DEPARTMENT OF PRIMARY INDUSTRIES Chilean needle grass (Nassella neesiana) Integrated grazing for success Charles Grech 2/11/05 DPI Agricultural weeds

DEPARTMENT OFPRIMARY INDUSTRIES

Chilean needle grass (Nassella neesiana) Integrated grazing for

successCharles Grech 2/11/05DPI Agricultural weeds


2

The problems • Chilean needle grass (Nassella

neesiana)

– Low feed value & physical damage to livestock when in seed

– replaces more productive improved pasture species

– invades native grasslands and conservation zones

– Seeds dispersed by adhering to machinery & animals

– Stem seeds and basal cleistogenes


3

Grazing management PhD• Two National projects:

– Chilean needle grass Regional Best Practice Management

– Grazing management for long term utilisation and control of Chilean needle grass

• To determine the stock density, species of grazer and time of grazing to maximise animal production

• Supervisors• Dr Brian Sindel - The University of New England,

Armidale• Dr David McLaren - Department of Primary Industries,

Frankston• Dr David Chapman - The University of Melbourne,

Parkville


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Trials underway...• Regional Best Practice Management

– NSW & Vic

• Feed evaluation of Chilean Needle Grass– fertiliser and clipping– spraytopping

• Reducing seed production– Comparison of stock class for Chilean Needle

Grass grazing – Time of Burning– Time of Slashing

• Competition and Selective manipulation– Pasture Species Competition– Soil Fertility and pH– Herbicide wiper


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Chilean needle grass Regional Best Practice

Management• The majority of knowledge concerning CNG comes from a study

undertaken at one location (near Armidale, NSW)

– seed production appeared to be sensitive to rainfall,

– interaction of temperature and rainfall.

– This makes the generalisation of management recommendations from one region to the next questionable


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• Four regional trial sites

– Glen Innes NSW (Property of Col & Andrew Say ‘Euroa’)

– Goulburn NSW (Property of Tony and Donna Kent ‘Dambreezi’)

– Toolleen Vic (Property of Roger & Brian Hickson )

– Greenvale Vic (Property of Ian & Margaret Souter ‘ The Elms’)

• Sites managed with regional staff - DPI NSW & VIC

– Lori McWhirter

– Jeff Lowien

– Natasha Baldyga

– Brad Westhead


Management


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• Treatments (applied autumn 2003 onwards)– Herbicide (Glyphosate; non selective &

spraytopping, Flupropanate)– Sheep grazing (strategic grazing, set stock, lockup)– Resowing (pasture, cropping)


Management

Treatment Grazing Spray Resow Crop1 Set Stock None None No2 Set Stock Selective (Glyphosate) None No3 Set Stock Glyphosate Sow pasture No4 Set Stock Glyphosate Sow pasture Yes5 Strategic Selective (Glyphosate) None No6 Strategic Glyphosate Sow pasture No7 Strategic Glyphosate Sow pasture Yes8 Set Stock Spray-top None No9 Strategic Spray-top None No10 Strategic None None No11 Set Stock Flupropanate None No12 Strategic Flupropanate None No

Treatment Grazing Fertiliser Spraying Resow1 Set stock No None No2 Set stock No Flupropanate No3 Lock up Yes Flupropanate Yes4 Lock up Yes None Yes5 Lock up No Flupropanate No6 Lock up No None No7 Strategic Yes Flupropanate Yes8 Strategic Yes None Yes9 Strategic No Flupropanate No

10 Strategic No None No

Glen Innes Greenvale, Toolleen, Goulburn


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Effect of spray type on CNG Basal cover - Toolleen d569

20

4 3

0

5

10

15

20

25

% c

ove

r No spray

Glyphosate & Sow

Flupropanate

Effect of Spray type on CNG Basal cover - Greenvale d601

16

7

00

5

10

15

20

% C

ov

er

No spray

Glyphosate

Flupropanate


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Effect of grazing regime on desirable perennial grass basal cover in

glyphosate plots - Toolleen d569

11

24

0

10

20

30

% c

ove

r

Lockup & Resow

Strategic graze &Resow

Effect of grazing regime on broadleaf weeds in flupropanate plots - Greenvale

d601

0

5

10

15

20

% c

ove

r Set stock grazing

Lockup

Strategic grazing


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• Strategic grazing after Flupropanate application (Winter 2003)– significantly less CNG than set stock

plots - Toolleen Dec04

Winter 2004 Spring 2004 Autumn 2005

Set stock

Strategic


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• Trends so far…

• Flupropanate– reduced CNG cover– proportional to grazing

• broadleaf weeds

• Glyphosate (& sow)– reduced CNG– increased perennial


Management


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Feed evaluation of Chilean needle grass Fertiliser addition & Clipping

