Peterson

Problem Weeds of the Sublette County Gas Regions: 

Problem Weeds of the Sublette County Gas Regions Eric Peterson Extension Educator, Mountain West Area, Wyoming

Define Weed: 

Define Weed A weed is a plant that grows in an environmental setting where it is not wanted. The determination of the value of a particular plant is subjective—one person’s weed may be another person’s prized plant. Managers need to be familiar with established definitions for types of weeds when dealing with weed problems.

Invasive vs. Noxious: 

Invasive vs. Noxious Invasive Plants Introduced from another place Lacks natural competition Becomes aggressive Noxious Weeds Harmful to agriculture, human health, and/or environment. The State has a noxious weed law giving them legal standing

Natives and Weeds: 

Natives and Weeds Can they be ???

WHERE DO THEY COME FROM:: 

WHERE DO THEY COME FROM: PURPOSEFUL introductions – Ornamental, esthetics and hardiness Erosion control problem solvers Pasture grasses with forage values ACCIDENTAL introductions – Seed contamination (labeling) Animal vectors Vehicles, travelers, souvenirs Construction and Industry equipment Construction and Industry materials

Our Vectors??: 

Our Vectors?? Natural dispersion - Wind, water, wildlife Equipment Supplies (industrial, seed, mulch) Traffic People ????? Another Infestation another place External Source

PREVENTING INTRODUCTION & ESTABLISHMENT: 

PREVENTING INTRODUCTION & ESTABLISHMENT Disturb as little as possible Specify weed-free materials Seed Mulch Soil gravel Clean off equipment between sites Compartmentalize infestations Train crews to identify weeds early Pre-disturbance inspection and control Aggressive management of infestations

WYOMING DESIGNATED LIST(or Prohibited): 

WYOMING DESIGNATED LIST (or Prohibited) Field bindweed Canada thistle * Leafy spurge Perennial sowthistle Quackgrass Hoary cress (whitetop) * Perennial pepperweed (giant whitetop) * Ox-eye daisy Skeletonleaf bursage Russian knapweed * (Yellow toadflax (Dalmatian toadflax Scotch thistle Musk thistle * Common burdock Plumeless thistle Dyers woad * Houndstongue Spotted knapweed * Diffuse knapweed * Purple loosestrife Saltcedar * Common St. Johnswort Common Tansy Russian olive

Declared Weed List: 

Declared Weed List Sublette County Black henbane * Scentless chamomile Sweetwater County Black henbane Foxtail barley Lady’s bedstraw

Annuals, Biennials, Perennials: 

Annuals, Biennials, Perennials Annuals – Grow from seed every year Quick, short, vigorous seed production Opportunistic – seed bank Biennials – Grow from seed – TWO year lifespan Vegetative year, Reproductive year Perennials – Long-lived Weak seed production, strong root system In it for the long haul

Plant Adaptations: 

Plant Adaptations Dry or Wet site Sandy, gravelly, clayey soils Early/Late starts Shallow/deep rooted Elevational Precipitation Etc. Some weeds aren’t adapted to some sites, just like some desirable or native plants aren’t adapted to some sites. An adapted weed will out-compete a poorly adapted desirable plant, every time, unless we apply artful management.

Good and Bad: 

Weeds are opportunistic pioneers Weeds may initially reduce erosion Weeds provide some habitat components Weeds are “low maintenance” Weeds steal resources from desired plants Weeds interfere with establishment of desired plants Good and Bad BUT!

It is a jungle out there!: 

It is a jungle out there! Competition for resources is keen Water Nutrients Light Space Competition between plants and plant species can make or break reclamation efforts We can affect competition to our advantage by applying stresses.

Our Common Weeds: 

Our Common Weeds Annuals Lambsquarter Kochia Russian Thistle Henbane Halogeton Bi/Perennial Canada Thistle Musk Thistle

The ones to watch for: 

The ones to watch for Annuals Cheatgrass Bi/Perennials Dyer’s Woad Saltcedar Knapweeds (Russian, Spotted) Hoary Cress Perennial Pepperweed Survey Says: Halogeton is the weed raising the most alarm!

LambsquarterChenopoduim album: 

Lambsquarter Chenopoduim album Annual Leaf underside covered with white mealy substance 1” – 2” long, I” wide leaves. Pointed Flowers – small green clusters

Kochia(Kochia scoparia): 

Kochia (Kochia scoparia) Annual Plants are erect, 1 to 6 feet in height Multiple branches. Slender, alternate leaves are smooth on top and hairy below. Flowers form short spikes in axils of upper leaves.

