Weed ID And Emerging Weed Pests In Florida
Weed ID and Emerging Weed Pests in FloridaChris MarbleUniversity of Florida MREC
Why is weed control so critical? 450 million in losses to Florida agriculture 75% of all pesticide sales are from herbicides Ornamental growers face unique dilemma:– Need to control weeds to reduce competition,AND pots must be weed-free to be marketable– Customers demand weed-free landscapes
Why does weed ID matter? Most important part of weed control:– Critical to always ID your pests beforebeginning your attack (step 1 in IPM)– Determines what control measures areneeded (and which ones will work) Some herbicides are weaker/better on certainweeds – no herbicide controls all weedsSystemics – perennialsContacts – will work on annuals– Could help identify cultural problems atyour site Growing too wet Liverwort, alligator weed,ecliptaDry areas – spurgesNematodes – Florida pusley– Promote professional image
Weed ID Basics Plant ID usually based on flowers/fruits– Can’t wait this long to ID weeds in the nursery Try to use growth habit, color, smell, feel,season, placement (shade/sun, dry/wet, etc.)to ID Goal is to ID and control before seed develops
Where to start GrassesMonocots(Grass like)SedgesWeed PestsDicots(Broadleaf)Primitive Weeds(No seeds)
Monocots: The grassy weeds One cotyledon or seed leaf inside seed coat One single leaf emerges during germination Hollow, rounded or flattened stems,closed/hard nodes Parallel veins
Monocots: Sedges Grass “like” but not true grasses “Sedges got edges”– solid triangular shaped stems,leaves extend in 3 directions Annual & perennial; perennial are TOUGH to control
Monocot IDLook for: Stem shapePresence and shape of: Stem/LeafLeaf 35/weed-identification-tools-and-techniques#.U86fa ldV1A; etc.usf.eduStem/LeafLigule – membranous scale on innerleaf sheath at junction with bladeAuricle – “claw” appendages at baseof bladeCollar – band of meristematic tissueat junction of blade and sheathSheath – tubular part of leaf thatwraps around stemMidrib – central veinRoot structures (bulbs, stonlons, etc.)Hair?Leaf ArrangementSedge
Dicots: Broadleaf weeds Two cotyledons inside the seed coatTwo leaves emerge when germinatingHighly variable in appearanceTypically “showy” flowers, net-like veins
Dicot IDOther ways to ID: Root structures Flowers FruitImages courtesy of UF Center for Aquatic and Invasive Plants http://plants.ifas.ufl.edu/education
Primitive, Non-vascular weeds Algae (cyanobacteria), moss, and liverworts Mossy, slime like plants Reproduce sexually by spores, gemmae, orasexually Primitive plants – ID by appearance, color,reproductive structures (cup or umbrella likestructures)Rob Routledge, Sault College, Bugwood.org
Where to start Know the life cycle AnnualsBiennialsPerennials(The once a year guests)(Few are far in between)(The permanent residents)Howard F. Shwartz, Colorado St. U., Bugwood.org This will help you determine what control options will work
AnnualsLife Cycles:– Complete life cycle in 1 year– Grasses, sedges, broadleaves– Life cycle can begin at different times of year Biennials– 2 year life cycle; germinate in fall, develop roots and leaves in first year– Produce seed and die in second year– Often form a basal rosette of leaves in first year, then “shoot” up andflower in the second (cudweed, thistles) Perennials– Live more than 2 years– Can reproduce from tubers, rhizomes, stolons, or seed– Go dormant, lose vegetative growth, regenerate from food reserves inroot systems– Hard to control with contact/PRE herbicides
Other ID Methods . Height and lateral spread Branching, arrangement of branches on mainstem Leaf size Leaf/stem color and shape Smell and taste (if you dare)Steve Dewey, Utah St. U., bugwood.org
Easy Ways to ID Common Nursery/LandscapeWeeds
