level 1 weeds - extension
TRANSCRIPT
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Weed
ScienceMike Maddox
Horticulture Educator
Rock Co. UW-Extension
What is a Weed?
• When weeding, the best way to make sure you
are removing a weed and not a valuable plant is
to pull on it. If it comes out of the ground
easily, it is a valuable plant.
~Author Unknown
What is a Weed?
• Plant out of place
• Plant with undesirable characteristics
• Plant with undiscovered virtues
• Or something else…
• How is a ‘weed’ different
from an ‘invasive species’?
What is a Weed?
• They compete with desirable plants for:
– Sunlight
– Nutrients
– Space
• They harbor insects and diseases
• Aesthetics
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What is a Weed?
• Abundant seed production
• Seed dormancy
• Seed survival
• Vegetative reproductive strategies
• Lack of ornamental appeal
• Offensive odor
• Toxic or noxious
• Dormancy
– Flowers/vegetables• Breeding has removed dormancy
• Seeds become less valuable if dormancy exists
– Weeds
• Dormancy allows weeds to survive harsh environmental
conditions
• May have different levels of dormancy within same plant
• Seed Survival
– Flowers/Vegetables
• Several years under ideal storage conditions
– Weeds
• Documented survival after 100 yrs. of burial
• Survival is possible with some species after
composting
• Seed production
– Flowers/Vegetables – few seeds per plant
• Sweet corn, up to 1000
• Pumpkins, several hundred
• “Seedless” watermelon
– Weeds
• Common purslane, 1,000,000+
• Common lambsquarters, 100,000
• Vegetative reproduction
– Flowers/Vegetables
• Very few perennials – those that are very few spreading root systems (Kentucky bluegrass)
– Weeds
• Perennials with spreading vegetative structures
• Annuals when pulled stem re-roots
• Tillage can propagate
• Toxic / Noxious
– Noxious
• Weed by law
• Why?
– Toxic
• Hazardous to humans and/or domesticated
animals
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Types of Weeds
• Annual and perennial weeds
• Grass-like and broadleaf weeds
• Weeds and invasive plants
• Control of each may vary
• Annual weeds
– Completes life-cycle in one year
– Reproduces primarily from seeds
– Examples:
• Summer annuals: common lambsquarters, redroot pigweed, giant foxtail, velvetleaf
• Winter annuals: common chickweed, field pennycress, shepherd’s purse
• Biennials: wild carrot, prickly lettuce, bull thistle
• Perennial weeds
– Life-cycle continues for 2 or more years
– Vegetative and sexual reproduction
– Examples:
• dandelion, quackgrass, Canada thistle
Types of Weeds
• Grass-like weeds
– Monocotyledons
– Annual or perennial
Types of Weeds
• Broad-leaf weeds
– Dicotyledons
– Annual or perennial
Weed Control
• Integrated Pest Management
– Culturally
– Mechanically
– Chemically
• Must recognize plant life cycle
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• Cultural
– Optimize planting density and plant health
• Proper plant spacing
• Proper mowing height
– Mulch
• Minimize exposed soil surface
• Prevent weeds from germinating
• Smother weeds
• Mechanical
– Physical removal of plant
• Severing annual weeds at ground line
• Pulling perennial weeds
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• Judicious and appropriate use of herbicides
– Selective herbicides
– Non-selective herbicides
– Pre-emergent herbicides
– Post-emergent herbicides
– Foliar applications
– Soil applications
• Selective herbicides
– Distinguish between broadleaf and grass-like
weeds
• Non-selective herbicides
– Does not distinguish between plants
• Pre-emergent herbicides
– Prevents seeds germination
• Post-emergent herbicides
– Applied to actively growing plants
• Contact
– Kills only the applied tissue
• Systemic
– Translocated throughout plant
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• Foliar application
– Applied to the leaves (or actively growing
tissue)
• Soil applications
– Applied to the soil
• Pre-emergence, selective herbicides
– Must be applied to soil before germination
– Used to kill annual grass and broad-leaved
weeds seedlings as they germinate
– Work best if mixed into upper 1-2” of soil or
watered in.
