Section 4 Control methods and management ... - Weeds Australia

Section 4 Control methods and management ... - Weeds Australia

Section 4Control methods andmanagement practicesNon-chemical control 58Manual removal/chipping 58Mulching 59Fire 59Chemical control 61Chemical selection 61Glyphosate 62Flupropanate 63C 3and C 4grasses 66Spot spraying 67Broadacre spraying 68Wick wiping 69Spray topping 70Competition 71Cropping/cultivation 71Pasture establishment/renovation 72Grazing management 74Afforestation 77Reducing spread 79General property hygiene 79Mesh fencing 81Shelterbelts/windbreaks 82Slashing/mowing 83Biological control 8457

Non-chemical controlManual removal/chippingNatasha BaldydaPeter FullertonChipping, also referred to as hoeing, is thephysical removal of the entire serrated tussockplant from the ground using a hoe or mattock. Inthe bare ground left by chipping, scatter pastureseed and fertiliser to increase ground cover andpromote competition.Once removed from the ground, shake soil fromthe roots or leave in a position with the rootsexposed to dry out. Otherwise the plant may rerootand grow. If chipped while in flower, bag thewhole plant, remove from the paddock and burn.Ease of chipping will depend upon soil type.Serrated tussock is more easily removed fromsoft/sandy soils compared to heavy/clay soils.Suitable for:• All land-use situations with scattered orlight infestation levels.• Follow up treatments to remove regrowth.Timing• All year, preferably before flowering. Ensureto treat any regrowth that follows.Advantages• Completely removes and kills plant.• Low soil disturbance.• Control without using chemicals.• Can be carried out while doing dailyproperty activities such as checking fencesor water. Always carry a mattock (andseed for revegetation) on the bike or in thevehicle.Disadvantages• Uprooted plants may survive if moist soil isleft around their roots.• Labour intensive.‘Can’t beat a mattock’(Canberra workshop).‘Hoe, hoe, hoe!’ (Bathurst workshop)‘It’s a matter of having a mattock onthe back of the ute’(Attwood workshop).Chipping will cause some degreeof soil disturbance, creating barepatches. Ensure you replace thesepatches with desirable species(Hobart workshop).58

MulchingMulching is the physical application of material,such as straw, wood chippings, plastic sheetingor carpet, over the ground to prevent weedgrowth. This method will stop all smotheredvegetation from growing, including all beneficialvegetation. To be effective, re-vegetate desirablespecies into the mulch layer.For best results:• chip serrated tussock plants or spot spraywith glyphosate• apply a mulch layer at least 10 cm thick tosmother all existing vegetation• plant seedlings or tube stock of desirablespecies into the mulch or weed mat toprovide competition with emerging weeds.Use a crow bar to create a hole for tubestock to be planted through the weed mator mulch• regularly monitor for emerging serratedtussock plants, and other weeds• follow up any regrowth by spot sprayingwith glyphosate or manually remove• maintain the depth of mulch levels, as overtime they will settle and decompose (Snell etal 2007).Suitable for:• Light or isolated infestations in urban areas.For example, parks, reserves, roadsides andbackyards.• Organic farming situations.• Small area, high density infestations inenvironmental areas where vegetationrehabilitation is required. For example, creekbanks or conservation native grasslands.• Light infestations in difficult to manageterrain. For example, rocky, steep or treedcountry, or along fence lines.Applying mulch to treat small infestations in a rockyoutcrop may be useful.TimingAll yearAdvantages• Does not require chemical application.• Does not disturb the soil.Disadvantages• Not suitable for large scale infestations.• Non-selective.• Can be expensive.• Labour intensive.In an organic farm situation, mulchmay be used to smother serratedtussock plants before flowering anddoes not disturb soil(Canberra workshop).Len MenzelFireA hot serrated tussock fire will not kill adultplants, though it will remove biomass anddestroy about 25% of the serrated tussockseed bank. Mostly surface seed is destroyed asburied seed is unaffected by fire. Only use fire incombination with other control methods.Burnt serrated tussock plants may regrow andfire stimulates the mass germination of serratedtussock seeds. Therefore, always carry out avigorous follow up control program to removeserrated tussock seedlings, using an appropriateherbicide control technique suited to preservingthe desirable background pasture species.Only use fire with appropriate permits and local fireauthority.Charles Grech59

Always follow up fire with a vigilantcontrol program using techniquessuch as spot spraying.Do not use glyphosate following fire until enoughgreen leaf material is available for chemicaluptake. Avoid using fire for at least 1 to 2 yearsfollowing the application of flupropanate as itremoves the herbicide residual from the soil.Serrated tussock will produce a hot fire yearround, which may have harmful effects ondesirable vegetation. Always use fire with cautionand seek advice when required.Suitable for:• Conservation native grasslands, whereecological biomass reductions areperiodically required to maintain the healthand rejuvenation of native species. Selectivegrazing by native and feral animals mayincrease serrated tussock populations insuch situations, so burning may be one offew management options available.• Degraded pasture situations where theremoval of dry matter prior to ploughing isrequired.• Urban areas such as large parks andreserves, only in collaboration with the localfire authority.TimingBest in late autumn to late winter—this mayreduce seed-set and the summer fire hazard. Ifusing fire, only burn once every two to threeyears.In native pastures, winter burns are moreeffective in reducing the regrowth of serratedtussock and is best conducted when at least1000 kg DM/ha (pasture about 3 cm high) ofdesirable competing vegetation is available(Badgery 2003).Advantages• Rejuvenates native grasslands to maintaindiversity and healthy growth.• May reduce the serrated tussock seed bank.• May postpone serrated tussock fromseeding for the current season.Disadvantages• Serrated tussock can regrow vigorouslyfollowing fire and may produce more seedin the following flowering season.• The seed bank of desirable native speciesmay be too low to successfully competewith serrated tussock following a fire.• Adult serrated tussock populations are a firerisk and should only be burnt with extremecare and caution—a hot burn conducted atthe wrong time may generate a wind stormof seed heads, creating a dangerous firerisk.• May leave large bare patches of ground.New South WalesRural Fire Service02 8741 Fire Service03 6230 land - Rural Fire Service02 6207 land - Parks, Conservation & Lands02 6207 2488South AustraliaCountry Fire Service08 8463 Fire Authority03 9262 Fire Service07 3247 contact the local fire authority, check current fire restrictions and if required, obtain permits.60

