Reducing Spread

Preventing serrated tussock from establishing on your property is the best method of control. Land holders with seeding serrated tussock should also make reasonable efforts to reduce seed spread to neighbouring areas.

As serrated tussock is readily spread by wind across paddock boundaries and to a lesser extent, spread by vehicles, machinery, stock, people and water, it is important to have procedures in place that will help reduce its spread.

The practices outlined are recommended for all land-use situations to prevent or limit the spread of serrated tussock. Prevention is a high priority in serrated tussock control.

Serrated tussock can leave a property through a number of means. - Source: DEPI Victoria 

General property hygiene

General property hygiene procedures will reduce serrated tussock, and other weeds, from entering or leaving a property.

Useful strategies to reduce spread include:

• Learn to correctly identify serrated tussock.
• Identify high risk areas of spread onto and within the property and regularly monitor these areas. For example, fence lines, stock yards and holding paddocks.
• Control serrated tussock as soon as it is found.
• Consider using vendor declarations for buying and selling stock feed, or anything that could be contaminated with seed.
• Do not harvest pasture, grain or fodder crops while serrated tussock is in seed.
• Do not allow contractors on site unless they are clean and free from serrated tussock seed.
• Consider using contractors who have a history of being weed-aware.

In all situations, make it a priority to control serrated tussock before flowering. If flowering, or seed-set, has occurred, use the following to help reduce further spread.

• Avoid working in infested areas until serrated tussock has been controlled.
• Minimise movement into and out of infested areas when serrated tussock is in seed.
• Stay on formed tracks and roads.
• Plan to work in clean areas first.

Advantages of maintaining general property hygiene

• Prevention is easier and cheaper in the long term.
• Able to target a number of weeds, not just serrated tussock.
• Early identification and control leads to better weed management.

Disadvantages of maintaining general property hygiene

• Can be labour intensive.
• Weeds like serrated tussock may blow in, irrespective of what weed dispersal strategies are implemented.

Cleaning all plant material from machinery and vehicles before moving from a site can reduce the spread of serrated tussock. - Source: DEPI Victoria 

Vehicle, Machinery and Equipment Hygiene

The small seeds and whole seed heads of serrated tussock can get caught in vehicles, machinery and equipment. Vehicles can potentially play a large role in the spread of seed, particularly 4WD vehicles that drive throughout infested paddocks.

Actions to help reduce the risk of spread can include:

• Undertake an accredited vehicle and machinery hygiene training course.
• Plan works. For example:
− slash before the main flowering period
− do not harvest crops or cut hay when serrated tussock is in flower and
− work in clean areas first.
• Consider using preventative equipment such as slasher covers.
• Inspect and where necessary, clean down vehicles, machinery and equipment before leaving an infested site. Dustpan and broom, air compressors and high pressure units are all practical options.
• Areas to pay attention include:
− on and around wheels, slasher decks and above bash plates
− air filters, radiators and engine components
− cabin interiors and ute trays.
• When cleaning down, always:
− appropriately dispose of any seed collected
− monitor the clean-down site for emerging serrated tussock seedlings and control as required.

Advantages to vehicle, machinery, and equipment hygiene

• Removes all other weed seeds from vehicle, machinery and equipment.

Disadvantages to vehicle, machinery, and equipment hygiene

• Time consuming.

For more information on the WeedStop Vehicle Hygiene Program visit http://www.dpi.vic.gov.au/agriculture/pests-diseases-and-weeds/weeds/weedstop

Transporting stock can also transport serrated tussock seeds. Keep animals quarantined for at least 10 days if suspected to be carrying serrated tussock seeds. - Source: DEPI Victoria 

Stock management

Stock can spread serrated tussock by:

• transporting seed attached to the coat or by mud in the animals hooves
• eating the plant while in seed, then excreting viable seed.

Stock can be an important source of serrated tussock weed spread and reducing all risks is important.

• Limit the movement of stock from serrated tussock infested areas to clean areas.
• Remove stock from infested paddocks before serrated tussock goes to seed. Note: serrated tussock should not be allowed to seed!
• Place stock in quarantine/holding paddocks if:
- stock are suspected to be contaminated with seed
- new stock are entering the property and suspected of being contaminated with weed seed.

If suspected of eating serrated tussock seed, quarantine stock for at least 10 days and provide with clean feed and water. Always use the same holding paddock, monitor for serrated tussock seedlings and control when required.

Advantages to stock management

• Infestations initially confined to holding paddocks are easier to eliminate.

Disadvantages to stock management

• Extra feed costs if stock are quarantined.

Mesh fencing can act as a barrier to serrated tussock spread. - Source: DEPI Victoria 

Mesh Fencing

Mesh fencing is a useful tool that captures serrated tussock seed heads, restricting the amount of seed heads blowing between properties or paddocks.

Fence at critical dispersal points such as, boundaries adjoining properties with high levels of serrated tussock, or along the direction of the most prevailing winds.