Chamaesyce ssp. (Spurges) C. hirta (sandmat spurge) C. hypericifolia (graceful sandmat)C. maculata (Spotted spurge)C. hyssopifolia (Hyssop spurge)C. graminea (Grassleaf spurge)Very common, drought tolerantLife cycle: summer annualLeaves: opposite, toothed, hairs bybaseStems: erect, glabrous, redFlower: white, appear clusteredRoots: taprootEZ ID: milky sap, reddish stems,spotted leaves, seed clustersControl: Handweed before seeding;Many herbicides DNA’s, less control withoxadiazon (Ronstar) oroxyfluorfen (Goal) Tower can control early POST
Eclipta prostrata (Eclipta) Life cycle: summer annual Leaves: elliptic to lanceolate,lack petiole, serrated at margins Stems: reddish brown/purple,root at nodes Flowers: white disk & rayflowers Roots: fibrous, shallow taproot,HARD TO HANDWEED! EZ ID: button-like green to blackseed head Control: Many herbicidesprovide fair control – Indaziflamlooks good
Phyllanthus spp. (Longstalk phyllanthus; Gripweed) P. tennellusLife cycle: summer annual, tropical perennialLeaves: oblong, smooth, in two rows on branchletsStems: single erect stem up to 2’Flowers: greenish white, round fruit on underside oflateral branches in axils of leavesRoots: extensive fibrous rootsEZ ID: longstalk leaves more round, fruit have longerpetioles, gripeweed fruit are sessile, resemble legumeControl: most PRE’s offer poor to fair control,handweed when small, scoutP. urinaria
Cardamine spp.(Pennsylvania bittercress, Hairy bittercress) Life cycle: winter annualLeaves: basal rosette of leavesStems: thin, greenFlowers: small white flowers and cigarshaped fruit – explosive! Roots: fibrous EZ ID: cigar-shaped fruit pop when mature Control: Most PREs – must stay on top due toprolific seed production; corymbosa spreadsby stolons (potentially new weed problem)Leslie J. Mehrhoff, Univ. Conn.,Bugwood.org
Oxalis spp. (Oxalis, woodsorrel)O. corniculataO. strictaJames H. Miller & Ted Bodner, SWSS, Bugwood.orgO. debilis Life cycle: spring/summer annual, into fall and winterLeaves: 3 heart-shaped leaflets, light green to reddish purpleStems: erect, weak, branched at baseFlowers: yellow (creeping and yellow ws), 5 petals, green capsulesfor fruit, become thin when maturing; EXPLOSIVERoots: taproot, rhizomesEZ ID: “tiny okra” fruit, heart leaves in 3’sControl: Most Pre’s; handweeding; Indaziflam SC takes it out earlyPOST (up to 2 -4 leaf stage)Bruce Ackley, Ohio St. U., Bugwood.org
Bidens alba (Beggarticks) Life cycle: annual or short lived perennialLeaves: opposite with depressed midvein, progress tocompound leaves with 3-9 saw toothed oval leafletsStems: purplish stemsFlowers: stalked clusters, white, has black seeds withhooks that attached to clothingRoots: taproot, can root at nodesEZ ID: “needle” like seeds, white 5 petal flowers withyellow centerControl: Most broadleaf herbicides (2,4-D, dicamba,triclopyr, broadspectrum PREs); Aminopyralid(Milestone) provides great control
Pectis prostrata (spreading chinchweed) Life cycle: AnnualLeaves: linear to lanceolate, 4-12 pairs of setae (bristles, hair-likestructures)Stems: prostrate to ascending, mat formingFlowers: July to November, yellow, 5 petalsRoots: fibrousEZ ID: hair-like spins (setae), mat-forming, yellow flowersControl: Broad spectrum PREs
Portulaca spp. (purslane)Portulaca pilosa (pink purslane, kiss-me-quick)Portulaca oleraceae (common purslane)Portulaca amilis (Paraguayan purslane) Life cycle: annualLeaves: alternate, spatulate to lanceolate, obovate; smooth marginsStems: succulent, smooth, fleshy, purplish to red, forms dense matsFlowers: yellow (oleraceae) to hot pink (amilis, pilosa),5 petalsRoots: taproot but rooting at nodesEZ ID: succulent stems and leavesControl: Most herbicides, control early due to prolific seedproduction
Youngia japonica (Asiatic hawksbeard) Life cycle: annual herb, can persist year roundLeaves: form rosette, hairy, round, wavy marginsStems:Flowers: long stalks, ray florets, yellow to orange-yellow, outerpetals have tiny teethRoots: short taprootEZ ID: basal rosette of leaves, yellow to orange flowers with 5 tinyteeth at end of outermost petalsControl: Most PREs, can survive winter in the Southeast