Chemical controlHerbicides are extremely beneficial in a serratedtussock integrated weed management plan;however, they should not be relied on as the solemethod of control. Inappropriate use or heavyreliance of chemicals may lead to increase thechances of resistance occurring (see page 24 formore information).Herbicide use requires correct timing andapplication rates to be effective, and will varydepending on the situation and density ofserrated tussock.When using herbicides, recording specificinformation may be required—each state hastheir own requirements for record keeping.For all current label and minor-use permit detailsfor serrated tussock control, visit the AustralianPesticides and Veterinary Medicines Authority carefully read and follow all labeldirections, material safety data sheets, and anyoff-label minor use permits.Always follow up chemical controlwith other control measures.Using only chemicals to controlserrated tussock is NOT the answer.Chemical selectionA number of herbicides are registered forcontrolling serrated tussock in Australianpastures. These include glyphosate, flupropanateand 2,2-DPA. Two main herbicides are currentlyused—glyphosate and flupropanate.The use of 2,2-DPA relied heavily on burning ofpastures after treatment. In areas where burningcould not be implemented, such as improvedpastures, or steep fire-prone areas, very highrates of the herbicide is necessary. The herbicideand the burning leave pastures very weak,unproductive, and vulnerable to invasion ofweeds. As such, this herbicide is not generallyrecommended in this management guide. Theremay be instances where 2,2-DPA may be usefulfor treating serrated tussock and other weeds.The density and location of serrated tussock willdetermine the herbicide and application methodto use.Find up-to-date chemicalregistration details and currentpermits on the AustralianPesticides and VeterinaryMedicines Authority (APVMA)website: 3: Herbicides currently registered for use on serrated tussock in pasture situations (September 2008).ActiveingredientState orTerritoryApplication methodCommentsFlupropanateNSW, ACT,Vic, Tas,Qld, SA,WAGround & aerial application, spotspraying, spray topping and wickwiping.Refer to label for details on timingand rates.See text. Can be combinedwith glyphosate products asinstructed on the label.Withholding periods apply.GlyphosateVic, NSW,Tas, ACTGround application, spot sprayingand spray topping.Aerial application.Refer to label for details on timingand rates.See text. Can be combined withflupropanate.No withholding period.2,2-DPAVic, NSW,Qld, SA,WABroadacre and spot spray.Refer to label for details on timingand rates.May take 6–8 weeks for fulleffect to be seen.May make pasture unproductivefor a long period.61

GlyphosateA non-selective herbicide that kills green, activelygrowing plants. Careful application is essential tominimise non-target damage.Characteristics of glyphosate include:• absorbed through the leaves and greenstems• fast acting—kills treated plants one to fourweeks after application• not residual—ceases to work once itcontacts the soil• no withholding period for grazing stock;however, avoid grazing stock for seven daysfollowing application to allow absorptioninto the plant.Regrowth of serrated tussock following mis-spray – willrequire follow up treatment.Suitable for:• All land-use situations. Application methodwill vary depending on the situation anddensity of the infestation.• Spot spraying with glyphosate is suitable forall land-use situations; all pasture types andas an effective follow up treatment.• If glyphosate is used prior to croppingor sowing new pasture, the land can becultivated soon after spraying.Application• Apply by spot spray or broadacre—ground/boom or aerial spray.• When spot spraying, always apply with acarefully directed spray, directly onto theplant to avoid over-spray.• Complete coverage of the plant is necessaryto kill serrated tussock. Any part missed,can survive independently. Take care toavoid over-spray to reduce damage to nontargetspecies.Bronwen Wicks• Selectivity of glyphosate may be achievedby utilising the lifecycle of the desiredpasture species, only if applied whiledesirable plants are completely dormant.• Adding a surfactant or wetting agent mayimprove glyphosate penetration. A dyemarker could also be added for spot sprayapplications to avoid spray misses or doubleapplications.• Always ensure equipment is properlycalibrated, and the directions on the labelare followed.• Spray top with low label rates of herbicideonly as a short term option to prevent seedsetin the current season.Cautions• If spraying around waterways, use aglyphosate formulation that is registered foruse in this situation.• Timing is critical when broadacreapplications are used in pasture situations.Protection of desirable species is essentialand land holders must be knowledgeableon the lifecycle of pasture species ifconsidering using this as an option. Alwaysseek specialist agronomist advice if indoubt. Be aware that some pasture damagemay still occur.TimingSpot spray – apply any time of the year whenserrated tussock plants are green, activelygrowing and not moisture stressed. Optimumtime for application is May to October.Broadacre spray prior to sowing crop or pasture– improved control can occur by removal of deadvegetation, and by encouraging fresh greengrowth. To do this either burn the paddock10–12 months prior to spraying, slash or heavilygraze two weeks before spraying. Follow criticalcomments on the label for best results.Herbicide training is highlyrecommended for all herbicide usersto ensure safe use of chemicals.Accredited training courses are runby organisations such as ChemCert,Smartrain and TAFE colleges.Other training courses may beavailable through state agencies,local councils or non-governmentorganisations.62

Spray top to prevent seeding – best results areobtained if applied prior to flowering, mid-August, or prior to seed set in mid-October.When using glyphosate to selectively removeserrated tussock. Know the lifecycle of thepasture species you want to protect. This willinvolve thorough inspection of the plant atdifferent parts of the year. Only apply glyphosatewhen the desirable plants are completelydormant. Get down at pasture level and check—ifany green parts are present on the plant thenglyphosate will affect it.Generally for annual pasture species, applyglyphosate to treat serrated tussock after theyhave set seed. For perennial grass species, applyin winter for summer growing (C 4) grasses, whilstapply in mid-summer for some winter growing(C 3) grasses when they are completely dormant,see page 66 for more information. Always seekadvice from an agronomist for your specificsituation.Advantages• Able to target other weeds at the same timewhen spot spraying.• A quick method of killing serrated tussock.• Nil grazing withholding period.• When applied accurately, is very effective.FlupropanateFlupropanate is a slow acting herbicidepredominantly absorbed through the roots andalso the leaves. It can take 2–12 months to killthe plant, particularly if affected by drought.Characteristics of flupropanate include:• A residual action in the soil that preventsor limits the growth of emerging serratedtussock seedlings. Residual life variesdepending on soil type and rainfall, butmay generally last 2–3 years. Time maybe reduced by large rain events or soilmovement from flooding. Residual actionin soil may allow tolerant desirable pasturespecies to increase in density, providinggood competition for serrated tussock oncethe residual effect has gone.• Some selectivity, but may cause non-targetdamage, particularly to native species. Seebelow for more information.• A long withholding period for grazinganimals which may have large implicationsfor grazing management. Spot application:14 days following treatment; broadacreapplication: four months followingtreatment. Lactating cows and goats mustnot be grazed in treated areas.Disadvantages• Unlikely to affect serrated tussock seedbank levels.• Broadacre treatments of glyphosate canlead to a monoculture of weeds. Replace thetussock with desirable species to preventthis from occurring.• Glyphosate is non-selective. Over-spray mayopen up bare areas, increasing the risk ofre-invasion, especially in a dry year.Glyphosate can provide you with adistinctive picture to see where youhave sprayed in the past(Cooma workshop).Michael MichelmoreAerial spraying of flupropanate in the Snowy mountains—before (top) and after (bottom). Note the serrated tussockhas returned following treatment; however, there is noother native vegetation left to compete.63

