Agriculture: Small Grains Pest Management Guidelines

Ergot

  • Claviceps purpurea
  • Symptoms and Signs

    An ergot infection is diagnosed by the presence of bluish-black, elongated sclerotia that replace one or more kernels of a grain spike.

    Comments on the Disease

    Ergot affects rye and triticale more frequently than wheat, barley, or oats. Over 400 grass species serve as hosts of this pathogen. Cultivated and wild grass species (e.g., bentgrass, fescue, bluegrass) are often the main reservoir of the disease. The fungus survives as sclerotia in or on the soil, producing airborne spores in spring. The spores infect floral tissue, eventually forming sclerotia in place of grain kernels. Ergot sclerotia are toxic to both humans and livestock.

    Management

    Cultural Control

    Use clean seed, crop rotation, and deep tillage to help control this disease. Sclerotia do not survive more than 1 year and do not produce spores if they are buried more than 4 inches deep. Ergot infections are rare in California. Infected fields may require specialized harvest plans.

    Chemical Control

    No fungicide treatments are recommended for this disease.

    Text Updated: 04/26

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