Amaranthus blitum (Purple/livid amaranth) Life cycle: summer annual “pigweed”Leaves: oval, wider at middle, often with notchedleaf tipsStems: prostrate to ascending, smooth, up to 3’Flowers: white to greenish/brown; terminal spikesRoots: taproot systemEZ ID: spikes, growth habit (prostrate), notched leaftipsControl: Most pre’s should work; control adjacentareas (mow, spot spray) next to pads or where soilwas disturbed
Cerastinum fontanum (Mouseear Chickweed) Life cycle: cool season perennial Leaves: dark green, opposite, bluntlypointed Stems: slender, weak, sticky pubescence Flowers: white with 5 petals Roots: fibrous, shallow EZ ID: perennial, sepals and leavespubescent, darker green foliage, flowerpetals only slightly notched Control: Most PREs provide controlTheodore Webster, USDA-ARS, Bugwood.orgOSU Weed Lab Archive, Bugwood.org
Stellaria media (Common chickweed) Life cycle: winter annual Leaves: opposite, oval or elliptic, hairy toward base of petiole, upper leaves sessile,lower (older leaves) have long petioles Stems: prostrate, rooting at nodes, freely branching, soft hairs, often appear reddish Flowers: solitary or in small clusters, white petals Roots: shallow, fibrous, a bit frail EZ ID: hairs pubescent in vertical lines but not distinct, lighter green foliage, notchesso deep it appears there are 10 petals Control: most PREs, oxadiazon (Ronstar) offers poor control
Conyza canadensis (Horseweed, marestail) Life cycle: winter annual (spring) Leaves: rosette of hairy leaves, oblanceolate,sessile, entire or toothed margins Stems: solid, erect, bristly hairs Flowers: numerous, small white and yellow(disc) flowers in panicle Roots: fibrous EZ ID: tall dark green erect plant, sessile leaves Control: Control with PREs. Glyphosateresistance reported
Cuscuta spp. (Dodder) Ronald F. Billings, TFS, bugwood.orgKim Camilli, TFS, bugwood.orgLife cycle: annual – can persist year round intropicsLeaves: very small “scale-like” 1/16” longStems: very thin, usually yellow/orange orpale greenFlowers: small white to pink or cream andbell-shapedRoots – “haustoria” invade plant vasculartissues; needs a host plant within severaldays of germinatingEZ ID: leafless looking vinesControl: Use non-host plants (grasses) Remove by hand If attached, prune host plant whereattachment was made Use PREs (trifluralin, Snapshot); POST(Scythe, others) but will harmornamentals
Cyclospermum leptophyllum (Marsh parsley) Life cycle: summer annualLeaves: finely dissected, opposite arrangementStems: numerous branched stems originating at baseFlowers: small clusters of tiny white/pinkish flowers inumbels, March - June Roots: taproot and secondary fibrous root system EZ ID: finely dissected leaves, upright growth habit, Control: Use broad-spectrum PRE herbicides
Emilia spp.(tasselflowers) Life cycle: summer annualLeaves: wider at base (oblanceolate), toothedmargins (resemble sowthistles), wingedpetioles, leaves on flower stalks clasp stemwith no petioleStems: hairy when young, upright (2-3’)Flowers: red, pink, light purple; seed headsare small, dandelion-like white globesRoots: taprootEZ ID: dandelion seed head, clasping leaves,pink-red flowersControl: Most PREs should work, keep noncrop areas mowedE. fosbergii (Florida Tasselflower)E. sanchifolia (Lilac Tasselflower)
Erechtites hieraciifolia (American burnweed) Life cycle: summer annual/perennial Leaves: elliptic with finely toothedmargins, mid-veins often red; maturetoothed leaves clasp stem Stems: erect, thick green stems, round,can grow up to 8’ tall Flowers: lack petioles, white/cream toyellow in color; seeds white puffy balls EZ ID: large growth habit, toothedleaves clasping stem Control: use multiple MOA – singleactive herbicides seem to be lesseffective
Eupatorium capillifolium (Dogfennel) Life cycle: annual/short lived perennialLeaves: once or twice pinnately dissected, glabrousStems: stout, woody base, hairy, rough (appears dying),unbranched lower down stem, reddish purple or brownFlowers: highly branched panicle with many heads;achene fruitRoots: taproot with coarse rhizomesEZ ID: tall, finely dissected leaves, lower stems brownControl: IMPOSSIBLE TO HAND-WEED; Hard to weedeat; control when young; use broad-spectrum PREherbicides, POST in non-crop areas
