A SURVEY OF FOLIAR DISEASES OF SPRING BARLEY IN ENGLAND AND WALES IN 1967

A total of 5,250 acres of spring barley was sampled in proportion to the barley acreage in each of eight regions. The percentage leaf area ‘affected’ by each disease was recorded for the first (flag) and second leaves at a growth stage when the grain was milky ripe. The operation was automated by punching the data directly on to computer paper tape and a programme was written to analyse the results. Mildew was found to be the most important disease, causing an average loss in yield of approximately 18 %, followed in descending order by brown rust 3%, leaf blotch 1 %, yellow rust 1 %, halo spot 1 %. The total loss due to foliar diseases was estimated to be 20–25% of the national barley yield. Diseases were more severe in the southern than northern regions, e.g. mildew severity was three times higher because of the greater popularity of mildew‐susceptible varieties, and the prevalence of weather more conducive to mildew development. Disease severity was not related to previous cropping, and in general the February‐sown crops had more mildew than the April‐sown crops. Copyright © 1969, Wiley Blackwell. All rights reserved