STB has become an increasingly important stubble-borne foliar disease of wheat, especially in higher rainfall zones of southern Australia.
Nick Poole, Managing Director of the Foundation for Arable Research (FAR) Australia, said STB was one of seven most problematic diseases encountered in southern Victoria over the past eight years.
“It’s a disease that’s reasonably endemic in wheat crops in Tasmania and southern Victoria, and last year we saw the spread of the disease into different parts of South Australia, as well as up into Southern New South Wales,’’ Nick said.
He said with the dry conditions in many areas this season, it could be considered that it should not be a problem, however this was not necessarily the case.
“We saw septoria tritici in some of the earliest wheat crops in early May.’’
“First lesions were showing up in crops in mid-June and now you can find the disease on lower leaves of some of our susceptible varieties.’’
As a result, Nick said it was still very worthwhile to be looking out for STB, especially through southern high rainfall zones.
“It’s easy to identify – with the black fruiting bodies on the leaf lesions.’’
He said disease control was important considering the cropping outlook was actually quite good in some southern areas, which traditionally can face water-logging issues most winters.
STB earlier became more difficult to control in cereals when two-gene fungicide resistance was discovered, indicating resistance to some of the common triazole fungicides used.
However, the arrival in recent seasons of the dual mode of action, broad spectrum foliar fungicide, Radial® from Adama, has helped growers to improve their management of the disease.