Weeds Will Be With Us So, How do you correctly identify a weed? we - - PDF document

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Weeds Will Be With Us – So, we need to develop weed management plans.

The First Step: Weed ID – Its more than a name

Landscape Weed Control – JC Neal, NCSU

How do you correctly identify a weed? Compare to a photo

Remember weeds can appear different due to site conditions Easiest to do when plant is flowering

Keys to Identification Send a sample to the University Extension Weed Scientists

Landscape Weed Control – JC Neal, NCSU

Identification Resources

For Piedmont and Coastal Plains

Identifying Seedling and Mature Weeds in the Southeastern US Weeds of Southern Turfgrass

Mountains

Weeds of the Northeast Weeds of Southern Turfgrass

On-line: Turffiles

http://www.turffiles.ncsu.edu/turfid/itemselector.aspx

Landscape Weed Control – JC Neal, NCSU

How to order:

Weeds of Southern Turfgrass

Publication Distributions Center IFAS Building 664

• P. O. Box 110011

University of Florida Gainesville, FL 32611 (352-392-1764)

PS: I think Clemson has some too)

Landscape Weed Control – JC Neal, NCSU

How to order:

Weeds of the Northeast

Cornell University Press

• P. O. Box 6525

Ithaca, NY 14851-6525 607-277-2211 $29.95 plus $5 shipping

Landscape Weed Control – JC Neal, NCSU

How to send a sample for ID

Fresh samples: moisten sample; wrap in DRY paper towel; put in a zip-lock bag and mail on Monday or Tuesday to the appropriate specialist If you cannot send it right away (or if you get the sample on Thursday or Friday: Lay flat on between newspaper; press. Mail the dried, pressed sample to the appropriate specialist

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Landscape Weed Control – JC Neal, NCSU

How NOT to send a weed sample

Too Dry Too Wet

Landscape Weed Control – JC Neal, NCSU

Step 2 -- Develop a weed management plan

Understand the weed and its life cycle Weed management options Optimum time to control the pest Proper application

Landscape Weed Control – JC Neal, NCSU

Life cycle of an annual weed

Seed Seedling Plant flowers Plant sets seed Plant dies

Landscape Weed Control – JC Neal, NCSU

Life cycle of a winter annual weed

Seed Seedling Plant flowers Plant sets seed Plant dies Fall Summer

Landscape Weed Control – JC Neal, NCSU

Common winter annual weeds

Landscape Weed Control – JC Neal, NCSU

Life cycle of a summer annual weed

Seed Seedling Plant flowers Plant sets seed Plant dies Spring Fall

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Landscape Weed Control – JC Neal, NCSU

Common Summer Annual Weeds

• J. Derr

Landscape Weed Control – JC Neal, NCSU

Life cycle of a perennial weed

Seed Seedling Plant Flowers Plant Over-winters Plant sets Seed Roots/ rhizomes spread New plant

Landscape Weed Control – JC Neal, NCSU

Some common perennial weeds

Landscape Weed Control – JC Neal, NCSU

Perennial Weeds Reproduce By:

Rhizomes Tubers Stolons Bulbs Seeds

Landscape Weed Control – JC Neal, NCSU

Types of Perennial Weeds Simple perennials Creeping perennials

Rhizomes Stolons Creeping roots that produce shoots

Tuberous perennials Bulbous perennials

Landscape Weed Control – JC Neal, NCSU

Simple Perennials Spread by seed Tap root or hardy fibrous root system Examples: dandelion, plantain, dogfennel, pokeweed

Tap root

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Landscape Weed Control – JC Neal, NCSU

Creeping Perennials

Reproduce and spread by

Underground stems (rhizomes) Above-ground stems (stolons) Creeping fleshy roots that produce new shoots

Many also reproduce by seeds or other means.

