The effect of benomyl systemic fungicide and the growth regulator CCC on eyespot disease of barley

SUMMARY The systemic fungicide benomyl was used as a seed dressing and as a spray at two concentrations, 250 and 500 ppm, on the winter barley variety Pella. An additional treatment was a spray application of CCC at 500 ppm. All spray treatments were applied at growth stage 3–4. Without fungicide treatment, total yield in the inoculated plots was approximately 40% of that in the uninoculated plots. The 500 ppm fungicide-spray treatment significantly decreased incidence and severity scores of eyespot, the seed dressing being significant only for the latter. The seed dressing and 500 ppm spray treatments significantly increased mean yield/head, fertile tiller number and 1000 grain weight. All the fungicide treatments significantly increased total yield in the inoculated plots. There were no significant effects of CCC upon disease or upon yield, neither was there any interaction between benomyl and CCC.