Australian farmers have been warned to brace for “potentially devastating” future virus disease epidemics in major food crops including wheat and barley.
The stark warning was contained in a comprehensive review of virus disease research in Australia’s cereal and oilseed crops since the 1950s, recently published in the journal Viruses.
The review’s lead author, Adjunct Professor Roger Jones from UWA’s Institute of Agriculture, said there were major future threats to effectively managing virus diseases of cereals and oilseeds.
“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.”
Prof. Jones said virus epidemics could drastically reduce the infected crop’s yield and seed quality, causing financial harm to growers and shortages in produce supply.
He said 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.
The review looked at all 31 viruses known to infect the diverse range of cereal and oilseed crops grown in Australia’s temperate, Mediterranean, subtropical and tropical cropping regions.
It found seven of those viruses occurred commonly and posed the greatest threat: barley yellow dwarf virus, cereal yellow dwarf virus and wheat streak mosaic virus in wheat, barley, oats, triticale and rye; Johnsongrass mosaic virus in sorghum, maize, sweet corn and pearl millet; turnip yellows virus and turnip mosaic virus in canola and Indian mustard; tobacco streak virus in sunflower; and cotton bunchy top virus in cotton.
Depending on the virus and climatic conditions, the most important virus vectors that spread each of the 31 viruses were aphids, whiteflies, thrips, leafhoppers or mites.
Prof. Jones said there was an acute need for more funding for research with a 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.