Stolon Rhizome

Landscape Weed Control – JC Neal, NCSU

Tuberous Perennials

Tubers are swollen, modified stems that are

• ften resilient to controls,

spread by cultivation, and may persist in the soil for years. Tubers form on rhizomes

Tubers

Landscape Weed Control – JC Neal, NCSU

Bulbous Perennials

Persist through the dormant season as a bulb Wild garlic and wild onion produce bulblets, aerial bulblets, and seeds

Landscape Weed Control – JC Neal, NCSU

Weeds Are Also Classified By:

Cotyledons (Seed leaves) Monocot (one seed leaf) Dicot (two seed leaves)

Landscape Weed Control – JC Neal, NCSU

Monocots One seed leaf when plant emerges Long narrow leaves Parallel veins

Landscape Weed Control – JC Neal, NCSU

Monocots -- Examples Grasses Onions Garlic Sedges Rushes Lilies Dayflower

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Landscape Weed Control – JC Neal, NCSU

Grasses

Rounded or flattened stems and nodes Have fibrous root systems Some have fibrous roots, rhizomes

• r stolons for reproduction

Growing point is below surface

Landscape Weed Control – JC Neal, NCSU

Grasses are identified by:

seedhead blade ligule auricles collar bud leaf rhizome stolon midrib sheath crown

Landscape Weed Control – JC Neal, NCSU

Vernation or Leaf Bud

Rolled in the bud Folded in the bud

Landscape Weed Control – JC Neal, NCSU

Absent Membranous Hairy

Ligules

Landscape Weed Control – JC Neal, NCSU

Ligules

Absent Membranous Hairy

Landscape Weed Control – JC Neal, NCSU

Absent Present Clasping

Auricles

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Landscape Weed Control – JC Neal, NCSU

Branched spike Panicle Spike

Seed heads

Landscape Weed Control – JC Neal, NCSU

Branched spike Panicle Spike

Seed heads

Landscape Weed Control – JC Neal, NCSU

Grass-Like Weeds

Sedges: Sedges have triangular “stems”. Grasses have flat or rounded “stems”.

Annual and perennial species Most common and difficult to control are yellow and purple nutsedge

Wild Garlic and wild onion: hollow leaves have a pungent onion-like or garlic-like aroma

Wild garlic is the most common

Landscape Weed Control – JC Neal, NCSU

Yellow and Purple Nutsedges (Cyperus spp.)

Grass-like, but “Sedges have edges” – triangular “stems” Leaves emerge 3-ranked Spread by rhizomes and

• ver-winter as tubers

Tubers often introduced in top soil

Landscape Weed Control – JC Neal, NCSU

Wild Garlic (Allium vineale)

Aerial bulblets Bulbous

perennial

Strong scent Reproduces by

bulblets, rarely by seed

Emerges in the

winter and dies back in late spring or early summer

Landscape Weed Control – JC Neal, NCSU

Dicots or Broadleaf weeds

Two seed leaves (cotyledons) Leaves have netted veins Largest group of weeds Often with bright showy flowers Exposed growing points ART FROM 2-2

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Landscape Weed Control – JC Neal, NCSU

How to ID Dicots

Flowers Unique Characteristics Growth Habit Leaf Orientation, Shape, Etc.

Landscape Weed Control – JC Neal, NCSU

Unique Characteristics Look for:

Thorns or spines Square or winged stems Compound leaves Whorled leaves Milky sap

Landscape Weed Control – JC Neal, NCSU

Growth Habits

• J. Neal

Upright Spreading

• J. Neal

Landscape Weed Control – JC Neal, NCSU

Leaf Orientation

Opposite Alternate Whorled Rosette

Landscape Weed Control – JC Neal, NCSU

Simple Verses Compound Leaves

Simple Pinnate Palmate Compound

Landscape Weed Control – JC Neal, NCSU

Other Ways to Identify Cont. Leaf shape Leaf margin

Toothed,entire,lobed, or deeply cut

Petiole length Hair on leaves or other parts

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Landscape Weed Control – JC Neal, NCSU

Leaf Shapes, tips & bases

Landscape Weed Control – JC Neal, NCSU

Leaf Margins

• J. Ditomaso

Entire Deeply lobed Shallow lobes or toothed

Landscape Weed Control – JC Neal, NCSU

Hairs – present or absent, & where?

Mouseear chickweed -- Hairs on stem & leaves Common chickweed -- Hairs absent

Landscape Weed Control – JC Neal, NCSU

Tell Me What You See?

Landscape Weed Control – JC Neal, NCSU

Tell Me What You See? Rosette Broad, nearly entire leaves 5 veins Flowers on spikes

Broadleaf plantain

Landscape Weed Control – JC Neal, NCSU

Tell Me What You See?

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Landscape Weed Control – JC Neal, NCSU

Tell Me What You See?

Alternate leaves Deeply divided (dissected)

• leaves. Twice

lobed.

Landscape Weed Control – JC Neal, NCSU

Assignment – Weed Collection

25 common weeds Press, dry and mount Correctly identified Include required specimen label information Due Date: October 20th