Flupropanate applied in certain situations can kill serratedtussock with minimal damage to desirable vegetation.SelectivityMany introduced and native grass species aretolerant to flupropanate; however, many are not.Before using flupropanate to control serratedtussock, know the composition of the pastureand how each species may be affected byflupropanate. Using flupropanate, particularlyin native pastures, may change its composition.For example, high rates of flupropanate canreduce the levels of weeping grass (Microlaenastipoides) and increase of level of red-leg grass(Bothriochloa macra).Flupropanate selectivity is also influenced by theapplication rate. For example, some plants havea low tolerance at high label rates.Tolerant speciesIntroduced pasture species tolerant to low labelrates of herbicide (less than 2 L/ha) includephalaris, cocksfoot and tall fescue. Whileconsidered ‘tolerant’, they may be affected by thetreatment, but should recover.Do not sow phalaris, cocksfoot, ryegrass, red,white and subterranean clovers and lucerne intoflupropanate treated areas until at least 100 mmof leaching rain has fallen (plant back period).Native species that are tolerant to flupropanate atthe recommended rates include:• kangaroo grass ( Themeda triandra)• red-leg grass ( Bothriochloa macra)• poa or silver tussock ( Poa labilardieri).Susceptible speciesThe following species are known to besusceptible to flupropanate:• weeping grass ( Microlaena stipoides)• wallaby grass ( Austrodanthonia spp.)• spear grass ( Austrostipa spp.)• legumes, particularly young subterraneanclover.Michael MichelmoreCautions• Some desirable grasses, such as nativespecies and perennial improved species,subterranean clovers and other annuallegumes may be damaged by flupropanateif exposed to the spray or if they germinateand grow before residues have dissipatedfrom the soil.• Flupropanate effectiveness may alteraccording to soil type. Flupropanate canbecome more active in lighter soils (shale/sandy) than heavy soils (clay).• Resistance to flupropanate has alreadydeveloped in a few populations of serratedtussock. More information on resistance isgiven on page 24.• The residual effects of flupropanate mustbe carefully managed in your soil. Avoidrepeated broadacre spraying that willincrease existing residual flupropanate inyour soils to levels where large areas ofsusceptible species are damaged.• Application of flupropanate on land thatcontains a high proportion of susceptiblespecies can leave ground bare and exposedto reinvasion.Suitable for:• Spot spraying in all situations, particularlywhen density levels are light and scattered.Spot spraying high density infestations ofserrated tussock in native pastures andgrasslands may also be effective.• Broadacre application in introduced pasturesdue to their greater tolerance levels andability to recover.• Wick wipe in pasture, urban and nativegrassland situations with infestations of amedium to high density.ApplicationMay be used in spot, broadacre (ground oraerial) and wick wipe applications. If broadacrespraying, the boom sprayer should have anautomatic rate controller and should be correctlycalibrated. This is particularly critical for aerialapplication. Always ensure rates are appliedaccording to the label.Spot spray using a carefully directed sprayinto the centre of the plant with a low volumeknapsack. Specific application at this pointwill reduce the risk of non-target damage, asflupropanate is largely taken up through theroots.64

Apply low label rates in a broadacre applicationto control serrated tussock seedlings (less than10 cm high) in an introduced pasture situation.Flupropanate can be mixed with glyphosatein a spot spray application to provide a quickknockdown while having a residual effect foremerging serrated tussock seedlings. However,glyphosate reduces the effect of flupropanateand should only be added as a marker whenabsolutely necessary. If quick brown out iswanted close to seeding, just use glyphosate or amixture of flupropanate and glyphosate.Flupropanate can decrease its residual activity ifthe area is burnt after application.Undertake broadacre applications of flupropanatewith care as off target damage to susceptiblespecies may occur, reducing production. Ensurethat the contractor uses an automatic ratecontroller and that this is correctly calibratedTimingSpot spray at any time of the year.Ideally, apply flupropanate during the vegetativestage of growth of serrated tussock to allowsufficient time for herbicide to take effect prior toflowering. This may be at least 3 months beforeflowering, depending on rainfall.Advantages• Residual herbicide will reduce the growth ofserrated tussock seedlings for an extendedperiod—up to a number of years under verylow rainfall conditions.• Tolerant desirable species are able toestablish and stabilise an area while thetussock degrades.Disadvantages• Residual effects may reduce the growth andestablishment of the crop or pasture.• Long withholding period for broadacreapplications may be a deterrent due tograzing management issues.• Application of high label rates offlupropanate may result in a loss of highlyproductive desirable pasture species.• Lactating stock must not graze treatedareas.Always ensure equipment isproperly calibrated for correctapplication rates.Charles GrechSuccessful application of flupropanate in an introduced pasture situation.65

C 3and C 4grassesC 3and C 4are terms used to describe thephotosynthetic pathway or system that aperennial grass uses. All it means is that someplants are better adapted for winter growth,while others are more adapted for summergrowth. This can have implications on thetiming of herbicide applications in the control ofserrated tussock.C 3grasses generally have active growthduring winter months and are dormant (donot actively grow) during summer. Howeverthere are exceptions to this rule. Weepinggrass (Microlaena stipoides) and wallaby grass(Austrodanthonia spp.) are two native perennialC 3grasses that are yearlong green species.Alternatively, C 4grasses actively grow in summerand are dormant during winter.This is only a guide of when some grasses havetheir period of dormancy. It is important to getto know the lifecycles of the grasses withinthe pasture. Herbicide application can then bemanipulated for the best possible results, withthe least amount of non-target damage. Getdown at grass level and thoroughly check thepasture before applying glyphosate. If any greenparts are on the plant, they will be affected byherbicide.Implications for glyphosate application:• Glyphosate must be applied to activelygrowing plants to be effective.• Appropriate timing of glyphosate can beused to protect desirable pasture species—when perennial plants are completelydormant (winter for C 4grasses and midsummerwhen soil moisture is low for C 3grasses) and after annual grasses have setseed.Implications for flupropanate application:• Not recommended for broadacre applicationon pastures containing high numbers ofsusceptible plant species—regardless oftheir lifecycle.• Do not use flupropanate in a broadacreapplication if the desirable native vegetationconsists predominantly of C 3native grasses.Further information may be obtained from anagronomist.C 3grasses (winter active) include:• Nassella trichotoma – serrated tussock• Nassella neesiana – Chilean needle grass• Phalaris aquatica – phalaris• Dactylis glomerata – cocksfoot• Lolium perenne – perennial ryegrass• Festuca arundinacea – tall fescue• Austrodanthonia spp. – wallaby grasses(native)• Poa labillardierei – tussock grass (native)• Poa sieberiana – snowgrass (native)• Microleana stipoides – weeping grass (native)• Austrostipa spp. – spear grasses (native)C 4grasses (summer active) include:• Pennisetum clandestinum – kikuyu• Paspalum dilatatum – paspalum• Sporobolus africanus – Parramatta grass• Themeda triandra – kangaroo grass (native)• Bothriochloa macra – red grass, red-leggrass (native)• Do not apply glyphosate until pasture hasbeen checked thoroughly and desirablespecies are completely dormant.• Do not use glyphosate in a broadacreapplication where C 4grasses grow alongside C 3grasses.• To succeed in rehabilitating an area infestedwith serrated tussock with glyphosate, theremust be adequate densities of desirableback ground pasture species present tofill the ‘gap’ when the serrated tussock isremoved (Verbeek 2007).66

Spot sprayingCharles GrechSpot spraying.Herbicides, glyphosate, 2,2-DPA andflupropanate, can be used to spot spray serratedtussock. Individual plants are treated usinga knapsack or spray unit with handgun. Spotspraying can be done on foot or on a vehicle.Include in daily farm activities.When spot spraying:• only spray the target plant—do not overspray• spray every serrated tussock plant you find• monitor where you spray• use a coloured marker dye• control scattered infestations first and workback into denser infestations• spray at optimum times for best results• spray with a carefully directed spray toavoid over-spray—stand over the plant for afull view• limit the areas you plan to spot spray—setachievable goals• take your time and have regular breaks.Always follow up treatments with further spotspraying or chipping, as some plants may havebeen missed and new seedlings will alwaysemerge.‘Spot spraying effective every day’(Bathurst workshop).Spot spraying—‘hard work paid off’(Attwood workshop).Using a dye marker can help you see whichplants have been treated.Suitable for:• All situations.• Best in light and scattered infestations;however, excellent results have beenobtained from diligent spot spraying ofmedium to high density infestations, whensufficient resources are available.• An effective follow up treatment.ApplicationApplication will vary depending upon the chosenchemical. Each chemical has a different mode ofaction.• Glyphosate – cover entire plant withherbicide, but not dripping, and apply whenthe plant is green and actively growing.• Flupropanate – apply a small amount ofherbicide into the centre of each tussock.This may reduce damage to non-targetspecies.Take your time to ensure treatment of all plants.A few tips are:• look behind to see if any plants have beenmissed• work with the sun behind you so that youare not squinting when looking for plants totreat• use flags, stakes or fence droppers to helpyou divide up and mark areas being treated.This may be particularly useful whenworking in gullies or hilly country• use a tracker, such as a GPS, in conjunctionwith a spray marker to indicate spray lines.Always carefully read and follow all labeldirections and use correctly calibratedequipment.Charles Grech67

