Family name Common name - University of Missourimm wide) covered with dense, soft hairs on both...
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Transcript of Family name Common name - University of Missourimm wide) covered with dense, soft hairs on both...
Family name Common name
Liliaceae . . . . . . . . Star-of-Bethlehem, Wild garlic, Wild onion . . . . . . . . . . . . . . . . . . . . 2
Poaceae . . . . . . . . . Annual bluegrass, Carolina foxtail, Downy brome . . . . . . . . . . . . . . . 3Foxtail barley, Quackgrass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Asteraceae . . . . . . . Butterweed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Cornflower, Dandelion, Fleabanes . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Horseweed, Pineapple-weed, Prickly lettuce . . . . . . . . . . . . . . . . . . . 6Western salsify . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Boraginaceae . . . . . Corn gromwell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Brassicaceae . . . . . Bushy wallflower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Field pennycress, Shepherd’s-purse, Smallflowered bittercress . . . . . . . 8Tansymustard (or flixweed), Virginia pepperweed, Wild mustard . . . . 14Yellow rocket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Campanulaceae . . . Venuslookingglass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Caryophyllacaea . . . Common chickweed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Mouseear chickweed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Chenopodiaceae . . . Kochia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Geraniaceae. . . . . . Carolina geranium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Lamiaceae . . . . . . . Henbit, Purple deadnettle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Onagraceae . . . . . . Eveningprimrose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Plantaginaceae . . . . Plantains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Polygonaceae . . . . . Broadleaf dock, Curly dock, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Prostrate knotweed, Wild buckwheat . . . . . . . . . . . . . . . . . . . . . . . . 19
Ranunculaceae. . . . Buttercups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Mousetail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Rubiaceae . . . . . . . Catchweed bedstraw. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Scrophulariaceae . . Common mullein . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Corn speedwell, Purslane speedwell . . . . . . . . . . . . . . . . . . . . . . . . 21
Violaceae . . . . . . . . Field pansy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Taxonomic keyGrasses and grasslike plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Plants with spines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Plants with an ocrea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Plants with square stems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Plants with milky sap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Plants with finely dissected leaves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Plants covered with hair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Plants that form dense mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Plants with a basal rosette . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Guide to herbicides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Credits and ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . inside back cover
Co
nte
nts
About this guideThis guide is intended to serve as
a practical reference for the identifi-cation of common weeds present inno-till production systems. Variouswinter annual, biennial and peren-nial species are usually present insufficient populations in early springto warrant a burndown herbicidetreatment before planting a summerrow crop. Proper identification iscritical for selecting herbicides andfor determining their appropriateapplication rates.
Numerous plant species are typi-cally present in no-till productionfields in the early spring beforeherbicide applications. Many ofthese species are winter annuals,which complete their life cyclesbefore summer crops are planted andthus will not pose a direct produc-tion problem. However, if they arestill actively growing and are notcontrolled, there will be a rapidincrease in the weed seedbank andfuture populations, which could poseproblems with nutrient managementand rotation to winter annual orperennial crops. Consultants andextension personnel are routinelyrequested to identify these speciesand to provide guidance on manage-ment of these fields. Thus, thepurpose of this guide is to providesome direction on identification andwhether or not it is normally neces-sary to make a herbicide applicationfor a particular species.
The weeds presented in thefollowing pages are organized bytaxonomic plant family. The grassesand grasslike plants — Liliacaea andPoaceae — appear first, followed bythe broadleaves.To identify a weed,you may follow either of two routes:(1) start with the taxonomic key onpages 9–12 and proceed to thephotographs at the page numbersindicated in the key, or (2) start withthe photographs and move to thetaxonomic key with the help of thethumbnail symbol beside eachdescription.
Italicized terms throughout thetext are included in the glossary.
description and photograph can befound. Some plants that have severaldistinct features will appear undermore than one heading in the key.For obvious reasons, this guide doesnot contain all plant species that maybe encountered in no-till production.If you need assistance in identifyinga weed, a sample can be submittedthrough your local UniversityOutreach and Extension Center tothe University Extension DiagnosticClinic in Missouri or through similarprograms in other states.
Using the planttaxonomic key
A simple taxonomic key hasbeen developed to assist in identify-ing common winter annual and earlyspring weeds in no-till fields. Lookfirst for the obvious features of theweed, such as square stems, whorledleaves, or the presence of thorns orspines. Then refer to the diagrams inthe taxonomic key to identify theplant. The key will refer you to thepage in this guide where a short
Field pennycress
Lil
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2 Early Spring Weeds of No-Till Crop Production
Similar in appearanceto wild onion andwild garlic, star-of-
Bethlehem does not have the charac-teristic odor of onion and garlic. Theleaves are grooved and dark greenwith a prominent white midrib. It isalso a bulbous perennial that diesback in late spring to early summer.
Star-of-Bethlehem(Ornithogalumumbellatum)
Wild garlic is abulbous perennial thatemerges in the early
spring and dies back in late spring.Leaves are hollow, lack hair and havea strong odor.
Wild garlic(Allium vineale)
Wild onion is similarin appearance to wildgarlic except that the
leaves are flattened and not hollow. Itslife cycle is a perennial.