• Low feed value in contrast with producer observations

• Feed value quantified throughout growing season (FeedTest)– compared to cocksfoot (Dactylis glomerata)

• Trial conducted at Greenvale Victoria (Property of Ian Souter) spring 2003 to winter 2005


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• Treatments– Clipped regrowth Vs unclipped growth– Fertiliser addition

TreatmentPhosphorus

(kg/ha)Nitrogen (kg/ha) Clipping

1 Control Control No2 0 0 Yes3 22A 0 Yes4 0 92B Yes5 22A 92B Yes


A 250kg/ha single super phosphate (8.8%P 11%S 19%Ca)B 200kg/ha urea (46%N) –split fertiliser applications of 100kg/ha over spring 2003


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• Results since spring 2003…

• Clipped CNG continues to have significantly more ME (2003 & 2004)

• N fertilised - significantly more ME at day 63 & day 398



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Feed evaluation of Chilean needle grass Spraytopping

• Feed value quantified throughout growing season (FeedTest)– compared to phalaris (Phalaris aquatica)

• Trial conducted at Bannockburn (Hamilton Hwy) Victoria spring 2003

• Treatments– Two spray times, linked to growth stage– Two spray rates (Glyphosate)

Treatment Growth stage at applicationGlyphosate (g a.i./ha)

1 No spray -2 Seedhead development – head at leaf sheath base 1283 Seedhead development – head at leaf sheath base 2554 Seedhead emergence 1285 Seedhead emergence 255


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Feed evaluation of Chilean needle grass Spraytopping

• Effect of spraytopping– irrespective of time of spray & rate of spray

• Plants that were spraytopped (both CNG & Phalaris)– significantly higher dry matter percentage (DM%)– significantly lower fibre content (NDF)

• Application rate (both CNG & Phalaris)– no significant responses


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• Clipped CNG - significantly more ME than unclipped (2003 & 2004)

• N fertilised - significantly more ME than non N at day 63 & day 398

• Spraytopped Plants (both CNG & Phalaris)– significantly higher dry matter percentage (DM%)– significantly lower fibre content (NDF)

Feed evaluation of Chilean needle grass


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Effect of Stock Class on Chilean needle grass seed production

• CNG can be valuable winter feed when in its vegetative state

• Grazing is a means to reduce seed production

• Cattle graze CNG better than sheep


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• Trial established to quantify the amount of standing seed remaining after grazing by sheep or cattle in different grazing regimes. – Animal production– pasture changes

• Treatments initiated spring 2004 ongoing– Cattle Vs Sheep

• Angus cows and calves• Suffolk X ewes and lambs

– Rotational Vs Set stock grazing• 12DSE/ha equivalent• 4 paddock time based rotation



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• Trial layout• Greenvale

VIC

• property of Ian Souter

• Managed by John & Alan McKenzie

• Weed CRC summer student Aaron Dodd

• 30ha trial area


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• Trial Measurements– Standing CNG seed

• panicle and stem • seed set harvest

– Pasture regrowth after grazing• Growth composition• BOTANAL

– Pasture composition change• Basal observations• Ground cover

– Animal liveweight & condition score

• Monthly• Fleece VM


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Results - Seed production• Grazing cw. ungrazed

– reduced standing seed• panicle • stem cleistogene

• Cattle cw. Sheep– cattle grazed more than

sheep

• approx 100 seeds/g

Effect of type of grazer on standing CNG seed

74

184

0

20

40

60

80

gram

s of

CN

G s

eed/

sq

m

Control (No graze)

Sheep

Cattle


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Results - Pasture regrowth

• Grazing cw. Ungrazed– BOTANAL (pasture cages)– early spring (d56)– grazing reduced CNG


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Results - Animal production

• Sheep Vs Cattle– Liveweight (kg/ha, DSE/ha)– Welfare


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Stockclass conclusions• Grazing

– significantly reduced CNG seed production (panicle & stem)– changed early spring regrowth to a more palatable composition– Cattle significantly more effective than sheep

• Managed grazing with cattle to reduce seed production


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Time of Burning - Chilean needle grass• Burning can sterilise weed

seeds both on the plant and in the soil seedbank

• Trial conducted at Greenvale Victoria (Property of L&J Karmel).– Summer 2004/2005 ongoing


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Time of Burning - Chilean needle grass

• Treatments – 3 burning times– 20x20m plots– drip torch strip ignition(leeward side)

Treatment Burn time Growth stage1 Control -2 Seedfall Seedfall3 Summer Dormant – Post seedfall4 Autumn Starting Vegetative growth


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• No effect of time of burn as yet...