– Will NOT kill emerged weeds
• Products: (pre-emergent, selective)
– Pendimethalin
– DCPA (Dacthal, Weed & Grass Preventer, and
many others)
– Trifluralin (Preen, Treflan, and many others)
– Dichlobenil (Casoron)
– Simizine (Princep)
– Oryzalin (Surflan)
– Siduron
• Post-emergence, selective herbicides
– Applied after weeds are up and growing
– Can present a problem by drifting onto non-
target plants
• Broad-leaved weed control products:
– 2,4-D (many brand names)
– MCPP (many brand names)
– Dicamba (Banvel and others)
– Combination formulas (Trimec)
• Grass weed control products:
– Fluazifop-butyl (Grass-B-Gone, Fusilade)
– Sethoxydim (Poast)
• Post-emergence, non-selective herbicides
– Applied after weeds are up and growing
– Are circulated within the plant, giving a better
chance of killing roots of perennial weeds
– Danger of drift to non-target plants
– Some root uptake is possible but herbicide
generally applied to foliage
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Weed Control
• Products; (post-emergence, non-selective)
– Glyphosate (Round-up, Kleenup, Killzall, and
many others)
– Triclpyr (Brush-B-Gon, Garlon)
Selecting a Herbicide
• Factors to consider
– Liquid or granular
– Timing
– Weather
– Formulation
• Liquid
– Easily applied to plant, good for spot-treating
– Drift may be an issue
– Read label for temperature requirements
• Granular
– Many times granule must stick to leaf to be effective
– Read label for temperature requirements
• Timing
– Plant life cycle
• Most susceptible at flower-stage or after first frost
• Early season application can reduce photosynthate
• Late season application can translocate to root
• Pre-emergence herbicides must be down before
germination begins
• Weather
– Low temperature - restrict absorption/translocation
– Warm to moderately high temperature - best
absorption/translocation
– Very high temp. - dries on surface prior to
absorption
– Best to spray on calm days to avoid drift from wind
• Formulations
– Esters
• Volatile
• Readily absorbed
• Use during cool temps or hard-to-kill weeds
• Salts (Amines)• Less volatile
• Use during hot temps
• Less smell
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• Labels
– Read label for usage restrictions and handling
regulations
– Look for precautionary labels on containers
– Keep all pesticides in original container and locked
up where children cannot get to them
– Do not eat, drink, or smoke while handling
pesticides
– Dispose of unused product as directed
Trade Name
Identifying Information
Mixing Instructions Contact info
Ingredient Statement
Identifying Information
First Aid
Safety Information
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Herbicide Injury
• Problems will arise
• Following the label will minimize
suprises
Grass Weed Identification
ligule
auricles
leaf blade
collar region
leaf sheath
Broadleaf Weed Identification
alternate leaves opposite
leaves
Broadleaf Weed Identification
Ochrea – thin paper-like
sheath surrounding stem
at leaf axilFound on:
Wild Buckwheat,
Pennsylvania Smartweed,
Ladysthumb Smartweed
Barnyardgrass
• Annual
• Leaf sheath &
blade hairless
• Flattened stem
• No ligule
Barnyardgrass
• Flattened stem
(cross-section)
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Yellow Foxtail
• Annual
• Long hairs on
upper leaf
surface near
base of leaf
blade
• Hairy ligule
Giant Foxtail
• Annual
• Larger seedheads
that tend to
droop
• Upper leaf surface
with short bristly
hairs
• Hairy ligule
Giant Foxtail
• Note hairy ligule,
hair on leaf
sheath margin,
and hairs on leaf
surface
Green Foxtail
• Annual
• Short seedhead
• Hairy ligule
• Leaf surface
generally smooth
Green Foxtail
• Thin hairy ligule
• Hair on leaf
sheath margin
Wild Proso Millet
• Annual
• Seedling often looks
like corn plant
• Hairy ligule
• Shiny seeds tan to
black
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Wild Proso Millet
• Hairy ligule
• Bristly hairs on
leaf sheath
margin
Large Crabgrass
• Annual
• Membranous
ligule
• Smooth stems
• Ability to root at
nodes
Large Crabgrass
• Membranous
ligule
• Leaf blade and
sheaths hairy
Quackgrass
• Perennial
• Leaf sheath &
blade nearly
hairless
• Short membanous
ligule
• Clasping auricles
Quackgrass
• Extensive
rhizome system
from a single
plant