Wild onion(Alliumcanadense)
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ac
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MU Extension 3
This winter annual hastwisted leaves (2–3.5mm wide) coveredwith dense, soft hairs on both surfaces.The ligule is a short membrane about1 mm long. The seed head is a droop-ing green or reddish purple panicleand appears from April to early June.Cheat, a closely related species, issimilar in appearance, especially inthe seedling stage, but becomes lesspubescent than downy brome as itmatures. The sheath of both species isclosed to near the top of the collar.
This clump-typewinter annual hascharacteristic “boat-shaped” leaf tips. The leaf blades areflat and smooth on both surfaces andhave a light green coloration. Theligule is 1 to 2 mm long and membra-nous. The seed head is a small, open,greenish white panicle. It tends toinhabit cool, moist areas and does nottolerate heat.
Downy brome(Bromus tectorum)and cheat (Bromus secalinus)
Annual bluegrass(Poa annua)
A winter annual,Carolina foxtail isfound primarily inmoist areas of fallow fields. It haserect stems and flat leaf blades thatare 1 to 5 mm wide. A membranousligule, normally 2 to 3 mm long,tapers to a pointed or rounded tip. Theseed head, which appears in April andMay, is a single spike similar to that oftimothy.
Carolina foxtail(Alopecuruscarolinianus)
Po
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eA
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4 Early Spring Weeds of No-Till Crop Production
Quackgrass is a peren-nial that produces anextensive rhizome
system. The leaf blades are thin,usually ranging from 3 to 6 mm inwidth. The plant possesses auriclesthat clasp around the stem. The liguleis membranous and short, less than 1mm in length. The presence of leafhair varies on the upper blade surface;but the lower blade is smooth. Theseed head is a long spike.
Quackgrass(Elytrigia repens)
Butterweed is mostcommonly found inwet areas. It is an
annual with smooth and hollowstems. At times there may be hair inthe leaf axils, giving it a “cobwebby”appearance. The leaves are irregularlyand deeply cut to the midrib and lackhair. Lower leaves have petioles whilethe upper leaves lack petioles. Often,the foliage turns reddish purple afterflowering.
Butterweed(Senecio glabellus)
Foxtail barley has abluish green appear-ance. It is a short-lived
perennial species with flat blades thatare 2 to 5 mm wide. The ligule is ashort truncate membrane less than 1mm long. The cylindrical seed headcontains long awns, giving it a“squirrel-tail” appearance. Foxtailbarley tends to be most abundant inpoorly drained sites with high pH.
Foxtail barley(Hordeum jubatum)
As
tera
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ae
Also called bachelor’sbutton, cornflowerbehaves like a winterannual. It appears to be covered withloose, white hair giving it a“cobwebby” appearance. The flowersare usually blue-purple in color.
Cornflower(Centaurea cyanus)
MU Extension 5
Dandelion is a cool-season perennial thatforms a large taproot.Like wild lettuce, itforms a basal rosetteof leaves. The leafmargins are very irregular, toothed orwavy with their deep lobes. All partsof the plant contain a milky sap. Theflower is large and yellow, and themature seed head has a “puffball”appearance.
Dandelion(Taraxacumofficinale)
Several species of flea-bane are common tothe Midwest. Theseform a basal rosette ofleaves before bolting.They are variable intheir life cycles. Some are winterannuals while others behave likeperennials or biennials. Flowers havethe characteristic “daisy” appearance.
Fleabanes (Erigeron spp.)
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Horseweed, alsoknown as marestail, isa winter annual or an
early-emerging summer annual plant.It forms a small basal rosette while aseedling. Later, the plant assumes anerect, columnar appearance. Thestems and leaves are covered withdense hairs. Leaves lack petioles andtend to be long and narrow.
Horseweed (Conyzacanadensis)
Pineapple-weed is aninconspicuous, low-growing annual weedwith finely cut, succu-lent, hairless leaves.When cut or bruised,the plant has a sweet
fragrance. Immature plants form basalrosettes. The conelike flowers aregreenish yellow and are borne onshort stems.
Pineapple-weed(Matricaria matricarioides)
Prickly lettuceproduces a basalrosette of bluish greenleaves with very fineprickles along themargins. The plant’smost characteristicfeature is the promi-nent midrib, whichdevelops a row ofspines on the lowerleaf surface as the
plant matures. When broken, stemsexude a milky sap. May be a summeror winter annual or a biennial.
Prickly lettuce(Lactuca serriola)
As
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Bo
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ae
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MU Extension 7
Also known as yellowgoatsbeard, westernsalsify is a biennialplant with a deep, fleshy taproot.Leaves are light green and grasslikewith a clasping base that surroundsthe stem. Stems are erect and branch-ing. All plant parts contain a milkysap. Large, yellow ray flowers areproduced in early summer anddevelop into large “puffball” seedheads that are 2 to 3 times larger thanthose of dandelion.
Corn gromwell is awinter annual or bien-nial with an erectgrowth habit. Leavesare alternate, haveentire margins, lackpetioles and are hairy on bothsurfaces. Toward maturity the highlybranched plant has a dense appear-ance. Flowers are small and white.
Western salsify(Tragopogondubius)
Corn gromwell(Lithospermumarvense)
Early in its growthstage, this winterannual is very incon-spicuous, like many of the mustards.The young rosette leaves of bushywallflower are variable; some aretoothed into 3 to 4 pairs of lobes witha larger terminal lobe, while othersare entire. Leaves on the floweringstalk are more linear with irregularsmall teeth along the margins. Theplant can become dense at maturity,when it produces its yellow flowers,which also have four petals.
