Effect of Eyespot (Cercosporella herpotrichoides) and Seed Treatments of Benomyl, Chlormequat and Organomercury on Rye

Abstract

SUMMARYA field trial of autumn‐sown rye cv. Lovaszpatonai subject to natural infection with Cercosporella herpotrichoides showed that eyespot, in the absence of lodging, was significantly correlated with reduced grain size and 1,000 grain weight but not with total yield in weight of grain. No seed treatment affected total yield although benomyl significantly increased fertile tiller number, increased the percentage of lesion‐free tillers in April, and by July, compared with the control, had reduced the number with eyespot lesions by 38 per cent. In laboratory experiments organomercury and a combined treatment of organomercury plus chlormequat protected seedlings from attack by seedborne fungi and in the field trial these treatments also increased the percentage of lesion‐free tillers in April but did not affect the numbers with eyespot in July.