Timing• Flupropanate may be spot sprayed at alltimes of the year.• Apply glyphosate when serrated tussockis actively growing and stress free, usuallyMay–October.Advantages• Possible to target other weeds at the sametime.Disadvantages• Can be easy to miss plants, particularlysmall plants hiding under larger ones.• Can be labour intensive.• Non-target damage may occur.Broadacre sprayingBroadacre spraying can be achieved via groundor aerial (helicopter or fixed wing) application. Itis important to use the correct herbicide for yoursituation. Broadacre spraying should not be usedin isolation. Know the dominant species withinthe pasture and their susceptibility to differentherbicides. Follow up with competition strategiesthat focus on enhancing pasture density andground cover.Aerial and ground spraying is strictly regulatedin Tasmania. Anyone wishing to undertakebroadacre spraying of serrated tussockin Tasmania should seek advice from theDepartment of Primary Industries and Water.Considerations before broadacre sprayingSelectiveness of the herbicide relies on thecorrect rate of herbicide per hectare beingapplied in an even and consistent manner acrossall vegetation. To achieve this, the sprayerneeds to be calibrated and driven accurately at aconsistent speed. It is important to:1.Know the type of paddock you will bedriving and consider what speed will beappropriate for the entire area – choose onespeed and stay constant, unless using aflow controller.Aerial spraying can be useful when the area is tooextensive to ground boom or the density is too large tospot spray.Malcolm Campbell2.3.Choose appropriate spray nozzles to suitthe ground speed and volume of waterto be applied per hectare (refer to theherbicide label). Avoid spray drift by usinglower pressures and nozzles (such as airinduction nozzles) that produce largedroplets. For example, coarse to very coarseclassification.Clean filters and check the spray patternand output of all spray nozzles on the sprayboom.4.Use a method of guidance when drivingacross the paddock to ensure that stripsare not missed or double overlapped. Forexample, foam marker or GPS systems.Aerial mis-spray of flupropanate.Charles Grech5. Use an automatic rate controller; particularlyfor aerial application. A rate controllermay save you money as you may use lesschemical and consequently do less damageto your pasture.Suitable for:• Situations where the density of serratedtussock is too high and extensive toeffectively conduct spot treatments.68

• Ground application on arable land and aerialapplication on difficult to access terrain.Also useful when the area affected byserrated tussock is so large it is more costeffective to apply herbicide by air.Application and timingCorrectly calibrate all spray equipment beforeuse, always use clean water and strictly follow allherbicide label directions and rates.Flupropanate• Low label rates of flupropanate can be usedto selectively kill serrated tussock seedlingsin introduced pastures. This should be donein April–August, before the spring flushor December–February when improved C 3pasture species are completely dormant.• In steep country, use low label rates ofaerially applied flupropanate and higherrates of water.• Success rate depends on the skill levelsof the pilot if not using a guidancesystem.• High risk of non-target damage.‘The most critical factor when hiringa contractor or doing broadacrespraying (air or ground) themselvesis making sure that the sprayequipment has an automatic ratecontroller and that this is correctlycalibrated.’ Alan McKenzieWick wipingWarning• There have been some disastrous eventsinvolving aerial spraying of flupropanate,where all species, including desirablenatives were destroyed. If using this option,ensure you use a GPS to mark areas treatedand flow control equipment. Exerciseextreme care and caution.• Do not broadacre spray native pastureswith flupropanate, or other areas, that havesusceptible native grasses as the dominantpasture species.Glyphosate• Aerial or ground application ofglyphosate in pasture or fallow situationsprior to sowing crops, fodder crops ornew pasture.− Removal of all vegetation prior tosowing crop or pasture – applyFebruary to May.• Spray-topping – use low label ratesof glyphosate in a ground or aerialapplication prior to seed-set (mid-Augustto mid-October).• If using in a pasture situation, applywhen desirable perennial species arecompletely dormant. See page 62 formore information.Advantages• More economical in large scaleinfestations.Disadvantages• Aerial spraying can be very expensivewhen using high water rates.A distinct height difference must occur between thedesirable vegetation and serrated tussock.Wick wiping is a technique that selectively ‘wipes’the herbicide onto weeds. Equipment can bemounted onto a vehicle or hand-held, and isapplied from a ropewick or rotating carpet wipersaturated with concentrated herbicide.Only use when a distinct height difference occursbetween beneficial pasture species and serratedtussock. Always monitor treated areas for small,missed plants and remove by chipping or spotspraying.Suitable for:• Removal of large serrated tussock plants inpasture situations.• Infestations on level ground—wiper heightcan not be automatically adjusted.Application1. Crash graze pastures to reduce the heightof all desirable species—serrated tussockshould be at least 15 cm taller than thedesirable vegetation.Malcolm Campbell69

2. Set wiper at a level of 10 cm above thepasture.3. Always keep wick wiping equipment higherthan desirable species.4. Travel at low speeds, less than 8 km/hr, with two passes of the wiper made inopposite directions.5. Keep wiper wet, but not dripping, withherbicide at all times.6. Avoid herbicide dripping onto non-targetspecies.Timing• All year. Avoid application in very drywinters.Advantages• Minimal damage to desirable vegetation.• Low risk of off target damage.• Requires small volumes of herbicide.Disadvantage• Only treats large plants, missing smalljuvenile plants.• Can be labour intensive.Spray toppingSpray topping uses low label rates of herbicideto reduce or prevent seed-set in serratedtussock, which may help in reducing the serratedtussock tussock while doing minimal damageto beneficial species. It can be used as a broadacre treatment to stop serrated tussock seeding.It will not kill serrated tussock plants, but willaffect them so that they do not flower, or ifalready in flower will not produce viable seed.However, spray topping will not kill seed once itas already formed on the plant.Always use with other methods of controlsuch as spot spraying, chipping and grazingmanagement.Suitable for:• A short term option only and particularly inpasture situations with medium to high levelinfestations of serrated tussock.Application• Broadacre applications of low rates ofglyphosate.• Low rates of flupropanate may be added toglyphosate to reduce re-invasion from theserrated tussock seedbank.Timing• Timing is critical for this method to beeffective.• For glyphosate treat prior to flowering—mid-August to mid-October.• Always apply herbicide in accordance withlabel directions.Advantages• Reduces seeding.• Less damaging done to desirable pasture.Disadvantages• Does not kill the plant.70