Fatoua villosa (Mulberry weed) Life cycle: summer annualLeaves: alternate, triangular, undulated or toothed marginsStems: upright green stems up to 4’ tallFlowers: feathery green/purple clusters (no petals) in leaf axilsRoots: taprootEZ ID: looks like mulberry seedling growing in pots with flowers inleaf axils; pubescent all overControl: Most PREs – be diligent in non-crop areas; hand weedescapes due to prolific seed production
Gnaphalium, Pseudognaphalium, Gamochaetaspp. (Cudweeds) Life cycle: annuals/short-lived perennialsLeaves: basal rosettes or whorled, simple, lobed or unlobed,oblanceolate to obovate to spatulate, taper toward base, noteeth or lobesStems: erect, whitish, can be thickFlowers: crowded, spikelike, arranged on stem or at base of leafstalksRoots: taprootEZ ID: white whooly hairs all over leaves and stemsControl: Typically grow in low fertility areas but thrive incontainers; Most PREs will work
Geranium carolinianum (Carolina geranium) Life cycle: winter annual/biennialLeaves: rosette of leaves, deeply 5 to7 lobed, dissected, bluntly toothed,hairyStems: hairy pubescent stems, oftenpinkish to red in colorFlowers: several flowers in compactclusters at stem tips,white/pink/purple flowers; crane’sbeak like fruitRoots: fibrous with shallow taprootEZ ID: dunce-cap (cranes’ bill) fruit,deeply dissected leavesControl: Many PREs
Parietaria floridana (Florida pellitory) Life cycle: cool season annual/sometimes perennialLeaves: alternated, ovate, rounded with short point,pale green in colorStems: fragile, translucent stems (called “clear weed”often)Flowers: form in the leaf axil, whitish to greenRoots: fibrous rootsEZ ID: Think triangular shaped leaves, cleartranslucent stems, flowers in leaf axilsControl: Loves shade and moist soil – most broadspectrum PREs should work
Richardia spp. (Florida, Brazilian pusley)R. brasiliensis R. scabraLife cycle: annualLeaves: opposite, ovate to elliptic lanceolate, smooth to rough on both surfaces, rough on main veins; leafapex rounded to pointedStems: hairy, usually do not root at the nodesFlowers: star shaped, terminal head like cluster of up to 20 flowers, usually accompanied by two smallerleaves; white to pinkRoots: deep fibrous root system, can harbor nematodes; brasiliensis has thicker rootsEZ ID: Florida pusley does not have thick, woody roots or stiff hairs on fruits, both have opposite leaves,white start shaped fruit, and small leaves by flowersControl: can bloom anytime there is no frost – best controlled using broad-spectrum PRE herbicides
Stachys floridana (Florida betony, Rattlesnake weed) Life cycle: summer/fall perennialLeaves: opposite, triangular, toothedmargins, long (1.5”) petiolesStems: greenish to reddish squarestemsFlowers: clusters of lavender/purpleflowers in upper leaf axilsRoots: thick, rhizomatous root system,segmented tubers (rattlesnake’s tail)EZ ID: segmented tubers, squarestems, triangular toothed marginsControl: prevention is best, most PREsineffective, dichlobenil (Cassaron) canbe effective; prodiamine (Barricade)will stunt plant; repated apps of Rup orbroadleaf herbicides will work
Ambrosia artemisiifolia (Ragweed) Life cycle: summer annualLeaves: simple, pinnately to bi-pinnately lobed,hairy on top, strong odorStems: erect, freely ascending, hairy when youngFlowers: green racemes at ends of branches,droop down often; woody achene fruitRoots: shallow taprootEZ ID: finely dissected leaves, underside ofcotyledons purple, green racemes, woody achenefruit looks like crownControl: More of a problem around beds, shadehouses etc.; broad spectrum PREs and POSTs
Cyperus croceus (Baldwin’s flatsedge) Life cycle: summer perennialLeaves: densely tufted leaves, flat smoothbladesStems: triangularFlowers: globe like clustersRoots: fibrous, extensive root systemEZ ID: globe like structures on stalks at top ofstemControl: Exclusion is best; some POST optionseffective, handweed quickly
