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Weed Management Options for Hay Producers

Tim MurphyExtension Weed ScientistUniversity of Georgia

2Weed competition, how serious is it?Weed competition, how serious is it?

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Common Bermudagrass, Ragweed and Nitrogen

Lbs/bermuda/ac

N = 34 lbs/ac

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Rule of thumb: When weeds are more than 20% of the hay field (really depends upon weed).

What is the Economic Threshold?

Woolly croton

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Do I spray or fertilize first?

Spray first.Control existing

weeds.Begin soil-test

based lime and fertilizer program.

Is 100% Weed Control Necessary?

Factors to considerBuyer preference (market value)Hay baling complicationsForage value of weedsToxicity of weed

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Digestibility of select cool season weeds

0102030405060708090

% I

VD

MD

Car ger Ev prim L.Barley

TallFescue

VegBootHead

Hoveland et al., 1986

Digestibility of select warm season weeds

0

10

20

30

40

50

60

70

80

% I

VD

MD

Pigweed Y. foxtail Crabgrass Bermudagrass

VegBootHead

Hoveland et al., 1986

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Haying and Grazing Restrictions for Dairy Animals (Cattle and Goats)

Lactating Non-lactating

Herbicide Grazing Hay Grazing Hay

Metsulfuron 0 0 0 0

Cimarron Plus 0 0 0 0

Milestone 0 0 0 0

Grazon Next 0 7 0 7

Chaparral 0 0 0 0

Grazon P+D 7 30 0 30

Remedy 14 NS* 0 7

Weedmaster 7 37 0 37

2,4-D 7 7 7 7

*Next season.

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Haying and Grazing Restrictions for Various Livestock Species

Beef Horses Goats Beef Horses Goats

Herbicide Grazing Hay

Metsulfuron 0 0 0 0 0 0

Cimarron Plus 0 0 0 0 0 0

Milestone 0 0 0 0 0 0

Grazon Next 0 0 0 7 7 7

Chaparral 0 0 0 0 0 0

Grazon P+D 0 0 0 30 30 30

Remedy 0 0 0 7 7 7

Weedmaster 0 0 0 37 37 37

2,4-D 0 0 0 7 7 7

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When do you spray? Winter annuals - henbit, chickweed,

buttercups, thistles, ryegrassNovember through March

Summer annuals - spiny amaranth, bitter sneezeweedApril through mid-July

Perennialsgrowth stage dependent

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Spray this size Not this size

Bitter sneezeweed

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Herbicide Options1. 2,4-D2. dicamba (Vanquish, Banvel)3. 2,4-D + dicamba (WeedMaster, others)4. dicamba+ diflufenzopyr (Overdrive) 5. diuron (Direx, Diuron) 6. triclopyr (Remedy)7. imazapic (Impose,Panoramic)8. 2,4-D + triclopyr (CrossBow)9. triclopyr + clopyralid (Redeem)10.2,4-D + picloram (Grazon P+D, HiredHand,

GunSlinger)11.fluroxypyr + picloram (Surmount)12.fluroxypyr + triclopyr (PastureGard)

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Herbicide Options (cont.)13.aminopyralid (Milestone)14.aminopyralid + 2,4-D (Grazon Next, ForeFront)15.aminopyralid + metsulfuron (Chaparral)16.nicosulfuron + metsulfuron (Pastora)17.metsulfuron (Cimarron, MSM E.Pro, others)18.metsulfuron + chlorsulfuron (Cimarron Plus)19.chlorsulfuron (Telar)20.metsulfuron + 2,4-D + dicamba (Cimarron MAX) 21.hexazinone (Velpar)22.sulfosulfuron (OutRider)23.pendimethalin – Prowl H2O24. tebuthiuron (Spike)25.paraquat (Gramoxone Inteon, Firestorm, Parazone)26.glyphosate (Roundup PowerMax, others)

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Newest Herbicides

Milestone – aminopyralid Grazon Next, ForeFront – aminopyralid + 2,4-D Chaparral – aminopyralid + metsulfuron Telar – chlorsulfuron OutRider - sulfosulfuron Prowl H2O – pendimethalin

Pastora - nicosulfuron + metsulfuron

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Milestone

2.0 lbs./gal. aminopyralidUse rate: 4.0 to 7.0 fl. ozs./acreNumerous broadleaf weeds – thistles,

horsenettle, tropical soda apple, buttercupDo not seed legumes year of application

(additional research being conducted)Delay application until grasses have 4 to 5

leaves.

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Milestone

Non-volatileInjurious to legumes No grazing or hay restriction for any type

of livestockWeak on sida species, dogfennel,

plantains, blackberry, wild radish, other mustards.

