Serrated Tussock - Management LC0370 Department of Primary Industries, Frankston ISSN 1329-833X

October 2004 Serrated tussock - Management LC0370 Department of Primary Industries, Frankston ISSN 1329-833X

This Landcare Note details options for the management West Gippsland Regions. Landowners in areas where of the weed serrated tussock Nassella trichotoma. serrated tussock is Regionally Prohibited must eradicate or control it on their land. Landholders in areas where See the Landcare Note LC0175: Serrated tussock – serrated tussock is Regionally Controlled must take all identification for a description and illustrations of the reasonable steps to control it and prevent its spread and plant. See the Agriculture Note AG0391: Serrated growth on their land and the roadsides that adjoin their tussock control for detailed information on control land. However certain roadsides are exempt. Contact the techniques and integrated management strategies. Further information on serrated tussock management regional Department of Primary Industries office for can be found in the Agriculture Note AG0940: Pasture further advice. management to reduce serrated tussock invasion and the Landcare Note: LC0268: Serrated tussock annual Origin and distribution control calendar. Native to Argentina, Chile, Peru and Uruguay. Thought to Common and scientific names have been introduced into Australia in the early 1900s but not recorded until 1935, with the first Victorian record in Serrated tussock 1954. Now occupies more than 1.1 million ha in south- Nassella trichotoma (Nees) Hack. ex Arechav. eastern Australia, with more than 30 million ha Family Poaceae (grasses) climatically suitable for invasion. The worst affected areas in Victoria are around Melbourne, Geelong and Bacchus The problem Marsh. Serrated tussock is a long-lived perennial, drought- resistant tussock grass that occupies over 150,000 ha in Management Victoria and has the potential to infest more than 4.6 Serrated tussock is difficult and expensive to control. million ha. It is one of the worst weeds of pastures, Management activities should aim to stop the plant setting potentially causing near total loss of carrying capacity, and seed and to exhaust the store of seed in the soil. Large eventually forms a monoculture unless controlled. Serrated infestations should be treated in manageable parcels, with tussock looks similar to native tussock grasses so can regular follow up over several years. remain unnoticed until significant infestations have A long-term strategic plan should be made for each developed. It is unpalatable to livestock, having very high infestation and this plan should fit within the broader fibre content (around 86%) and low protein (around 4%). regional control strategy. Infestations should be quantified The leaves can form indigestible balls in the rumen, and mapped to enable success of management programs to causing loss of condition and eventual death. Stock forced be measured. All stakeholders should be involved in the to graze it can starve to death, despite a full stomach. formulation of management plans, and implementation When desirable pasture species are present, it is selectively should be a cooperative venture. Sharing responsibility for avoided by grazing animals, leading to its eventual the serrated tussock in your area is part of the solution. dominance. The seeds damage the mouths of livestock and Change of land use, eg. from pasture to cropping, may be contaminate wool. Serrated tussock is also a weed of the most appropriate management option in the longer native ecosystems where it reduces biodiversity. The soil term. The best land use for the infested land should be seedbank in old, established infestations can contain up to identified in advance. 120,000 seeds per square metre. Control of dense infestations requires an integrated Status approach incorporating a number of control techniques. On arable lands, cultivation and cropping or pasture Weed of National Significance. State Priority Weed in renovation are generally important. On poorer land, Victoria. Under the Catchment and Land Protection Act herbicides and mechanical removal are usually employed. 1994 serrated tussock is a Regionally Prohibited Weed in In all cases the ultimate aims is the establishment of Mallee, North Central, Corangamite, Goulburn Broken, competitive vegetation that will resist serrated tussock North East and East Gippsland Regions, and a Regionally invasion. Long-term control is dependent not only on Controlled Weed in Glenelg-Hopkins, Port Phillip and