CompetitionSerrated tussock is a weak competitor as aseedling. Maintaining a healthy ground coverof desirable species is the key for long termmanagement and control. Competition should bemade an integral part of any control program.Cropping/cultivation[In our district] serrated tussock haschanged farm management fromgrazing stock to cropping(Geelong workshop).Cultivation on its own is a short term methodto control serrated tussock and reduce the seedbank. For long term control, sow cultivatedareas to crop or pasture. Cropping can be analternative to grazing, provide an alternativesource of income and reduce the soil seed bank.On arable land, a cereal crop rotation can reduce theserrated tussock seed bank and compete strongly withemerging seedlings.Brassica forages crops are an alternative to cereal crops.Scarified serrated tussock—control was ineffective.Charles GrechPeter FullertonCharles GrechPrior to sowing a crop, a soil test should beconducted to determine fertiliser, lime andgypsum requirements. If suitable, land can becontinually cropped or sown to pasture after acouple years of cropping rotations.Specific advice on suitable crops for your locationmay be obtained from your local agronomist.Suitable cereal crops may include wheat, triticaleand oats; summer forage crops may includebrassicas.Suitable for:• Arable, agricultural land, where the pastureis rundown and requires renovation.Application:• Prepare paddock to be cultivated by:− heavy grazing, burning or slashing toremove excess plant litter in heavyinfestations− broadacre application of glyphosateto kill all existing vegetation prior tosowing.Note:1. New areas may require high sprayinputs to effectively kill high densities ofserrated tussock.2. Do not heavily graze pastures thatcontain only serrated tussock.• Use a disc plough, or similar, and ploughdeep enough for serrated tussock plantsto be over turned and broken up. Afterploughing, paddocks can be either left tofallow or sown to crop.• Prior to sowing crop, apply fertiliser, limeand/or gypsum as per soil test results.• Treat fence lines and any other area that arenot able to be cultivated by spot sprayingwith glyphosate or flupropanate.• Once crops have emerged, spot spray anyemerging serrated tussock seedlings withglyphosate.71

• If suitable, land may be continually croppedor sown to pasture following two years ofcropping rotations.Specific information such as crop varieties,sowing rates and crop nutrition may be obtainedfrom an agronomist.Timing• For winter crops, prepare paddocks to sowin autumn.• For summer crops, prepare paddocks to sowin spring.• Time of sowing will vary depending onrainfall.Advantages• Continued cultivation kills serrated tussockplants.• Cropping rotations provide strongcompetition with emerging serrated tussockseedlings.• Reduces the serrated tussock seed bank.• Forage crops may be used in a croppingrotation as grazing feed.• Cropping may provide income.Disadvantages• Disturbance of the soil caused by ploughingwill result in a mass germination of serratedtussock.• Cropping requires high labour and costinputs, particularly if changing land-usefrom solely grazing.• Ploughing around rocks and obstacles canbe a problem as tussock seedlings canremain trapped, causing a re-invasion.• Cultivation areas still need to be spottreated along fence lines and areas not ableto be cultivated.Warning: Cultivating or cropping native pasturemay be illegal depending on federal and statelegislation. Do not destroy native pastures byany means unless prior approval has been givenby a relevant government authority.Pasture establishment/renovationPasture establishment can be the complete resowingof a pasture following a cropping rotationor the renovation of an existing pasture toincrease the density of desirable pasture species.Serrated tussock is very vulnerable at theseedling stage as it is slow growing andsusceptible to high competition levels. Whenthere is limited bare ground available and highercompetition for water and nutrients, serratedtussock plants have difficulty surviving past theseedling stage. Having a strong, competitivepasture is a long term control measure thattargets this feature.Don’t forget to spot treat fence lines and rocky areasunable to be cropped.Charles GrechCharles GrechImproving the productivity of land by usingfertiliser and introduced pasture species canhelp reduce the incidence of serrated tussockinvading.Suitable for:• Introduced pastures that are in a degradedstate and require complete re-establishmentto be competitive with serrated tussock.• Mixed native and improved pastures thatrequire the addition of desirable speciesfollowing treatment of serrated tussock toimprove the health and competitive value ofthe pasture.• Steep or rocky land with vegetationthat requires improvement to be morecompetitive with serrated tussock.Specialised equipment is required forsowing pasture in these situations.72

ApplicationOn arable land, crop paddocks for at least twoyears before sowing pasture, to reduce theserrated tussock soil seed bank. Information oncropping and cultivation is on page 71.• If sowing a pasture after cropping, abroadacre application of glyphosate maythen be required to remove any emergingweeds before sowing.• Apply fertiliser, lime and gypsum asrequired by soil test results. With adequaterainfall, the aim of fertiliser is to providerapid growth of desirable pasture species, toimprove the quality and density of pasture.• Sow pasture into warm soil that hasreceived adequate moisture to ensureoptimal establishment and pasture growthto compete with serrated tussock seedlings.• Suitable pasture species will vary betweenregions depending on climate. Possibleintroduced species may be a mix ofperennial grasses, for example, phalarisand cocksfoot with legumes such assubterranean clover.• Clovers are an important component ofa pasture as they provide nitrogen to thegrasses and help improve soil fertility.• Competitive native pasture species includekangaroo grass and poa or silver tussock.Newly sown pastures established byconventional methods or direct drilled mustbe locked up for 12 months to allow time forestablishment and development. Dependingon soil moisture, a quick graze once plants arewell anchored can help plants to thicken up andincrease in size.Remove all grazing pressure, including nativeand pest grazing animals, from establishingpastures. This can be helped by fencing offpastures (with rabbit proof mesh) and conductingferal animal control programs.To maintain productivity and competitiveness,improved pastures require strategic grazingmanagement, fertilising and spot treatments tocontrol any emerging serrated tussock.Always seek advice from your agronomist onsowing rates, timing and the most suitablepasture species and cultivars for your area.In small areas where bare ground has been leftas a result of killed serrated tussock plants, reseedingof pasture species can be achieved bybroadcast seeding and a viable option. Native pasture such askangaroo grass (Themeda triandra) can be verycompetitive with serrated tussock.Pastures aerially sown usually take longerto establish and have more variable resultscompared to ground sown pastures. They alsoneed to be locked up from grazing for the firstthree spring/summer periods after sowing(Campbell & Vere 1995) to allow establishment ofdesirable pasture species.In rocky terrain, specialised all terrain seedingequipment can be used to direct drill pastures.An all terrain seeder can be useful if wanting to either sowa new pasture or crop on rocky land.Pasture re-development is crucial formaintaining sufficient competitionagainst tussock (Cooma workshop).David McLaren David McLarenBroadcast or aerial application (dependingon aspect) of pasture seed and fertiliser ontomodified native pastures may be an option.Native seed costs are currently very highand results highly variable, so this may not73

TimingDepending on location, sow pasture duringthe autumn/winter period when sufficientsoil moisture is available, or spring followingsufficient rain. Spring sowing may not be suitablefor areas with an annual rainfall of less than600 mm. Start paddock preparation for pastureestablishment in the year prior to planting.Once pasture has established and at least oneyear old, flupropanate may be applied at lowlabel rates to remove serrated tussock seedlings.If flupropanate was used to kill serrated tussockprior to sowing pasture, 100 mm of leachingrainfall (plant back period) must fall prior tosowing pasture species to remove residual fromthe soil.Advantages• A densely growing pasture with goodground cover is crucial for maintainingsufficient competition against serratedtussock.• Improving pastures may help to increasethe carrying capacity and productivity of aproperty in the long term.Disadvantages• Grazing is limited on newly establishedpastures particularly if they have beenaerially sown.Grazing managementGrazing and pasture management is the totalprocess of ensuring pasture persistence andground cover, maintaining soil nutrition forgrowth and organising livestock to make the bestuse of the pastures grown. It is about managingthe frequency (how often the stock are removed)and intensity (how hard and how many) livestockgraze pasture (MLA 2008).Good grazing management is necessary tomaintain pasture cover and density to effectivelycompete with serrated tussock. Total grazingimpact includes domestic livestock and bothnative wildlife and introduced feral grazers.Serrated tussock seedlings are slow growing andrelatively weak competitors; however. if they areable to survive to maturity, they may dominatethe grassland indefinitely, requiring activeremoval. It is cheaper and easier to stop serratedtussock seedlings from establishing.Suitable for:• All pastures on all land-uses.Grazing management is essentialin the integrated management ofserrated tussock.Type of grazing animalResearch has shown that the type of animal thatis grazed is not of concern; the importance ismanaging the pasture and ground cover. Someanimals are more selective grazers and thegrazing habits of different animals should betaken into account when managing the pasture.All animals will avoid eating serrated tussockif there is more palatable and nutritious feedavailable. Paddocks need to be properlymanaged so they remain healthy, vigorous andcompetitive, and not overgrazed.Application and timingIntroduced pasturesA mix of perennial and annual, grass and legumespecies, in a pasture will help provide a strongpasture base to manage.The density of the pasture is the key. Ideallymaintain a ground cover of at least 90−100%,and pasture density of at least 1200 kg DM/ha (about 4 cm high). This will help to reducethe establishment of serrated tussock from thesoil seed bank and minimise the chance of newinfestations developing from windblown seed.Example of a competitive introduced pasture withshelterbelt along boundary.‘For a dry season pasture should beno less than the depth of a beer canon its side and for a good season, noless than a can standing up’(Bathurst workshop).Peter Fullerton74

