Crown Rust
Close up & Crown rust of oats (Photo G. Bubb)
Close up & Crown rust of oats (Photo G. Bubb)
Fungus
Oats, grasses especially perennial rye-grass.
First signs are small rounded orange-yellow coloured pustules, usually on both sides of the leaves. Later the pustules join together to form evenly affected areas. Small black pustules are produced late in the season.
Infection comes from windborne spores arising from volunteer host plants.
20C temperature with high humidity favours the disease.
Crown rust is host specific to oats (and some grasses). Because of the need for great warmth the disease occurs only shortly before harvest but it can cause large reduction in yield and quality.
Find out more information on the key disease threats to your cereal crop. For each disease you will find out the importance of the disease in terms of potential yield penalty, how to identify the disease in its early stages and our advice on the best control strategies.