Bushy wallflower(Erysimumrepandum)
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Leaves along the stemof field pennycresslack hair and petioles.
They have lobes at their bases wherethey clasp the stem. Crushed vegeta-tion of this winter annual has a foulodor. The small white flowers havefour petals. The fruit is flat and roundwith a small notch at its tip.
Field pennycress (Thlaspi arvense)
While in the rosettestage, leaves aredeeply or irregularly
cut, similar to dandelion. Later, leavesalong the stem are arrow-shaped.Flowers are small and white with fourpetals. The most characteristic featureof the plant is the seedpods, whichare triangular. Shepherd’s-purse is awinter annual.
Shepherd’s-purse(Capsella bursa-pastoris)
The basal leaves ofthis winter annual aredeeply cut, giving it
the appearance of 3 to 6 pairs ofleaflets. Leaves have terminal leafletsthat are rounded. Flowers are smalland white with four petals.
Smallflowered bittercress,(Cardamineparviflora)
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Wild mustard is foundthroughout theMidwest. Leaves are
rough-textured and variable. Lowerleaves have irregularly lobed marginsand petioles; upper leaves are muchsmaller and lack lobes and petioles.Flowers are produced in bright yellowclusters with four petals. It usuallybehaves as a winter annual.
Wild mustard (Brassica kaber)
14 Early Spring Weeds of No-Till Crop Production
Tansymustard is anerect-growing winterannual. In a commonvariation, hairs on thestem are tipped withglands. Rosette leavesare divided into small,
fine teeth. Late in the season, finelydissected leaves give the plant a fern-like appearance. Flowers are usuallyyellow-green, sometimes white. Fruitor seedpods are linear and narrow.Flixweed, closely related, has largerseedpods.
Tansymustard(Descurainiapinnata) or flixweed(Descurainia sophia)
This winter annual hasdeeply lobed leaveswith long petioles
while in the rosette stage. After bolt-ing, the basal leaves drop. Leavesproduced in the upper portion of theplant lack petioles and are long andnarrow. The fruit is flat and round andcontains a small notch at the tip; ithas a pepperlike flavor. Several relatedpepperweed species with similar fruit-ing structures also occur in the region.
Virginia pepperweed(Lepidiumvirginicum)
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MU Extension 15
Yellow rocket mayoccur as a winterannual or biennial inMissouri. Leaves in the lower portionof the plant have oppositely arrangedlobes with a large terminal lobe.Leaves in the upper stem are smallerand alternately arranged with lessconspicuous lateral lobes. Like manyof the other mustards, yellow rockethas bright yellow flowers with fourpetals.
Yellow rocket (Barbarea vulgaris)
Venuslookingglass, anannual, is most oftenfound on nutrient-deficient, sandy soil.Stems contain milkysap; leaves arearranged alternatelyalong the stem and lack petioles. Theplant is short in stature with an erectgrowth habit. Flowers have fivepetals and range from pale to deeppurple.
Venuslookingglass(Triodanis perfoliata)
Common chickweedforms mats and canappear as several varia-tions. Some plants have hairy petioleswhile others lack hair. Leaves of theupper stem have no petioles. Leavesare smooth and usually have a light-green appearance. The white flowerswith five notched petals are similar tothose of mouseear chickweed but aremore deeply cut. The life cycle ofcommon chickweed is similar to thatof mouseear chickweed.
Common chickweed(Stellaria media)
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aG
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16 Early Spring Weeds of No-Till Crop Production
Mouseear chickweedforms dense matsbecause of its natureto root at the nodes.The small leaves of theplant lack petioles and
are densely hairy. The flowers arewhite and have five notched petals. Incool, moist climates, this species canbehave like a perennial.
Mouseearchickweed(Cerastiumvulgatum)
Kochia has a highlybranched, shrublikeappearance. Severalvariations exist in thestate. The “fire bush”variation has linear
leaves that turn a deep purplish redtoward maturity. Another has leavesthat are broader and hairier, withloosely spreading branches. Leaves onboth variations lack petioles and aredensely pubescent as seedlings. Kochiais an early-germinating summer annual.
Kochia (Kochia scoparia)
Carolina geraniumproduces a taprootand generally behaves
like a winter annual. Its palmately cut,rounded leaves are attached to longpinkish brown petioles that appear asa “spokelike” arrangement. Bothleaves and stems are covered withhairs. Flower color is variable, rangingfrom pale pink to purple.
Carolina geranium(Geraniumcarolinianum)
La
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On
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MU Extension 17
Henbit is responsiblefor painting many fieldswith a pinkish purplecast in the early spring. It is a winterannual with square stems, the upperleaves of which appear to encircle theentire stem. A related species, purpledead nettle, has foliage that is morered in color and more compact in itsarrangement along the stems. Bothspecies are rarely greater than 12inches in height.
Henbit (Lamium amplexicaule)
Different varieties ofeveningprimrose havelife cycles that rangefrom annual to bien-nial to perennial. Theleaves are typicallyalternate with simple blades, wavymargins and varying degrees of pubes-cence. In the spring the plant oftenappears as a basal rosette. The stemsare later erect, highly branched andhairy, often giving the stem a redappearance. Flowers can be white toreddish yellow.
