Loose Smut
Ustilago nuda (Barley), Ustilago tritici (Wheat), Ustilago avenae (Oats)
Pathogen
Fungus
Hosts
Barley, wheat and oats
Symptoms
The ear emerges as a black sooty mass of spores. The flag leaf (especially in wheat) often becomes discoloured.
Development
Infection arises solely from infected seed. The seeds become infected at harvest time when spores from infected ears land on open flowers and infect the developing grains.
Favourable Factors
Cool, wet conditions that prolong the flowering period and therefore increase the opportunity for grain infection.
Importance
Has been known for yield reduction to be up to 25% but 1% to 3% more common.
Control
Use clean certified seeds and effective seed treatments
