The Australian Bureau of Agricultural and Resource Economics and Sciences quantified the hypothetical damage bill from an outbreak of the wheat rust strain in a report published last week, highlighting the importance of keeping Australia’s $6 billion wheat industry free of the disease. According to the report, the most severe and recent outbreak of wheat rust was the 1973 event, estimated to have cost the wheat industry between $200 million and $300 million. Around 30 per cent of current wheat varieties show moderate to high susceptibility to the Ug99 strain. Wheat stem rust can affect all above-ground parts of a plant, including stem, leaves, and inflorescence. Infected wheat plants could also produce shrivelled grain, with an untreated infection able to reduce grain yield by up to 90 per cent. ABARES executive director Steve Hatfield-Dodds said while Ug99 is not present in Australia, it poses a risk to the wheat industry in terms of revenue loss and increased production cost. “It is a highly virulent strain of wheat stem rust that has overcome 17 of 34 stem rust resistance genes found in wheat,” Dr Hatfield-Dodds said. Dr Hatfield-Dodds said the results of the study highlighted the importance of keeping Australia Ug99 free. Dr Hatfield-Dodds said eradication of Ug99 could only be feasible if the rust was detected while contained in a small area. “It is crucial we take measures to keep Ug99 from entering the country in the first place,” Dr Hatfield-Dodds said. “Significant work is being done in surveillance, monitoring pathogen populations over time to track potential virulence evolution, and pre-breeding for germplasm resistance.” According to the report, the Ug99 fungus is generally spread by wind, movements of infected plant materials and contaminated farm equipment. There are a number of ways to prevent crop losses and control spread of the fungus within a wheat farm, such as planting a resistant variety, and using herbicide sprays and livestock grazing between two planting seasons tor educe density of self-sown cereals and grasses. Source - https://www.weeklytimesnow.com.au