Diagnosing take-all in cereals

A fungal root disease that can cause severe yield losses of wheat and barley especially in medium- to high-rainfall areas.

What to look for

Patches (up to several metres in diameter and with indistinct and irregular edges) of white coloured tillers and heads containing shrivelled or no grain.
Affected plants can be individuals scattered among healthy plants or entire populations of plants over a large area.

Control First obvious signs of infection are seen after flowering with the development of white heads.
Roots of affected plants are blackened and brittle and break easily and are black to the core not just on outer surface.
Severely affected plants can also have blackened crowns and lower stems.

The fungus that causes take-all survives over summer on residues of cereals and grasses.
Take-all is most prevalent in the wetter western and southern areas of the wheatbelt.
Take-all risk is highest after grassy pastures or wheat or barley.

By far the most effective method of reducing take-all is to remove grasses in the year before the crop with a grass-free pasture or 'break' crop.
Seed, fertiliser or in-furrow applied fungicides are registered for take-all control.
Acidifying fertilisers can slightly reduce disease severity (take-all severity may increase following liming).
Control volunteer grasses and cereals.
Delay sowing following the opening rains by implementing a short chemical fallow.