• Burning prior to seedfall reduced panicle seeds left standing• patchy burns

• Burning significantly increased CNG seedlings when compared to unburnt

• decreased vegetative litter• increased bare soil

Time of Burning - Chilean needle grass

Early summer Mid Summer Autumn


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Time of Slashing - Chilean needle grass

• Slashing reduces dry matter during reproductive phases– reduced panicle seeds (regeneration)

• Vector for the spread of CNG.

• Evaluation of different times of slashing related to CNG growth stage

• Trial conducted at Greenvale Victoria (Property of L&J Karmel).– Summer 2004/2005 ongoing


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Time of Slashing - Chilean needle grass• Treatments

– 7 slashing combinations– 5x20m plots– 3 point linkage rotary slasher

Treatment Slashing frequency Slash time growth stage1 None Control -2 Single Oct Swollen/emerging3 Single Nov Emerged/flowering4 Single Dec Seedfall5 Double Oct & Nov Combinations of above6 Double Nov & Dec Combinations of above7 Triple Oct, Nov & Dec Combinations of above


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Time of Slashing - Chilean needle grass

• Time of slashing (from 2004 only)– no effect on seedlings in following season– no effect on botanical composition

• CNG• Desirable perennials• litter (Dec Slash)


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Pasture competition - species• Pasture competition can make soil resources unavailable to

weed species

• This trial evaluated the competitiveness of 3 pasture species at different sowing & fertiliser rates.

• Trial conducted at Wildwood Victoria (autumn 2004), on the property of Robyn Kissel ‘Grevisfield.’ – non arable infestation of CNG.


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Pasture competition - species• Treatments

– 3 species• Phalaris aquatica,• Dactylis glomerata• Festuca arundinacea

– 2 sowing rates– 2 fertiliser rates (Di ammonium Phosphate)

– 45x20m plot area (one grazing cell), – Sowing using all terrain disc seeder

(RockHoppa by AgReCon) – Tractor fitted with high flotation tyres

(Trelleborg)

• The trial plots were made up of 30 grazing cells across 15 lanes of a 16 lane grazing system operating on a 90-100day rotation stocked equivalent to 35DSE/ha (Cattle).


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Pasture competition - speciesTreatment Pasture Species Seed Rate Fertiliser

1 ControlA - None2 Tall FescueB High yes3 Tall FescueB Normal yes4 Tall FescueB High None5 CocksfootC High yes6 CocksfootC Normal yes7 CocksfootC High None8 PhalarisD High yes9 PhalarisD Normal yes

10 PhalarisD High None

A Control plots were not fertilised or sown to any pasture species

B Jessup MaxP Tall fescue (Festuca & Goulburn Subterranean clover.

C Kara Cocksfoot (Dactylis glomerata) & Goulburn Subterranean clover.

D Holdfast Phalaris (Phalaris aquatica) & Goulburn Subterranean clover.

E Seed ratesJessup MaxP Tall fescue (Goulburn sub clover)Normal rate 22kg/ha (6kg/ha)

High rate 44kg/ha (12kg/ha)

Kara Cocksfoot (Goulburn sub clover)Normal rate 7kg/ha (6kg/ha)


Holdfast Phalaris (Goulburn sub clover)Normal rate 8kg/ha (6kg/ha)


Note: Sub clover seed was lime coated and inoculated. Seed rate is expressed as equivalent sowing rate of bare seed.


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Effect of Soil fertility and pH• Nassella species may be less responsive to soil

fertility than phalaris species

• Trial established to evaluate the response of Chilean needle grass to different levels of soil fertility and pH

• Glasshouse trial - DPI Frankston Winter/spring 2005– LaTrobe university honours student James Winters

• Treatments (fully factorial)– 3 levels of Phosphorus– 3 levels of Nitrogen– 3 soil pH levels


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Effect of Soil fertility and pH• Measurements

– seedling vigour (destructive harvest)– mature plants (still growing!)

• Results - Response to soil Phosphorus– Seedling height

• Phalaris plants significantly higher than CNG (d19 onwards)

– Shoot weight• Phalaris plants significantly higher than CNG

– Leaf area• Phalaris leaf area significantly higher than CNG (78cm2 vs 19cm2)

– Root Length• Phalaris roots significantly longer than CNG • CNG root length increased less than Phalaris in response to P


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Conclusion• Feed evaluation of Chilean Needle Grass

• fertiliser and spraytopping had limited effects

• Reducing seed production/seedbank– Grazing

• significantly reduced CNG seed production (panicle & stem)

• Cattle significantly more effective than sheep– Burning

• reduced panicle seeds• increased seedlings

– Slashing• decreased panicle seeds

• Competition and Selective manipulation– Herbicide integration

• Flupropanate & allow pasture regeneration

– CNG slow response to soil Phosphorus

Documents

DEPARTMENT OF PRIMARY INDUSTRIES Chilean needle grass (Nassella neesiana) Integrated grazing for success Charles Grech 2/11/05 DPI Agricultural weeds