Pest of the month: Eucalyptus rust, Guava rust (Puccinia psidii)
Category name: Fungi
Importance: Emergency disease, however currently found only in Eastern Australia.
Symptoms: The fungus attacks young tissues of new leaves, fruits, flowers, shoots and succulent twigs. The disease can cause deformation of leaves, heavy defoliation of branches, dieback, stunted growth and even death.
Transmission: Spores from infected plants and infected plant debris are spread by wind and water splash, also on clothes, hands and equipment.
Favoured by: Warm, humid weather and leaf moisture is needed for spores to germinate and infect the plant.
Host range: Eucalyptus, Corymbia, Angophora, Leptospermum, Melaleuca, Metrosideros, Callistemon, Syzygium, Melaleuca, Eugenia and also mangroves. On guava, lesions occur mostly on buds and young fruits that eventually rot, as the rust matures.
Further industry pest information is available at www.pestid.com.au
An initiative of the National Nursery Industry Biosecurity Program (NY15004) and Building the resilience and on-farm biosecurity capacity of the Australian production nursery industry (NY15002).