean.

The ADAS-led review appraised academic and non-academic (grey) sources, which included information from industry stakeholders and current ergot management guidelines.

It identified four key management strategies, which have been published on the AHDB website, with further details available in Research Review 102.

Ergot is a fungal pathogen (Claviceps purpurea) that can infect major UK cereals during flowering, causing hard, dark ergots to develop in place of grain. Ergot is highly toxic when ingested (by humans and livestock).

GB has contractual limits for ergot by weight for feed grain and zero tolerance for all other grain. In 2022, the EU implemented stricter levels for specific cereals and products traded in the EU (including Northern Ireland), which introduced maximum levels (MLs) for ergot alkaloids for the first time. Adoption into UK law is being considered. As alkaloids can be detected in grain with no visible ergot symptoms, they provide a tougher test for grain quality.

The ergot review was funded via a levy-payer-led commissioning process and developed with input from the Ergot Working Group, which is chaired by UK Flour Millers (UKFM).

Joe Brennan, UKFM Head of Technical, said: "The AHDB contaminants monitoring project shows that ergot alkaloid levels in UK cereals are generally very low, but spikes are seen in some cereal samples in some years.

"Ergot is adding costs across the cereal supply chain and contributing to food waste. Adopting efficient approaches to tackle ergot at source is crucial to reduce these costs and enhance food safety."

Management strategies

The four management strategies tackle specific points in the ergot life cycle, with higher-impact interventions summarised below:

1. Reduce initial inoculum: Reduce the amount of ergot and its viability to limit the production of primary spores

   Higher-impact interventions cover the strategic use of cultivations and drilling high-quality, clean seed (whether certified or home-saved). Cultivations should aim to bury ergots to at least 5 cm for at least one year. Although ploughing is best for burial, any cultivation is more effective than direct drilling.

2. Reduce infection risk: Grow lower-risk crops to reduce infection events

   Higher-impact interventions include rotational adaptations, such as growing a non-cereal crop or a less-susceptible cereal crop (in order of decreasing susceptibility: rye, triticale, wheat, barley and oats). Although information on varietal risk is limited, higher risk is associated with varieties that are open-flowering, flower for longer or produce more late tillers.

3. Reduce secondary spread: Manage grass weeds to stop them becoming a spore source

   Ergot affects a wide range of grass species, including black-grass. As black-grass flowers earlier than cereals, it is a key target for management. The higher-impact interventions are based on integrated weed management approaches to reduce grass-weed pressures.

4. Reduce contamination: Know where ergot is and manage infected grain to keep clean crops clean

   Higher-impact interventions require careful management of high-risk fields or areas (such as headlands and tramlines) and grass margins. It is particularly important to harvest infected areas separately and segregate contaminated grain from other grain. Although it is possible to clean grain to some degree, it is not always completely effective, especially as some ergot fragments are extremely small.

Kristina Grenz, AHDB Senior Cereal Product Quality Scientist (Contaminants), said: "We now know far more about ergot. By mitigating ergot risks in the field and in grain, combined with modern production practices, we have much greater ability to manage ergot than we did in the past.

"The ergot management interventions will need careful integration in production systems, especially to deal with competing objectives, such as the use of reduced tillage or ergot-susceptible grass species in field margins. The strengthened guidance will help farmers balance decisions, in view of the risks and the opportunities."

The full set of interventions, which also covers valuable moderate- and lower-impact approaches, is available on the AHDB website: ahdb.org.uk/ergot