Biology Net blotch is a common, destructive foliar disease of barley in western Canada, second only to scald as a cause of yield loss.
Net blotch is more common than scald in the warmer, drier regions of the prairies.
The fungus overwinters on the seed or crop residue. Spores are produced and spread by wind and rain. Spores produced on infected plants are mainly responsible for destructive, secondary spread of the disease within the crop. Spore production and infection of the growing crop is favoured by high relative humidity and temperatures around 20 degrees Celsius. Damage Description Light brown spots with distinctive dark brown net-like patterns appear on the leaves, sheaths and glumes.