Eyespot (wheat)

Eyespot (also known as Strawbreaker foot rot) is a common disease affecting wheat crops. It is caused by the fungus Oculimacula yallundae and Oculimacula acuformis. The disease is named for the characteristic 'eyespot' lesions that form on the wheat stem base.

Symptoms

The primary symptom of Eyespot is the presence of eye-shaped lesions on the stem base of the wheat plant. These lesions are typically tan in color with a dark brown border, resembling an 'eye'. As the disease progresses, the lesions can girdle the stem, causing it to break (strawbreaker) and resulting in significant yield loss.

Cause

Eyespot is caused by two species of the fungus Oculimacula, O. yallundae and O. acuformis. These fungi survive in wheat residue left on the field surface and infect the next wheat crop. The disease is more severe in continuous wheat cropping systems and under wet, cool conditions.

Management

Management of Eyespot involves a combination of cultural practices and fungicide application. Cultural practices include crop rotation with non-host crops, removal of infected residue, and use of resistant wheat varieties. Fungicides are typically applied in the spring when the first lesions are observed.

Impact

Eyespot can cause significant yield loss in wheat crops, particularly in cool, wet climates. The disease can reduce grain yield and quality, and cause lodging, which makes harvest more difficult.

See also

• Wheat diseases
• Fungicide
• Crop rotation