© State of Victoria, Department of Sustainability and Environment Page 1 Serrated tussock - management LC0370 killing plants, but also replacing them with improved Agriculture Note: Agricultural chemical user permits pasture or trees and then careful management of the area to (ACUP) and chemical control areas (CCA). minimise re-infestation. Information on ACUPs, CCAs and other chemical Monitoring is an important aspect of management. Treated information can be found under Chemical Use in the areas should be inspected twice a year, for 5 to 10 years or General Farming section under Agriculture and Food at until regrowth from the soil seed bank ceases. the website www.dpi.vic.gov.au or ring the Chemical Information Service on (03) 9210 Prevention 9379. The service is available from 9.00am until 4.30pm To prevent the establishment of serrated tussock, purchase Monday to Friday. livestock from areas free of the weed and hold in Herbicide treatment should be part of an integrated quarantine areas for 10 days any animals suspected to have management plan involving the planting of competitive grazed on infested pastures; purchase seed that is certified replacement species and rehabilitation. Chemical treatment free of weed seeds; ensure machinery, vehicles, grain, hay without follow up work usually results in reinfestation and other fodder brought into an area are not from the soil seedbank. contaminated; plant shelter belts and employ appropriate When spot spraying aim to completely wet the plant to fencing along boundaries with infested properties to limit cause run-off. Add a dye to the spray mixture to identify the dispersal of seed heads. treated areas. Understand and follow best practice hygiene and clean- Glyphosate is a non-selective, non-residual herbicide down procedures for machinery and equipment and use absorbed through the leaves. It is relatively fast acting. only those contactors who have adopted such practices. All Unless a total kill is required, eg. as part of a pasture projects and activities which result in site disturbance (eg. improvement program, an application method should be fire management, road construction and maintenance) chosen that enables selective treatment of the serrated should incorporate weed prevention and control measures tussock eg. carpet-wiper or direct spot spraying. However, at the design and implementation stages, for example by appropriate timing of applications can protect desirable minimising travel through infested areas and identifying species, eg. spraying after annual grasses have set seed or suitable sites for cleandown activities. spraying when perennial grasses are dormant. Glyphosate Be vigilant in identifying serrated tussock and take prompt is the best option if the intention is to sow a new pasture or action to remove or kill it when it is found. All land at risk crop. should be checked annually for newly established plants. 2,2-DPA is a residual herbicide absorbed through leaves Isolated plants and small patches should always be chipped and roots, which is selective for some grasses at low out or treated with herbicide as soon as they are detected. application rates. Some infestation sites can be more important than others as sources of seed for dispersal, eg. on prominent hills. Flupropanate-sodium is a selective, slow acting herbicide, Consider the prevailing winds at the time when seed heads absorbed through the roots, with some soil residual effect break off. Serrated tussock plants in areas carrying heavy and a long stock withholding period. A major advantage of stock or human traffic should be another priority. flupropanate is that some pasture species, native grasses and trees are tolerant to it, but many native pasture grasses Good pasture management with annual applications of are very susceptible. Effects of spraying may not be visible fertiliser and strategic grazing will help defend against for 2 to 5 months after application and it may take up to 18 serrated tussock infestation. months for serrated tussock plants to die. This is a benefit Chemical control in highly erodible soils as alternative species can be established to stabilise the area while the tussock degrades. Under Victorian legislation there are controls on To prevent seed set, flupropanate must be applied before various aspects of the uses of agricultural chemicals. It July to allow time for it to act. Flupropanate soil is the responsibility of chemical users to familiarise persistence means it will kill emerging tussock seedlings themselves with these controls. for several months after application. The length of time it Choose only products registered for use on serrated is active within the soil is dependent on the amount of tussock in your particular situation. Read the product label rainfall. Always follow label instructions and note and follow all label instructions carefully. withholding periods when using flupropanate. Both flupropanate and 2,2-DPA kill annual grasses and Not all products containing the same active constituent some native grasses, which is why reseeding is necessary. will be registered for the same uses. You should use a Flupropanate is less damaging to improved perennial product with a label recommendation for the situation in which you wish to use that product. grasses such as phalaris, cocksfoot, fescue and ryegrass than 2,2-DPA. Phalaris is the most tolerant pasture species See your chemical retailer for further advice. to flupropanate. Grazing down pastures before spraying, or spraying in summer when improved pasture species are Legal use of some chemicals requires the user to dormant or not actively growing, and spraying at the possess an Agricultural Chemical User Permit (ACUP). Other chemicals have restrictions on their use in correct rate will minimise pasture damage. Chemical Control Areas (CCAs). Refer to the Both atrazine and hexazinone are foliar contact and root absorbed herbicides with long, soil residual properties.

