THE first cases of stripe rust and wheat streak mosaic virus in WA have been reported for this season.
The stripe rust was found in an early sown crop of Calingiri wheat at the flag leaf emergence, growth stage, at a property near Cunderdin.
The pustules were found scattered over several plants throughout the crop which received no seed or in-furrow fungicide treatment at sowing.
Plant pathologist Geoff Thomas said this year¹s stripe rust discovery had arrived much later than last season.
³The late planting of some crops in the central agricultural region has meant that currently they could be at a growth stage that is vulnerable to rust infection even though they may be an intermediate or moderately resistant variety,² Mr Thomas said.
³The full level of adult plant resistance of wheat varieties to stripe rust does not usually develop until the flag leaf emergence to booting stages.³
Mr Thomas said farmers should monitor their crops closely for the presence of stripe rust, particularly susceptible varieties and those without seedling fungicide protection.
The first known case of wheat streak mosaic virus for the season was found in a wheat crop growing south of Koorda.
Elders agronomist Jason Stokes, who detected the virus, said the symptoms were easily noticed while observing the crop from the roadside.
Yellow coloured parallel streaking and blotching along the leaf veins, especially on the lower leaves, were quite obvious within a patch of the crop covering more that 100m.