Investment

Septoria tritici blotch (Zymoseptoria tritici) (STB) is a damaging disease of wheat that without control can cause extensive losses in susceptible wheat cultivars in high rainfall (HRZ) situations, but in the medium (MRZ) and low rainfall zones (LRZ) of the southern grain growing regions of Australia its impact on yield is less understood.

The introduction and widespread use of wheat cultivars with partial resistance to STB provided long term control of this disease (Murray et al. 1990), but in recent times with evolution in the pathogen population the majority of wheat cultivars currently grown in the MRZ and LRZ are either Susceptible (S) or Very Susceptible (SVS) to STB.

Recent surveys have shown that STB is now widespread across Victoria and South Australia's MRZ and LRZ. Despite it being widespread field studies in the Victorian Wimmera and South Australia's Mid North and upper York Peninsula failed to show economic yield losses due to this disease, again showing the role of seasonal conditions on disease impact. This variability in impact increases the uncertainty for growers when deciding how to manage this disease.

The objectives of this project are to provide an improved understanding of the conditions that are likely to result in economic impact from STB and the strategies that growers can use to reduce its impact in the MRZ and LRZ regions of southern Australia.