ergot of rye + cereals

Symptoms

Hard purple-black curved sclerotia (5-30mm long) replacing kernels in cereal heads (very distinctive — looks like a black banana stuck in the head), honeydew (sticky yellow exudate) on flowering heads during infection phase, sclerotia drop to ground at harvest + survive winter, contaminated grain dangerous for human + animal consumption.

Plants affected

• bread wheat
• Italian ryegrass
• Cock's-foot (orchard grass)
• Cockspur grass
• Timothy
• Smooth brome
• Tufted hair-grass
• Couch grass
• Yorkshire fog
• Green foxtail
• Meadow foxtail
• Sweet vernal-grass

Easily confused with

• fusarium head blight / scab

  How to tell them apart: Fusarium graminearum (Fusarium head blight): one or more spikelets, or a whole section of the ear, bleach to a pale straw colour while the rest of the head stays green; in humid weather look for salmon-pink to orange spore masses (sporodochia) at the base of the glumes and along the rachis. Infected grains shrivel into chalky-white, lightweight 'tombstone' kernels but stay inside the floret. Claviceps purpurea (ergot) instead replaces individual kernels with a hard, protruding body: first a sticky, sweet yellowish 'honeydew' drop oozes from the floret, then it hardens into a dark purple-black, curved horn (sclerotium) that sticks out well beyond the glumes, far larger than a normal grain. Key tell: pink/orange fuzz and shrivelled pale grains = Fusarium; a black horn-shaped lump replacing a grain = ergot.

Common questions

How do I recognise ergot of rye + cereals on bread wheat?

Hard purple-black curved sclerotia (5-30mm long) replacing kernels in cereal heads (very distinctive — looks like a black banana stuck in the head), honeydew (sticky yellow exudate) on flowering heads during infection phase, sclerotia drop to ground at harvest + survive winter, contaminated grain dangerous for human + animal consumption.

Do I have to report ergot of rye + cereals?

No. ergot of rye + cereals is not a notifiable organism, so there is nothing to report to an authority. Treat it as a normal garden problem.

How is ergot of rye + cereals treated?

Mainly with biological and cultural measures — removing affected material, changing the conditions that favour it, and treating with agents approved in your country. The exact steps and their timing depend on the plant, the season and where you live: Dr. Phyto works them out in a free diagnosis.