The Relationship Between Eyespot Severity and Yield and Quality Losses in Winter Wheat

Abstract

We estimated yield and quality losses in winter wheat due to eyespot disease based on field experiments over three years in Hokkaido. The yield and quality of wheat decreased when the stems were completely girdled by lesions but no lodging occurred. Eyespot infection did not affect ear number per m² and grain number per ear, but reduced 1,000-grain dry weight under severe infection, resulting in a decrease in the yield. The yield did not decrease significantly when less than 90% of stems were covered with lesions and disease severity index was less than 40.