Presentation on theme: "Weed Control in Pastures"— Presentation transcript:
1 Weed Control in Pastures Troy D. CooperUSU ExtensionDuchesne County
2 Introduction Weed control in pastures can be a very difficult challenge.Plant species are unique in livestock grazingsystems.Focus on the plants that animals avoid eatingand those containing low nutritional value.Good weed control takes dedication and utilizationof several weed control methods.
3 Cultural controls Weed Control Options Desirable plant growth Proper grazing managementIrrigation, FertilizationCompetitive desirable plant species
4 Weed Control Options Mechanical Control Chemical Control Physically disrupts weed growthTillageMowingMulchingBurningChemical ControlThe use of herbicides
5 Weed Control Options Biological control Uses organisms to disrupt weed growthInsectsDisease organismsSheepGoatsCattleOr other large herbivores
6 Basic Principles of Chemical Weed Control Know your weedsChoose the right herbicideMatch equipment with needsCalibrate your sprayerSpray at the proper timeRead and FOLLOW label instructions
7 Weed Identification Plant Type Broadleaf Dicots Net Vein Grass and Grass-likeMonocotsParallel veinsLance-like leaf
8 Weed Identification Life cycle Annual Biennial Grow from seed, mature, and produce seed in one year or less.Biennial2 year life cycle. Grow from seed and develop a rosette 1st year. 2nd year mature, produce seed and die.
9 Weed Identification Perennial Growing season Plants that live more than 2 years. Most plants mature and reproduce in the first year and then repeat the vegetative, seed production and maturity stages for several following years.Growing seasonCoolFall - SpringWarmSpring - Fall
10 Lambsquarter, annual, rapid growth and high water use.Reproduced by seed.
11 Down brome, is an annual or winter annual.Reproduced by seed.
12 Foxtail barley, perennial. Reproduces by seed.Common in wet alkalinesoils, meadows, and pastures.
13 Field bindweed is a perennial which has an extensive rootsystem. Seeds remain viable upto 50 years.
14 Russian knapweed, perennial spread by black deep growingroots. Forming dense colonies.
15 Musk thistle, biennial or sometimes a winter annual. Forms extremely dense stands.
16 Scotch Thistle, Grows up to 8ft tall. Flower is pale purple toviolet. Leaves are spiny edgedand form wings around thestalk.
17 Perennial pepperweed, perennial. Also referred to as tall whitetop.Deep seated rootstock.
18 Leafy spurge, perennial. Plant contains a milky juice. Seedcapsules explode projectingseeds as far as 15 feet.
19 Purple loosestrife, is a prolific seed producer and has a perennialroot system. Each plant canproduce 2 million seeds.
20 Common burdock is a biennial, producing a rosette of large,thickly hairy leaves the first yearand an erect, much branched,coarse stem feet tall thesecond year.
21 Canada thistle is a colony forming perennial from deepand extensive horizontalroots. Flowers are purple.Flowering occurs during Junethrough August.
22 Common cocklebur, an annual 2-4 feet tall with the stem erect,branches ridged, potted andvery rough. The burs are irritatingboth to humans and animals.
23 Curly dock is a robust tap-rooted perennial growing 2-5 feet tall. Inflorescences and even entire plantturns reddish-brown at maturity.
24 Hoary cress is a deep rooted perennial up to 2 feet tall.Sometimes called whitetop.
25 Kochia is an annual, 1-6feet tall, stems muchbranched, round, slender,usually soft-hairy, butoccasionally smooth, oftenred-tinged. Sometimescontains high nitratelevels and can be toxic.
27 Herbicide labelsBefore using a herbicide check and read the label carefully.Each of the recommended herbicides has benefits and risks associated with its use.Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by Cooperative Extension is implied.
28 • 2,4-DSeveral products Rate: 0.71 to 2 lb ae/ATime: Spray when annual weeds are young, succulent, and actively growing. Treat perennial weeds at the specific growth stage(s) described on the label.Remarks: Controls many annual, biennial, and perennial broadleaf weeds in rangeland and grass pastures. Also controls certain brushy species. Deep-rooted perennial weeds and woody plants usually require repeated applications for maximum control. See label for rates for various weed species and for proper application timing.
29 2,4-DCaution: Do not apply if spray drift may contact nearby crops or desirable plants or contaminate water for irrigation or domestic use.Do not graze meat animals within 3 days of slaughter.Do not graze dairy animals within 7 days after application.Do not cut hay within 30 days after application.Do not use on bentgrass, alfalfa, clover or other legumes, or on newly seeded pasture. When grass seed production is desired do not apply after heading begins or when grass is in the boot to milk stage. Kills legumes.