Cyperus compressus (Annual Sedge)Photos courtesy of Charles T. Bryson, USDA-ARS, bugwood.orgCharles T. Bryson, USDA-ARS, bugwood.org Life cycle: summer annual Leaves: three ranked, dark green,linear lanceolate Stems: triangular Flowers: erect, spreading from base,scale like Roots: fibrous, reddish in color EZ ID: annual, no bulbs stolons, seedhead is flat Control: PREs effective because it is anannual (spreads only by seeds)
Cyperus esculentus (Yellow Nutsedge) Life cycle: warm season perennialLeaves: three ranked, mostly basal leaves, prominentmid-vein, long attenuated tipStems: triangular, born individually from tuberFlowers: yellowish brown/straw colored spikelets,denseRoots: fibrous, extensive from tubers, rhizomes, andbulbsEZ ID: densely arranged yellow seed heads, prominent“nuts”Control: Glyphosate, halosulfuron, others POST; Donot till!Howard F. Shwartz, CSU, bugwood.orgSteve Dewey, Utah State U., bugwood.orgMark Czarnota, UGA, bugwood.org
Cyperus rotundus (Purple Nutsedge) Life cycle: warm season perennialLeaves: three ranked, mostly basal leaves, darkgreen, prominent mid-vein, abruptly tapering attipStems: triangular, individually born from tuber orbulbFlowers: linear, dark red or purple or reddishbrown, loosely disposed (not crowded)Roots: fibrous, slender white rhizomes coveredwith scales, connected togetherEZ ID: reddish purple seed heads, extensiverhizomes, tubers “on a string”Control: Halosulfuron, glyphosate; less tolerant tocultivation/tillingCharles T. Bryson, USDA-ARS, bugwood.orgJoseph M. DiTomaso, UC Davis, bugwood.orgJoseph LaForest, UGA, bugwood.org
Digitaria sanguinalis (Large, hairy crabgrass) Life cycle: summer annualLeaves: 1 to 10 inches long, usually hairy on both surfaces, hairy closed sheathStems: prostrate, spreading, branched at older nodes, rooting at nodesFlowers: 4 to 6 spike heads that are 2 to 10 inches longRoots: fibrousEZ ID: very similar to smooth crabgrass but has hairsControl: POST grass herbicides [Fluazifop (Fusilade), clethodim (Envoy), Sethoxydim(Vantage)], DNAs PRE, many others
Digitaria ischaemum (Smooth crabgrass) Life cycle: summer annualLeaves: 2 to 8 inches long, glabrous (no hairs) on both sidesStems: prostrate, up to 2” branching at lower nodes, notrootingFlowers: seed head composed of 2-6 fingerlike branchesRoots: fibrousEZ ID: no hairs, can have some at mouth of sheathControl: POST grass herbicides [Fluazifop (Fusilade), clethodim(Envoy), Sethoxydim (Vantage)], DNAs PRE, many othersJoseph M. DiTomaso, UC Davis, bugwood.orgLynn Sosnoskie, UGA, bugwood.org
Murdannia nudiflora (Doveweed) John D. Byrd, Mississippi State, bugwood.org John D. Byrd, Mississippi State, bugwood.orgLife cycle: summer annual, in spiderwortfamily (not a grass, it laughs at you if youuse grass herbicides)Leaves: narrow, 2 to 5” long, pointed,parallel veins, alternate and clasping at stemStems: succulent, roots at nodesFlowers: blue to purple colored flowers,open clusters, short stalksRoots: fibrousEZ ID: thick green leaves, rooting at nodes,thick clumps, what’s left in the lawn afterapplying herbicideControl: difficult to control. Repeatedapplications of MSMA 2,4-D post,sulfentrazone – Broadstar (flumioxazin),Pennant Magnum (s-metolachlor) andTower (dimethenamid-P) controlled thisweed PRE (Walker et al., 2010)
Eleusine indica (Goosegrass)Joseph M. DiTomaso, UC Davis, bugwood.orgRebekah D. Wallace, Univ. of GA, bugwood.org Joseph M. DiTomaso, UC Davis, bugwood.org Charles T. Bryson, USDA-ARS,bugwood.orgLife cycle: summer annualLeaves: 2 to 14” long, glabrous or few hairsStems: flat, erect to spreading, up to almost 3’ tallFlowers: 2 – 13 fingerlike spikesRoots: fibrousEZ ID: stems flattened, whitish green, almost parallelto ground on new plantsControl: PREs, selective grass herbicides
Paspalum dilatatum (Dallisgrass)Rebekah D. Wallace, Univ. of GA, bugwood.orgJames H. Miller and Ted Bodner, SWSS,bugwood.orgBarry Rice, sarracenia.com, bugwood.org Life cycle: warm season perennialLeaves: up to 15” long, glabrous except baseStems: flat, erect to spreading, up to almost 3’ tallFlowers: 3 to 7 erect branches not paired on stemRoots: fibrous with short rhizomesEZ ID: hairs at base of leaf, 3 to 7 racemes not pairedwith long hairs in the axilsControl: PREs, selective grass herbicides
