Spot Form Net Blotch Factsheet

Spot form net blotch (SFNB) is the most common foliar disease of barley in Australia. It can be economically important in favourable seasons. Management relies on a combination of crop rotation, variety selection and strategic fungicide applications.

Key Points

• Spot form net blotch (SFNB) is the most common foliar disease of barley in Australia across all rainfall zones
• It is favoured by close rotation of susceptible barley varieties and crop residue retention practices
• SFNB frequently causes yield loss where grain yield potential exceeds 2.5 tonnes per hectare
• Significant losses are possible in all varieties given conducive conditions, with potential losses greatest in varieties rated susceptible to very susceptible (SVS) or very susceptible (VS)
• When susceptible varieties are grown in situations where disease is present, fungicides are likely to provide economic return where grain yield potential exceeds 3t/ha
• The most effective fungicide application strategies include treatment at two stages − either seed/fertiliser treatment and foliar at Z39, or foliar at both Z31 and Z39