Managing the myrtle rust menace

Managing the myrtle rust menace

Plant Biosecurity CRC research is helping the Australian lemon myrtle industry with management strategies to reduce production losses from myrtle rust, an industry which has been hard hit since the introduction of the disease in 2010.

Myrtle rust (Austropuccinia psidii, formerly Puccinia psidii) can cause substantial production losses in lemon myrtle if left untreated.

The disease leads to branch defoliation, dieback and stunted growth – yield losses can be to be up to 70 per cent.

Emily Lancaster, a Plant Biosecurity CRC supported PhD student at the University of Queensland, is assessing myrtle rust management strategies and resistance to the disease.

“I have been looking at the disease cycle of myrtle rust and identifying factors that may be influencing the spread of the disease within plantation-grown lemon myrtle. I am especially quantifying the effect myrtle rust has on the yield of lemon myrtle, in terms of leaf biomass at harvest and quality of the oil,” said Emily.

“I am also continuing on with work already started to screen lemon myrtle germplasm, which will help identify more resistant clones that can be used in commercial production. I hope to provide the industry with the knowledge to support more effective disease management strategies and help reduce the impact of the disease on production.”

Emily’s research will provide recommendations to the lemon myrtle industry that will help them reduce the production and economic impact of myrtle rust.

Overview of the lemon myrtle industry

Lemon myrtle leaves contain the highest amount of citral, more than 90 per cent, of any plant in the world- it has been described as ‘lemonier than lemon’!

The leaves are dried and milled for use in teas or as a spice.

Steam distillation is used to extract the essential oil from the leaf material which can then be used as food flavouring, in aromatherapy products, cosmetics and toiletries.

In 2012, production of lemon myrtle was estimated to be between 575 and 1,100 tonnes of leaf, and three to eight tonnes of oil, with a farm gate value of between $7 and $23 million.

Source: PBCRC