Hexazinone and atrazine + hexazinone products are populations resistant to flupropanate were discovered in available in granular form for direct application to soil or 2002 in Victoria, but it is not known how widespread the as formulations for dispersal in water. problem might be. To avoid the development of resistant Repeated treatment of a weed with herbicides from the strains, rotate between products from different mode of same ‘mode of action’ group can result in the selection of action groups and employ non-chemical management plants that are herbicide resistant. Serrated tussock methods in an integrated strategy.

Table 1. Active constituents with products registered for use on serrated tussock throughout Victoria. Y indicates a product registered for the indicated situation. Chemicals marked with * require the user to possess an Agricultural Chemical User Permit. Chemicals marked with # have restrictions on their use in Chemical Control Areas. Chemical Information accurate October 2004. Use Situation Active Constituents SALT # SALT # GLYPHOSATE HEXAZINONE # 2,2-DPA SODIUM SALT ATRAZINE* + HEXAZINONE # MONOETHANOLAMINE SALT # FLUPROPANATE-SODIUM SALT GLYPHOSATE ISOPROPYLAMINE GLYPHOSATE ISOPROPYLAMINE AND MONO-AMMONIUM# SALTS GLYPHOSATE POTASSIUM SALT # GLYPHOSATE POTASSIUM SALT GLYPHOSATE MONO-AMMONIUM Berries, Fruits, Nuts over three years old Almond, Blueberry, Citrus, Dessert Fig, Kiwi Fruit, Olive, Y Peanut, Pecan, Persimmon, Pistachio, Pome Fruit, Raspberry, Stone Fruit, Vineyard, Walnut Other Agricultural Agricultural Area – General; Weed Control Around Y Agricultural Buildings Chickpea; Cotton; Hops; Navy Bean; Onion – Pre-emergent; Y Soybean Pasture YYY Prior to Establishing Crops; Prior to Improved Pasture YYY Suppression Prior to Establishing Crops or Improved Pasture YYY Forestry Forest Y Pine Plantation - Pre-planting; Pinus radiata Plantation - Post- Y planting Pine plantation - Post-planting YY Miscellaneous Aquatic Weed Control; Margins of Dams, Lakes and Streams; Y Channel, Drain or Irrigation Weed Control; Buildings - Around; Commercial Area - General; Domestic and/or Public Area; Industrial Land or Area; Public Service Area; Right-of- Way - General Non-crop Area - General Y Prevention of Seed Formation; Seed Head Emergence - YYY Prevention Prevention of Seed Head Emergence and Seed Formation YYY

This list of chemicals is based on information supplied to the Department of Primary Industries by the Australian Pesticides and Veterinary Medicines Authority (APVMA). The State of Victoria through the Department of Primary Industries has not assessed or checked the accuracy of the information supplied to it from the APVMA as that responsibility rests with the APVMA.

