Person planting seedlings for plant risk assessment in Namadgi National Park near Canberra, in the Australian Capital Territory (ACT).

Plant risk assessment trials being conducted near Canberra in Namadgi National Park, in the Australian Capital Territory (ACT).

Weeding out the risk of pest plants

Reference: 07/33

More accurate assessments of the environmental risks associated with the release of disease-resistant plants are now possible following CSIRO’s development of a new framework that identifies potential weed pests.

8 March 2007

CSIRO Plant Industry scientist, Dr Bob Godfree, says knowing the risks is crucial to ensuring both natural and agricultural environments are protected against the threat of plants which could become invasive.

“The new framework is a very exciting development,” Dr Godfree says. “It will allow us to capture information that has been difficult to obtain previously and it has major positive implications for both the agricultural and natural resource management industries.”

“The framework has been used to assess the ‘weediness’ of white clover resistant to the disease Clover Yellow Vein Potyvirus in a variety of environments and accurately predicted where the plants would most successfully establish.”

He says disease is sometimes the major natural factor keeping certain plants from eventually dominating a particular environment.

“If that limiting factor is removed, plants bred for agricultural purposes can very quickly spread and reduce biological diversity in the natural environments of an area. It is therefore really important that such plants undergo trials to determine if they pose a threat.”

The conceptual framework developed by Dr Godfree provides an accurate picture of the risk presented by a particular plant to a particular environment.

“Plants will respond differently given different environmental conditions and we have found we can identify environments where disease-resistant plants have a better chance of over-running local plant populations.”

The framework has been used to assess the ‘weediness’ of white clover resistant to the disease Clover Yellow Vein Potyvirus in a variety of environments and accurately predicted where the plants would most successfully establish.

“From this information we are able to formulate strategies to manage the release of plants and prevent them from becoming invasive pests in natural environments,” Dr Godfree says.

His findings were published recently in the respected science journal, Proceedings of the National Academy of Sciences. The research was supported by Dairy Australia.

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Robert C. Godfree*,, Peter H. Thrall, and Andrew G. Young. Enemy release after introduction of disease-resistant genotypes into plant–pathogen systems. Published online before print February 13, 2007, 10.1073/pnas.0608356104 PNAS | February 20, 2007 | vol. 104 | no. 8 | 2756-2760