Ergot is a fungal pathogen that infects cereal crops during the flowering period, causing hard, dark ergots to develop in place of grain.
Ergot is highly toxic when ingested by humans and livestock.
A recently completed review of ergot management practices has allowed the Agricultural and Horticultural Development Board (AHDB) to issue new guidance to help farmers reduce disease pressure, limit crop infection, and keep clean grain clean.
The review work was undertaken by the UK-based agricultural consultancy ADAS.
Reducing ergot levels
The guidance provided by AHDB recommends four main ergot management prevention strategies: reducing initial inoculum levels, infection risks, secondary spread, and contamination
Reduce initial inoculum levels
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 5cm for at least one year.
Although ploughing is best for burial, any cultivation is more effective than direct drilling.
Reduce infection risks
Growers are advised to include rotational adaptations, such as growing a non-cereal crop or a less susceptible cereal crop.
In order of decreasing susceptibility, these are: 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.
Reduce secondary spread
Ergot affects a wide range of grass species, including blackgrass. As blackgrass flowers earlier than cereals, it is a key target for management.
The use of integrated pest management approaches can reduce reduce grass-weed pressures.
Careful management of high-risk fields or areas – such as headlands, tramlines and grass margins – will always be required.
Reduce contamination
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.
The risk of ergot infection is especially high in wet seasons, so be on the lookout for this pathogen when combining or buying grain for livestock feed.
Infected grain can make cattle seriously ill by constricting blood vessels and damaging the nervous system, resulting in seizures, loss of muscle strength, poor co-ordination and, in severe cases, death.
Grain bought from merchants is usually checked at intake, so the risk of encountering an ergot challenge from these sources is low. However, the same cannot be said for home save grain or cereals bought privately.
One of the most alien-looking of all cereal pathogens, ergot infection occurs early in the plant’s life.
Right from the seed, the fungus grows with the plant with symptoms only becoming evident at grain formation.
Growers see the grain replaced with a long, hard, black mass often slightly larger than the grains themselves.