Eveningprimrose(Oenothera spp.)
Purple deadnettle is arelative of henbit andclosely resembles it.Both are square-stemmed winterannuals that flower in the early spring.The difference between purple dead-nettle and henbit is that deadnettleleaves are more densely hairy, petio-lated (in the lower ortion of the plant),more triangular in shape, and moretightly compacted in the upper stems.Flowers are light purple in color.
Purple deadnettle (Lamiumpurpureum)
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eP
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18 Early Spring Weeds of No-Till Crop Production
Generally speaking,there are twocommonly occurring
groups of plantains: narrow- andbroad-leaved plantains. Depending onthe species, the amount of leaf hairwill vary. Most species of plantains inMissouri have a well-defined parallelvein pattern in their leaves. Most ofthe broadleaf species produce a “rat-tail” seed head, while the narrow-leafspecies form a shorter “cone-shaped”seed head.
Plantains (Plantago spp.)
Curly dock regener-ates from a large,perennial woodytaproot and producesa large rosette. Rosetteleaves have wavy
margins and upon approaching matu-rity, take on a reddish purple color.Like other members of this plantfamily, curly dock produces leaveswith a membranous sheath, called anocrea, where they join the main stem.At maturity, flowers and fruiting struc-tures take on a “rust” color.
Curly dock(Rumex crispus)
Broadleaf dock hasmuch wider leavesthan the morecommon curly dock.The basal leaves areslightly wavy with
reddish veins, and the lobes that jointhe petiole are heart-shaped. An ocreais also present. Like curly dock,broadleaf dock is a perennial.
Broadleaf dock (Rumexobtusifolius)
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eR
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MU Extension 19
Although a member ofthe same family as thedocks, prostrate knot-weed may be mistakenfor a grassy weedbecause the leaves arelinear as the seedling emerges. Itemerges in late winter to early springbut is classified as an early summerannual because it germinates in cooltemperatures. This weed thrives incompacted areas and forms dense mats.An ocrea is evident at the base of thesmall leaves where they join the stems.
Prostrate knotweed,(Polygonum aviculare)
Wild buckwheat, asummer annual, is amember of the samefamily as the docks. However, it canbe mistaken for a morningglorybecause of its heart-shaped or arrow-head leaves and twining growth char-acteristics. The leaves are alternate,with pointed tips and basal lobesdirected backward. The flower isgreenish white, sometimes purple-spotted. An ocrea is present whereleaf petioles join the stem. Seeds aretriangular.
Wild buckwheat(Polygonumconvolvulus)
About 20 species ofplants known collec-tively as buttercupsoccur in the Midwest. Many of theseoccur as winter annuals; however,several have a perennial life cycle. Ingeneral, this group of plants has“crow-foot”-shaped leaves producedon long petioles. Stems and petiolesmay or may not have hair. With oneexception, all species of buttercupsproduce flowers that are shiny yellowwith five to seven petals.
Buttercups(Ranunculus spp.)
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nc
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20 Early Spring Weeds of No-Till Crop Production
Mousetail is a smallwinter annual thatusually occurs in
moist areas of fields. Leaves aredistinctly linear and appear to emergefrom a central crown, making it easilymisidentified as a grassy weed. Theflower/fruiting structures are alsolinear, upright and rounded, giving ita “mouse-tail” appearance.
Mousetail (Myosurusminimus)
Also known ascleavers because ofthe many short, hook-like spines on itssquare stems, catch-weed bedstraw is a
weak-stemmed winter annual. Theleaves are narrow and hairy and occurin whorls around the stem. Extremelysmall white flowers are produced inthe leaf axils. This weed mostcommonly occurs in moist, shadyareas with rich soil.
Catchweed bedstraw(Galium aparine)
Common mullein is abiennial plant,producing a largerosette during its firstyear of growth. Theleaves are densely
hairy, giving it a fuzzy texture. Thedense hair gives the plant a grayishappearance. Flowers produced duringits second year of growth are brightyellow and occur on long terminalspikes.
Common mullein(Verbascum thapsus)
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MU Extension 21
Field pansy, alsocalled Johnny-jump-up,is short in stature withan erect growth habit and a delicateappearance. Flowers are borne onshort stalks and may be white withblue veins or entirely bluish to bluishviolet. It is a winter annual.
Field pansy(Viola rafinesquii)
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Corn speedwell is awinter annual thatresembles mouseearchickweed. It also hasthe small egg-shaped,hairy leaves that growin mats along the soil surface. It canbe distinguished from mouseearchickweed by the presence of notchesin its leaves and by alternate leaves onflower stems. Also unlike mouseearchickweed, the flowers are generallyblue in color.
Corn speedwell (Veronica arvensis)
Purslane speedwell isa winter annual likecorn speedwell, whichit resembles closely. The two can bedifferentiated by the fact that purslanespeedwell lacks hair on its stems andleaves. The smooth variation of thisweed has glandular-hairy stems.
