The Department of Agriculture, Western Australia is working with the local wheat industry to consider additional risk measures to prevent the establishment of wheat streak mosaic virus (WSMV) in the State.

The meetings were called following the recent discovery of severe infection of WSMV in crops in New South Wales, clear evidence of seed transmission of the virus and its movement in wheat seed, in addition to indications of the widespread presence of wheat streak mosaic virus vector mites in the Western Australian wheatbelt. 

Department of Agriculture principal plant virologist Roger Jones said the virus was first detected in Australia in early 2002.

“Wheat streak mosaic virus has not yet been found in Western Australia, but is established in New South Wales, the Australian Capital Territory, Victoria, South Australia and Queensland,” Dr Jones said.

“Western Australia currently places restrictions on the importation of known and potential wheat streak mosaic virus host plants and sweet corn seed to minimise the likelihood of introducing the virus into the State,” he said.

The virus has been known to cause yield losses in the Great Plains region of the United States, and in other parts of the world such as the Middle East, Europe and North Africa.

To gauge the virus’s potential to affect Western Australia’s wheat production, Dr Jones recently visited NSW where wheat streak mosaic virus infection has caused severe damage over a wide area of the state’s high rainfall wheatbelt zone, from Coonabarabran in the north to Holbrook in the south.

“Although the virus has not been detected in the field in Western Australia, vector mites resembling wheat leaf curl mite, that can spreads the virus, are widespread in our wheatbelt,” Dr Jones said.

“These vector mites are also widespread in affected wheat growing areas of New South Wales,” he said.

Dr Jones said recent research demonstrated wheat streak mosaic virus is seed-borne, providing confirmation that the virus can be introduced to new locations by sowing infected wheat seed.

“To protect the State’s wheat crops, measures are urgently being considered to minimise the risk of introducing the virus with wheat seed. These include temporary restrictions on all wheat seed entering the State.