Marchantia polymorpha (Liverwort) Life cycle: Can survive anytime temperaturesare mild (not extremes) and moist Leaves/Stems: produces thalli, moss-leaf-likemats on soil surface and ground cloth/nurserypads Flowers: gemmae cup-like structures – canspread sexually by spores or asexually Roots: rhizoids that attach plant to soil EZ ID: umbrella or cup-like heads, densegreen mats, alien-lookin’-deal Control: can be suppressed by some PREs(flumioxazin, dimethenamid-P) and someorganics (oregano oil and others); best tochange cultural practices, increase air-flow,drainage, allow greenhouse space to dry
Nostoc spp. (Blue-green algaes) Description: primitive, root-less plantlike organisms; dark green gelatinousmasses on plastic, ground cloth, gravelpads; scientifically a bacteria; cancause ground cloth to be very slick EZ ID: gelatinous greenish brownmasses Control: improve drainage, reduceirrigation or irrigate earlier in the day,some peroxide based disinfectants canbe successful (label?)"Nostoc commune" by YAMAMAYA - Photo taken by YAMAMAYA. Wikipedia.com
“New” Emerging Weed Problems in FL
Alternanthera philoxeroides (Alligator weed) Life cycle: perennialLeaves: opposite, entire, elliptic with distinct midveinStems: simple or branched, smooth, hollowFlowers: solitary white head on long peduncles;spreads vegetatively but seeds have beenconfirmed as viable (Holm et al., 1997)Roots: fibrous roots at stem nodesEZ ID: aquatic (mostly) with hollow stems,opposite leaves, solitary white flower headsControl: remove from ponds, streams, non-cropsites; POSTs are effective, no good PREsCharles T. Bryson, USDA-ARS., bugwood.orgJohn D. Byrd, MississippiState U., bugwood.orgJames H. Miller, USDAFS bugwood.org
Commelina benghalensis (Bengal Dayflower, Tropical Spiderwort) Life cycle: perennial, can act as an annualLeaves: broadly ovate to lanceolate, entire margins, parallel veins, pubescentStems: erect or prostrate along ground and can root at nodes, pubescentFlowers: often in clusters, funnel shaped, violet to light blue in color (other day flowers often have darkerflower colors); can produce subterranean flowers/seedsRoots: fibrousEZ ID: white underground stems and flowers, parallel veins, wide leaves, violet flowersControl: Prevent, eradicate, eliminate. Inspect new shipments and sources of materials for presence of BDF.Noxious weed. Glyphosate tolerant. Flumioxazin (SureGuard/Broadstar) provides good PRE control
Mikania micranthra (mile-a-minute) Life cycle: Perennial vine; vigorous growthLeaves: pale green/yellow, opposite, heart-shaped, 2 to 5 in. long,taper to an acute point, serratedStems: glabrous, highly branched, can root at nodesFlowers: panicled corymbs, 4 flowers per cluster, white, single stalkcan produce up to 40,000 seedsRoots: fibrous, can be thickEZ ID: heart-shaped leaves, thick stems, white flower clusters – stillsimilar to native species (M. scandens)Control: Can grow 3’ a week. Call FDACS if spotted. Noxiousweed; mowing/cutting does no good; glyphosate (2-3%) triclopyr(1-2%) will control; dig up, remove, incinerateAndrew Derksen, FDACS/DPI, bugwood.orgAndrew Derksen, FDACS/DPI, bugwood.orgAndrew Derksen, FDACS/DPI, bugwood.org
Parthenium hysterophorus (Ragweedparthenium, Whitetop) Life cycle: annual Leaves: alternate, firstform basal rosette, finelylobed (pinnatifid tobipinnatifid), pubescent Stems: erect, paniculatlybranched and pubescent Flowers: white diskflowers on stem tips Roots: taproot EZ ID: light green/whitepubescent on leaves,white flowers (“whitetop” name) Control: glyphosatetolerant; PREs areeffective
