Black Stem Rust
Puccinia graminis
Pathogen
Fungus
Hosts
Wheat, oats, barley, rye and grasses
Symptoms
Streaky rust-brown pustules appear on the leaves, leaf sheaths, stems and glumes. These develop into darker pustules, particularly on the leaf sheaths and stems.
Development
Black stem rust is spread by means of wind borne spores. There is an overwintering stage which re-infects crops via an intermediate host, the shrub barberry. In the UK, barberry is not believed to be an important factor in disease spread. E pidemics usually start from wind borne spores from continental Europe, and for this reason the disease tends to be confined to the South West of England.
Favourable factors
Moist, warm weather.
Importance
Despite attacks coming late in the season the extremely rapid spread can lead to shrivelled grain, reducing yield and baking quality.
Control
Use of an effective fungicide programme
Removal of intermediate hosts will lower disease levels
