Pasture Weed Control

Ralph E. Whitesides

Utah State University

Plants, Soils, and Climate

Is it possible to fight weeds effectively on small acreages in Utah?

What is a weed?

Any plant growing where you don’t want it.

Are weeds bad?

What function do weeds play in the environment?

What are weeds telling us?

Why Worry About Weeds?

They are just plants. Right? Its not like you have a rampaging grizzly

in your garden. Right?

No!

Once weeds move in they stay. They multiply. Soon the unwanted and uninvited

guests have taken your land and won’t give it back without a fight!

What is the first step?

Take inventory of property If you try to control weeds without a

game plan there is a good chance you won’t succeed.

4 Golden Guidelines of Weed Control for Small Acreage

Properties

1. Know what you want to do with your property. (Why did you buy it in the first place?)

2. Promote healthy vegetation.

3. Implement good land use practices.

4. No one weed control method works alone.

Controlling weeds in your pasture

• Prevention

• Detection

• Control• Cultural

• Mechanical

• Biological

• Chemical

• Restoration

Weeds are best controlled through an integrated approach using several of the following methods

Two Working rules for controlling weeds in your pasture

“Prevention”

1. Prevent weeds in the first place

2. If you cannot do #1 everything else will be more work, more time, and more money. More of everything!

Controlling weeds in your pasture

How practical is Rule #1?

Controlling weeds in your pasture

How practical is Rule #1?

Where do weeds come from?

Controlling weeds in your pasture

How practical is Rule #1?Where do weeds come from? (prevention)

1. Seed Bank in the soil

2. Irrigation Water

3. Off-site Feed – Hay

4. Bedding materials

5. Wind borne – animal borne (field bindweed seeds can survive 144 hrs in stomach of migrating birds)

6. Seed Mixtures

Controlling weeds in your pasture

How do we implement Rule #2? (control)

1. Management

2. Knowledge

3. Judgment

4. Experience

5. Work – Time – Money

6. More Work – Time – Money

7. Constant Work – Time – Money

Controlling weeds in your pasture

How do we implement Rule #2? (control)

What caused us to get weeds in the first place?

Controlling weeds in your pasture

How do we implement Rule #2? (control)

What caused us to get weeds in the first place?

The answer to that question will aid us in our work to control weeds.

Controlling weeds in your pasture

How do we implement Rule #2? (control)What caused us to get weeds in the first place?

The answer to that question will aid us in our work to control weeds.

Grazing Issues – Overgrazing, timing, wrong animals

Soil Issues – Fertility, salt, texture, etc

Water Issues – irrigation and natural precipitation, too much or too little

Seed mixture- not suited to environment

Controlling weeds in your pasture

How do we implement Rule #2? (control)

Cause: Improper grazing – treating the pasture as a corral instead of as a pasture.

Controlling weeds in your pasture

How do we implement Rule #2? (control)

What is a Corral? What is a Pasture?

Controlling weeds in your pastureWe may want something like this?

Controlling weeds in your pastureThese may be more realistic.

Controlling weeds in your Pastures

“Detection”What am I trying to control? Identify the weed.

Grass – Broadleaf

Annual – Perennial

Edible – Poisonous

Spreading – Non-spreading

HOW DID IT GET TO BE A WEED?

Controlling weeds in your pastures

Whatever caused the weed to become a problem or concern in the first place must be addressed to help you in controlling it.

Each potential solution is as individual as is the problem and the person wanting to solve it.

Controlling weeds in your pastures

“Control”

General Guidelines:

• Proper irrigation and soil fertility

• Mowing to prevent from going to seed

• Spot spraying as soon as weeds are detected

• Monitoring the Pasture (high eyes to acre ratio)

Range and Range and Pasture Weed Pasture Weed ManagementManagement

Approved Herbicides 2,4-D / MCPA

Amber

Cimarron / Escort

Cimarron Max

Clarity / Banvel

Crossbow

Curtail

Garlon / Remedy

Grazon P+D

Journey

Milestone

Plateau

Redeem R&P

Roundup

Spike

Transline / Reclaim

Telar

Tordon

Transline

Weedmaster

Approved Herbicides 2,4-D / MCPA

Amber

CimarronCimarron / Escort

Cimarron MaxCimarron Max

Clarity / Banvel

Crossbow

Curtail

Garlon / Remedy

Grazon P+D

Journey

MilestoneMilestone

Plateau

Redeem R&P

Roundup

Spike

Transline / Reclaim

TelarTelar

Tordon

Transline

Weedmaster

Dyer’s WoadIsatis tinctoria

Perennial PepperweedLepidium latifolium

Hoary CressCardaria draba

Cimarron Metsulfuron (Escort renamed) Hoary cress, dyer’s woad, perennial

pepperweed, thistles, houndstongue Must add surfactant or COC No grazing restrictions Tall fescue and perennial ryegrasses are

sensitive (damage)

Cimarron Max Metsulfuron + dicamba + 2,4-D Ratio: 5 oz Part A + 2.5 gal Part B Greater weed spectrum controlled Must add surfactant or COC Dicamba’s grazing restrictions Tall fescue and perennial ryegrasses are

sensitive (damage)

Telar

Chlorsulfuron Hoary cress, dyer’s woad, perennial

pepperweed, thistles, houndstongue Must add surfactant or COC No grazing restrictions Tall fescue and perennial ryegrasses are

sensitive (damage)

Russian Knapweed Centaurea repens

Spotted KnapweedCentaurea maculosa

Yellow StarthistleCentaurea solstitialis

Milestone

Aminopyralid Knapweeds and thistles Weak on mustards Closely related to Tordon Not “Restricted-Use” Wildland and recreation sites

MedusaheadTaeniatherum caput-medusae

Plateau Imazapic Winter annual grasses

Downy Brome Medusahead

Rangeland improvement Safe on most established

perennial grasses

Some poisonous weeds of pasture

HoundstongueCynoglossum officinale

Houndstongue

Foothills, pastures, roadsides

Horses, cattle, sheep

Fresh (unpalatable) or in hay

Cummulative, may taint milk

Houndstongue(Symptoms)

Dullness, wandering

Increased pulse and respiration

Weakness, nervousness

Constipation or diarrhea

Death by liver hemorrhage

Houndstongue(Management)

Avoid contaminated hay

Digging / pulling

Escort (Cimmaron), Ally, Tordon,

Clarity (Banvel), 2,4-D

Poison HemlockConium maculatum

Poison Hemlock

Wet areas, disturbed sites

Sheep, cattle, horses, humans

Coniine and other alkaloids

4 to 8 oz sheep, 10 to 16 oz cow

Poison Hemlock(Symptoms)

Salivation, nervous trembling

Bloating, lack coordination

Pupil dilation, rapid pulse

Blue mouth lining

Respiratory paralysis, coma

Poison Hemlock(Symptoms - cont.)

Abortion Crooked calf disease

(same timing and effect as lupine)

Death in 2 to 3 hours Confused with wild edibles, has

caused death of children

Poison Hemlock(Management)

Animals normally avoid (fresh)

Do not cut in hay

2,4-D, Ally, Escort (Cimmaron), digging

Weed Control in Pastures

“Restoration”

Summary Thoughts-

• Fertilizer- 150 lbs/a split in 3 treatments (50+ 50+ 50 in April- July- September)

• Irrigation- improve distribution and training

• Spot treat weeds- use a backpack or hand held sprayer, and treat problem areas (especially fence lines on a regular basis)

Controlling weeds in your pastures

Questions?