Crotalaria lanceolata (Lanceleaf rattlebox)and other Crotalaria spp. (Rattlebox) Life cycle: annual legumeLeaves: alternate, 3 foliate or simple, linear to lanceolate to elliptic,upper surface usually glabrous, lower pubescentStems: slightly pubescent, greenFlowers: racemes at top of plant, usually yellow to purplish brown;pod darkens with ageRoots: taprootEZ ID: cylindrical pods with inflated appearance, rattle sound whenshaken (at maturity)Control: Broad spectrum PREs could work; Lontrel possibly
Regulated Ornamentals What is a regulated ornamental (or plant)?– Plant that has causes severe economic/ecological damage and isnow a serious pest– State and Federal (USDA) lists noxious weed lists“It is unlawful to introduce, multiply, possess, move, or releaseany noxious weed or invasive plant regulated by FDACS or USDA”– Can be any living part of the plant– Nurseries can be subject to inspections, fined, placed underquarantine, have shipments seized, etc.Complete listing of all FL noxious weeds and additional information:www.flrules.org & www.plants.usda.gov
Schinus terebinthifolius (Brazillian peppertree)Photo courtesy of UF/IFAS Center forAquatic & Invasive Plants Photo courtesy of UF/IFAS Center for Aquatic & Invasive PlantsIntroduced into FL because of attractivered berries and other uniquecharacteristicsProlific seed producer, spread by birds,waterVery aggressive, wide-spread in FL, outcompetes natives in forest understoryIn Anacardiaceae family (poison oak, ivy,sumac), can cause dermatitis
Ardisia creneta (Coral ardisia) Often sold as “ChristmasBerry” Bright red berries carried offby birds Become naturalized in manyparts of FL, dominatesforest floor and shades outnatives Suspected to be poisonousChris Evans, IL Willife action plan, bugwood.orgto livestock/petsPhoto courtesy of UF/IFAS Center for Aquatic& Invasive PlantsPhoto courtesy of UF/IFAS Centerfor Aquatic & Invasive Plants
Ardisia elliptica (Shoebutton) Evergreen glabrous shrub orsmall tree with smoothstems Started to invadehammocks, old fields,disturbed wetlands, marshlands, cypress andmangrove areasAll photos courtesy of UF/IFAS Center for Aquatic & Invasive Plants
Cupaniopsis anacardioides (Carrot wood) Attractive grey bark,evergreen foliage,orangeish/yellow fruit Produces a lot of seed, spreadby birds, high germinationpercentage Now invading beach dunes,islands, marshes, tropicalhammocks,mangrove/cypress swampsAll photos courtesy of UF/IFAS Center for Aquatic & Invasive Plants
Ligustrum sinense (Chinese privet)All photos courtesy of UF/IFAS Center for Aquatic & Invasive Plants Tolerates many different growing conditions (made ita desirable landscape plant) Produces hundreds of seeds, spread by wildlife Spreads by seeds, or from root or stump sprouts Forms dense thickets in natural areas and inlandscapes if allowed Plant non-invasive cultivars (i.e. variegatum)
Sapium sebiferum(Chinese tallow/Popcorn tree)All photos courtesy of UF/IFAS Center for Aquatic & Invasive PlantsCheryl McCormick, Univ. Florida, bugwood.org Can tolerate a variety of growing conditions, growing up to 50’ tall Deep tap-roots make young seedlings very drought-tolerant Produces a lot of seed, young seedlings sprout up quickly in natural areas andlandscapes Invades many different areas, sun or shade; leaves and fruit are toxic to cattle
Mimosa pigra (cat-claw mimosa) Mimosa with thorns on stems,branches, leaves retract when touched Can withstand total submergence byforming adventitious roots from stems Mature plants can produce over 40,000seeds per year in pods Can tolerate a wide variety of growingconditions (wet to dry)Photo courtesy of UF/IFAS Center for Aquatic & Invasive Plants
Potentially Invasive Ornamentals Ornamentals that are not regulated, but could becomeregulated due to invasive potential– Associated with higher maintenance costs in the landscape– Could possibly spread throughout your nursery Category I or II invasive pests by Florida Exotic Plant PestCouncil (FLEPPC)– Category I – invasive exotics that are altering native plantcommunities by displacing natives, changing community structures,ecological functions, or hybridizing with natives– Category II – exotics that have increased in abundance but not yetaltered FL plant communities the way Category I plants have– Complete listings available at www.fleppc.org
