Six six-row Nordic spring barley genotypes (Hordreum vulgare L.) were
assessed in the field in Finland (1994 and 1995) for resistance to Rhy
nchosporium secalis (Oud.) J.J. Davis, the causal pathogen of scald, i
n artificially inoculated plots. The barleys were known not to contain
major genes for resistance to scald and the purpose of these experime
nts was to identify quantitative differences in resistance to scald wh
ich might be exploitable in a breeding programme, Disease development
was monitored, grain yield and yield components were recorded, and the
se data were compared with measurements taken from plants in plots kep
t free of disease. Data, averaged over both years, for disease develop
ment on the uppermost three leaves - areas under disease progress curv
es, terminal severity and apparent infection rates - indicated that 'V
erner', 'Pohto' and 'Pokko' were symptomatically significantly more re
sistant to scald than 'Arve', 'Loviisa' and Jo 1599. Grain yields, tho
usand-grain weights, test weights and proportions of plump grains were
all significantly reduced in plots inoculated with scald compared wit
h those kept free of disease;'Verner' appeared to be the most useful g
enotype for use in crossing programmes to improve scald resistance in
Finnish barleys.