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You are here: Agriculture » About Agriculture » Newsletters and Updates » Weed Spotter Newsletter » Weed Spotter Newsletter - Winter 10

Weed Spotter Newsletter Winter 2010

Issue Number 10

Welcome to issue 10 of the Weed Spotter newsletter. There are now more than 2,800 registered Weed Spotters in Victoria. This edition contains a short survey and quiz which, if you complete, puts you into a draw to win a weed book. Good Luck!

Survey and Quiz

To complete the Weed Spotter Survey and Quiz 2010, please click on following the link. https://www.surveymonkey.com/s/wssurvey2010

1. Tropical Invader found in West Gippsland

Drew Sutton, Weed Alert Contact Officer

Photo: Salvinia infestation

A trained Weed Spotter and Wild Dog Controller from the Department of Primary Industries (DPI) found a significant infestation of salvinia (Salvinia molesta) in a farm dam at Dawson, in West Gippsland.

Inspections of properties downstream were conducted which revealed a further four dams to be infested.

As a State prohibited weed, it is the Department’s responsibility to treat the infested dams and survey other water bodies to ensure that all sites are detected and treated..

Salvinia floats on the water surface. It’s leaves can measure up to six centimetres wide, are bright green, oval shaped and covered in waxy hairs that repel water from the leaf surface. Leaves are arranged in pairs on a ‘string’ and fold together when bunched up. It can be confused with azolla, which has fern shaped leaves and is usually pink in colour.

The detection of salvinia in these dams, which were close to a major river system, highlights the importance of Weed Spotters in detecting and reporting suspected State prohibited weeds so that DPI can provide a timely response.

Wild Dog Controllers and other DPI employees are an important group to be involved in Weed Spotter activities as they cover a large number of properties in their day-to-day work. Having staff trained in the identification of State prohibited weeds greatly increases our chances of finding infestations before they become widely established.

If you think you may have seen salvinia or any other State prohibited weed please contact
DPI on 136 186.

2. Weed Alert news

Don’t underestimate Japanese knotweed

Greg Johnson, Weed Alert Contact Officer

Photo: Searching for Japanese Knotweed in the Alpine region

Eradication is the aim for all State prohibited aweeds. Within the Weed Alert program, a protocol has been developed which states that a site can only be called eradicated after a thorough investigative process is followed, including a delimitation survey. Delimitation surveys involve surveying the area around an infestation to ensure that the full extent of the infestation is known to allow successful treatment. Careful site assessment, delimitation and treatment needs to occur until an infestation can ultimately be deemed as eradicated.

After treatment and monitoring for six years, a site of Japanese knotweed at Falls Creek had not had any re-emergence for a number of years and it was hoped that the site was on its way to being declared eradicated. However, in February 2010 a careful assessment of the steep and thickly vegetated site and its surrounds was carried out. About 10 metres from the original site, a number of new stems were found hidden under dense yarrow. It is thought that due to the extensive root system of Japanese knotweed, segments of root had survived earlier treatments.

Following this detection, a broader area around the site was also surveyed by DPI and Alpine Resort staff to determine if Japanese knotweed had spread any further. Fortunately, no new infestations were found. The emerging stems have since been treated and the site and its surrounds will continue to be treated and surveyed in the future.

The moral of the story is that without careful site assessment and delimiting surveys, achieving eradication of State prohibited weeds will not be possible.

Launch of weed displays at Melbourne Zoo

Daniel Joubert, Senior Project Officer

Photo: Melbourne Zoo State prohibited weed display

A range of State prohibited weeds, including horsetails, alligator weed, salvinia and knotweed, have been locked up as exhibits in a new display at the Melbourne Zoo.

Launched on July 1, this joint project between DPI and Melbourne Zoo, gives visitors the opportunity to view and identify some of the highest priority invasive plants in Victoria. This display will encourage the 1.6 million visitors who visit the zoo each year to report any sightings.

When launching the display Biosecurity Victoria Executive Director Dr Hugh Millar said it was an opportunity for Victorians to discover which weed species are a significant threat to many aquatic and terrestrial plants and animals.

The majority of State prohibited weeds reported are from Melbourne’s metropolitan areas. State prohibited weeds are the highest priority declared noxious weed class and either do not occur in Victoria, or are here but can be eradicated. Visitors to the Melbourne Zoo can play a vital role in maintaining biodiversity by reporting these weeds.

Weed Spotters can now visit the Melbourne Zoo to see the State prohibited weed display and refresh their memory on the different characteristics used in identifying these species.

3. Aquatic weeds can be found in fish tanks too.

Melissa Semken, Partnerships officer

Photos: Backyard pond- possible infestation place

It is common to look in waterways and wetlands for aquatic weeds but what about fish tanks and backyard ponds?

State prohibited weeds such as salvinia and water hyacinth were both introduced into Victoria as ornamental plants in ponds and aquariums. They have also been used in fish farms to help keep water clean and as a source of fish food. It is suspected that there is still an informal trade of these species within the ornamental fish industry.

Although it is illegal under the Catchment and Land Protection Act 1994 to grow, propagate or trade these plants, there may be groups that are not aware of the status of these species or unaware that the DPI is trying to eradicate them from the state.

Photos: Fishtank with Salvinia

The majority of introduced aquatic weeds that have colonised in our waterways have originated from backyard ponds or aquariums. These plants then go on to adversely affect our aquatic ecosystems, the economy as well as recreational activities.

Most aquatic weed infestations occur after plant fragments enter our waterways. Often this is through ponds overflowing during flood events or by cleaning and emptying aquariums into stormwater drains. These are major risks in the spread of aquatic weeds.

