Diagnosing barley leaf rust
A fungal leaf disease specific to barley that can spread rapidly within and between crops causing yield losses of up to 45% in susceptible varieties.
What to look for
- Generally uniform infection across a crop, can start as 'hot spots' (foci) of infection in paddock from which disease rapidly spreads.
- Small, circular to oval pustules with light brown powdery spores on upper surface of leaves and on leaf sheaths in cases of heavy infection.
- As the crop matures, pustules darken and produce black spores embedded in leaf tissue.
- Leaf rust spores rarely appear on back of the leaf.
- Yellowing spreads around pustules and leaves wither and die back from the tip.
- Shrivelled grain with severe infection.
Where did it come from?
- Leaf rust requires a green host plant to survive the summer, so disease risk is highest when a green bridge allows the fungus to survive into the new season.
- Leaf rust can occur throughout the season and develops rapidly in moist conditions when temperatures are between 15-22°C.
Green bridge control
- Avoid sowing susceptible varieties.
- Destroy green bridge.
- Seed dressing fungicides are not registered for this disease but some products can delay disease onset.
- Monitor crops and apply registered foliar fungicide at first sign of leaf rust.
Where to go for expert help
+61 (0)8 9892 8477
+61 (0)8 9368 3262
DDLS Seed Testing and Certification
+61 (0)8 9368 3721
Page last updated: Thursday, 16 April 2015 - 10:15am