Focus management on continually improvingthe quality of pasture by promoting the growthof desirable species that will minimise serratedtussock invasion. Strategic fencing of largerpaddocks and rotational grazing of thesepaddocks are tools that may help to achieve ahighly productive and competitive pasture. Doingthis will also increase productivity and profits(MLA 2003).Strategic rotational grazing involves shortperiods of grazing with high stocking rates,followed by periods of no grazing, allowing thepasture time to rest and for desirable species togrow, set seed and allow seedlings to establish ifpasture recruitment has occurred.‘Grazing management, particularlythe resting is important.’ Rotatinglivestock allows your paddock to restin an attempt to build up thickergroundcover (Cooma workshop).Overgrazing can cause an increaseof tussock when competition isreduced (Cooma workshop).Overgrazing pastures may result in thedegradation of desirable species, reduced groundcover and pasture density, and increased risk ofserrated tussock invasion. Set stocking placescontinual pressure on the pasture and barepatches of ground are likely to form as stockheavily graze palatable feed. Rotational grazingallows even pasture recovery of all species,including the more palatable species.Established pastures• Graze pastures until total dry matter is1200–1500 kg DM/ha (around 4 to 5 cmhigh) then remove stock from the paddock.Try to maintain a 90−100% ground cover,avoiding bare patches of ground. Constantmonitoring of pasture levels is crucial inrotational grazing.• Summer and autumn are critical periodsof time for serrated tussock seedlingrecruitment and survival. Keep competitionlevels high at these times.• Regularly fertilise to maintain pastureproductivity and competitiveness.Source: Vic DPI 2004; Vic DPI 2007; Ayres &Leech 2006.Even in times of drought always tryto maintain ground cover.Grazing management is a ‘shift inmanaging animals to managinggrass.’ (Canberra workshop)Native pasturesNative pastures may contain all native species ora mix of native grasses, subterranean clover andannual grasses—modified native pasture.Strategic grazing management must be used asone component of an integrated managementplan. Always monitor pastures for serratedtussock seedlings and follow up with spotspraying or chipping.Newly sown pastures• Avoid grazing in the first 12 months toallow the pasture time to establish and setseed in its first summer. Only lightly graze ifthere is enough soil moisture once the newplants are well anchored.• In the first three years after establishment,lightly graze with periods of rest in thespring/summer period to allow plantsto increase in size and become wellestablished.A competitive native pasture.Long-term grazing management strategies areessential to encourage the growth of nativespecies. Graze the pasture for short periodsof time followed by long periods of rest toallow native grasses to regenerate and set seed(deferred grazing).Steve Taylor75

The optimum duration of these phases will varyand should be decided on the basis of regularinspection of the pasture and the stock. Pasturesshould be grazed only if they will recoverrapidly. If pastures are not growing in summerthey should not be grazed hard, even for shortperiods.The optimum density of a native pasture toprevent serrated tussock seedling recruitmentis greater than 800 kg of perennial grasses perhectare (pasture about 5 cm high over summer)and 90–100% ground cover. Rotational grazingwill help maintain adequate levels of dry matterand ground cover.Maintaining high levels of cover may be difficultto achieve, so concentrate management on:• promoting desirable perennial grass contentin the critical summer months. This willhelp to reduce serrated tussock seedlingsurvival over summer and serrated tussockgermination the following autumn• ensuring a desirable proportion of legume(25–30%) persists in the pasture• ensuring the grazing program contains long,strategically timed rests that coincide withthe seeding period of native grasses• reducing stocking rates in the first yearor two to increase the level of desirablepasture species• allowing pasture to increase in biomassduring times of increased soil moisture.Start in spring, when soil moisture levels areadequate for plant growth.In modified native pastures, regularly fertiliseto boost clover growth and rotationally graze tohelp keep a balance of native grasses. Paddocksmanaged in this way can become very productiveyet sustainable.Further advice may be obtained from anagronomist. A range of pasture managementcourses are run by different organisations, seepage 89 for more information.An example of a rotational grazing system oneland manager has used is:• During the spring, two mobs of rotationalgrazers were on a 7–10 day grazing cyclefollowed by a period of 6–8 weeks of rest toallow for the native grasses to seed andthicken up.Source: Badgery et al 2008a; Badgery et al2008b.Advantages‘Sheep and bad management, bestspreaders I know’(Canberra workshop).• Rotational grazing may increase theproductivity of a pasture in the long termand improve returns when compared toset stocking (MLA 2003).• Having a healthy vigorous pasture ismore likely to withstand invasion fromserrated tussock and other weeds.• Rotational grazing to maintain a goodground cover with a variety of perennialgrass species is also regarded as goodsoil carbon management which may havepositive implications in the future.Disadvantages• May require additional labour.• May need to increase infrastructure, suchas fencing and watering points, to gainmaximum benefit.If using herbicide in conjunction withgrazing management it is importantto observe withholding periods andmanage stock around this.76

AfforestationOver time a small plantation of pines can out shade theserrated tussock.Michael MichelmoreAreas such as steep gorge country can provideideal habitat for serrated tussock to dominate.An escarpment dominated by serrated tussockmay be a seed source, infecting neighbouringproperties. Such areas are difficult to manage dueto their aspect and limited options for control.Planting trees or shrubs, for conservation orcommercial purposes, is one way to manageserrated tussock in these areas.In the long-term, trees and/or shrubs may reduceserrated tussock dominance by:• providing competition for light andnutrients—a plantation of trees can form acanopy that will help out-shade the tussock,reducing its dominance• reducing seed spread by altering windconvections.Commercial forestry may sometimes be an option forserrated tussock control; however, expert forestry adviceis necessary before embarking on such a project.DPI VictoriaIf commercial farm forestry is not a feasibleoption, consider retiring the land from all formsof agricultural production and increase thebiodiversity value of the property by plantingnative trees and shrubs, or allow naturalregeneration.Suitable for:• Steep escarpments and ridges, erosionprone soils, creek valleys and otherinaccessible areas.• Windbreaks or shelterbelts along propertyboundaries. Plant trees of differing heightsto capture seed heads and reduce spread.• Areas with a large, dense serrated tussockinfestation, and where soil fertility andrainfall is not suitable for establishing astrong vigorous pasture.ApplicationTree establishment is a complex procedure. Ifconsidering a farm forestry operation, involvea farm forestry adviser in the process as theycan advise on site preparation, fertiliser andherbicide requirements, species of tree to plantand ongoing management.Fence off plantations, or provide protection,from rabbits and grazing stock while trees areestablishing. These animals will interfere ingrowth and development of saplings—stockcan remove entire plants, while rabbits eat newgrowth. Firebreaks will also need to be made.77

