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

Transcription

1 Weeds Will Be With Us So, we need to develop weed management plans. The First Step: Weed ID Its more than a name 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 Identification Resources For Piedmont and Coastal Plains Identifying ling and Mature Weeds in the Southeastern US Weeds of Southern Turfgrass Mountains Weeds of the Northeast Weeds of Southern Turfgrass On-line: Turffiles How to order: Weeds of Southern Turfgrass Publication Distributions Center IFAS Building 664 P. O. Box University of Florida Gainesville, FL ( ) PS: I think Clemson has some too) How to order: Weeds of the Northeast Cornell University Press P. O. Box 6525 Ithaca, NY $29.95 plus $5 shipping 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 1

2 How NOT to send a weed sample 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 Too Dry Too Wet Life cycle of an annual weed Life cycle of a winter annual weed dies ling dies Summer Fall ling sets seed flowers sets seed flowers Common winter annual weeds Life cycle of a summer annual weed dies Fall sets seed flowers Spring ling 2

3 Common Summer Annual Weeds Roots/ rhizomes spread Life cycle of a perennial weed ling J. Derr Over-winters Flowers New plant sets Some common perennial weeds Perennial Weeds Reproduce By: Tubers s Bulbs Stolons Rhizomes Types of Perennial Weeds Simple perennials Creeping perennials Rhizomes Stolons Creeping roots that produce shoots Tuberous perennials Bulbous perennials Simple Perennials Spread by seed Tap root or hardy fibrous root system Examples: dandelion, plantain, dogfennel, pokeweed Tap root 3

4 Creeping Perennials Stolon Tuberous 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. Rhizome Tubers are swollen, modified stems that are often resilient to controls, spread by cultivation, and may persist in the soil for years. Tubers form on rhizomes Tubers Bulbous Perennials Persist through the dormant season as a bulb Wild garlic and wild onion produce bulblets, aerial bulblets, and seeds Weeds Are Also Classified By: Cotyledons ( leaves) Monocot (one seed leaf) Dicot (two seed leaves) Monocots One seed leaf when plant emerges Long narrow leaves Parallel veins Monocots -- Examples Grasses Sedges Onions Rushes Garlic Lilies Dayflower 4

5 Grasses seedhead Rounded or flattened stems and nodes Have fibrous root systems Some have fibrous roots, rhizomes or stolons for reproduction Growing point is below surface Grasses are identified by: sheath midrib stolon blade ligule auricles collar bud leaf crown rhizome Vernation or Leaf Bud Ligules Rolled in the bud Folded in the bud Absent Membranous Hairy Ligules Auricles Absent Membranous Hairy Absent Present Clasping 5

6 heads heads Panicle Branched spike Spike Panicle Branched spike Spike 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 Yellow and Purple Nutsedges (Cyperus spp.) Grass-like, but Sedges have edges triangular stems Leaves emerge 3-ranked Spread by rhizomes and over-winter as tubers Tubers often introduced in top soil Wild Garlic (Allium vineale) Bulbous perennial Strong scent Reproduces by bulblets, rarely by seed Emerges in the winter and dies back in late spring or early summer Aerial bulblets 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 6

7 How to ID Dicots Flowers Unique Characteristics Growth Habit Leaf Orientation, Shape, Etc. Unique Characteristics Look for: Thorns or spines Square or winged stems Compound leaves Whorled leaves Milky sap Growth Habits Leaf Orientation Opposite J. Neal Upright J. Neal Spreading Alternate Whorled Rosette Simple Verses Compound Leaves Pinnate Palmate Simple Compound Other Ways to Identify Cont. Leaf shape Leaf margin Toothed,entire,lobed, or deeply cut Petiole length Hair on leaves or other parts 7

8 Leaf Shapes, tips & bases Leaf Margins Entire Shallow lobes or toothed Deeply lobed J. Ditomaso Hairs present or absent, & where? Tell Me What You See? Mouseear chickweed -- Hairs on stem & leaves Common chickweed -- Hairs absent Tell Me What You See? Broadleaf plantain Rosette Broad, nearly entire leaves 5 veins Flowers on spikes Tell Me What You See? 8

9 Tell Me What You See? Alternate leaves Deeply divided (dissected) leaves. Twice lobed. Assignment Weed Collection 25 common weeds Press, dry and mount Correctly identified Include required specimen label information Due Date: October 20th 9