Ergot of rye – Infecting Plants or People?

by Ben Shaw – Sustainable Plant Systems Major, Agronomy Specialization

Stephen Patton. University of Kentucky Agricultural Communication Services,

Stephen Patton. University of Kentucky Agricultural Communication Services,

What causes it?

Claviceps purpurea is the pathogen responsible for ergot. It thrives in areas of high moisture, but also requires a freezing winter period of 4-8 weeks. This is for their sclerotia to increase survival and reduce competition because most fungi will not withstand that. This, in my opinion, is just incredible that it has adapted to colder temperatures to increase it’s survival.

What does it do?

Ergot is a disease that infects the ovaries of cereal and grain plants. Dating back to the Middle Ages, this disease has caused numerous outbreaks in humans and animals commonly known as ergotism, by eating the disease along with the rye flour. “Holy Fire”, as it was called, would cause horrible symptoms including extreme hallucinations, convulsions, loss of limbs, excruciating burning pains, and death was certain if enough was ingested. I cannot imagine the pain that these people went through, and to top it off they had no idea what was causing it.

Is it still an issue today?

Yes ergot is still an issue facing agriculture today. However, it is due to downgraded loads and in livestock rather than “Holy Fire” in humans. According to The Western Producer, 50% of wheat from Alberta was downgraded due to ergot in 2015.

How can we control it?

A good crop rotation with a non-susceptible host will prevent the disease from returning. Deep plowing will also bury the sclerotia and prevent them from germinating next spring.

I have never been exposed to ergot, however don’t think it can’t affect you. Keep your eyes peeled and alert for any signs of this disease, unless you want to experience “Holy Fire” first hand.

Sources Cited:

Schumann, Gail L. APS. “Ergot of Rye.”

Stephen Patton. University of Kentucky Agricultural Communication Services,

Cross, Brian. The Western Producer. “Experts fear ergot may become perennial problem.”

This blog post was an assignment for Societal Issues: Pesticides, Alternatives and the Environment (PLNTPTH 4597). The views expressed are those of the author and do not necessarily reflect the views of the class, Department of Plant Pathology or the instructor.





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