Purslane speedwell(Veronica peregrina)
Grasses and grasslike plants
Leaves from bulb
Garlic odor No garlic odor
Star-of-Bethlehempage 2
Stemsflattenedand solid
Wild onionpage 2
Wild garlicpage 2
Stems roundand hollow
Leaves from fibrousroot system
Leaves from rhizomesPlants with auricles
Quackgrasspage 4
No ligule presentLeaves from central point
Seedheads long and narrow
Mousetailpage 20
Downy bromepage 3
Plant covered withdense, short hair
Membranous ligule
Rounded ligule1-2 mm long,
Prow-shaped leaf tips
Ligule 2-3 mm long,tapering to a point
Tufted annual
Very short ligule< 1 mm
Tufted perennial
Annual bluegrasspage 3
Carolina foxtailpage 3
Foxtail barleypage 4
Leaves from taproot, has milky sap
Western salsifypage 7
9
Plants with a basal rosette
Buttercupspage 19
Leaves deeplycut or toothed
Leaves irregularlycut or toothed
Leaves not cut Leaves may ormay not be cut
Carolina geraniumpage 16
Dandelionpage 5
Prickly lettucepage 6
Shepherd's-pursepage 8
Smallflowered bittercresspage 8
Tansymustardpage 14
Virginia pepperweedpage 14
Wild mustardpage 14
Fleabanespage 5
Purslane speedwellpage 21
Shepherd's-pursepage 8
Wild mustardpage 14
Kochiapage 16
Common mulleinpage 20
Plantainspage 18
Bushy wallflowerpage 7
Field pennycresspage 8
Yellow rocketpage 15
Plants with finelydissected leaves
Fernlikeappearance
Tansymustardpage 14
Plants coveredwith hair
Long, loose,white hair
Cornflowerpage 5
Dense, short,fuzzy hair
More or less hairywith erect growth
habit
Horseweedpage 6
Corn gromwellpage 7
Hairy, notched leavesopposite on upper
parts of plant
Corn speedwellpage 21
Small leavesPlant forms
a mat
Mouseear chickweedpage 16
Leaves clasparound stem
Fleabanespage 5
Large gray-greenleaves form
a rosetteFlannel-like feel
Common mulleinpage 20
Plants that formdense mats
Plant hasan ocrea
Plant withoutan ocrea
Prostrate knotweedpage 19
Small, oppositesmooth leavesUpper leaveslack petioles
Common chickweedpage 15
Hairy, notchedleaves opposite
on upperparts of plant
Small, oppositepubescent leaves
Mouseear chickweedpage 16
Plants with spines
Spines on midvein Spines on stems
Catchweed bedstrawpage 20
Prickly lettucepage 6
Plant formsdense mats
Plant formsa rosette
Curly dockpage 18
Prostrate knotweedpage 19
Broadleaf dockpage 18
Leaves havewavy margin
Leaves are wide andlobed at base
Plants with square stems
Stems with shortprickles
Stems without pricklesPink to purple flowers
Catchweed bedstrawpage 20
Henbitpage 17
Purple deadnettlepage 17
Plants with milky sap
Spines on midvein No spines
Prickly lettucepage 6 Dandelion
page 5
Western salsifypage 7
Venuslookingglasspage 15
Curly dockpage 18
Broadleaf dockpage 18
Young seedlingplants form abasal rosette
Twining growthhabit
Wild buckwheatpage 19
Hairy, reddish,highly branched
stem
Eveningprimrosepage 17
Eveningprimrosepage 17
Plants with an ocrea
Kochiapage 16
Corn gromwellpage 7
Corn speedwellpage 21
Sweetaroma
Pineapple-weedpage 6
Pineapple-weedpage 6
Butterweedpage 4
Field pansypage 21
Venuslookingglasspage 15
Alternate leaveslack petioles
Hairy on both sides
No spines
10 12
Guide to herbicides for control of early–spring weeds in no–till fields
Herbicide Lab
el a
llow
s fa
ll ap
plic
atio
n
Lab
el a
llow
s sp
rin
g a
pp
licat
ion
Ro
tati
on
al in
terv
al
bef
ore
pla
nti
ng
co
rn
Ro
tati
on
al in
terv
al
bef
ore
pla
nti
ng
soy
bea
n
An
nu
al b
lueg
rass
Bro
adle
af d
ock
Bu
shy
wal
lflo
wer
Bu
tter
cup
s
Bu
tter
wee
d
Car
olin
a fo
xtai
l
Car
olin
a g
eran
ium
Cat
chw
eed
bed
stra
w
Co
mm
on
ch
ickw
eed
Co
mm
on
mu
llein
Co
rn g
rom
wel
l
Co
rn s
pee
dwel
l
Co
rnfl
ow
er
Cu
rly
do
ck
Dan
del
ion
Dea