Albizia lebbeck, julibrissin (woman’s tongue,mimosa)A. lebbeckPhotos courtesy of UF/IFAS Center for Aquatic & Invasive Plants Attractive but can become invasive dueto fast growth and wind dispersed seed Brittle wood prone to wind damage Large diameter roots can damagepatios/sidewalksA. julibrissinPhotos courtesy of UF/IFAS Center for Aquatic & Invasive Plants
Wisteria sinensis (Chinese wisteria) Introduced in 1800’s because ofornamental value Showy blooms in spring, but aggressivegrowing vine Stems can reach 15” in diameter,damaging fences and other structures Can grow from seeds or rooted stolons(hard to hand weed new seedlings)Photo courtesy of UF/IFAS Center for Aquatic & Invasive Plants
Ruellia simplex (Mexican petunia)Photos courtesy of UF/IFAS Center for Aquatic & Invasive Plants Still widely used as an ornamental for showy flowers, but can become hard to controlSeed spread by storm-water, spreads vegetatively by rhizomesCan recover following glyphosate applicationsHard to remove from
Why does weed ID matter? Most important part of weed control: - Critical to always ID your pests before beginning your attack (step 1 in IPM) - Determines what control measures are needed (and which ones will work) Some herbicides are weaker/better on certain weeds -no herbicide controls all weeds Systemics -perennials
3.2 Chemical Weed Control 10 3.3 Thermal Weed Control 14 3.4 Biological Weed Control 15 4.0 Natural Areas Weed Management 16 4.1 Purpose 16 4.2 Limitations 16 4.3 Study Area 16 4.4 Weed Management Site Prioritisation 18 4.5 Weed Monitoring 20 4.6 Weed Prevention 22 4.7 Weed Control 24 4.8 Partnerships 28 5.0 Parks and Urban Landscaping
W-253 2018 NORTH DAKOTA WEED CONTROL GUIDE Compiled by: Rich Zollinger Extension Weed Science Contributors: Mike Christoffers Research Weed Science, Weed Genetics Caleb Dalley Research Weed Science, Hettinger R&E Center Greg Endres Extension Area Agronomist, Carrington R&E Center Greta Gramig Research Weed Science, Weed Ecology Kirk Howatt Research Weed Science, Small Grains/Minor Crops
Introduction to Weed Science and Weed Identification . Definition of a Weed A plant growing where it is not wanted (Oxford Dictionary) Any plant or vegetation, excluding fungi, interfering with the objectives or requirements of people (European Weed Science Society)
A guide to spring weed control Spring weed control in established pasture There are three key steps to effective spring weed control in established pasture - timing, weed identification and product selection. 1. Timing One of the most common mistakes made with spring weed control is spraying too late.
control, weed control, weed control '. Of course there are other important tasks, but weed control is surely one of the most vital! It is important to achieve good weed control in the 1m2 around each seedling. However the amount of ground disturbance should be kept to a minimum as open ground is an invitation to fresh weed establishment.
Cultural and mechanical weed control emove light or spotty weed infestations by hand-hoeing or R spot cultivation to prevent spreading weed rhizomes, roots, or seed. hen plowing perennial weeds, take care to prevent trans W - porting and spreading plant parts to other areas of the field. se weed-free planting seed to prevent weed infestations in U
of Pasture Weed Control Controlling weeds shifts site resources to grow more grass. If weeds are present, horses tend to preferentially graze where weed pressure is less. When given a choice, horses will preferentially graze the weed free areas and the amount of grass will decline due to spot grazing and weed competition.
Weed control in GraSS and ForaGe cropS Table 1 showing the cost of replacing lost grass production on 1ha with high energy concentrates ( 270/tonne) as a result of weed infestation. Table 2 showing lost sales /ha (2012 prices) from 10% weed infestation due to reduction in stock carrying capacity. Cost of weed infestations Effects