Wild Buckwheat
• Annual
• Heart shaped
pointed leaves
• Triangular seeds
• Ochrea present
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Wild Buckwheat
• Ochrea
(hairless) at
leaf axil
Ladysthumb Smartweed
• Annual
• Alternate leaf
pattern
• Ochrea (papery
sheath) with
fringe of hairs
Ladysthumb Smartweed
• Stem bent back
to expose ochrea
with a fringe of
hairs
Pennsylvania Smartweed
• Annual
• Alternate leaf
pattern
• Ochrea (papery
sheath) without a
fringe of hairs
Pennsylvania Smartweed
• Ochrea (hairless)
Field Bindweed
• Perennial
• 3-cornered
triangualar leaves
• Deep spreading
root system
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Field Bindweed
• Note leaf shape
and flowers
Hedge Bindweed
• Perennial
• Leaves tend to be
more 5 cornered than
field bindweed
• Shallow extensive
root system
Hedge Bindweed
• Extensive but
relatively
shallow
rhizomes lead to
quickly
developing
patches of
bindweed
Eastern Black Nightshade
• Annual
• First leaves have purple undersides
• Similar to pigweed when young but no notch at tip of leaf
• Prolific producer of berries that turn from green to purple to black
Bitter Nightshade
• Perennial
• Produces woody tissue
• Young leaves
• Older leaves
• Berries that turn from green to red
Redroot Pigweed
• Annual
• Leaves have small
notch at tip
• Petioles generally
have purple
coloration
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Prostrate Pigweed
• Annual
• Glossy small
leaves
• Red petiole
coloration
• Spreads out along
soil surface
Common Ragweed
• Annual
• Finely divided
lacy leaves
• Very thick
cotyledons
Giant Ragweed• Annual
• Mature leaves
are 3-lobed
• Mature height
up to 15 feet
Broadleaf Plantain
• Perennial
• Low growing
• Broad, simple leaves
• Common in lawns, often in shaded areas
Velvetleaf
• Annual
• Alternate heart
shaped leaves with
serrated margins
• Stem and leaves
densely hairy
Common Lambsquarters
• Annual
• First 2 leaves are opposite, later leaves are alternate
• Cotyledons and leaves covered with white, mealy granules
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Ground Ivy
• Perennial
• Often referred to as “creeping charlie”
• Small bluish-purple flowers borne in leaf axils
Common Purslane
• Annual
• Opposite leaves with
each pair rotated
around the stem 90o
from previous pair
• Thick fleshy leaves
w/o hair
• Red prostrate stems
Pineappleweed
• Annual
• Stems smooth
• Leaves finely divided,
smell like pineapple
when bruised
• Greenish-yellow
flowers
Common Yellow Woodsorrel
• Perennial or annual
• Stems hairy, may
root at joints
• Leaves with long
petioles, divided
into 3 heart-shaped
leaflets
Jimsonweed
• Annual
• Leaves are smooth and alternate
• Hypocotyl (stem below cotyledons) is very hairy
• Plant has unpleasant odor when crushed
Jimsonweed
• Seed pod
• Leaf shape
• Large white
flowers
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Carpetweed
• Annual
• Smooth green stems branching along ground forming circular mat
• Leaves in circles of 5 or 6 at each joint of stems
Common & Mouse-ear
Chickweed
• Annual
• Pictured: left-
common, right-
mouse-ear
• Petioles with line of
hairs on one side
Jerusalem Artichoke
• Perennial
• Fibrous roots with
rhizomes and tubers at
tips
• Hairy stems up to 9 foot
• Leaves very hairy
• 2-3 inch yellow flowers
similar to sunflower
Jerusalem Artichoke
• Mature plant
Jerusalem Artichoke
• Large roots and
tubers contain
extensive energy
reserves (hard to
kill)
Bull Thistle
• Biennial
• First leaves are oval
with a rough,
bumpy surface
• Adult leaves form
rosette, with dense
hairs on undersides
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Musk Thistle
• Biennial
• Adult leaves
forming rosette with
whitish margin
• Dense hairs on leaf
upper and lower
surfaces
Canada Thistle
• Perennial
• Leaves are alternate
with crinkled edges
and spiny margins
• Spreads with
rhizomes
Canada Thistle
• Note very wavy
leaf margin
Canada Thistle
• Rhizomes often
lead to thick
patches
INVASIVE PLANTSIN
WISCONSINKelly Kearns
Plant Conservation Program ManagerEndangered Resources Program
Wisconsin Department of Natural [email protected]
608-267-5066
INVASIVE PLANTS are non-indigenous species or strains
that become established in natural plant communities and
wild areas and replace native vegetation.