Weed Spotters can play an important role in preventing the establishment of State prohibited weeds in waterways by reporting any backyard pond or aquarium sightings to DPI.

4. Weed Spotter training leads to noxious discovery

Bronwyn Grass, Weed Alert Contact Officer

Photo: Horsetail In Backyard Pond

Weed Spotter training paid off recently when a North Central waterway manager correctly identified a new horsetail infestation at Woodend. The Weed Spotter, who was recently trained as part of a group of employees from Coliban Water, noticed horsetail growing in an ornamental pond and reported it promptly to DPI.

If not removed, horsetails have the potential to become persistent weeds in wetlands and other low-lying areas in southern Australia. They are difficult to control because of their extensive and inaccessible underground root systems. All species are thought to also contain chemicals that are toxic to livestock.

North Central Weed Alert staff inspected the property and found one large pot of horsetail growing submerged in a pond situated in the front yard of the property. The landowner said she was given the plant about four years ago by a neighbour. The landowner was not aware that horsetails are a State prohibited weed and gladly surrendered the pot when she was informed. The neighbouring property was also inspected and a large infestation of horsetails growing around the edge of a dam was identified. Further investigations and eradication efforts are currently underway at the property.

5. Weed Spotter Training

Weed Spotter recruitment of Parks Victoria and Department of Sustainability and Environment staff

Annie Lamb, Weed Alert Contact Officer

Photo: Parks Victoria staff getting to know State Prohibited Weeds

In April this year 22 Parks Victoria and DSE staff attended a Weed Spotter training session. The session educated land management agency staff in identifying State prohibited weeds and broadened their knowledge of weeds, outside their usual suite of species.

The training session gave an overview of the Weed Alert program, identification of State prohibited weeds and how to report them to DPI. The participants enjoyed the activities and valued being able to see and touch some of the State prohibited weeds on display, for example horsetails, water hyacinth and hawkweed, and to discuss the distinguishing characteristics of each plant.

If you are a registered Weed Spotter and have not yet attended a training session, please contact your local Weed Alert Contact Officer to be invited to a training session in your local area.

Aquatic weed training for Bushfire Recovery project.

Sarah Partington, Weed Spotter Coordinator

Photo: Aquatic State prohibited weed identification guide

As part of the DPI Bushfire Recovery project "Rebuilding Together", DPI has collaborated with Melbourne Water to deliver aquatic weed identification training to their staff that work along waterways or who may encounter aquatic weeds as part of their everyday work.

In total, 185 Melbourne Water staff have now been trained during 14 training sessions delivered. Staff stated that they found it to be a very valuable experience. Participants were shown live samples, including aquatic State prohibited weeds and priority species that Melbourne Water are treating on their waterways.

The aim of the training was to increase the State’s surveillance capacity of State prohibited weeds on waterways in areas affected by bushfires. This project has also enabled Melbourne Water to increase their surveillance capability of waterways for their priority weed species.

Feedback from all participants was very positive, with many requesting further training sessions.

An environmental planner from Frankston City Council said “the session was presented very well and provided a good balance between theoretical and practical, and believed everyone who attended got a lot out of the morning”.

For more information please email Weed.Spotters@dpi.vic.gov.au.

6. Spot the difference: Horsetails and its look-alikes

Julie Gooding and Hannah Cooke, Weed Alert Contact Officers

Photo: Horsetail cones	Photo: Horsetail hollow stem	Horsetail stems showing the joint node and sheath

Horsetails are among the world’s worst agricultural weeds due to their resilience, toxicity and ability to dominate poorly drained farmland and pastures. However, they are commonly confused with native sedges and rushes.

ID characteristics

Horsetails have longitudinal grooves along a hollow stem. The leaves of horsetails are reduced to form sheaths around the stem. Instead of flowers horsetails produce cones which can produce spores in the right conditions. Horsetails have extensive underground root systems that allow them to travel up to 2m in depth and 100m laterally. Stems are also joined by nodes that can potentially form new plants. The root system, combined with the plant’s ability to fragment makes horsetails highly invasive and difficult to eradicate.

Look-alikes

Horsetails can be mistaken for restios and rushes such as zebra rush. Restio species can closely resemble horsetails, and often have sheaths around the joints; however horsetails can be easily separated at the node. Rushes are also similar looking to horsetails; however they are also quite firm, not hollow, like a horsetail stem.

Photo: Horsetail restio, Elegia capensis.	Photo: Australian rush sp. Baloskion tetraphyllum.	Photo: Horsetail restio stem

Know your local Weed Alert Contact Officer

	Name	Region	Location	Phone
	Kate Cunnew	Goulburn Broken	Seymour	03 5735 4300
	Robert Metcalfe	Mallee	Mildura	03 5051 4327
	Julie Graham	North Central	Kyneton	03 5421 1722
	Bronwyn Grass	North Central	Bendigo	03 5430 4426
	Greg Johnson	North East	Wodonga	02 6043 7967
	Drew Sutton	East Gippsland	Bairnsdale	03 5152 0645
	Kim Gowers	West Gippsland	Leongatha	03 5662 9919
	Pam Allan	West Gippsland	Ellinbank	03 5624 2272
	Annie Lamb	Port Phillip	East Frankston	03 9785 0109
	Kylie Woods	Port Phillip	East Attwood	03 9217 4240
	John Matheson	Glenelg Hopkins	Hamilton	03 5573 0900
	Roger MacRaild	Port Phillip West	Bacchus Marsh	03 5366 0024
	Julie Gooding	Port Phillip West	Bacchus Marsh	03 5366 0022
	Hannah Cooke	Corangamite	Geelong	03 5226 4560
	Lucy Ivey	Wimmera	Horsham	03 5362 0787