How to Manage Pests

UC Pest Management Guidelines

Small Grains


Pathogen: Claviceps purpurea

(Reviewed 2/07, updated 2/07)

In this Guideline:


The presence of bluish black, elongated sclerotia that replace one or more kernels of a grain spike signals an ergot infection.


Ergot affects rye and triticale more frequently than wheat, barley, or oats. Grasses 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. Sclerotia are toxic to both humans and livestock.


Clean seed, crop rotation, and deep tillage help to control this disease. Sclerotia do not survive more than one year, and do not produce spores if they are buried more than 4 inches deep. There are no recommended chemical treatments for this disease.


[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Small Grains
UC ANR Publication 3466


R. M. Davis, Plant Pathology, UC Davis
L. F. Jackson, Agronomy, UC Davis

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