EXOTIC/NONNATIVE PLANTS are species that have
been purposefully introduce for medicinal, agricultural
and/or ornamental purposes, or have been introduced accidentally.
NATIVE PLANTS are indigenous species naturally
occurring in a specific area or plant community, not
introduced.
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ECOLOGICAL IMPACTS OF INVASIVE PLANTS
• Displaces native vegetation
• Limits tree regeneration in forests
• Degrades wildlife habitat
• Contributes to endangerment of rare plant and animals
• Homogenizes the landscape
Kudza invades a forest
Reed Canary Grass
invades a wetland
SOCIO-ECONOMIC IMPACTS OF INVASIVE PLANTS
• Recreational boating and fish habitat disrupted.
• Decreased aesthetics resulting in loss of tourism.
• Hunting/hiking land rendered impassable by invasive shrubs.
• Long-term forest production declines due to tree seedlings
being outcompeted.
• Human health concerns from toxic and allergenic plants.
• Pastures degraded.
• Agricultural cost of controls and loss of production.
Purple Loosestrife
•
Buckthorn
Invasive Plants Association of Wisconsin (IPAW)
Categories of troublesome plants:
Weeds
Known Invasive Plants
Potentially Invasive Plants
Sometimes Invasive Natives
CONTROL METHODS:
• Manual- pull out, cut, girdle, graze, burn
• Mechanical- mow, plow, scrape
• Chemical- foliar, cut stump, basal bark herbicide
application
• Biological- use of natural insects or diseases
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Common Buckthorn Glossy Buckthorn(Rhamnus frangula)(Rhamnus cathartica)
Glossy
Buckthorn
Buckthorn
The leaves of Glossy Buckthorn are a more vibrant
green and are glossy or shiny compared to the dull leaves of
Common Buckthorn. Glossy Buckthorn leaves also lack the
small teeth found on Common Buckthorn.
Ken
neth
J. S
yts
ma
(Rhamnus cathartica)
(Rhamnus frangula)
Tartarian honeysuckle (Lonicera tatarica)
Michael Clayton
Kennith J. Sytsma
Autumn Olive(Elaeagnus umbellata)
Oriental bittersweet (Celastrus orbiculatus)
TNC
TNC
TNC
Garlic mustard (Alliaria petiolata)
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Dame’s rocket (Hesperis matronalis)
Dennis D. Horn
Multiflora Rose
(Rosa multiflora)
Black locust (Robinia pseudoacacia)
Michael Clayton
Robert W. Freckmann
William S. Justice
Japanese Knotweed (Polygonum cuspidatum)
Spotted knapweed (Centaurea maculosa)
K.Holmes-GLIFWC
Miketyler Jr.
Leafy spurge (Euphorbia esula L.)
Norman E. Rees, USDA ARS
Leslie J. Mehrhoff
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Wild parsnip (Pastinaca sativa)
Kitty Kohout
Crown vetch (Coronilla varia)
Dan Tenaglia
Dan Tenaglia
Bird’s-foot trefoil (Lotus corniculatus)
Richard Baur
Photographer: B. Eugene Wofford
© 2001 Steven Thorsted
Reed canary grass (Phalaris arundinacea)
Paul E. Berry
© 1997 Purdue University Agronomy Extension
Common Reed Grass (Phragmites australis)
Native Broad-LeafNarrow-Leaved Hybrid Cattail
NRC S
(Typha latifolia)(Typha x glauca)(Typha angustifolia)
Notice the difference in both the width of the leaves and the spike and also the
distance between the staminate and pistillate portions of the spike in each species.