dn
ettl
e
Dow
ney
bro
me
Eve
nin
gp
rim
rose
Fie
ld p
ansy
Fie
ld p
enny
cres
s
Fle
aban
es
Fox
tail
bar
ley
Hen
bit
Ho
rsew
eed
/Mar
esta
il
Ko
chia
Mo
use
er c
hic
kwee
d
Mo
use
tail
Pin
eap
ple
–wee
d
Pla
nta
ins
Pri
ckly
lett
uce
Pro
stra
te k
no
twee
d
Pu
rsla
ne
spee
dwel
l
Qu
ackg
rass
Sh
eph
erd
’s–p
urs
e
Sm
allfl
ow
ered
bit
terc
ress
Sta
r–o
f–B
eth
leh
em
Tan
sym
ust
ard
/Fix
wee
d
Ven
usl
oo
kin
ggla
ss
Vir
gin
ia p
epp
erw
eed
Wes
tern
sal
sify
Wild
bu
ckw
hea
t
Wild
gar
lic
Wild
mu
star
d
Wild
on
ion
Yello
w r
ock
et
2,4-D – 1 QT (F/S)
y y b b 3 4
8
7
8
3 –
9
5/5
8
4 4 4 4
8
/7
8
/7 0
8
5
9 8
0 5
9/8
7
8 9
6 7
8.5 8.5
7 3
9 9
5
9 9 9 9
5 7
9
7
9
Atrazine (S)
a y 0 h
8
3
9 9 9 9 9 9 8
6 7 – 5 4 4
8.5
7
8
5
8
7 7
8 8 9
7
9 9
5
9
7
9
6
9 9
–
9 9 8 8 8
4
9
4
9
Backdraft (F/S)
y y c 0
9
7
9 9 9 9
–
9 9
/7
9
– –
9
–
8
/6
8
/5
9
– –
9
–
9 9
/
8 9/8 8 9 9 9
7
8
–
9
–
9 9
–
9 9
– – – –
9
–
9
Backdraft + 2,4-D (F/S)
y y c b – 7
9 9 9
– – –
9
/7 – – – – –
9
/
8 9
/6 – – – – – –
9
/
8 9
– – – – –
9
– – – – – – – – – – – – – –
9
Basis + 2,4-D (F)
y y 0 i
9
–
9 9 8 9
–
9 9 8
– – – –
8 8.5
–
8
–
9 8
–
9 9
–
8 9
– –
9
– – –
9 9
–
9 9 9 9
– –
9
–
9
Canopy XL + Express + 2,4-D (F)
y y d e
9
–
9 9 8
– –
9 9 8
– – – –
9 9
–
8
–
9 8
–
9 9
–
8 9
– –
9
– – –
9 9
–
9 9 9 9
– –
9
–
9
Canopy XL +2,4-D (S)
y y d j 6 –
9 9 8
– –
9
6
8
– – – –
8 8
–
8
–
9 8
–
9 8
–
8 9
– –
9
– – –
9 9
–
9 9 9 9
– –
9
–
9
Dicamba
y y 0 k 3
9
7
9
5 3 7
9
7
9
4 7
9 9 8
5 3 7 7 6
9
3 6
8 9
7 –
9 9 8 8
7 3
8
4 4 7
9 8 9 9
5 7 6
9
Dicamba + 2,4-D
y y b l 3
9 9 8
5 5 –
9
7
9
–
9 9 8 9
7 –
9
–
9 9
–
8 9 9 9 9
–
9 9 8 9
–
9 9
–
9 9 9 9
5 7
9 9 9
Express + 2,4-D (F)
y y e e 3 –
9 9 8
5 –
9 9 8
– – – – 7
8
–
8
–
9 8
–
8 9
0
8 9
– –
9
– – –
9 9
–
9 9 9 9
– –
9
–
9
Glyphosate (F/S)
y y 0 0
9
7
9 9 9 9
7
9 9
/7
9
6 –
9
4
9
/6
8
/5
9 8 8 9 8 9 8 9
/
8 8 9 9 9
6
8
6
9 9 9 9
7
9 9 8
– 7
8 9 8 9
Glyphosate + 2,4-D (F/S)
y y b j
9 8 9 9 9 9 8 9 9
/
8 9
– –
9
5
9
/
8 8
/5
9 8 8 9 9 9 8 9 8 9 9 9
7
8.5 8 9 9 9 9 9 9 9 9 9 9 8 9 8 9
Gramoxone + Sencor +2,4-D (S)
y y b j
9
5
9 9 8 9
–
9
7
8
– – – –
9 8.5
–
8
–
9
–
8 9 8 9 9 9 8.5
–
9
– 7 –
9 9
–
9 9 9 9 9
–
9
–
9
Gramoxone (S)
y y 0 0
9
5
9 9 9 9 8 8
6 5 6 – – 2 4 5
8
7
8 8
6
8 8.5
5
8 9 9 8
6 6 7 7
8 9 9
–
8 8 8
6
9
6 6 4
9
Harmony Extra + 2,4-D (F)
y y e e –
9 9 8 8
– –
9 9 8
– – – – 7
8
–
8
–
9
– –
9 8
0 –
9
–
8 9
– – –
9 9
–
9 9 9 9 9 9 9
7
9
Sencor + Python + 2,4-D
y y b j 4 –
8
7
8
7
9
7
8
– – – – 7 7 –
8
–
9 8
– 9 9 – 8.5 9 – – 9 – – – 9 9 – 9 9 9 9 – – 9 – 9
Sencor y y 0 0 4 5 7 – 5 8 6 6 7 4 4 – – 4 6 8 6 6 – 8 – 6 8 4 – 9 – 5 – 6 6 3 2 8 8 – 7 7 5 7 8 3 9 3 7
Sencor + 2,4-D y y b j 4 – 8 7 8 7 – – 7.5 – – – – – 7 9 – – – – – – 9 9 8 – – – – 9 – – – 9 – – – – – – – – – – 9
Simazine + 2,4-D (F) y y b m 8 5 8 7 8 8 – 9 9 – – – – – 9 8.5 – 8 – 9 8 – 9 9 – 8 9 – – 9 – – – 9 9 – 9 9 9 9 – – 9 7 9
Valor + 2,4-D y y f j 6 5 8 7 8 – – 9 4 – – – – – 7 8 – 8 – 9 8 – 9 9 0 6 9 – – 9 – – – 9 9 – 9 9 9 9 – – 9 7 9
Valor + Express + 2,4-D y y g e 6 5 8 7 8 – – 9 9 – – – – – 7 8 – 8 – 9 8 – 9 9 0 9 9 – – 9 – – – 9 9 – 9 9 9 9 – – 9 7 9
Notes:Boldface ratings (8–9) indicate good weed control.a. not in most states; see specific state labelsb. 7 days or more
c. 9.5 monthsd. 10 monthse. 45 days or moref. 30–60 days or more depending on Valor rate
g. 45–60 days depending on Valor rateh. following yeari. 15 daysj. 7 days or more depending on 2,4-D formulation & rate
k. 30–45 days/pint depending on rainfalll. 30–45 days/pint of dicamba depending on
rainfallm. 12 months or more
Annual: a plant that completes its life cycleduring a single growing season.