Burning 2. Conduct a soil test. Burning does not kill serrated tussock but it is a useful tool 3. Control rabbits. for reducing seed set and preparing infestations for 4. Determine the most appropriate method of sowing. herbicide application or cultivation. Burning is most 5. Begin weed control the year prior to establishing an successful in dense infestations. improved pasture. Serrated tussock will burn throughout the year, with late 6. Remove excess pasture trash. winter being the recommended time for reducing seed set. 7. Order chemicals, seed and fertilisers and organise Burning in late winter can also reduce the fire hazard in contractors or equipment. summer. 8. Spray with herbicide to achieve a total weed kill. Before burning, check with the local Council to see 9. Control redlegged earth mites and pest insects. what permits may be required. Take appropriate precautions such as clearing firebreaks. Notify your 10. Treat pasture seed with appropriate seed dressings. neighbours and the local Country Fire Authority. 11. Select recommended pasture species. 12. Sow seed and fertiliser in May. Cultivation/cropping Serrated tussock can be successfully controlled using a 13. Check the pasture for weed germination and insect program of cultivation and cropping followed by attack. establishment of improved pasture. Cultivation and 14. Spell pasture until well established. cropping can be used to control existing infestations as For information on each step refer to: well as reducing the seed bank. • Agriculture Note AG0391: Serrated tussock control The program involves burning in late winter followed by • Landcare Note LC0268: Serrated tussock: annual ploughing to a depth of 10 to 20 cm. Serrated tussock control calendar seedlings cannot emerge when seed is buried deeper than 2 cm. Mouldboard and disc ploughing are the most effective Grazing management methods. Chisel ploughing is not effective. Paddocks are Grazing management can be used to control serrated left fallow and cultivated again in late summer to kill new tussock seedlings, as they are weak and susceptible to serrated tussock and other weed seedlings. Cropping grazing pressure and competition from actively growing programs should be conducted for two years before pasture species. Good pasture cover (70%) and avoidance establishing improved pasture. of overgrazing is important to prevent serrated tussock Control in native grasslands taking over. Grazing management is one element that helps promote healthy and productive pastures. Another There are no selective herbicides that can be used to essential component is annual applications of remove serrated tussock from native grasslands. Kangaroo phosphorous-based fertilisers like superphosphate, plus grass, silver tussock and red-leg grass have shown other nutrients required to remedy deficiencies. Soils tests tolerance to flupropanate, however wallaby grasses and and plant tissue tests can determine nutrient deficiencies. spear grasses are susceptible. The basic steps in a grazing strategy to control serrated Control programs should aim to limit invasion by tussock are as follows. strategically using chipping, spot spraying, weed wiping and where appropriate grazing management. Grazing Summer strategies for native grasslands are the same as for 1. Monitor paddocks for seedling appearance. improved pastures, except grazing should be reduced in 2. Maintain grazing pressure until pasture dry matter spring and summer to encourage seed set. falls below 1000 kg/ha (approx. 30% bare ground) Pasture establishment then remove stock. Note: Phalaris will tolerate heavy Improved perennial pasture is an effective long-term stocking over summer, but cocksfoot will send up management regime for serrated tussock after initial green shoots in response to summer rainfall and if infestations have been killed. Serrated tussock seedlings continually grazed the plants will die. will reinvade improved pasture; however, they are weak Autumn and can be smothered by vigorous, actively growing 3. Crash graze to remove excess feed if dry matter is perennial pasture species. Phalaris and cocksfoot are two greater than 1000 kg/ha. of the most competitive pasture species. Both these perennial grasses are deep rooted and drought tolerant, and 4. Start rotational grazing. therefore more persistent than perennial ryegrass in areas Winter with dry summers. Suitable subclover species also need to be included in any pasture mix. 5. Use rotational grazing throughout winter. Successful pasture establishment relies on following Spring proven techniques and not taking any short cuts. The steps 6. Maintain pasture height at 6 to 10 cm to shade out for successful pasture establishment are: serrated tussock seedlings by either rotational or set 1. Start planning 12 months ahead and seek advice. stocking grazing.