NRC SNRC S
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Purple loosestrife (Lythrum salicaria)Eurasian watermilfoil (Myriophyllum specatim)
Robert L. Johnson
Robert H. Mohlenbrock
Alison Fox
Curly-leaf pondweed (Potamogeton crispus)
Virginia Kline
Curly-leaf pondweed (Potamogeton crispus)
Virginia Kline
INVASIVE COMMON GARDEN
PLANTS
Japanese barberry (Berberis thunbergii)
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Common tansy (Tanacetum vulgare)
Herbal Nexus
Yellow Iris (Iris pseudacorus)
Paul Drobot
Paul Drobot
Lily of the valley (Convallaria majalis)
Orange daylily (Hemerocallis fulva)
Britt Slattery
Dan Tenaglia
Common periwinkle (Vinca minor)
USDA NRCS Archives
Moneywort(Lysimachia
nummularia)
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White poplar (Populus alba)
Michael Clayton
Robert W. Freckmann
Potential
New
Invaders
Great Lakes Early Detection Network
(GLEDN)
(www.gledn.org or Mobile App)
• To find, report and control invasives BEFORE
they become serious problems.
• Target plants: 1) New invaders, and 2) Ones
already here, but in small numbers or limited areas.
• Develop a model for early detection and response
that can be adopted by other states.
TARGET SPECIESUpland
-- Common Teasel (Dipsacus fullonum) [WI]
-- Cut-leaved Teasel (Dipsacus laciniatus) [WI]
-- Giant Hogweed (Heracleum mantegazzianum) [WI]
-- Japanese Hops (Humulus japonicus) [WI]
-- Japanese Stilt Grass (Microstegium vimineum)
-- Wine Raspberry (Rubus phoenicolasius)
-- Japanese Hedge-parsley (Torilis japonica) [WI]
-- Spreading Hedge-parsley (Torilis arvensis)
-- Black Swallow-wort (Vincetoxicum nigrum) [WI]
-- Pale Swallow-wort (Vincetoxicum rossicum)
Common Teasel(Dipsacus sylvestris)
. kelly S Kearns
Stephen L. Solheim
Cut-leaved Teasel(Dipsacus laciniatus L.)
Wisconsin DNR
Wisconsin DNR
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Giant Hogweed (Heracleum mantegazzianum)
Donna R. Ellis
Terry English
Donna R. Ellis
Hedge Parsley (Torilis japonica, T. arvensis)
Japanese Stilt Grass(Microstegium vimineum)
Japanese Hops(Humulus japonicus)
TARGET SPECIESAquatic/Wetland
-- Flowering Rush (Butomus umbellatus) [WI]
-- European Marsh Thistle (Cirsium palustre) [WI]
-- European Frog-Bit (Hydrocharis morsus-ranae)
-- Hydrilla (Hydrilla verticillata)
-- Water Chestnut (Trapa natans)
European Marsh Thistle(Cirsium palustre)
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Flowering rush (Butomus umbellatus)
Kitty Kohout
Water Hyacinth (Eichornia crassipes)
Douglas Barbe
Jeff Abbas
Hydrilla (Hydrilla
verticillata)
Others not yet widespread
in Wisconsin
Tree of Heaven (Ailanthus altissima)
Dennis W. Woodland
Porcelain Berry
(Ampelopsis
brevipedunculata)
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Japanese Honeysuckle(Lonicera japonica)
Michael Clayton
Lowell Urbatsch
Amur honeysuckle (Lonicera maackii)
James H. Miller, USDA Forest Service, www.forestryimages.org
Herman, D.E. et al. 1996
Herman, D.E. et al. 1996
Giant Knotweed(Polygonum sachalinensis)
Emmet J. Judziewicz
Emmet J. Judziewicz
Garden Heliotrope (Valeriana officinalis)
Paul E. Berry
Richard Bauer
Burning Bush (Euonymus alatus )
Photos by James H. Miller
Without earthworms With earthworms
Photos and diagram courtesy of
University of Minnesota Agricultural
Experimental Station