Add 2,4-D or Remedy for weeds above.

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Grazon Next, ForeFront0.33 lbs./gal. aminopyralid + 2.67 lbs./gal 2,4-DUse rate: 1.5 to 2.6 pts./acreNumerous broadleaf weeds – thistles,

horsenettle, buttercup, henbit, plantains, verbena

Do not seed legumes year of application (additional research being conducted)

Delay application until grasses have 4 to 5 leaves.

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Grazon Next, ForeFront

Injurious to legumes No grazing restriction for any type of

livestock.7 day hay harvest restrictionBetter control of plantains and common

pokeweed than Milestone

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Chaparral

Bermuda, orchardgrass, tall fescue (up to 2.0 oz/a

Apply to fully tillered or establishedSame tall fescue precautions as

metsulfuron products (2 yr establishment)

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Chaparral

Rate (oz. product/a)

Act. Ingredient 1.5 2.0* 3.0

aminopyralid 0.049 0.066 0.098

metsulfuron 0.009 0.012 0.018

*Chaparral at 2.0 oz./a = 4.0 fl. oz/a of Milestone 2SC + 0.3 oz/a Metsulfuron 60DG

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Chaparral

Non-volatileInjurious to legumes Do not seed legumes year of application

(additional research being conducted)

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Aminopyralid- It’s Good - BUT!!!!!

Do notuse hay from treated areas for compost or mulchtransfer livestock to untreated areas without

3 d cleanoutuse manure for fertilizing broadleaf cropsuse in any temporary forage system involving

broadleaf crops

USE ONLY ON PERMANENT GRASS FORAGE SYSTEMS

Aminopyralid

For Milestone, ForeFront, Grazon Next, Chaparral:

Aminopyralid is prohibited from use on hay that will be distributed or made available for sale off the farm where harvested unless allowed by supplemental labeling.

Get aminopyralid stewardship info at: http://www.dowagro.com/range/

aminopyralid_stewardship.htm

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Telar Sulfonylurea

Chlorsulfuron 75.0% Bahiagrass, bermudagrass - 0.25 to 1.0 oz/a Tall fescue – 0.25 to 0.5 oz/a

Telar controls: Blackberry, pigweed(s), wild radish Many annual broadleaf weeds < 4.0 in. tall Does not control grass weeds, horsenettle, ragweed, fireweed

(southern nettle) Add nonionic surfactant at 0.25% v/v Highly injurious to legumes No grazing or haying restrictions

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Grass Control Options - Bermudagrass

Dormant bermudaGlyphosate – 1.0 pt./acre (4.0 lb./gal.)Gramoxone Inteon – 1.0 to 2.0 pts./acre

Active Growth Bermuda ‘Pensacola’ bahiagrass – Cimarron, Chaparral,

ImposeSmutgrass – VelparAnnual grasses

Roundup PowerMax, after first hay cut Impose (imazapic)

Johnsongrass – OutRider, Impose Spot treat or ropewick glyphosate

OutRider - Monsanto

Sulfosulfuron, 75WDGApproved in 2008New name for MaverickControls johnsongrass and sedges in

bermudagrass and bahiagrassUse rate – 1.33 ozs./acreAdd a nonionic surfactant at 0.25% v/v.

OutRider - Monsanto

Johnsongrass 18 to 24 inches tall, up to seedhead stage of growth

Nutsedges – 4 to 8 inches tallDoes not control annual grasses,

dallisgrass, smutgrass, etc.Tank-mix with other herbicides for

broadleaf weed control

OutRider - Monsanto

Grazing and haying restriction14 days – all livestock types

Treated fields may be rotated only to wheat.

Injurious to clovers.

Maverick treated plotUntreated

Maverick treated plot Untreated

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Prowl H20 - BASF

Pendimethalin Preemergence herbicide: 3.2 to 4.2 qts/acre

Needs rainfall for incorporation within 30 days of application

Labeled on dormant forage bermudagrass hay or pasture (NOT LABELED ON TALL FESCUE)

45 day hay harvest restriction 60 day grazing restriction – all livestock types See supplemental label at: http://www.cdms.net/LDat/ld6CT014.pdf

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Prowl H20 - BASF

PRE control of crabgrass, goosegrass, sandbur, Texas and fall panicum

Also controls some annual broadleaf weeds such as pigweed

Apply February to early March to dormant bermudagrass

Must be applied before annual grasses germinate (crabgrass begins germination at soil temps. of 50 to 55 F.)

Prowl H20 Effect on the Stand Density of Irrigated Tifton 85 Pasture

Applications made to dormant bermudagrass on 3/5/10.