30 • dicambaBanvel, Vanquish, or Clarity; Rate: 0.25 to 2 lb ae/ATiming: Apply after weeds emerge. Treat annuals whensmall and actively growing. See label for proper timingand rates on perennials.Remarks: Controls many annual, biennial, and perennialbroadleaf weeds and many woody brush and vinespecies. Rate depends on weed species and growthstage at time of treatment. Can be applied using water,oil—water emulsions, or sprayable fluid fertilizer as thecarrier. May also be applied as a cut-surface treatmentto control unwanted trees or to prevent sprouts on cuttrees.
31 dicambaCaution: No waiting period between treatment andgrazing for nonlactating animals (see label for timingrestrictions on dairy animals). Meat animals must beremoved from treated areas 30 days before slaughter.Rates over 2 Ib ai/A may temporarily injure many grassspecies. Newly seeded grasses (see label) may beinjured at rates exceeding 0.75 Ib ai/A. Do not exceed8 Ib ai/A per season. Kills legumes.
32 • glyphosateRate to 3.75 lb ae/ATime: Annual weeds are best controlled when small andactively growing. Apply to actively growing perennialweeds at or beyond full flower. Results are best if appliedin late summer or fall after seed forms. Fall treatmentsmust be before a killing frost.
33 • glyphosateRemarks: Controls many annual and perennial weedspecies before renovating pastures. Rates depend onweed species, stage of growth, and density. Repeattreatments may be necessary to control weedsregenerating from underground parts or seed. May alsobe applied as a spot treatment or by wiper application toestablished pastures, but no more than 0.1 of any acreshould be treated at one time. Further applications maybe made to the same area at 30-day intervals.
34 · glyphosateCaution: A nonselective herbicide that kills forage plantscontacted. Total of all treatments must not exceed8 lb ai/A per year. Remove domestic livestock beforeapplication. Wait 8 weeks after broadcast applicationand 14 days after spot or wiper application beforegrazing or harvesting. Some glyphosate products ifapplication is 2 qts/A or less no waiting period betweentreatment and feeding or livestock grazing is required.Check label for specifics.
35 • clopyralid + 2,4-DCurtail Rate: 2 to 4 quarts product/ATime: Apply when weeds are young and activelygrowing.Remarks: Use 2 quarts on light to moderate infestationsof Canada thistle and knapweeds (spotted and diffuse)in good growing conditions. Use 3 quarts for denseinfestations or under poor growing conditions. OnRussian knapweed, use 3 to 4 quarts.
36 CurtailCaution: Do not plant grasses for 30 days afterapplication. Do not use on newly seeded grass areasuntil grass is well established. Do not use on bentgrass.Do not spray pastures containing desirable forbs,especially legumes, unless injury can be tolerated.Do not use hay or straw from treated area for compostingor mulching on susceptible broadleaf crops. Do not grazedairy cattle in treated area for 14 days after application.Remove meat animals from area 7 days before slaughterif pasture was treated less than 2 weeks earlier. Do notcut for hay within 30 days after application. Do not usestraw or manure from treated areas for compost or mulch.
37 • metsulfuronEscort, Ally, or CimarronRate: 0.33 to 2 oz product/A Escort0.1 to 0.4 oz product/A Ally0.1 to 1 oz product/A CimarronTime: Apply postemergence to actively growing weeds.Remarks: Controls a wide range of broadleaf weeds.For best results, use a nonionic or organosiliconesurfactant.
38 Escort, Ally XP, or Cimarron Max Caution: Consult labels for each product; labels differsignificantly. Note restrictions on labels for use on fescue,timothy and ryegrass pastures. Note recroppingrestrictions on label.Ally XP, no grazing restrictions.Cimarron Max, Remove meat animals from treated area30 days prior to slaughter. No grazing restriction for non-lactating animals.
39 Other products labeled for pastures Tordon – restricted-use herbicideCrossbowSpikeMCPA – several productsPlateauGramoxomeStingerTranslineRemedyRedeem R&PTouchdown
40 SummaryProvide proper nutrients and management for desired forage species.Identify weed problems and locations.Select which options or combination of options you plan to use for controlPerform the practices.Evaluate outcome
41 CreditsUniversity of Minnesota Extension, Weed Control in Pastures – Lesson 4Colorado State University Extension, Range and Pasture Weed Management by K.G. BeckSmall Pasture Management Guide for Utah, Project Coordinator: James Barnhill, USU Extension Agent, Weber County.PNW Weeds – Pasture and Rangeland Weed Control Guide.Weeds of the West.