A foliar disease of wheat, Septoria tritici blotch has a significant impact in the high-rainfall zones, and occasionally the medium-rainfall zones, of southern and eastern Australia.

Key points

• Septoria tritici blotch (STB) is a damaging and widespread stubble-borne foliar disease of wheat.
• Stubble-retention farming systems support STB carryover from one season to the next.
• When inoculum is present, disease build-up is greater when susceptible varieties are grown.
• STB can cause grain yield losses of up to 46 per cent in susceptible varieties in high-rainfall zones (HRZ). Yield loss is sporadic in medium-rainfall zones (MRZ) and rare in low-rainfall zones.
• STB requires regular and ongoing management in the HRZ and, in some seasons, in the MRZ.
• STB management requires an integrated approach: combine variety selection, paddock selection and stubble management; avoid early sowing of highly susceptible varieties; and, when required, make timely fungicide application/s.
• Effective control is challenged by limited availability of resistant varieties and increasing pathogen resistance or reduced sensitivity to fungicides.
• Consult the latest cereal disease guide for your region for variety resistance ratings.
• Use appropriate fungicide management strategies to delay further development of STB resistance.