WHITE and pink streaks along the length of the leaves and leaf curling were the first signs for Vic agronomist Simon Mock that something was wrong with a late April-sown barley crop.
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He found the first South East outbreak of Russian wheat aphid in a client’s crop near Bordertown, which had been undersown with balansa clover for livestock feed.
“The paddock had volunteer wheat from last year, which had grown with rain in January. Where there was more wheat, there was more of this damage.”
Early last week he turned to GRDC’s Crop Nutrition App looking to identify the issue with no luck. But after posting a photo on Twitter he was alerted to it possibly being an exotic disease.
SARDI confirmed this late last week after aphid samples were sent for testing.
Mr Mock said it was fortunate the damaging insect could be controlled with a relatively cheap insecticide, and returning to the affected paddock this week, he said the crop had recovered well.
There was little chance of it being contained though, with more infestations found earlier this week in the Upper SE and Vic, he said.
“It is in all the other major wheat-growing countries throughout the world, so it was only a matter of time before we got it here,” he said. “Like any new pest, we have got to learn ways to be able to manage it going forward.”
Mr Mock encouraged growers not to panic, but to look closely at their emerging cereal crops and treat the aphid if present, rather than blanket spraying.
“Become educated and aware of what the symptoms are and what the aphid looks like,” he said.
“Russian wheat aphid is similar in length to other aphids, but thinner across the middle with black eyes.”
SA growers should report concerns to the Exotic Pest Plant Hotline on 1800 084 881. West Vic growers can send samples to Crop Safe, 110 Natimuk Road, Horsham, Vic, 3400, with their GPS coordinates.