For re-vegetation purposes on steep terrain,tube stock saplings are generally planted. Aerialsowing of seed (tree species) may be an option;however, results are highly variable. Saplings willalso need to be protected from grazing animalssuch as rabbits and kangaroos until they haveestablished.Continue to chip or spot spray serrated tussockplants with herbicide until trees have grown andthe canopy has closed. Pine plantations can takeup to 4 years to suppress the growth of serratedtussock and up to 10 years to kill it (Campbelland Vere 1995).Always continue with a control program in areasof the property that have not been planted totrees.Some tree species suitable for plantations includeradiata pine, eucalypts such as spotted gumand sugar gum, tea-tree and she-oak. Species toconsider as bush regenerators may include selfregenerating shrubs such as Acacia, Cassinia orLeptospermum species (Michelmore 2003).TimingSpecific timing will vary between locationsdepending on rainfall, soil types and topography.When planting trees as a control measure forserrated tussock, always seek specialist advicefrom a forestry professional.Advantages• Plantations may significantly reduce severeserrated tussock infestations.• Farm forestry can be income producing,turning unproductive land into productiveland.• May double as a windbreak for reductionof serrated seed blowing into or out of theproperty.• May provide shelter for habitat, encouragebiodiversity and increase the environmentalhealth of a paddock.• Trees planted in a linear design, at least tenmetres in width, may be eligible for futurecarbon credit schemes.Disadvantages• It can take many years for a canopy todevelop and suppress the growth ofserrated tussock.• Labour intensive and costly to initiate.• If trees are harvested, for example, forcommercial purposes, there is a risk ofserrated tussock invading once the trees areremoved.• Difficult to drag a spot spraying hoseamongst the trees.Re-vegetating a steep area back to native vegetation maybe an option.DPI Victoria78

Reducing spreadPreventing serrated tussock from establishing onyour property is the best method of control. Landholders with seeding serrated tussock shouldalso make reasonable efforts to reduce seedspread to neighbouring areas.As serrated tussock is readily spread by windacross paddock boundaries and to a lesserextent, spread by vehicles, machinery, stock,people and water, it is important to haveprocedures in place that will help reduce itsspread.Preventative measures are essentialto reduce the spread of serratedtussock.The practices outlined are recommended for allland-use situations to prevent or limit the spreadof serrated tussock. Prevention is a high priorityin serrated tussock control.General property hygieneGeneral property hygiene procedures will reduceserrated tussock, and other weeds, from enteringor leaving a property.Useful strategies to reduce spread include:• Learn to correctly identify serrated tussock.• Identify high risk areas of spread onto andwithin the property and regularly monitorthese areas. For example, fence lines, stockyards and holding paddocks.• Control serrated tussock as soon as it isfound.• Consider using vendor declarations forbuying and selling stock feed, or anythingthat could be contaminated with seed.• Do not harvest pasture, grain or foddercrops while serrated tussock is in seed.• Do not allow contractors on site unless theyare clean and free from serrated tussockseed.• Consider using contractors who have ahistory of being weed-aware.• Avoid working in infested areas untilserrated tussock has been controlled.• Minimise movement into and out of infestedareas when serrated tussock is in seed.• Stay on formed tracks and roads.• Plan to work in clean areas first.Advantages• Prevention is easier and cheaper in the longterm.• Able to target a number of weeds, not justserrated tussock.• Early identification and control leads tobetter weed management.Disadvantages• Can be labour intensive.• Weeds like serrated tussock may blowin, irrespective of what weed dispersalstrategies are implemented.In all situations, make it a priority to controlserrated tussock before flowering. If flowering,or seed-set, has occurred, use the following tohelp reduce further spread.‘There are two types of properties—those that have it and those that aregoing to get it’ (Geelong workshop).‘One thing you have to be careful isyour hygiene’ (Hobart workshop).79

Stock managementVehicles/machinery/equipmentIf stock are suspected of eating seed, quarantine beforemoving onto clean paddocks.Ryan MelvilleDPI VictoriaStock can spread serrated tussock by:• transporting seed attached to the coat or bymud in the animals hooves• eating the plant while in seed, thenexcreting viable seed.Stock can be an important source of serratedtussock weed spread and reducing all risks isimportant.• Limit the movement of stock from serratedtussock infested areas to clean areas.• Remove stock from infested paddocksbefore serrated tussock goes to seed.Note: serrated tussock should not beallowed to seed!• Place stock in quarantine/holding paddocksif:− stock are suspected to be contaminatedwith seed− new stock are entering the property andsuspected of being contaminated withweed seed.If suspected of eating serrated tussock seed,quarantine stock for at least 10 days and providewith clean feed and water. Always use the sameholding paddock, monitor for serrated tussockseedlings and control when required.Advantages• Infestations initially confined to holdingpaddocks are easier to eliminate.Disadvantages• Extra feed costs if stock are quarantined.Washing and brushing down machinery and implementsfollowing work in known serrated tussock areas is arecommended hygiene practice.The small seeds and whole seed heads ofserrated tussock can get caught in vehicles,machinery and equipment. Vehicles canpotentially play a large role in the spread of seed,particularly 4WD vehicles that drive throughoutinfested paddocks.Actions to help reduce the risk of spread caninclude:• Undertake an accredited vehicle andmachinery hygiene training course.• Plan works. For example:− slash before the main flowering period− do not harvest crops or cut hay whenserrated tussock is in flower and− work in clean areas first.• Consider using preventative equipment suchas slasher covers.DPI VictoriaMany local councils have cleandownpoints along roadsides.80

• Inspect and where necessary, clean downvehicles, machinery and equipment beforeleaving an infested site. Dustpan andbroom, air compressors and high pressureunits are all practical options.• Areas to pay attention include:− on and around wheels, slasher decks andabove bash plates− air filters, radiators and enginecomponents− cabin interiors and ute trays.• When cleaning down, always:− appropriately dispose of any seedcollected− monitor the clean-down site for emergingserrated tussock seedlings and control asrequired.Advantages• Removes all other weed seeds from vehicle,machinery and equipment.Disadvantages• Time consuming.Accredited vehicle and machineryhygiene courses are available.Contact your local DPI for moreinformation.Mesh fencingMesh fencing is a useful tool that capturesserrated tussock seed heads, restricting theamount of seed heads blowing betweenproperties or paddocks.Fence at critical dispersal points such as,boundaries adjoining properties with high levelsof serrated tussock, or along the direction of themost prevailing winds.Fencing may also be incorporated into the overallproperty management program. For example:• divide into paddocks for rotational grazing• separate land-uses that require differentmanagement• may assist in the control of pest animals,such as rabbits.Regularly check fence lines and spot treat.Suitable for:• All situations; except very steep areas.• Particularly useful where a distinctivedifference occurs between a hard-to-managepatch of seeding serrated tussock and anadjacent ‘easier-to-manage’ area.Timing• Erect fences at any time of the year.Advantages• May reduce that amount of serrated tussockseed entering or leaving a property.• Can act as a barrier to other pests such asrabbits and foxes.• May be useful for stock and grazingmanagement.Disadvantages• Costly in the short term.• Requires regular maintenance.• Does not actively control or reduce serratedtussock infestations.• A number of seeds may still blow over thefence.Malcolm CampbellIncorporate fencing strategies intoyour overall management program(Geelong workshop).Mesh fencing may reduce serrated tussock seed enteringan area.81

