Barley yellow dwarf virus
Barley yellow dwarf virus (BYDV) causes stunting of barley plants and subsequent loss of yield and quality. BYDV can be damaging in the high and very high rainfall areas of the south-west or, more rarely, in nearby medium rainfall areas. BYDV is spread from infected grasses and volunteer cereals to barley by cereal aphids. The greatest risk of significant yield and quality effects is from early infection during the first 8-10 weeks of crop growth. Risk of early aphid arrival largely depends on the amount of summer and autumn rainfall and the availability of green vegetation before the growing season. Details and more photos of the symptoms of barley yellow dwarf virus are available on the MyCrop page.
Control
- Sow varieties that are less susceptible to BYDV. Variety resistance is an effective management option in high risk locations.
- Applying a seed dressing containing imidacloprid (for example, Hombre®, Zorro®), or spraying the crop with registered insecticides in the first 3-7 weeks of crop growth, can substantially reduce BYDV infection. Growers need to assess BYDV risk each season for their location and time of sowing to determine the most appropriate insecticide application strategy.
- Further information is available from the page Managing barley yellow dwarf virus and cereal yellow dwarf virus in cereals.
More information is available on Managing barley dwarf virus.
Wheat streak mosaic virus
Barley is a host for wheat streak mosaic virus (WSMV) but this disease is not currently considered to be yield or quality limiting in barley. More information on the symptoms is available on the MyCrop page and information on managing it and the wheat curl mite on the Wheat streak mosaic virus and wheat curl mite page.
Other leaf diseases
Ring spot (Pyrenophora semeniperda), halo spot (Selenophoma doncis) and Wirrega blotch (Pyrenophora wirreganensis) do not normally require specific control measures.
Disease diagnosis
It is important to remember that abiotic factors such as nutrient deficiencies or adverse weather conditions can also cause abnormalities in barley leaves. Some barley genotypes exhibit varying degrees of physiological spotting on leaves which can be confused with disease symptoms. An important starting point in disease management is correct identification as diseases differ in their best management strategies. Further assistance with disease identification can be obtained from DDLS - Plant pathology services.
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