Auricle: in grasses, small appendage found wherethe blade meets the sheath.
Awns: slender bristles.Axil: position between the stem and leaf.Biennial: plant that requires two years to
complete its life cycle.Bolt: to produce a stem from a basal rosette.Bulbous perennial: plant which regenerates from
year to year from a thickened undergroundshoot where food is stored.
Collar: the outer side of a grass leaf blade at thejuncture of the blade and sheath.
Entire: a continuous, untoothed margin.Gland: a structure which secretes.Lateral lobe: a projecting segment on the margin
of the leaf that is larger than a tooth.Leaflet: one subunit of a compound leaf.Ligule: in grasses, a thin membranous appendage
or ring of hairs on the inside of the leaf bladeat the junction of the sheath and blade.
Lobe: a projecting segment that is larger than atooth.
Midrib: the central vein of a leaf.Node: a place on a stem where a leaf is or has
been attached.Ocrea: a papery sheath that encloses the stem at
the nodes.Palmate: lobed or divided in a handlike fashion.
Panicle: grass seed heads with a main axis andsubdivided branches; may be compact oropen.
Perennial: plants that generally live for more thantwo years.
Petiole: the stalk between the leaf blade and thestem.
Pubescent: with hairs.Ray: a single strap-shaped unit of a flower.Rhizome: a creeping underground stem which
vegetatively regenerates new growth.Rosette: a circular cluster of leaves radiating from
the stem of the plant at the ground.Sheath: in grasses, the lower part of a leaf that
encloses the stem and younger leaves.Simple: a leaf blade that is all one unit.Spike: an unbranched seed head.Summer annual: a plant that germinates in the
spring or summer and completes its life cycleduring a single growing season.
Taproot: an enlarged vertical main root.Terminal leaflet: a single subunit that occurs at
the tip of the main compound leaf.Terminal lobe: a projecting segment that is larger
than a tooth occurring at the tip of the leaf.Terminal spike: an unbranched seed head occur-
ring at the top of the plant.Whorl: three or more leaves per node; in a circle.Winter annual: a plant that germinates in the late
summer to early spring, flowers and producesseeds in mid to late spring, after which it dies.
Annual bluegrass . . . . . . . . . . . . . . . . . . . . . 3Broadleaf dock . . . . . . . . . . . . . . . . . . . . . 18Bushy wallflower . . . . . . . . . . . . . . . . . . . . . 7Buttercups . . . . . . . . . . . . . . . . . . . . . . . . . 19Butterweed . . . . . . . . . . . . . . . . . . . . . . . . . 4Carolina foxtail . . . . . . . . . . . . . . . . . . . . . . 3Carolina geranium . . . . . . . . . . . . . . . . . . . 16Catchweed bedstraw . . . . . . . . . . . . . . . . . 20Common chickweed . . . . . . . . . . . . . . . . . 15Common mullein. . . . . . . . . . . . . . . . . . . . 20Corn gromwell . . . . . . . . . . . . . . . . . . . . . . 7Corn speedwell . . . . . . . . . . . . . . . . . . . . . 21Cornflower . . . . . . . . . . . . . . . . . . . . . . . . . 5Curly dock . . . . . . . . . . . . . . . . . . . . . . . . 18Dandelion . . . . . . . . . . . . . . . . . . . . . . . . . . 5Downy brome . . . . . . . . . . . . . . . . . . . . . . . 3Eveningprimrose . . . . . . . . . . . . . . . . . . . . 17Field pansy . . . . . . . . . . . . . . . . . . . . . . . . 21Field pennycress . . . . . . . . . . . . . . . . . . . . . 8Fleabanes . . . . . . . . . . . . . . . . . . . . . . . . . . 5Foxtail barley. . . . . . . . . . . . . . . . . . . . . . . . 4Henbit. . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Horseweed . . . . . . . . . . . . . . . . . . . . . . . . . 6
Kochia. . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Mouseear chickweed . . . . . . . . . . . . . . . . . 16Mousetail . . . . . . . . . . . . . . . . . . . . . . . . . 20Pineapple-weed. . . . . . . . . . . . . . . . . . . . . . 6Plantains . . . . . . . . . . . . . . . . . . . . . . . . . . 18Prickly lettuce . . . . . . . . . . . . . . . . . . . . . . . 6Prostrate knotweed . . . . . . . . . . . . . . . . . . 19Purple deadnettle. . . . . . . . . . . . . . . . . . . . 17Purslane speedwell . . . . . . . . . . . . . . . . . . 21Quackgrass . . . . . . . . . . . . . . . . . . . . . . . . . 4Shepherd’s-purse . . . . . . . . . . . . . . . . . . . . . 8Smallflowered bittercress . . . . . . . . . . . . . . . 8Star-of-Bethlehem . . . . . . . . . . . . . . . . . . . . 2Tansymustard (or flixweed) . . . . . . . . . . . . . 14Venuslookingglass . . . . . . . . . . . . . . . . . . . 15Virginia pepperweed . . . . . . . . . . . . . . . . . 14Western salsify . . . . . . . . . . . . . . . . . . . . . . 7Wild buckwheat . . . . . . . . . . . . . . . . . . . . 19Wild garlic . . . . . . . . . . . . . . . . . . . . . . . . . 2Wild mustard. . . . . . . . . . . . . . . . . . . . . . . 14Wild onion . . . . . . . . . . . . . . . . . . . . . . . . . 2Yellow rocket. . . . . . . . . . . . . . . . . . . . . . . 15