Shelterbelts/windbreaksCharles GrechPeter FullertonShelterbelts planted along property or paddock boundariescan help to reduce an influx of airborne seed.Shelterbelts and windbreaks are alternatives tofencing as a physical barrier to catch wind blownserrated tussock seed heads.Tree barriers may be used along property orpaddock boundaries, or along ridgelines of steepterrain. The type of tree planted is important sothat seed heads are trapped and restricted fromblowing over. A windbreak that contains treeswith 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 ofserrated tussock both up-wind and down-wind,and density and height of the trees. Windbreaksprovide a wide range of benefits to agriculture,environment, and amenity. Consider thesebenefits before planting a windbreak solely forserrated tussock control.Suitable for:• All land-use categories.• May be particularly beneficial in areassuch as steep areas, erosion prone soils,rocky country and valleys.Radiata pines can be useful shelterbelts, as well asproviding a dense canopy to ‘shade out’ serrated tussock.TimingGenerally planted during winter; however,successful establishment of trees requiresplanning and advice from a forestry specialist.Advantages• A long term, proactive control method.• May reduce wind induced soil erosion.• May reduce wind induced damage topasture and crops, including sand abrasion.• A wide windbreak (more than 10 m) mayqualify for possible future carbon creditschemes.Disadvantages• Takes many years for trees to grow to thestage required to effectively catch seedheads.• May take up valuable pasture or crop space.• May provide competition with pasture orcrop within short distance of windbreak.• Initial set up can be labour intensive andcostly.• Control of serrated tussock amongst treesmay be difficult.82

Slashing/mowingA roadside slasher taking part in a weed spread preventionwashdown project.Slashing involves cutting serrated tussock plantsto a height just above ground level using aslasher, mower implement or brushcutter.A short term control method that may be usedto delay seed-set in serrated tussock plants.Slashing stimulates the growth of the serratedtussock plants and must be used in combinationwith herbicide application. Only use as a lastresort to reduce the amount of seed formed ifunable to use other control methods prior toflowering.For roadside managers slashing areas of serratedtussock, it is important that:• slashing is conducted prior to flowering• machinery is cleaned down at specifiedclean down points• serrated tussock infestations on roadsidesand public reserves are mapped andmonitored• weed free ‘clean’ areas are slashed first andserrated tussock infested areas are slashedlast• operators are trained in machineryhygiene procedures and serrated tussockidentification• tools that help reduce machinerycontamination are used, such as slashercovers.Cautions• A seed head will still generate if slashing isconducted too early.• Slashing equipment may become a vectorfor spreading seeds if slashed when serratedtussock seed is present. Machinery hygieneis critical in preventing spread.• Not considered a control technique forcompliance purposes.DPI VictoriaSuitable for:• Roadsides and other urban situations toreduce grass biomass and serrated tussockseed-set.• Removal of excess dry matter whenpreparing a paddock for sowing a crop orpasture.• If flupropanate was applied too late in theseason, serrated tussock may still produceviable seed. Slash prior to flowering toprevent seed head development. This willstill give flupropanate residual control intothe next season.• Reduction of plant biomass in the fireseason.Do not harvest slashed serrated tussock materialfor fodder conservation (hay). Serrated tussockis a declared noxious weed throughout all ofAustralia and cannot be sold or knowinglytransported. As such, if serrated tussock isinadvertently harvested for fodder, the hay balesmust not leave the property or be sold. Balinghay in paddocks with seeding serrated tussock isstrongly discouraged.Timing• To prevent seed-set—slash in late winter/early spring prior to flowering. If slashed atflowering, prior to the seed head forming,there is a risk of some seed contaminatingmachinery. Machinery hygiene proceduresare a must.• To prepare a paddock to sow a crop orpasture—slash in winter or early spring.• To reduce fire risk—slash at any time, butDO NOT slash when serrated tussock is inseed.Advantages• May limit seed production if conducted atthe right time of the year.• May reduce fire risk during summer months.• Limited soil disturbance.Disadvantages• Will not always prevent seeding in a currentseason—only delay it.• Does not kill the plant.• Will not reduce the size of the serratedtussock population.• Can stimulate serrated tussock growth.• May increase the spread of serrated tussockseed if precautions are not taken.83

Biological controlWhat is biological control?Biological control is a long-term managementoption that uses the natural enemies of a weed,such as insects (moths, beetles) or fungi (rusts,smuts), imported from the weeds country oforigin, to slowly reduce its density in Australiaover time.Biological control is not a silver bullet. Abiological control program may take years ordecades to become established and will nevereradicate the weed. Instead, it may reduce theweeds competitiveness and limit its impact.stringently tested to ensure it does not attacknative species that are related to or similar tothe target species. For serrated tussock, speciessuch as spear grasses (Austrostipa spp.) andbeneficial introduced grasses (phalaris andperennial rye grass) are among many species thathave to be tested.No biological control agents are currentlyavailable for serrated tussock in Australia.The process of finding a biological control agentis long, with no guarantees of success. Beforea potential agent can be released, it must bePotential for serrated tussock biological control in Australia.Serrated tussock was declared a target forbiological control in 1999. Previous work haddetermined that insects were not sufficiently hostspecific for biological control of serrated tussock.A group of organisations (NSW Shires, Meatand Livestock Association, State Governments,Federal Government) have funded theexploration and testing of potential pathogensfor biological control agents of serrated tussockfound in Argentina and South America.Three potential agents have been identifiedand tested to date. Unfortunately, none ofthese pathogens look like a suitable candidatefor biological control of serrated tussock inAustralia.A rust fungus,1. Puccinia nassellae, wasidentified attacking serrated tussock inArgentina and in some instances, wasobserved killing plants. However, dueto issues of its host specificity, massrearing and uncertainties of its life cycle,it is unlikely that this rust fungus will beprogressed as a biological control agent.A dead serrated tussock infected with the rust Puccinianassellae.Freda Anderson Freda AndersonClose up of rust Puccinia nassellae infecting some serratedtussock leaves in Argentina.84

2.A smut is a fungus that destroys the plantsseeds—mostly infecting the plant at seedgermination or during the seedling stage. Itdoes not kill the plant, but prevents it fromreproducing. A smut infecting serratedtussock, Ustilago spp., was found inisolated populations in Argentina. Attemptsat culturing this smut have been largelyunsuccessful to date, and only three plantsof more than 500 inoculated with thesmut, became infected. Further research isrequired to progress this potential biologicalcontrol agent.The serrated tussock smut, Ustilago spp. preventing seedproduction. The arrow points to millions of dust like smutspores spilling out of the serrated tussock reproductiveshoots.Freda Anderson3. A Corticium spp. fungus has been identifiedkilling serrated tussock plants in Argentina.It is a soil borne fungus that rots the crownsand roots of serrated tussock. It has notbeen possible to culture this pathogenmaking it an unlikely biological controlcandidate.Freda AndersonThe serrated tussock Corticium spp. fungusinfecting the roots.An observation made in Argentina by scientistsis that they rarely see serrated tussock seedlings,suggesting that a potential area of investigationis the serrated tussock seed bank and itsassociated soil pathogens.If land managers observe serrated tussockplants dieing or sick for no apparentreason, it is important they report this totheir local weeds officer.85

More magazines by this user
Similar magazines