Increasing virus epidemics threaten Australia's cereal and oilseed crops

A researcher from The University of Western Australia’s Institute of Agriculture has led a comprehensive review of virus disease research in Australia's cereal and oilseed crops since the 1950s.

The review, recently published in the journal Viruses, warned that the Australian agriculture industry must prepare for “potentially devastating” future virus disease epidemics.

Due to the current COVID-19 pandemic, lead author UWA Adjunct Professor Roger Jones said virus epidemics were on the public’s mind.

“However, few people realise that epidemics of virus diseases threaten not just humans, but all types of organisms including the food crops that humankind depends on,” Professor Jones said.

Virus epidemics in crops around Australia can drastically reduce the infected crop’s seed yield and seed quality, causing serious financial hardship to growers and shortages in produce supply.

Image: Wheat showing wheat streak mosaic virus disease symptoms.

Professor Jones said these virus-induced crop losses ranged from minor to complete crop failure and were increasing in magnitude.

“A comprehensive review of the biology, epidemiology and management of damaging virus diseases of these critically important crops was therefore both overdue and timely,” he said.

All 31 viruses known to infect the diverse range of cereal and oilseed crops grown in the continent’s temperate, Mediterranean, subtropical and tropical cropping regions were included in the review.

Seven of these viruses are currently of major economic importance.

Depending on the virus concerned and climatic conditions, the most important virus vectors that spread each of the 31 viruses were aphids, whiteflies, thrips, leafhoppers or mites.

Professor Jones said there were major future threats to managing virus diseases of cereals and oilseeds effectively.

“Climate change, induced climate instability and extreme weather events have altered virus epidemiology and vector distributions and decreased the effectiveness of virus and vector control measures,” he said.

“Effective virus management is being influenced by increased insecticide resistance in key insect and mite vectors, the development of resistance-breaking virus strains, and insufficient industry awareness of virus diseases.

“Further even more damaging crop viruses and more-efficient virus vector species are also likely to spread to Australia from other world regions.”

Professor Jones said there was a pressing need for more research funding and other resources to focus on addressing virus disease threats to Australia’s grains industries.

“The review recommends that future research into virus diseases in Australian cereal and oilseed crops should be adequately resourced to ensure they are protected,” he said.

Professor Jones co-authored the review with Dr Benjamin Congdon from the WA Department of Primary Industries and Regional Development, Dr Murray Sharman from the Queensland Department of Agriculture and Fisheries, and Drs Piotr Trebicki and Solomon Maina of Agriculture Victoria, Department of Jobs, Precincts and Regions.