Russian ThistleSalsola iberica: 

Russian Thistle Salsola iberica “Tumbleweed” Annual 20K-50K seeds Germinate quickly after precip. Well branched, bushy Wind-blown

Black HenbaneHyoscyamus niger: 

Black Henbane Hyoscyamus niger Annual or biennial Robust – 3 feet plant is covered with greasy hairs Leaves up to 8 inches long and 6 inches wide, shallowly lobed Heavy scented Huge seed production from capsules Poisonous/medicinal properties Weak competitor

HalogetonHalogeton glomeratus: 

Halogeton Halogeton glomeratus A small forb 3 to 12 inches Stems red when young, turning yellow to white Stems are branched from base, spreading first, and then growing vertical. Flowers July to September Flowers Small and inconspicuous, in leaf axils. Saline or alkaline soil DROUGHT TOLERANT Allelopathy

Canada ThistleCircium arvense: 

Canada Thistle Circium arvense Perennial Deep and extensive horizontal roots Leaves are wavy, up to 6 inches long, and armed with yellowish spines. Stems are 1 to 6 ½ feet tall, rigid, and branching above. Flowers are purple, occasionally white, in head ½ to ¾ inch in diameter, clustered at the top of the stems. Bracts below flower are spineless

Musk ThistleCarduus nutans: 

Musk Thistle Carduus nutans Biennial Up to 8 feet tall. Leaves are up to 10 inches long, dark green Solitary, lightly spiny, and nodding Heads develop at the stem tips in midsummer and grow to a diameter of 1½ to 3 inches. Blossoms are deep rose to violet or sometimes white in color.

Cheatgrass – Downy BromeBromus tectorum: 

Cheatgrass – Downy Brome Bromus tectorum Annual grass 2 inches to 2 feet tall. Has a branched base and is typically rusty-red to purple at maturity. Has rapid spring growth Early maturity Aggressive. Open, drooping, much branched seedhead

Dyer’s WoadIsatis tinctoria: 

Dyer’s Woad Isatis tinctoria Winter annual, biennial, or short-lived perennial Basal leaves up to 8 inches long Thick taproot Lance shaped stem leaves clasp the stem Leaves all have a prominent whitish midvein Up to 4 feet tall ¼-inch wide, yellow flowers in flat-topped clusters Seeds teardrop shaped, ¾-inch long, purplish-brown pendulous

SaltcedarTamarix ramosissima: 

Saltcedar Tamarix ramosissima long-lived dense growing shrub or tree 6 to 26 feet tall. The crown is narrow or rounded. deep taproot and extensive lateral rhizomes. Flowers are white to pink, each 1/16-inch long, and grow in long (1-2 inches), narrow, drooping cluster

KnapweedsRussian, Spotted, Diffuse: 

Knapweeds Russian, Spotted, Diffuse Perennial Branched and up to 4 feet tall. Leaves are up to 6 inches long near the base of the plant, The flower heads are about ½ inch in diameter and are borne on branch tips during summer and fall. Flowers may be white or pink to lavender-blue

Hoary CressCardaria draba: 

Hoary Cress Cardaria draba “Whitetop” Perennial Up to 3 feet tall. Leaves are grayish-green, clasping, up to 4 inches long, shaped like arrowheads Flowers are white with 4 petals, ¼ inch across, Dense flower clusters give the weed a flat-topped appearance early in the season, but this is lost as the stem elongates.

Perennial PepperweedLepidium latifolium: 

Perennial Pepperweed Lepidium latifolium Perennial Up to 6 feet tall Basal leaves that are lance shaped, are up to 12 inches long, waxy Stem leaves are smaller Flowers are white, less than 1/8 inch wide in dense, rounded clusters at the branch tips Fruits are roundish, measure 1/16 inch in diameter, and contain 2 tiny seeds.

Management/Control: 

Management/Control Mechanical Chemical Bio-agents Insects Disease Cultural Genetic IPM (Integrated Management)

Weed Strategies: 

Weed Strategies Early detection Reporting Control (contractors) Surveillance Planning/Awareness Vector Sanitation Communication

Reporting: 

Reporting County Weed and Pest Control Districts All 23 Counties Mandate for noxious weed control Networked with independent contractors http://www.wyoweed.org/wp_dist.html The Weed Underground

Thanks!: 

Thanks! Questions???