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