News

Weed is threat to agriculture

By Country News

How big a problem is serrated tussock for cropping farmers and the environment as a whole?

Serrated tussock is an agricultural and environmental weed that is estimated to cost Victoria $5million a year to control.

Agriculture Victoria works in partnership with industry and the community to manage the risk of this weed through programs that focus on containment of serrated tussock.

How does it specifically interfere with these sectors?

Serrated tussock affects the environment by displacing native flora and reducing biodiversity, especially in native grasslands.

The impact on agricultural systems differs depending on the enterprise.

The effect on cropping is limited due to the controlling effect on the weed through cultivation.

Serrated tussock may have a significant impact on grazing enterprises through displacement of desirable pasture species and detrimental effects on stock.

The weed is unpalatable to stock, with low nutritional value.

Carrying capacity of pastures with dense infestations is significantly reduced, leading to loss of production potential.

Does it carry any pests or diseases?

Serrated tussock, like many plants, may be affected by diseases and pests. However, serrated tussock is no more likely a vector of pest and disease than many other species in Victoria.

How common is it in our region?

Serrated tussock is a Regionally Prohibited Weed in the Goulburn Broken Catchment region.

Regionally Prohibited Weeds are not widely distributed, however, they are capable of spreading further.

The weed is not common in the Goulburn Broken Catchment, with about 75 known infestations of serrated tussock.

Most are located in the southern parts of the catchment and consist of very small infestations.

Sites in the northern part of the Goulburn Broken Catchment mostly consist of historical garden infestations, where the weed has been mistaken for a native tussock.

Is the weed in other parts of northern Victoria?

Serrated tussock occurs in small, isolated infestations across northern Victoria.

The majority of infestations in northern Victoria are located in the southern parts of the region, with most occurring in the areas such as Kilmore, Broadford and Redesdale.

Serrated tussock is classified under the Catchment and Land Protection Act as a Regionally Prohibited Weed in the Goulburn Broken, north-east, north-central, Mallee, Wimmera and Glenelg Hopkins catchments.

Agriculture Victoria conducts proactive annual compliance programs visiting all known sites within these catchments.

What conditions does it need to grow?

Serrated tussock can grow in a wide variety of climates, however, plant growth is best suited to cooler areas that do not experience hot summers.

The weed prefers well-drained soils and areas with annual rainfall between 450mm and 1000mm.

The plant can be found in many types of landscape, including native and grassy woodlands, pastures, urban disturbed sites or wasteland and roadsides.

Serrated tussock is more likely to infest disturbed areas and over-grazed pastures.

How is it removed?

Serrated tussock is best controlled through integrated weed management, using a range of treatments at appropriate times of year.

In small infestations the weed is can be successfully controlled by physical removal of plants including the roots.

The soil can be removed from the roots and the plant left at the site to die.

Where seed is present the plant must be bagged and disposed of to destroy the seed.

Where this method is used, the plant must be disposed of in a manner which will not cause contamination off-site.

A permit may be required to facilitate the movement of contaminated material to ensure that the weed does not spread to new areas. Further information can be obtained from Agriculture Victoria.

It may also be controlled through application of a registered herbicide in accordance with the directions of use.

Cultivation is also an appropriate technique.

The aim of any serrated tussock control program should be to prevent seed-set by treating infestations each season to eventually deplete the seedbank.

■To report a suspected infestation of serrated tussock, or for further information on identification and control, visit the Agriculture Victoria website: www.agriculture.vic.gov.au or the Victorian Serrated Tussock Working Party website: www.serratedtussock.com or phone the Agriculture Victoria Customer Call Centre on 136 186.