Fencing may also be incorporated into the overall property management program. For example:

• divide into paddocks for rotational grazing
• separate land-uses that require different management
• may assist in the control of pest animals, such as rabbits.

Regularly check fence lines and spot treat.

Mesh fencing is suitable for:

• All situations; except very steep areas.
• Particularly useful where a distinctive difference occurs between a hard-to-manage patch of seeding serrated tussock and an adjacent ‘easier-to-manage’ area.

Advantages to mesh fencing

• May reduce that amount of serrated tussock seed entering or leaving a property.
• Can act as a barrier to other pests such as rabbits and foxes.
• May be useful for stock and grazing management.

Disadvantages to mesh fencing

• Costly in the short term.
• Requires regular maintenance.
• Does not actively control or reduce serrated tussock infestations.
• A number of seeds may still blow over the fence.

A shelter belt is a long term management tool for stopping serrated tussock spread. - Source: DEPI Victoria

Shelterbelts

Shelterbelts and windbreaks are alternatives to fencing as a physical barrier to catch wind blown serrated tussock seed heads.

Tree barriers may be used along property or paddock boundaries, or along ridgelines of steep terrain. The type of tree planted is important so that seed heads are trapped and restricted from blowing over. A windbreak that contains trees with a range of heights is beneficial.

Examples of trees to plant include eucalypt, pine, tea-tree and she-oak.

Windbreaks may not always meet their purpose. Their efficiency is dependant on the density of serrated tussock both up-wind and down-wind, and density and height of the trees. Windbreaks provide a wide range of benefits to agriculture, environment, and amenity. Consider these benefits before planting a windbreak solely for serrated tussock control.

Shelterbelts are suitable for:

• All land-use categories.
• May be particularly beneficial in areas such as steep areas, erosion prone soils, rocky country and valleys.

Advantages of shelterbelts 

• A long term, proactive control method.
• May reduce wind induced soil erosion.
• May reduce wind induced damage to pasture and crops, including sand abrasion.
• A wide windbreak (more than 10 m) may qualify for possible future carbon credit schemes.

Disadvantages of shelterbelts

• Takes many years for trees to grow to the stage required to effectively catch seed heads.
• May take up valuable pasture or crop space.
• May provide competition with pasture or crop within short distance of windbreak.
• Initial set up can be labour intensive and costly.
• Control of serrated tussock amongst trees may be difficult.

Successful establishment of trees in a shelterbelt or windbreak requires planning and advice from a forestry specialist.

Thorough machinery hygiene practices, including using a slasher cover can help prevent the spread of serrated tussock infestations. - Source: DEPI Victoria 

Slashing

Slashing involves cutting serrated tussock plants to a height just above ground level using a slasher, mower implement or brushcutter.

A short term control method that may be used to delay seed-set in serrated tussock plants. Slashing stimulates the growth of the serrated tussock plants and must be used in combination with herbicide application. Only use as a last resort to reduce the amount of seed formed if unable to use other control methods prior to flowering.

For roadside managers slashing areas of serrated tussock, it is important that:

• slashing is conducted prior to flowering
• machinery is cleaned down at specified clean down points
• serrated tussock infestations on roadsides and public reserves are mapped and monitored
• weed free ‘clean’ areas are slashed first and serrated tussock infested areas are slashed last
• operators are trained in machinery hygiene procedures and serrated tussock identification
• tools that help reduce machinery contamination are used, such as slasher covers.

Caution:

• A seed head will still generate if slashing is conducted too early.
• Slashing equipment may become a vector for spreading seeds if slashed when serrated tussock seed is present. Machinery hygiene is critical in preventing spread.
• Not considered a control technique for compliance purposes.

Slashing is suitable for:

• Roadsides and other urban situations to reduce grass biomass and serrated tussock seed-set.
• Removal of excess dry matter when preparing a paddock for sowing a crop or pasture.
• If flupropanate was applied too late in the season, serrated tussock may still produce viable seed. Slash prior to flowering to prevent seed head development. This will still give flupropanate residual control into the next season.
• Reduction of plant biomass in the fire season.

Do not harvest slashed serrated tussock material for fodder conservation (hay). Serrated tussock is a declared noxious weed throughout all of Australia and cannot be sold or knowingly transported. As such, if serrated tussock is inadvertently harvested for fodder, the hay bales must not leave the property or be sold. Baling hay in paddocks with seeding serrated tussock is strongly discouraged.

Advantages to slashing

• May limit seed production if conducted at the right time of the year.
• May reduce fire risk during summer months.
• Limited soil disturbance.

Disadvantages to slashing

• Will not always prevent seeding in a current season—only delay it.
• Does not kill the plant.
• Will not reduce the size of the serrated tussock population.
• Can stimulate serrated tussock growth.
• May increase the spread of serrated tussock seed if precautions are not taken.

 

More detailed information on reducing spread can be found in the National Serrated Tussock Best Practice Manual.