Prowl H20 Effect on Crabgrass Control in Irrigated Tifton 85 Pastures

Applications made to dormant bermudagrass on 3/5/10.

Pastora – DuPont - 2010

Sulfonylurea Nicosulfuron 56.2% + Metsulfuron 15.0%

Pastora controls: Sandbur, panicum sp., foxtails, barnyardgrass, signalgrass < 2.0 in. tall Pensacola bahiagrass, before seedheads emerge in spring Vaseygrass (after hay cutting) Italian ryegrass < 6.0 in. tall Johnsongrass – 6 to 10 in. tall annual broadleaf weeds < 4.0 in. tall

Use rates: 1.0 to 1.5 oz./acre + NIS Will be used on bermudagrass only (injures tall fescue and

legumes) No grazing or haying restrictions

Effect of Pastora Applied during Greenup on Southern Crabgrass Control. 2009.

Pastora applied Apr. 15, 2009 – seedling crabgrass

Effect of Pastora Applied mid-July on Southern Crabgrass Control. 2009.

Pastora applied July 20, 2009 – multi-tillered crabgrass

Effect of Pastora on Goosegrass Control in Irrigated Tifton 85 Pasture. Wrens.

Applications made on 5/6/10 and 5/27/10 for the 20 day reapplication treatment.

‘Russell’ Bermudagrass Tolerance to Pastora - 2009

Conducted at EatontonPastora 1.5 oz/ac – dormant appl. – Mar. 6Pastora 1.0 oz/ac – 40% green-up – Apr. 15Pastora 1.0 oz/ac – 18 days after 1st

harvest – June 26Pastora 1.0 oz/ac – 5 days after 2nd

harvest – July 20

‘Russell’ Bermudagrass Tolerance to Pastora - 2009

Pastora at 1.5 oz/ac applied March 6 to dormant bermuda caused no injury and did not affect hay yield at any harvest.

‘Russell’ Bermudagrass Tolerance to Pastora – 40% Green-up, 2009.

Pastora applied Apr. 15, 2009

(Oz/ac)

‘Russell’ Bermudagrass Tolerance to Pastora – 18 d after 1st harvest, 2009.

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% I

nju

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Jul. 7 Aug. 3 Aug. 17

Pastora 1.0 + NIS

Pastora applied June 26, 2009 – 7 in. tall bermudagrass

(Oz/ac)

‘Russell’ Bermudagrass Tolerance to Pastora – 5 d after 2nd harvest, 2009.

Pastora applied July 20, 2009 – 5 d after second hay harvest

(Oz/ac)

Effect of Pastora Applied during Greenup on ‘Russell’ Hay Yield 2009.

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ld (

lbs/

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Jun. 8 Jul. 15 Aug. 24

Harvest Date

UTC Pastora 1.0 + NIS

Pastora + 2,4-D 1.0 + 1.0 qt. Pastora 1.0 oz + 50% UAN

Pastora 1.0 oz + 75% UAN Pastora 1.0 oz + 100% UAN

Pastora applied Apr. 15, 2009 – 40% Green-up

(Oz/ac)

NS at all harvests

Effect of Pastora Applied 18 d after first harvest on ‘Russell’ Hay Yield 2009.

600

1000

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Yie

ld (

lbs/

ac)

Jul. 15 Aug. 24

UTC Pastora 1.0 + NIS

Pastora applied June 26, 2009 – 7 in. tall bermudagrass

(Oz/ac)

NS at all harvests

Hay harvested 19 d after appl.

Effect of Pastora Applied 5 d after 2nd harvest on ‘Russell’ Hay Yield 2009.

Pastora applied Jul. 20, 2009 – 5 d after second harvest

(Oz/ac)

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* *

Effect of Pastora Applied during Greenup on Italian Ryegrass Control. 2009.

Pastora applied Apr. 15, 2009

(Oz/ac)

Conclusions - Pastora

Will control Italian ryegrassCrabgrass not as sensitive as other annual

grasses (best control of crabgrass is at seedling stage)

Established bermudagrass (one growing season)

Application TimingsWinter – dormant bermudaSpring – before 2 inches of new growthSummer – within 7 days of hay cutting

Conclusions

Pastora applied with water effectively controls:little barleylittle quakinggrassrattail fescueItalian ryegrass

Addition of 75% v/v UAN to Pastora decreased control of all grasses except Italian ryegrass.

Conclusions

Pastora also controls:field pansyCarolina geraniumsticky chickweedcorn speedwell

No effect of UAN on broadleaf weed control with Pastora

Addition of 2,4-D did not improve control of above weeds

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Identify weedSelect the right productTime the application correctlyApply accuratelyFollow haying restrictions

Keys to Herbicide Use

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