Ergot (Claviceps purpurea)

Ergot: biology

Ergot is a soil- and seed-borne fungal disease affecting cereal crops including rye and wheat. Sclerotia (aka ergot bodies) near the soil surface produce wind-borne spores. There can be a secondary spread from spores in the sticky liquid that develops on the surface of infected florets. This spread depends mainly on insects and rain splash.

Kernel-sized protruding purple to black sclerotia (ergot bodies) replace some kernels. May be more severe at field margins adjacent to grasses. Sclerotia occur in harvested grain. At flowering early infections appear as droplets of yellowish sticky liquid (honeydew) and may appear dirty because of attached dust.

Small yield losses occur as infected florets either form sclerotia or are sterile. Downgrading of grain occurs because sclerotia contain toxic compounds. Feeding grain with greater than 0.1% ergot is considered dangerous to livestock.