Symptoms vary with the variety and weather. Yield loss is proportional to the amount of leaf area destroyed on the upper two leaves. The average yield loss in Alberta is about 1.5 per cent. Losses of 50 per cent and more have occurred in highly susceptible varieties such as Elrose. Net blotch lowers grain yield and brewing quality by reducing the carbohydrate content of kernels.
Diagnosis Use the barley scald assessment procedure to obtain an indication of crop loss.
Management Strategy Use resistant cultivars. Bury crop residue and destroy volunteers. Use balanced applications of nitrogen and phosphorus. Heavy nitrogen applications generally produce conditions favourable to outbreaks of this disease. Follow a crop rotation for at least two years with non-susceptible hosts.