For specific information on grazing strategies see: should include prevention and control works and • Agriculture Note AG0940: Pasture management to replacement with appropriate competitive vegetation if reduce serrated tussock invasion long-term control is to be achieved. In management plans, it is important to build in short-term wins to maintain Trees enthusiasm and confidence. The number of heavily Trees can play two roles in serrated tussock control. Firstly infested properties in Victoria has been falling, significant they can provide a physical barrier to intercept wind blown numbers of previously infested properties are now free of seed heads and secondly they can function as a the weed, and major landscape renovation projects are competitive species to kill and suppress serrated tussock. under way in the worst affected areas. Don’t give up, be The most effective species are those that create heavy vigilant and protect your investment. shade, eg. radiata pine. Serrated tussock can be beaten! On non-arable land where pastures are difficult or impossible to establish, dense tree plantings can be an Further advice effective long-term method for controlling serrated tussock. Examples are stone barriers, steep escarpments, Contact your local Catchment Management Officer for erosion prone soils, creek valleys and other inaccessible further advice on serrated tussock management and areas. Tree plantations can be established as a commercial community control programs. venture but they also provide the benefits of shelter, wood, habitat and aesthetic value. References The successful establishment of a tree plantation requires Agriculture & Resource Management Council of Australia & planning similar to the establishment of any other crop. New Zealand, Australian & New Zealand Environment & Conservation Council and Forestry Ministers (2000) Weeds of Site preparation and continued management are essential National Significance Serrated Tussock (Nassella trichotoma) in achieving a healthy plantation. Strategic Plan. Launceston, National Weeds Strategy Executive Steps for successful tree establishment (winter planting) Committee. http://www.weeds.org.au/docs/ststrat.pdf are: Campbell, M.H. and Vere, D.T. (1995) Nassella trichotoma 1. Seek advice and plan at least 12 months ahead. (Nees) Arech. In Groves, R.H., Shepherd, R.C.H. and Richardson, R.G. (Eds.) The Biology of Australian Weeds 2. Control weeds in the year prior to planting. Volume 1. Melbourne, R.G. and F.J. Richardson, pp. 189-202. 3. Select and order trees for the site well in advance. Crowe, B. (2004) Victorian Weednet. A Guideline for the 4. Control vermin. Prevention of the Spread of Serrated Tussock. Geelong, Catchment and Agriculture Services, Department of Primary 5. Rip the site in late summer. Industries. 6. Control weeds prior to planting. Michelmore, M. (2003) The Serrated Tussock Managers’ 7. Plant in winter. Factpack. New South Wales Agriculture. http://www.weeds.org.au/docs/serrated_tussock_fact_pack.pdf 8. Continue to monitor for weeds, vermin and other pests. Muyt, A. (2001) Bush Invaders of South-east Australia. Meredith, Vic., R.G. & F.J. Richardson. For detailed information on tree establishment refer to: Parsons, W.T. and Cuthbertson, E.G. (2001) Noxious Weeds of • Landcare Note LC0104: Tree planting and aftercare Australia. 2nd Ed., Collingwood, CSIRO Publishing. • Landcare Note LC0268: Serrated tussock: annual Shepherd, R.C.H. and Richardson, R.G. (eds.) (1998) The control calendar Nassella Workshop. Plant Protection Quarterly 13(2), 59-103. Verbeek, B., Leech, F. & Ayres, L. (2004) Glyphosate – another Biological control tool for managing serrated tussock. 14th Australian Weeds Investigations are under way in Argentina and Australia to Conference Papers and Proceedings, pp. 245-248. identify pathogens suitable for development as bio- Weed Society of Victoria (2002) Exotic stipoid grasses: impacts herbicides or for release as biological control agents. A and control in Australia. Plant Protection Quarterly 17(3), 82- relatively rich and unrecorded fungal flora associated with 126. serrated tussock has been found in Argentina with three potentially useful fungi currently being evaluated. These Acknowledgements are a rust, Puccinia nassellae, that attacks the leaves; a 2002 version compiled by Vicky Cleland, Ian Faithfull and smut, Ustilago sp., that attacks the flowers, replacing seeds Trevor Hunt. Information and comment by Graeme Pritchard, with smutted heads; and a rot fungus in the family Lisa Miller and David McLaren. Revised by Ian Faithfull, Corticiaceae, that limits root and crown growth. Endemic October 2004. Australian soil fungi which reduce the germination of seed This publication may be of assistance to you but the State of Victoria also have potential. Detailed testing of promising agents and its employees do not guarantee that the publication is without will take a number of years. flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or Ongoing management other consequence which may arise from you relying on any information in this publication. Serrated tussock is a difficult weed to control and requires long-term management plans. Management activities