22 Early Spring Weeds of No-Till Crop Production
Glo
ss
ary
Ind
ex
AuthorsFred Fishel
Department of Agronomy, University of Missouri-ColumbiaBill Johnson
Department of Botany and Plant Pathology, PurdueUniversity
Dallas PetersonDepartment of Agronomy, Kansas State University
Mark LouxDepartment of Horticulture and Crop Science, The OhioState University
Christy SpragueDepartment of Crop Science, University of Illinois atUrbana-Champaign
ProductionExtension and Agricultural Information
University of Missouri-ColumbiaGarry Brix and Dennis Murphy, illustrators Dale Langford, editor
AcknowledgmentsThe authors wish to thank all the external reviewers of thispublication for their helpful and constructive comments:
Bill Curran, Pennsylvania State UniversityJerry Doll, University of WisconsinBob Hartzler, Iowa State UniversityJ.D. Green, University of KentuckyAaron Hager, University of IllinoisBill Helvey, Lincoln UniversityAlex Martin, University of NebraskaMarshal McGlamery, University of IllinoisLeon Wrage, South Dakota State University
Special thanks are extended to Aaron Hager and MarshalMcGlamery for also providing additional photographs andcritique of the final draft.
Line drawings of cornflower, mousetail, and star-of-Bethlehemare reproduced, with permission, from Julian A. Steyermark’sFlora of Missouri (1963, Missouri Department of Conservation).
This publication was coordinated by IDEA — InformationDevelopment • Expanding Awareness, a collaborative effortinitiated by the North Central Cooperative ExtensionServices to increase the efficiency and effectiveness ofdeveloping, producing, and/or marketing educationalproducts nationwide. Publications are subject to peerreview and prepared as a part of Cooperative ExtensionActivities in cooperation with the Cooperative StateResearch Education and Extension Services (CSREES)- U.S.Department of Agriculture, Washington, D.C. The followingstates cooperated in making this publication available. Foradditional copies contact the publishing university. Forcopies of this and other North Central Regional Extensionresources contact the distribution office of the universitylisted below for your state. If your university is not listed,contact the producing university (marked with an asterisk).
*University of MissouriExtension Publications2800 MaguireColumbia, MO 65211-0001(573) 882-7216
University of NebraskaDept. of Ag. Comm.105 Ag. Comm. BuildingLincoln, NE 68583-0918(402) 472-3023
North Dakota State UniversityExtension CommunicationsBox 5655, Morrill HallFargo, ND 58106(701) 231-7882
Ohio State UniversityPublications Office385 Kottman Hall2021 Coffey RoadColumbus, OH 43210-1044(614) 292-1607
South Dakota State UniversityAg. Comm. CenterBox 2231Brookings, SD 57007-0892(605) 688-5628
*Publishing university
Published by MU Extension, University of Missouri-Columbia© 2000 University of Missouri
Sponsored in part by the Missouri Soybean MerchandisingCouncil and Soybean Farmer Checkoff Dollars.
Issued in furtherance of Cooperative Extension work, Acts ofCongress of May 8 and June 30, 1914, in cooperation withthe U.S. Department of Agriculture and CooperativeExtension Services of Illinois, Indiana, Iowa, Kansas,Michigan, Minnesota, Missouri, Nebraska, North Dakota,Ohio, South Dakota, and Wisconsin.
Programs and activities of the Cooperative Extension Serviceare available to all potential clientele without regard torace, color, national origin, age, sex, religion, or disability.
In cooperation with IDEA (Information Development • Expanding Awareness)
On the coverField pennycress in no-till fieldin early spring, by Garry Brix
North Central Regional Extension Publication No. NCR 614
An Integrated Pest Management publicationPublished by MU Extension, University of Missouri-Columbia 10/00/17M
