Eucalyptus Rust News

New threat to eucalyptus plantations in South Africa

A particularly destructive fungus, Puccinia psidii, or commonly called the Eucalyptus Rust has been detected in KZN, South Africa. Below is a short brief on the disease by Professor Jolanda Roux, plant pathologist at FABI:

Researchers at FABI this week confirmed the presence of the myrtle rust pathogen, Puccinia psidii, in South Africa. The possible presence of the pathogen was brought to our attention by an alert forester, Marcel Verleur of Sappi, who spotted a diseased Myrtus communis (myrtle) plant on the KZN south coast. He immediately sent photos of the infected plant to Izette Greyling and Jolanda Roux of the TPCP and CTHB extension programme, who requested samples for analyses. The identity of the pathogen as P. psidii has been confirmed through the use of DNA sequence data and morphology.

Puccinia psidii is one of the most important invasive alien plant pathogens and has been described as “the biggest threat to the ecosystem” in Australia. The confirmation of the presence of this globally important quarantine pathogen in South Africa is likely to have substantial negative long term consequences for both forestry and for plant conservation in the country.

We urge all foresters, farmers, botanists and other plant lovers to keep their eyes open for this pathogen and to let us know immediately if you suspect its presence in your area. The pathogen is known only from plants in the Myrtaceae, so start by closely inspecting any such ornamental in your garden. These include genera such as Eugenia, Heteropyxis, Syzygium, Eucalyptus, Metrosideros and others. Since the first incidence of myrtle rust was confirmed from the KZN south coast, we especially urge people along the KZN coast to be especially vigilant. However, it is possible that the pathogen could have been present for much longer and in a much wider area.

Please contact: Jolanda Roux (jolanda.roux@fabi.up.ac.za; 0829093202) or Izette Greyling (izette.greyling@fabi.up.ac.za) if you suspect the presence of the disease in your area.

For more information on this fungus – download the TPCP information sheet on our Resources Page or contact the staff at FABI directly.

The pictures below illustrate some of the symptoms of this disease: