the biology of canadian weeds. 141. setaria … nurse...the biology of canadian weeds. 141. setaria...

The Biology of Canadian Weeds. 141. Setaria faberi Herrm.

Robert E. Nurse1, Stephen J. Darbyshire2, Cecile Bertin3, and Antonio DiTommaso4

1Agriculture and Agri-Food Canada, Greenhouse and Crop Processing Centre, 2585 County Road 20, Harrow,Ontario, Canada N0R 1G0 (e-mail: [email protected]); 2Agriculture and Agri-Food Canada, Central ExperimentalFarm, Saunders Building #49, Ottawa, Ontario, Canada K1A 0C6; 3Department of Horticulture, Cornell University,Ithaca, NY, USA 14853; and 4Department of Crop and Soil Sciences, Cornell University, Ithaca, NY, USA 14853.

Received 17 March 2008, accepted 13 November 2008.

Nurse, R. E., Darbyshire, S. J., Bertin, C. and DiTommaso, A. 2009. The Biology of Canadian Weeds. 141. Setaria faberiHerrm. Can. J. Plant Sci. 89: 379�404. Setaria faberi, commonly known as giant foxtail, is an annual graminaceous weedthat is native to eastern China, has colonized eastern North America and is expanding its range westward. This species isprimarily self-pollinated and the only mechanism of reproduction is by seed. Adult plants may reach 2 m in height andproduce over 2000 seeds per panicle. Seeds may possess non-deep physiological dormancy when freshly produced, and canform small persistent seed banks. If not controlled, S. faberi populations can cause severe yield reductions in corn andsoybean crops. Several herbicides are available to provide chemical control; however, resistance to some modes of action,(ALS, ACCase, and Photosystem II) have been identified in Canada and the United States. Leaves and seeds of this speciesprovide a food source to several species of mammals, birds, and insects.

Key words: Setaria faberi, giant foxtail, growth, development, seed germination, diseases, herbicide

Nurse, R. E., Darbyshire, S. J., Bertin, C. et DiTommaso, A. 2009. La biologie des mauvaises herbes au Canada. 141.

Setaria faberi Herrm. Can. J. Plant Sci. 89: 379�404. La setaire geante (Setaria faberi) est une graminee annuelle originairede l’est de la Chine. Apres avoir colonise l’est de l’Amerique du Nord, elle poursuit son expansion vers l’ouest.Essentiellement autogame, l’espece n’a que les graines pour moyen de reproduction. Le plant adulte peut atteindre jusqu’a2 metres de hauteur et chaque panicule produit au-dela de 2 000 semences. Fraıches, les semences entrent en dormance afaible profondeur et peuvent engendrer de petites reserves de graines persistantes. Si on ne lutte pas contre eux, lespeuplements de S. faberi entraınent a l’occasion de fortes diminutions de rendement chez le maıs et le soja. Bien queplusieurs herbicides offrent un moyen de lutte chimique, au Canada et aux Etats-Unis, la plante resiste a certains de leursmodes d’action (ALS, ACCase et Photosystem II). Plusieurs especes de mammiferes, d’oiseaux et d’insectes vivent desfeuilles et des graines de la setaire geante.

Mots cles: Setaria faberi, setaire geante, croissance, developpement, germination, maladies, herbicides

1. NameSetaria faberi R. A. W. Herrm. * Incorrect spelling:Setaria faberii * giant foxtail, Chinese foxtail, Chinesemillet, giant bristle grass, Japanese bristlegrass, noddingfoxtail; setaire geante; setaire de Faber (Rominger 1962;Darbyshire 2003; USDA, NRCS 2007). Poaceae (Gra-mineae), grass family, Graminees. European and Med-iterranean Plant Protection Organization Code (BayerCode): SETFA.

2. Description and Account of Variation(a) Species Description * The following description isbased on published information (Hitchcock 1950; Fair-brothers 1959; Pohl 1962; Rominger 1962), supplemen-ted with measurements from herbarium specimens madeby the authors. Measurements are given as the typicalrange with unusual extremes in parentheses.

Plants are annual. Stems single or branching near thebase, (8) 50�200 (250) cm high; leaf sheaths are smooth,with the upper margins hairy. The ligule is a fringe ofshort hairs about 2 mm long. Leaf blades are flat, 15�30cm long and 10�20 mm wide, narrowing to a fine point

at the tip, usually finely pubescent with soft straighthairs on the upper surface or both surfaces (see alsoSection 2c). The inflorescence is a dense spike-likepanicle, usually nodding or drooping from near thebase and 6�20 cm long. The inflorescence rachis isdensely villose with long whitish hairs and the spikeletsare densely grouped in a green, soft bristly, elongatedhead, which resembles a slender bottle brush. On thepedicels at the base of each spikelet are (1) 3 (6) bristlesabout 10 mm long, which remain on the plant after thespikelet has fallen from its minute cup-like base. Thespikelets are 2.5�3 mm long; the lower glumes are about1 mm long and acute; the upper glumes about 2.2 mmlong, 2/3 to 5/6 as long as the upper fertile lemma andobtuse; the lower sterile lemmas are about 2.8 mm long;the lower paleas are about 2/3 as long as the lowerlemmas; the upper lemmas are pale greenish or yellow-ish, finely to distinctly transversely wrinkled (rugose);and, the upper palea is similar to upper lemma. Theexserted anthers are about 1 mm long.

Chromosome counts reported from Canadian popu-lations are 2n�36 (Warwick et al. 1987, 1997). The

379

same tetraploid number has also been reported from theUnited States (Fairbrothers 1959; Pohl 1962), Japan(Kishimoto 1938; Tateoka 1955) and Russia (Probatovaand Sokolovskaya 1983).

(b) Similar Species and Distinguishing Features * Fivespecies of Setaria have been reported in Canada. Acomparison of some morphological characteristics isgiven in Table 1 and a key to the species is given inAppendix 1. Setaria faberi can be distinguished fromother grasses by the presence of a hairy ligule and hairson the upper side and margins of the leaf blade (see alsosection 2a). The inflorescence is characteristic of thefoxtail family and often droops once mature (Fig. 1).

(c) Intraspecific Variation * No intraspecific taxa havebeen described. However, variation in the leaf bladepubescence has been reported. Forms with both leafblade surfaces pubescent as well as non-hairy (glabrous)have been reported from within populations of typicalplants (Monachino 1959; Pohl 1962) (See also Section7c). Fairbrothers (1959) reported the morphologicalvariation found in populations from New Jersey, mea-suring 150 plants (12 populations) grown in the field and20 plants (10 populations) grown in the greenhouse.

Wang et al. (1995) reported that S. faberi is nearlymonomorphic as a species, which is remarkablegiven the geographically diverse sampling used for theirstudy, which included accessions from at least threedifferent continents. Strong inbreeding processes (cleis-togamy or self pollination) occur, because little hetero-zygosity was detected (Wang et al. 1995). Like S. pumila(Poir.) Roem. & Schult. (�S. glauca of authors) andS. parviflora (Poir.) Kerguelen (�S. geniculataP. Beauv.), S. faberi, populations are largely homoge-nous, but are differentiated from one another in thefixation of different alleles at one or more loci (Wanget al. 1995). When Benabdelmouna et al. (2001a)performed an analysis of phylogenetic and genomicrelationships among species in the genus Setaria theyfound that S. faberi rDNA contained an additional 450bp that were not present in other species within the genus.(d) Illustrations* The habit of S. faberi is illustrated inFig. 1 and details of the spikelets are illustrated in Fig. 2.Pohl (1962) provided illustrations to contrast the seeds

of S. faberi and S. viridis. For photographic compar-isons among S. pumila, S. viridis, S. faberi, and S.verticillata see Bouchard and Neron (1991).

3. Economic Importance(a) Detrimental* Considered a major weed worldwide,S. faberi is an annual grass found in a wide range ofcropping systems, but causes the most economic lossesin field corn (Zea mays L.), and soybean [Glycine max(L.) Merr.] and is responsible for crop yield reductions,increased cleaning costs, and the necessity for imple-mentation of expensive cultural and chemical controlmeasures (Knake 1977; Zimdahl 1980). The detrimentaleffects of S. faberi also include production of secondaryallelopathic chemicals, serving as a secondary host forinsect pests, and the ability to survive in a persistent seedbank (see also section 8c).Setaria faberi is often found in mixed communities

with other Setaria species such as S. pumila, andS. viridis. Of the three species S. faberi is consideredthe most competitive species due to its adaptability todiverse environments, delayed germination and highfecundity (Santelman et al. 1963; Schreiber 1965; Knake1977; Buhler et al. 1997; Moechnig et al. 2003).Generally, comparisons among species for effects oncrop yield are hard to distinguish, because accounts ofcrop yield losses are often reported for mixed stands oftwo or more of the Setaria species. Although, in a 3-yrstudy, Staniforth (1965) demonstrated that the vigorousgrowth of S. faberi caused greater soybean yieldreductions than did S. pumila or S. viridis. Moechniget al. (2003) developed empirical models describing thecompetitiveness of S. faberi in relation to Chenopodiumalbum L. in corn. Competition coefficients that werebased on relative leaf area revealed that S. faberi wasmore competitive than C. album. In other mixedcommunities such as old-field successions, S. faberi isoften ranked as the most competitive graminaceousweed (Wakefield and Barrett 1979; Parrish and Bazzaz1982; Facelli and Pickett 1991b).

Corn and Soybean * The presence of S. faberi at lowpopulation densities within a corn crop is sufficient tocause significant yield losses. For example, S. fabericaused a 24% reduction of corn yield when present in

Table 1. Comparison of Setaria species in Canada

Character S. italica S. faberi S. pumila S. viridis S. verticillata

Culms (cm) 100�250 50�200 30�130 20�250 30�100Ligules (mm) 1�2 2 9 1 1�2 to 1Blades (mm wide) 10�30 10�20 4�10 4�25 5�15Panicle (cm) 8�30 6�20 3�15 3�20 5�15Rachis hispid to villose densely villose hispid hispid to villose retrorsely hispidBristles (mm) to 12 9 10 3�8 5�10 4�7Spikelets (mm) 9 3 2.5�3 (2)3�3.4 1.8�2.2 2�2.3Upper glume to lower lemma 9 3/4 9 2/3 9 1/2 9 � 9 �

380 CANADIAN JOURNAL OF PLANT SCIENCE

the interrow, and 37% reductions when between therows (Donald and Johnson 2003). In a 3-yr study inIllinois, 17 S. faberi plants m�1 of crop row wereresponsible for a 25% reduction in corn yield (Knakeand Slife 1961). Also in Illinois, four S. faberi plantsm�2 reduced soybean yield 5%, and 200 plants m�2

reduced soybean yield by 30% (Knake 1990). Knake(1987) generalized that each kilogram of S. faberiaboveground biomass results in a 1 kg decrease incrop yields. Lindquist et al. (1999) developed a rectan-gular hyperbola-based model to predict the thresholddensity of foxtail species (predominately S. faberi) incorn and concluded that while variable by year, theeconomic threshold was 3 to 4 foxtail plants m�1 ofrow. In Michigan, a hyperbolic equation described up toa 14% reduction in corn yield from the presence of 10 S.faberi plants m�1 of row (Fausey et al. 1997).

Conley et al. (2003a, b) quantified the relativecompetitive ability of S. faberi in soybean and concludedthat the critical period of S faberi removal was at the V2leaf stage, and that if S. faberi was present at popula-tions of 64 plants m�2 then soybean yield may bereduced by up to 86%. Mulugeta and Boerboom (2000)also demonstrated that the critical period of S. faberiaremoval in soybeans was between the V2�V4 stages.Harrison et al. (1985) described a soybean yield reduc-tion of 26% when S. faberi was present at 10 plants m�1

of soybean row in Illinois. Even at these lower densities(B 16 plants m�2), S. faberi individuals may produceup to 28 000 seeds plant�1 (Conley et al. 2003a).Seeding soybeans in narrow rows (38 cm) versus widerows (76 cm) may reduce foxtail biomass and maximizesoybean yield; however, this strategy does not reduce thetotal number of seeds produced (Schmidt and Johnson

Fig. 1. Setaria faberi habit. Inset: upper (adaxial) surface of leaf blade.

NURSE ET AL. * SETARIA FABERI HERRM. 381

2004). This may be problematic, because after 35 yr ofcontinuous crop rotation and tillage, S. faberi seedbanks were found to be highest (6890 seeds m�2) ofseveral weed species in a no-till corn and soybeanrotation in Ohio (Cardina et al. 2002).

Differences in germination timing, growth and com-petitiveness of S. faberi cause the species to be less of aproblem in a 3-yr corn�soybean�winter wheat rotationthan in a corn�soybean or a continuous corn croppingsystem (Staniforth 1965; Schreiber 1992). The addition

of lucerne (Medicago sativa L.) and/or triticale (Tritico-secale sp.) into a rotation with corn and soybeanseffectively reduced field populations of S. faberi inIowa (Heggenstaller and Liebman 2005).Setaria faberi is also a problem in container-grown

ornamentals. For example, the growth and developmentof the container-grown bush cinquefoil (Potentillafruticosa L.) were negatively affected when grown withgraminaceous weeds, such as S. faberi (Walker andWilliams 1989). Pohl (1951) also reported that it was a

Fig. 2. Setaria faberi: A. Inflorescence branch; B. Spikelet, adaxial view showing second glume and fertile lemma; C. Fertile floret,abaxial view showing fertile lemma; D. Fertile floret, adaxial view showing fertile palea and lemma margins.


common weed in Iowa gardens. Seeds of S. faberi arealso frequently a problem as contaminants of seedcommodities such as millet (Chase 1948) and clover(Pohl 1951). See also Section 3c.

There is quantitative evidence that S. faberi mayproduce secondary alleopathic chemicals that mayimpact the growth of other species. For example,leachates from live and desiccated S. faberi tissue causedup to a 36% reduction in loblolly pine (Pinus taeda L.)seedling growth (Gilmore 1980). Using similar metho-dology, Keoppe and Bell (1972) demonstrated that S.faberi exudates from mature plants impacted corngrowth by up to 40% during the first month aftercrop emergence.Setaria faberi may also serve as a potential host for

several detrimental insects. In greenhouse studies, thewestern corn rootworm [Diabrotica virgifera virgiferaLeConte (Coleoptera: Chrysomelidae)] had good survi-vorship on S. faberi (Chege et al. 2005; Oyediran et al.2005). Clark and Hibbard (2004) tested 28 species ofgrasses for non-corn host suitability for western cornrootworm and S. faberi ranked 13th out of the 28 species,but was shown to be a less suitable host than S. viridis. Incorn fields, S. faberi can also be a suitable host for theNorthern Corn Rootworm [Diabrotica barberi Smith &Lawrence (Coleptera: Chrysomelidae)] (Oyediran et al.2004).

(b) Beneficial * Willson and Harmeson (1973) foundthat when presented with a choice of seeds from sixdifferent weed species, cardinals and song sparrowspreferred to consume seeds of S. faberi. The seedsof this species may also be a valuable food source forother granivorous birds and rodents and, whenfound near wetland areas, S. faberi seeds may beconsumed by various species of waterfowl (Anonymous2003).

As a pioneer species of open disturbed soils, S. faberiis sometimes useful for soil stabilization. In old-fieldcommunities where sludge has been discarded bymunicipalities, S. faberi has been shown to readilyuptake and sequester Cd, Cu, Pb, and Zn in roots,shoots, leaves and seeds (Levine et al. 1989; Peles et al.1998). When grown in mixed communities with grassspecies that are used for prairie restoration, low densitiesof S. faberi have been shown to be beneficial as a nursespecies (Endress et al. 1999).

(c) Legislation * In Canada, S. faberi is not currentlylisted as a noxious or invasive weed in any province orterritory (Agriculture Canada 1986; Darbyshire 2003),although it is currently listed as a prohibited noxiousweed, Class 1, in the Weed Seeds Order, 2005, under theCanada Seeds Act. Presently in the United States S.faberi has been documented in at least thirty-five statesand is currently considered a noxious weed in AR, CAand KY (USDA, NRCS 2007).

4. Geographical DistributionAlthough S. faberi is native to eastern Asia (Wang et al.1995), its range has greatly expanded as a result ofglobal trade and human-mediated dispersal (Haflingerand Scholz 1980). It occurs as an introduced species ineastern Canada in Southern Ontario and Quebec (Fig.3). Simultaneously, the species also colonized most ofthe eastern United States as well as California andArizona (USDA, NRCS. 2007). Elsewhere it is reportedas a non-native weed in central Europe, Russia, theMiddle East, and eastern Asia (Wang et al. 1995). Thenorthern limit of its distribution in North America isabout 46.58N latitude in Canada (Warwick et al. 1987;herbarium specimen data).

5. Habitat(a) Climatic Requirements * This species has a widedistribution, suggesting that S. faberi has adapted to abroad range of environmental conditions. In the north-ern Canadian range of S. faberi, seeds experienceJanuary temperatures of �17.68C, and plants experi-ence July/August maximum temperatures of 27.98C(Table 2). In the same area precipitation ranges from alow of 42.6 mm to a high of 127.8 mm during thegrowing season (Table 2). In the United States, thetemperature extremes during the calendar year are �15.48C (low) and 40.18C (high), and the precipitationextremes are 1.3 mm (low) and 204.2 mm (high)(Table 2).

(b) Substratum * A wide range of soils support thegermination and growth of this species. In Quebec, S.faberi seeds were found in soil seed banks of the clayloam soil series: St. Urbain, Du Jour, Ste. Rosalie, andSt. Blaise (fine, mixed, mesic, Typic Humaquept)(Vanasse and Leroux 2000). The occurrence of S. faberihas been documented on soils ranging from sandy loam(Brunisolic Gray Brown Luvisol; 83% sand, 5% silt,13% clay, 2.6% organic matter and pH 6.4) to clay loam(Orthic Humic Gleysol, mixed, mesic, and poorlydrained; 30% sand, 40% sand, 30% clay, 4.5% organicmatter, and pH 7.8) in southwestern Ontario (R.E.Nurse, personal observations). In Ohio, S. faberipopulations were established on a silt loam (fine, mixed,mesic, Typic Fragiaqualf) that was 11% sand, 75% silt,14% clay and 1.9% organic matter (Cardina et al. 2007).Populations of S. faberi in Michigan were also found infields with silt loam soils (43% sand, 40% silt, 17% clay,1.1% organic matter and pH 6.7) (Davis and Renner2007).

(c) Communities in Which the Species Occurs * Setariafaberi thrives in a wide range of communities through-out Ontario, Quebec, and the United States, includingcultivated fields, gardens, railway lines, roadsides, anddisturbed areas (Darbyshire 2003).

In old fields, S. faberi is an early successional species,typically occurring in fields that are less than 4�5 yr old.


In a 4-yr-old Ohio abandoned field undergoing second-ary succession, S. faberi was found growing with Festucaelatior L., Poa pratensis L., Solidago canadensis L.,Ambrosia artemisiifolia L., Barbarea vulgaris R. Br.,Oenothera biennis L., Phalaris arundinacea L., Melilotusofficinalis L. (Pall.), and Phleum pratense L. (Sedlacek etal. 1988). In a 1-yr-old successional field in Illinois, S.faberi co-occurred with Abutilon theophrastiMedic., andPolygonum pensylvanicum L. (Wieland and Bazzaz1975). Setaria faberi was also found in a first-year oldfield in Indiana with Abutilon theophrasti, Acalyphavirginica L., Ambrosia artemisiifolia, Asclepias syriacaL., Chenopodium album, Cirsium arvense (L.) Scop.,Datura stramonium L., Daucus carota L., Digitariasanguinalis (L.) Scop., Hedeoma pulegioides (L.) Pers.,Oxalis stricta L., Solidago canadensis, Solanum caroli-nense L., Taraxacum officinale G.H. Weber ex Wiggers,Trifolium spp. and Triticum aestivum L. (Squiers 1989).In an Illinois successional old field grassland communityS. faberi co-existed with Panicum anceps Michx.,Cardamine hirsute L., Andropogon virginicus L., Sor-ghum halepense (L.) Pers., Festuca arundinacea Schreb.,Tridens flavus (L.) A.S. Hitchc., Lespedeza cuneata(Dum.-Cours.) G. Don., and the shrubs Elaeagnusumbellata Thunb., Rubus pensilvanicus Poir., and Rosamultiflora Thunb. (Spyreas et al. 2001). In old-fieldcommunities in New Jersey, S. faberi was the dominantspecies and highly competitive with Ambrosia artemisii-folia, Calystegia sepium L., Digitaria sanguinalis, Oxalisstricta, Panicum dichotomiflorum Michx., and Solanum

carolinense (Hunt et al. 1979; Facelli and Pickett 1991a).Raynal and Bazzaz (1975) found S. faberi in abandonedIllinois fields with Ambrosia artemisiifolia, Polygonumpensylvanicum L., Abutilon theophrasti, and Chenopo-dium album. Although rarely found in more advancedsuccessional systems, Maly and Barrett (1984) reportedS. faberi, Ambrosia artemisiifolia, and A. trifida L. to bepresent in a 7-yr-old old field that had been supple-mented with fertilizer or sludge. In Ohio, S. faberidominated successional corridors. The successionalcorridors were established by plowing and disking anarea and then seeding it to Festuca spp., Poa pratensis,and Trifolium hybridum L. The corridors were then leftundisturbed and allowed to enter secondary successionfor 10 yr. After this period S. faberi was found alongwith Ambrosia artemisiifolia, A. trifida, Asclepias syr-iaca, Convolvulus arvensis L., and Polygonum persicariaL. (Kemp and Barrett 1989).

In Ontario, S. faberi has been observed growing inmixed stands within corn with Amaranthus retroflexusL., Amaranthus powellii S. Wats., Abutilon theophrasti,Ambrosia artemisiifolia, Setaria viridis (L.) Beauv.,Echinochloa crus-galli (L.) Beauv., Setaria pumila, Era-grostis cilianensis (All.) E. Mosher, Panicum capillare L.,Panicum dichotomiflorum, Chenopodium album, Solanumptychanthum Dun., and Polygonum spp. (Hamill et al.2004; R. Nurse, personal observations). Vanasseand Leroux (2000) found S. faberi seeds in the soilseed bank of corn and soybean fields in Quebecalong with Abutilon theophrasti, Ambrosia artemisiifolia,

Fig. 3. Distribution of Setaria faberi in Canada. Locations based on 257 herbarium specimens from the following herbaria: CAN,DAO, HAM, MT, QFA, QUE, TRT, TRTE, and UWO [abbreviations according to Holmgren et al. (1990)].


Table 2. Maximum and minimum mean temperature and precipitation throughout the North American range of Setaria faberiz

Means (from monthly normals)

Data Daily max. Daily min. Max. total Min. total

Country City Prov/State Latitude Longitude Total years Temp. (8C) Month Temp. (8C) Month Precip. (mm) Month Precip. (mm) Month

CAN Quebec QC 46848?N 71823?W 25 25.0 Jul. �17.6 Jan. 127.8 Jul. 70.6 Feb.CAN Montreal QC 45828?N 73845?W 30 26.2 Jul. �14.7 Jan. 92.7 Aug. 61.5 Feb.CAN Ottawa ON 45819?N 75840?W 30 26.5 Jul. �15.3 Jan. 90.6 Jul. 58.9 Feb.CAN Kingston ON 44813?N 76835?W 26 24.8 Jul. �12.2 Jan. 99.0 Dec. 58.8 Jul.CAN Toronto ON 43840?N 79837?W 30 26.8 Jul. �10.5 Jan. 79.6 Aug. 42.6 Feb.CAN Niagara Falls ON 43808?N 79805?W 25 27.2 Jul. �7.9 Jan. 95.2 Sep. 67.4 Feb.CAN Guelph ON 43833?N 80813?W 21 25.9 Jul. �11.4 Jan. 95.9 Aug. 50.8 Feb.CAN London ON 43801?N 81809?W 30 26.3 Jul. �10.1 Jan. 97.7 Sep. 60.0 Feb.CAN Windsor ON 42816?N 82857?W 30 27.9 Jul. �8.1 Jan. 96.2 Sep. 57.3 Feb.US Little Rock AR 34845’N 92814?W 30 33.8 Jul. �0.7 Jan. 145.5 Nov. 74.4 Aug.US Phoenix AZ 33826?N 112800’W 30 40.1 Jul. 6.3 Jan. 27.2 Mar. 2.3 Jun.US Sacramento CA 38830?N 121830’W 30 33.6 Jul. 3.2 Dec. 97.5 Jan. 1.3 Jul.US Hartford CT 41856?N 72841?W 30 29.4 Jul. �8.2 Jan. 111.5 May. 75.2 Feb.US Tallahassee FL 30824?N 84821?W 30 33.3 Jul. 4.3 Jan. 204.2 Jul. 82.6 Oct.US Atlanta GA 33838?N 84826?W 30 31.9 Jul. 0.8 Jan. 136.7 Mar. 79.0 Oct.US Des Moines IA 41832?N 93840?W 30 30.0 Jul. �11.3 Jan. 116.1 Jun. 26.2 Jan.US Springfield IL 39851’N 89841?W 30 30.3 Jul. �8.3 Jan. 103.1 May. 41.1 Jan.US Indianapolis IN 39843?N 86816??W 30 29.8 Jul. �7.5 Jan. 112.3 Jul. 61.2 Feb.US Topeka KS 39804?N 95838?W 30 31.7 Jul. �8.2 Jan. 124.0 Jun. 24.1 Jan.US Frankfort KY 38814’N 84852??W 30 30.5 Jul. �6.2 Jan. 117.1 May. 78.2 Feb.US Baton Rouge LA 30832?N 91809?W 30 32.7 Aug. 4.6 Jan. 157.2 Jan. 96.8 Oct.US Boston MA 42822?N 71801?W 30 27.9 Jul. �5.5 Jan. 101.1 Nov. 77.7 Jul.US Baltimore MD/DC 39810?N 76841?W 30 30.7 Jul. �4.7 Jan. 101.1 Sep. 76.2 Apr.US Lansing MI 42847?N 84835?W 30 27.8 Jul. �10.1 Jan.. 91.4 Jun. 36.8 Feb.US Minneapolis MN 44853?N 93814’W 30 28.5 Jul. �15.4 Jan. 110.2 Jun. 20.1 Feb.US Jefferson City MO 38835?N 92811?W 30 31.9 Jul. �7.9 Jan. 123.2 May. 41.9 Jan.US Jackson MS 32819?N 90805?W 30 33.0 Jul. 1.7 Jan. 151.9 Apr. 82.0 Sep.US Raleigh NC 35852?N 78847?W 30 31.7 Jul. �1.3 Jan. 109.0 Jul. 71.1 Apr.US Lincoln NE 40850?N 96846?W 30 32.0 Jul. �11.4 Jan. 107.4 May. 16.8 Feb.US Concord NH 43812?N 71830?W 30 28.3 Jul. �12.4 Jan. 90.7 Nov. 59.9 Feb.US Newark NJ 40843?N 74810?W 30 29.6 Jul. �4.2 Jan. 118.9 Jul. 75.2 Feb.US Albany NY 42845?N 73848?W 30 27.9 Jul. �10.4 Jan. 95.0 Jun. 57.7 Feb.US Wooster OH 40847?N 81855?W 30 27.8 Jul. �8.4 Jan. 102.4 Aug. 50.0 Feb.US Oklahoma City OK 35823?N 97836?W 30 33.9 Jul. �3.2 Jan. 138.2 May. 32.5 Jan.US York PA 39855?N 76845?W 30 30.3 Jul. �6.2 Jan. 109.5 Jun. 70.4 Feb.US Providence RI 41843?N 71826?W 30 28.1 Jul. �6.5 Jan. 112.5 Mar. 80.5 Jul.US Columbia SC 33857’N 81807?W 30 33.4 Jul. 1.1 Jan. 140.7 Jul. 73.2 Nov.US Pierre SD 44823?N 100817?W 30 31.8 Jul. �13.5 Jan. 88.6 Jun. 12.2 Dec.US Nashville TN 36807?N 86841?W 30 31.5 Jul. �2.3 Jan. 128.8 May. 72.9 Oct.US Richmond VA 37831?N 77819?W 30 30.8 Jul. �2.4 Jan. 118.6 Jul. 75.7 Feb.US Montpelier VT 44812?N 72835?W 30 25.6 Jul. �13.6 Jan. 101.9 Aug. 49.8 Feb.US Madison WI 43808?N 89821?W 30 27.8 Jul. �12.6 Jan. 110.0 Aug. 31.8 Jan.US Charleston WV 38823?N 81835?W 30 29.4 Jul. �4.3 Jan. 123.4 Jul. 67.8 Oct.

zSource for Canadian data: Environment Canada (http://www.climate.weatheroffice.ec.gc.ca/climate_normals/index_e.html).Source for US data: US National Climatic Data Center (http://cdo.ncdc.noaa.gov).

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M.

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Echinochloa cus-galli, Oxalis stricta, Panicum dichotomi-florum, Setaria pumila, Setaria viridis, Taraxacum offi-cinale, Plantago major L., and Chenopodium album. Incorn fields throughout the United States, S. faberi ismost commonly associated with Abutilon theophrasti,Amaranthus powellii, A. retroflexus, Ambrosia artemisii-folia, A. trifida, Bromus japonicus L., Cannabis sativa L.,Capsella bursa-pastoris (L.) Medik., Chenopodium al-bum, Cirsium arvense, Conyza canadensis (L.) Cronquist,Cyperus esculentus L., Digitaria sanguinalis, Echinochloacrus-galli, Erigeron annuus (L.) Pers., E. strigosus Muhl.ex Willd., Ipomoea hederacea Jacq., Muhlenbergia fron-dosa (Poir.) Fern., Panicum dichotomiflorum, Polygonumpensylvanicum, Setaria pumilla, Sinapis arvensis L.,Taraxacum officinale (Abul-Fatih and Bazzaz 1979;Buhler 1998; Pavuk et al. 1997). In glyphosate resistantsoybean fields in Iowa, S. faberi was found in mixedpopulations with Abutilon theophrasti, Amaranthus spp.,Chenopodium album, Digitaria sanguinalis, Echinochloacrus-galli, Elytrigia repens, Polygonum convolvulus, Poly-gonum pensylvanicum, Portulaca oleracea, Setariapumila, S. viridis, and Xanthium strumarium L. (Buck-elew et al. 2000). Setaria faberi was one of the top threedominant species in oats prior to a burning of the fieldwith fire. After the burn, S. faberi became the mostdominant species (Crowner and Barrett 1979). In Ohiowheat fields, S. faberi was found along with Ambrosiaartemisiifolia, Aster pilosus Willd., Chenopodium album,Cirsium arvense, Dactylis glomerata L., Daucus carota,Erigeron annuus L., Melilotus officinalis, Phleum pra-tense, Polygonum pensylvanicum, Trifolium repens L.,and Triticum aestivum (Sedlacek et al. 1988).Setaria faberi has also been found among mixed

populations in grassed waterways with Agropyronsmithii (Rydb.) A. Love., Bromus inermis Leyss., Hor-deum jubatum L., and Panicum virgatum L. in Iowa(Bryan and Best 1991).

6. HistoryIn Canada, S. faberi was first detected in 1975 in cornfields near Nicolet and Saint-Hyacinthe, Quebec (Do-yon et al. 1988; herbarium specimen data). Since then ithas rapidly expanded its range and abundance in thesouthern part of the province (Doyon et al. 1988). Thefirst specimens of S. faberi from Ontario were collectedin 1976 along railway tracks around Toronto, Fort Erieand Niagara Falls (Catling et. al. 1977). By 1981 it hadbeen collected in corn fields in eastern Ontario (War-wick et al. 1987). By the time of its discovery in southernCanada, S. faberi was clearly well established. Its arrivalseems to have coincided with the expansion of corncultivation in the 1960s (Doyon et al. 1988) and to havebeen established from several independent sources(Warwick et al. 1987; Doyon et al. 1988).

In the United States, S. faberi was first collected atPhiladelphia, PA, in 1923 (McCormick and Kay 1968)and at Long Island, NY in 1925 (Fairbrothers 1959). Ithas been hypothesized that seeds were also introduced

to North America near New York city (Fairbrothers1959) as a contaminant of millet imported from China inthe 1920s (Chase 1948). In 1936, S. faberi was reportedto be growing in northern Virginia (Allard 1941) whereseveral varieties of millet were being cultivated between1909 and 1925.

After its introduction into North America, S. faberirapidly spread throughout the eastern half of the UnitedStates (Fernald 1944; Evers 1949; Pohl 1951; Wood1956; Santelmann and Meade 1961). By 1950 it wasdescribed as "becoming a weed in waste and cultivatedground, apparently spreading rapidly, New York toNebraska and Arkansas, North Carolina, Kentucky,and Tennessee" (Hitchcock 1950). It is now also presentthroughout the eastern United States to South Dakota,Kansas and Oklahoma as well as Arizona and Califor-nia (USDA, NRCS 2007). The extensive use of 2,4-D tocontrol dicotyledonous weeds has contributed to apopulation shift to grass weeds such as Setaria spp.(Rominger 1962; Dekker 2003a). Moreover, the devel-opment and utilization of selective herbicides in cornand soybean production has exacerbated this trend. Inthe 1970s, S. faberi was also reported to be present in theRed River Valley of North Dakota (Dekker 2003a).Currently, the North American range of S. fabericontinues to expand.

7. Growth and Development(a) Morphology * The height and biomass of S. faberiplants is largely dependent on the maternal environment(Dekker 2003a). Setaria faberi can reach 2 m in heightwith leaves between 8 and 17 mm wide. The leaves areminutely pubescent beneath and strigose on the uppersurface. The panicles, cylindrical, densely flowered, andspicate are flexuous or slightly arching, 1�17 cm longand 2�3 cm thick. Based at the soil surface, the thread-like subcrown of S. faberi provides nutrients from theseed to the emerging plant until the crown roots areestablished. Before the crown root is established, theseedlings are very sensitive to physical control measuressuch as rotary hoeing (Knake 1987).

(b) Perennation * No perennial growth of this annualgrass has been reported. It overwinters only as seeds.

(c) Physiological Data * The C4 photosynthetic path-way of S. faberi is of the NADP-malic enzyme type(Gutierrez et al. 1974). Like other Setaria species, S.faberi competes efficiently for resources due to its highlyplastic growth (Dekker 2003a). However, some studieshave shown that in its early stages of growth, S. faberi isnot competitive for light, moisture or nutrients (Schrei-ber and Williams 1967). Many physiological mechan-isms, mostly not yet characterized, are responsible forthese plastic responses. These in turn, influence thestature and fitness of the plants especially as they relateto the size and extent of tillering (Dekker 2003a).


Setaria spp. exhibited an exceedingly low degree ofgenetic variation when accessions from at least threedifferent continents were sampled (Wang et al. 1995).Setaria geniculata shows the highest genetic diversityfollowed by S. viridis, S. pumila and S. faberi which isnearly monomorphic. Heterozygosity is rarely detectedin populations of S. faberi, suggesting that stronginbreeding occurs through self-pollination. Populationsof S. faberi are homogeneous but are differentiated fromone another via fixed alleles at one or more loci.Although differences were noted in the pattern ofregional differentiation, S. faberi was nearly invariant.

Mester and Buhler (1991) reported that soil tempera-tures did not affect S. faberi seedling development;however, when mulch was added to the soil, the soiltemperatures decreased, which in turn increased S.faberi shoot and root growth. The early root growth(4 to 7 d after seed germination) of S. faberi was thelowest when compared with three other Setaria species(Orwick and Schreiber 1975). However, root diameterand root surface area and volume were highest amongstthe Setaria species when the root lengths were equatedby substituting the length of S. faberi roots with the rootradii of each species. Due to these characteristics,control with soil applied herbicides should be improvedfor S. faberi in a wider range of soil herbicide activationzones (Orwick and Schreiber 1975). The below-groundroot biomass of S. faberi is shallow and fibrous, but isable to occupy a large volume and can overlap withseveral other successional species (i.e., Abutilon theo-phrasti, Ambrosia artemisiifolia, and Chenopodium al-bum), thus allowing S. faberi to compete for nutrientssuch as nitrogen, potassium, calcium, and magnesium(Wieland and Bazzaz 1975; Parrish and Bazzaz 1976).

Soil nitrogen level has been shown to influence thegrowth of S. faberi (Salas et al. 1997). Total dry biomassincreases with increasing nitrogen rates, regardless ofwhether nitrogen is applied as NH4 or NO3 (Salas et al.1997). However, the authors showed that seed produc-tion was reduced at higher nitrogen rates when nitrogenwas applied as NH4. Schreiber and Orwick (1978)measured the dry weight of S. faberi shoots from plantsgrown in sand-soil nutrient solutions where nitrogenlevels varied 0.5, 1, or 3 times that of the nitrogenpresent in a Hoagland’s (Hoagland et al. 1938) solution.Dry weights of the shoots were significantly affected bynitrogen level and plant biomass increased when nitro-gen level was increased by a factor of three. This resultdemonstrated a direct relationship between S. faberibiomass and the amount of nitrogen available in thesoil.

Root residues collected from S. faberi have allelo-pathic effects on corn root development (Schreiber andOrwick 1978) and overall corn growth (Bell and Koeppe1972). Additionally, other Setaria spp. except S. pumilado not develop in close proximity, possibly due toalleopathy. This allelopathic effect is enhanced by lownitrogen levels such as those encountered in fencerows

and waste areas where S. faberi is commonly thedominant species (Schreiber 1977). Leachates extractedfrom live and dead tissue of S. faberi were shown todecrease loblolly pine seedling growth by up to 36%(Gilmore 1980). These leachates also reduced the abilityof the pine seedlings to take up potassium, phosphorusand magnesium, while enhancing their ability to take upnitrogen and manganese. Extracts from mature S. faberistem tissue resulted in a 50% reduction in the seedgermination and seedling growth of Italian ryegrass(Lolium perenne L.) and alfalfa (Medicago sativa L.)(Martin and Smith 1994).

There are concerns that increased competitivenessbetween crop and weeds might evolve as atmosphericCO2 concentration increases. Therefore, studies wereconducted to evaluate the effect of atmospheric CO2

enrichment on C4 grasses including S. faberi in responseto water stress. Sionit and Patterson (1984) reported thatunder water stress, the stomatal conductance under highCO2 conditions is not significantly affected; whereasturgor pressure and net photosynthetic rates increased.Garbutt et al. (1990) tested the growth response of S.faberi to three ambient CO2 concentrations (350, 500,and 700 mL L�1). Their study yielded the followingresults: (1) there was no detectable effect of elevatedCO2 on timing of seedling emergence; (2) the waterpotential of shoots increases with increasing CO2 con-centrations; (3) stomatal conductance decreased withincreasing CO2 concentrations when light levels werehigh; (4) intercellular CO2 levels increased as ambientCO2 levels increased; (5) flowering was delayed at thehighest CO2 concentration (700 mL L�1); and (6)reproductive biomass did not change with increasingCO2. Flowering was also delayed for greenhouse-grownplants when nutrient levels were low and CO2 levelselevated (McConnaughay et al. 1993). However, theoverall growth of the plants was not affected by elevatedCO2. Other studies have also reported photosyntheticrate in S. faberi to be increased (Ziska and Bunce 1997)or unchanged (He et al. 2002) in response to elevatedCO2, and no effect on above-ground biomass produc-tion or seed production (Bazzaz and Garbutt 1988;Ziska and Bunce 1997).

The amount of solar UV-B reaching the earth’ssurface has dramatically increased in recent years dueto ozone depletion (Kane 1998). This increase in UV-Bradiation has been shown to influence the growth ofsome grass species (Tosserams et al. 1996; 1997).Cybulski and Peterjohn (1999) demonstrated that theabove-ground biomass of S. faberi was not influencedby UV-B levels that were at least 90% of ambient UV-Blevels (8.1 kJ m�2 d�1) in West Virginia.

The daily water potential of S. faberi leaves is morenegative than that of Abutilon theophrasti and Poly-gonum pennsylvanicum when the species co-exist in anold-field successional community (Wieland and Bazzaz1975). Under optimal conditions, S. faberi can maintaina photosynthetic rate of 38 mg CO2 dm�2 h�1 at leaf


water potentials as low as �1.2 MPa and 30% of thisrate at leaf water potentials as low as �2.4 MPa.

Drought stress and low temperatures have beenshown to increase epicuticular leaf wax levels inS. faberi (Hatterman-Valenti et al. 2006). Alternatively,growth under low light conditions decreases the amountof leaf wax produced. This shift in leaf wax productionmay impact the absorption of some herbicides (see alsoSection 11).

(d) Phenology* Setaria faberi is sensitive to shade, anda decrease in incident radiation of 95% in soybean orcorn may cause cessation of growth (Knake 1987).Generally, dry weight production decreases linearlywith increases in shade levels (Santelmann et al. 1963;Knake 1972). Peak flowering of greenhouse-grown S.faberi plants in Wisconsin occurred 63 to 67 d afterplanting of seeds (Volenberg and Stoltenberg 2002b). Inabandoned fields in Illinois, S. faberi populationsshowed a bimodal pattern of seed germination wherethe densities of the populations first peaked in May andthen in July/August (Raynal and Bazzaz 1975). Asimilar bimodal pattern of seedling emergence was alsodocumented in the Northeastern United States (Myerset al. 2005).

(e) Mycorrhiza * In greenhouse experiments, S. faberiwas found to be only weakly colonized by arbuscularmycorrhizal fungi with mean colonization rates up to3% (Vatovec et al. 2005). The mycorrhizal responsive-ness (effect on biomass production) was greater underhigher light and temperature conditions, although thecolonization rate was not significantly different betweentheir two experiments.

8. Reproduction(a) Floral Biology * Setaria faberi is primarily selfpollinated (Dekker 2003a). Autogamy has been shownin the closely related S. viridis (Mulligan and Findlay1970) and agamospermy has been noted in the polyploidS. macrostachya species complex (Emery 1957) and thuscannot be ruled out in S. faberi, although Brown andEmery (1958) found no evidence of apospory in the eightspecies of Setaria studied. The pollen to ovule ratio ofS. faberi was determined to be 1212941.3, in compar-ison to a ratio of 754.7942.1 for the closely relatedS. pumila (Cruden 1977).

(b) Seed Production and Dispersal* Seed production inS. faberi has been estimated to range from 165 to 2127seeds per panicle (Dekker 2003b). Variability in seedproduction is directly related to the number of fertilespikelets per panicle and this characteristic is plastic(Dekker 2003b). Seed numbers were generally greaterfor S. faberi plants that emerge early in the season(Schreiber 1965). Maximum seed rain occurs from Julythrough December (Peters et al. 1963; Dekeer 2003b).Forcella et al. (2000) found that on average S. faberi

produced 246 seeds per panicle. Overall seed productionwas shown to follow a curvilinear relationship withpanicle length with seed production in panicles 100 mmlong averaging 323 seeds per panicle (Forcella et al.2000). Additionally, S. faberi fecundity (seeds per plant)increased linearly with increases in shoot biomass(Conley et al. 2002). Seed production has also beenlinked to shoot biomass and this grass has been shownto produce 88 and 154 seeds per gram of shoot biomassin each of two years (Moechnig et al. 2003). On a wholeplant basis, Schreiber (1965) showed production of morethan 10 000 seeds per plant. Seed production of about1000 seeds per plant was also found after additions ofswine manure compost in Iowa, but the manure addi-tions did not affect total seed production (Liebman et al.2004).

Crop competition may significantly influence S. faberiseed production. Seed production is higher in corn thansoybean because of higher plant and panicle densities(Forcella et al. 2000). Estimates of 90 000 seeds m�1 ofcorn row have been reported (Fausey and Renner 1997).Bussan et al. (2000) recorded seed production of up to4000 seeds per plant in competition with soybean. In asoybean crop not treated with herbicides, the averageseed production was about 600 seeds per plant (11 400seeds m�2) (DeFelice et al. 1989). In the same study,sethoxydim did not reduce seed production per plant orper panicle; however, it did reduce seed production to aslow as 1020 seeds m�2. Early application of glyphosatereduced S. faberi seed production per plant by up to96% (3167 seeds in control vs. 114 seeds in glyphosatetreated plots) (Biniak and Aldrich 1986).

Seeds of S. faberi are physiologically independentfrom the plant when mature, but do not disperse untilthe pedicel degrades (Dekker 2003b). Timing of dis-persal is variable and dispersal may occur by gravity,animal, wind, water, and humans (Dekker 2003b).Additionally, birds, cattle and small mammals probablyassist in disseminating seeds (Rominger 1962; McCor-mick and Kay 1968). Its rapid and wide dispersal inNorth America appears to have been primarily due tocontamination of seed commodities such as millet,soybean, red clover and possibly garden flowers (Pohl1951; McCormick and Kay 1968). Other pathways likelyto have contributed to its spread include manure, hay,livestock bedding, contaminated machinery and birdseed mixtures (McCormick and Kay 1968).

(c) Seed Banks, Viability of Seeds and Germination *Germination occurs throughout the growing season(King 1952) and S. faberi may form a small persistentseed bank (Buhler and Hartzler 2001; Leck and Leck1998). Seeds within the seed bank are subject todepletion and may decline rapidly if there is high annualseedling emergence (Forcella et al. 1997; Buhler 1999).Zhang et al. (1998) showed that 80% of above-groundS. faberi populations can be explained by the analysisof the soil seedbank. According to Buhler (1999), a


high-density weed seed infestation in Minnesota com-prised 60 000 seeds m�2 of S. faberi, whereas a lowinfestation was 1000 seeds m�2 (Buhler 1999). Leck andLeck (1998) found an early seed bank of about 10 000seeds m�2 in a successional old-field, which decreased toan average size of less than 2000 seeds m�2 after 4 yr. Ina corn/soybean rotation in Wisconsin, the seedbankoscillated between 5000 and 10 000 seeds m�2 over a 20-yr period (Bussan and Boerboom 2001). Rothrock et al.(1993) found much smaller persistent seed banks inIndiana where size ranged from 152922 to 1994 seedsm�2. The authors measured a seed bank size of about164 seeds m�2 10 yr prior to the start of the experimentsuggesting that the persistent seed bank of S. faberi isstable. The persistence of the S. faberi seedbank acrosseight mid-western US states was found to be 60% of itsoriginal size after 3 yr (Davis et al. 2005).

Tillage and crop type have substantial effects on seedbank size as well as the depth of seeds within the soilprofile. The maximum depth for S. faberi seedlingemergence is estimated at 10�12 cm (King 1952; Mesterand Buhler 1986), although this is undoubtedly depen-dant on soil compaction and moisture. In a 30-yr longtillage trial in Ohio, Cardina et al. (1998) found that seedbanks were larger in no-till soils (1140 seeds m�2) whencompared with soils that were chisel (210 seeds m�2) ormoldboard (70 seeds m�2) plowed. Tillage reduced seedbank size in the top 5 cm of soil from 139 to 54 seedsm�2 in Indiana (Rothrock et al. 1993). After 35 yr ofcontinuous crop rotation and tillage, S. faberi seedbanks were found to be highest (6890 seeds m�2) in ano-till corn and soybean rotation at one site and in acontinuous corn rotation (also 6890 seeds m�2) on no-till soils at a second site (Cardina et al. 2002). Reducedtillage or no-till has been shown to concentrate S. faberiseeds in the upper horizons of the soil profile. InWisconsin, S. faberi was the largest component of seedsin the soil seed banks of no-till soils with 40% of S.faberi seeds emerging from the top 1 cm of no-till soilsand less than 5% at a depth of 4 cm (Buhler and Mester1991). Several other studies have also documented thatS. faberi seeds remain within the top 5 cm of the soilprofile in no-till fields and old field communities (Big-wood and Inouye 1988; Hoffman et al. 1998; Leck andLeck 1998; Reuss et al. 2001). In Iowa, a soybean/cornrotation had the majority of seeds in the top 5 cm, whilea continuous corn rotation caused seeds to move deeperwithin the profile (10�15 cm) (Hoffman et al. 1998). InMaryland, dormant seeds of S. faberi were buried atdepths of 2.5, 7.6 and 15.2 cm and germination wasmonitored after burial lengths of between 3 and 6 mo.After 6 mo of burial, seeds entered into secondarydormancy. Percentage germination was greatest at the2.5 cm depth (Taylorson 1986). The highest seedlingemergence of S. faberi in Michigan was from a depth of1 cm (74% after 21 d) and 1 to 2.5 cm (64% after 21 d).Only about 3% of seeds emerged from a depth of 7.5 cmor greater (Fausey and Renner 1997).

Seedling emergence from the seed bank is negativelyaffected by tillage (Buhler and Daniel 1988; Buhler andOplinger 1990). Buhler et al. (1996) found that S. faberiemergence was greater in no-till (100 to 1700 plantsm�2) versus conventionally tilled plots (100 to 500plants m�2). Alternatively, Myers et al. (2005) found noeffect of tillage on emergence pattern and that tillagehad little effect on the total number of seedlings presentin the field. When corn residue was added to the plots,emergence was further reduced by 42 to 95%. Similarly,no-till plots yielded 500�800 plants m�2 versus about200 plants m�2 in conventional tillage 60 d after cropplanting in Wisconsin (Buhler and Oplinger 1990). InMinnesota, S. faberi comprised 32% of the viable seedbank and 5% of the total seed bank under long-termconventional tillage (Reuss et al. 2001). In Indiana,tillage may result in 55% of seeds becoming seedlings(Rothrock et al. 1993). In Iowa, S. faberi seeds emergedonly in the first 3 yr of a 4-yr study in tilled soil. In thefirst year, 30% of the original seed bank emerged andthe seed bank was reduced by 42% after 3 yr (Buhlerand Hartzler 2001). A similar study showed that while43% of seeds emerged in the first 2 yr of a burial study,only 1% of the total seeds emerged in the third year(Hartzler et al. 1999). For seedlings that do emerge, atleast 10% of the emergence was shown to occur after180 degree days (DD) (from late April to early May inPennsylvania) with 75% emergence between 200 to 500DD (Myers et al. 2004). The density of seedlingemergence in their study ranged from 148 plants m�2

to 1040 plants m�2. Menalled et al. (2005) demonstratedthat the addition of composted swine manure decreasedS. faberi seedling emergence from 15 to 57%.

Herbicide control of S. faberi reduces the soil seedbank. In Iowa, when herbicides were banded or omitted,Setaria spp. dominated the weed seed bank. Setaria spp.only constituted 25% of the seed bank with broadcastspraying (Hoffman et al. 1998). Buhler (1999) compareddifferent management practices and found that the seeddensities in weed-free (herbicide, cultivation, bi-weeklyhandweeding) plots were reduced from 57 000 to 9000seeds m�2 in 4 yr. In the same study, herbicides alonereduced seed banks from 61 000 to 36 000 seeds m�2,while mechanical control increased seed banks from 59000 to 76 000 seeds m�2. The greatest decreases were inthe first two years (78%) which then stabilized insubsequent years at about 15% of the initial density(Buhler 1999). Glyphosate application at the first head-ing stage reduced the weight of S. faberi seeds (1.026 g1000�1 control vs. 0.539 g 1000�1) and germination byup to 95% (Biniak and Aldrich 1986).

Viability and germination of freshly collected S. faberiseeds is variable. Viabilty was about 80% in Illinois(King 1952), 63�75% in western Minnesota and SouthDakota (Forcella et al. 2000), 91% in Minnesota (Reusset al. 2001), 78 to 92% in Iowa (Leon et al. 2004), and90% in New York (DiTommaso and Nurse 2004).Germination of seeds collected from within a corn/


wheat rotation ranged from 21 to 59% in Iowa (Davisand Liebman 2003). Seed collected in Minnesota from afield under long-term conventional tillage, and seeded toannual crops had viability increased from 2 to 42% afteran over-wintering period, possibly due to after-ripeningor additional seed deposition. Highest seed viability wasfound in soil aggregates of 1�2 mm size (25%), butviability of 21% was also found in aggregates�12 mmin size (Reuss et al. 2001). When buried in soil at a depthof 7.6 cm, S. faberi seeds lost viability most rapidly outof six weed species tested in Maryland (Taylorson 1972).In the same study, approximately 35, 2, and 67% ofseeds remained viable at burial depths of 2.5, 7.6, and15.2 cm, respectively. In a burial study in Iowa, seedviability of S. faberi decreased from �93% at the timeof burial to B20% after only one year (Buhler andHartzler 2001).

Two unidentified soil fungi were reported in caryopsesof S. faberi by Pitty et al. (1987) which had a detrimentaleffect on germination. The extent of colonization by thefungi was correlated with soil depth and tillage system(see also Section 13bi).

Seeds of S. faberi possess non-deep physiologicaldormancy (Baskin and Baskin 1998) that is affected bytemperature, aeration and moisture (King 1952). Ex-periments by King (1952) suggest the presence of water-soluble germination inhibitors; however, the authors didnot make conclusions as to the source of the inhibitors.Environmental factors may also cause non-dormant orseeds that have previously lost dormancy to enter into asecondary dormancy (Taylorson 1982). Temperaturesgreater than 308C were needed to induce secondarydormancy, possibly due to changes in membrane func-tion and metabolism (Taylorson 1982; Taylorson 1986;Kegode and Pearce 1998; Leon et al. 2004). Forcella etal. (1997) suggested that once soil temperatures reach178C within the top 10 cm, conditions are appropriatefor S. faberi seeds to enter secondary dormancy. Levelsof dormancy in freshly collected seeds are quite variable.

An attempt to germinate freshly collected seeds fromMissouri at alternating temperatures of 208C (8 h light)to 308C (16 h dark) for 21 d revealed that almost allseeds were dormant (Stanway 1971). Similarly, Mulu-geta and Stoltenberg (1997) reported high levels(�77%) of seed dormancy in freshly collected seeds inWisconsin. Low temperatures (�20 to �508C) andaerobic conditions have been shown to effectively slowafter-ripening and retain seed viability (Dekker 2003a).Conversely, accelerated after-ripening occurs whenseeds are exposed to temperatures greater than 508Cfor up to 14 d increasing percentage germination incomparison to a control at lower temperatures (Fauseyand Renner 1997; Dekker 2003a). Taylorson and Brown(1977) found that dormancy was best overcome by after-ripening seeds in the light at constant temperatures of40, 50, and 608C for between 3 and 14 d. Leon et al.(2004) found that seed germination was increased bycombinations of alternating temperatures of 8, 14, 20,

26, and 32oC (producing 25 different alternations) witha 16-h photoperiod in comparison to each at a constanttemperatures for 24 h (40 vs. 70%, respectively).

Germination of S. faberi seeds occurs over a widerange of temperatures. Optimal germination was at248C for seeds collected in Iowa (Leon and Owen2003). At constant temperatures, higher percentagegermination was obtained at 208C (77%) than at 308C(61%) (Fausey and Renner 1997). Seed germination of81% was obtained at an alternating temperature of 14/288C for 9 h day/15 h night, which simulated June andJuly temperatures and photoperiods in Michigan (Fau-sey and Renner 1997). King (1952) found the highestgermination with pre-treatments at alternating tempera-tures of 21/378C for 8 h day/16 h night (48%) asopposed to 21/308C (20%) or constant temperatures(10%) of 21, 30 or 378C. Setaria faberi seeds collected inIowa germinated best at temperatures between 20 and248C, reaching a plateau at 288C. Temperatures above308C reduced the germinability of seeds (Leon andOwen 2003). A similar study in Iowa showed that theminimum and optimal temperatures for germinationwere 14 and 248C, respectively (Leon et al. 2004). In thesame study, increased amplitude of the diurnal tempera-ture alternation increased germination to over 50% atmean temperatures between 20 and 258C. Germinationat 10, 15 and 208C was 20, 77 and 72%, respectively.Moist stratification was not effective in breakingdormancy of seeds collected in a different Iowa study,but the viability of non-germinating seeds was low.Germination started when soil temperatures were at 10to 158C and peaked when soil temperatures reached208C. Natural seed banks required about 100 GDD(base 108C) to reach 50% emergence (Leon and Owen2004). Pre-chilling seeds at 58C for 1 mo followed by thepiercing of the seed coat was effective in relievingdormancy of seeds collected in Missouri (Stanway1971). Moreover, dormancy was reduced by dry storageat room temperature for 1 yr. In monoculture field potexperiments in Michigan, seedling emergence was 22% 7d after planting (DAP) at May temperatures of 7/208C;and 33% 21 DAP. Overall, S. faberi had highergermination at lower versus higher temperatures (Fau-sey and Renner 1997).

Dormancy in S. faberi may be partially regulated byphytochrome. In Iowa, light quality did not affect seedgermination; however, far-red light reduced germinationin pre-chilled seeds (Leon and Owen 2003). Largechanges in far-red light levels were found to only addsmall increments of germination to an already smallpopulation of dark germinating seeds (Taylorson 1972).Taylorson (1982) showed that 0.1 M ethanol and otherchemicals such as methanol, and 1-propanol preventedsecondary dormancy induction in S. faberi. Germinationwas initially insensitive to light, but a response to redirradiation was triggered by the addition of 0.5 Methanol. Furthermore, the ethanol allowed germinationto occur after a treatment had been previously applied to


induce secondary dormancy (Taylorson 1982). Gallagherand Cardina (1998) observed that field emergence ofS. faberi was increased by 30% when tillage operationswere performed during the day rather than at night.

Maternal environment may influence dormancy levelsof seeds prior to dispersal from the maternal plant.Studies in Iowa showed that seeds of S. faberi producedby a greenhouse population were more dormant thanseeds collected from a field population. This waspossibly the result of development and maturation ofseeds at higher temperatures (Kegode and Pearce 1998).In the same study, moist stratification increased overallseed germination and reduced differences in percentagegermination between field and greenhouse producedseed lots. These authors suggest that genetic controlsmay also be regulating seed dormancy in S. faberibecause when germination was tested for seeds fromdifferent populations in a common environment, therespective populations retained differences in germina-tion (Kegode and Pearce 1998).

Pickett and Bazzaz (1978) demonstrated that S. faberiseeds would not germinate in waterlogged soil. In fact,S. faberi seeds were very tolerant to moisture stress(Raynal and Bazzaz 1973) and, in some cases, germina-tion of S. faberi seeds increases under moisture-stressedconditions (Taylorson 1986). Seed germination was 55%in water, but increased to �90% after pre-treatment inpolyethylene glycol (PEG) 8000 at �0.3 MPa or less(Taylorson 1986). Continuous exposure to water poten-tials of �0.5 MPa or less inhibited germination, butcaused an increase in germination when seeds were laterexposed to water (up to 96% vs. 52% in control).Leakage of electrolytes over the first 15 min of imbibi-tion was reduced by PEG due to its direct effect onwater uptake (Taylorson 1986). Additionally, seedgermination was found to be positively affected byincreasing O2 levels above 20%, although germinationwas not affected when O2 levels were lowered from 20 to10% (Dekker and Hargrove 2002). Carbon monoxide(CO) stimulated germination when seeds were exposedto low levels of the gas (Dekker and Hargrove 2002).Carbon dioxide (CO2) increased the rate of germinationwhen applied exogenously at a concentration of 20mmol mol�1; CO2 also accelerated the entry of seedsinto secondary dormancy when environmental condi-tions suitable for germination were not present(Yoshioka et al. 1995).

Soil nutrient levels may also influence S. faberi seedgermination. Under nutrient levels of 0.03 g N, 0.06 gP, and 0.03 g K, the rate of germination of Setariaseeds was reduced in comparison to seeds sown in soilsthat only had 1/4 or 1/8 the level of nutrients (Parrishand Bazzaz 1985). The emergence of S. faberi seedlingswas stimulated when at least 249 g m�2 hairy vetch(Vicia villosa Roth) residues were placed on the soilsurface, presumably due to an increase in availablenitrogen provided by the vetch (Teasdale et al. 2005).This effect was enhanced when reduced rates of the

herbicide s-metolachlor were also incorporated into thesoil.

(d) Vegetative Reproduction* Setaria faberi reproducesonly by seed, although tillering readily occurs. Tilleringin S. faberi is known to be strongly influenced byphotoperiod and competition (Dekker 2003). For ex-ample, under long photoperiods and reduced competi-tion S. faberi may produce several primary, secondaryand tertiary tillers, all with the ability to set seed. Undershorter photoperiods, there may be no tillering at all(Dekker 2003). Tillers may also root when in closeproximity to moist soil (Santleman et al. 1963).

9. HybridsAn extremely rare allo(tetra)polyploidization event mayhave caused a fertile hybridization product in southernChinawhere an ancient cross ofSetaria viridis (L.) Beauv.with S. adhaerans (Forssk.) Chiov., led to the formationof the tetraploid species, S. faberi (Li et al. 1942).Benabdelmouna et al. (2001b) using genomic in situhybridization showed that in S. faberi, one set of18 chromosomes shared the genetic makeup of S. viridis,and the second set of 18 chromosomes with S. adhaerans.

Seedswere producedwhenS. viridis (n�9) andS. faberi(n�18; tetraploid) were cross pollinated (Willweber-Kishimoto 1962). Li et al. (1942) and Pohl (1962) reportedproducing the artificial hybrids S. faberi�S. italica (L.)P. Beauv. as well as (S. viridis�S. italica)�S. faberi,but the crosses were sterile.

10. Population DynamicsSetaria faberi is very sensitive to shade and plant heightis reduced by more than 50% when plants are heavilyshaded (Peters et al. 1963). This annual grass is mostcommonly classed as a dominant early successionalspecies (Parrish and Bazzaz 1982). Being a drought-tolerant species with a high photosynthetic rate con-tributes to the competitiveness of S. faberi in earlysuccessional communities (Perozzi and Bazzaz 1978).Setaria faberi was the most dominant and most

competitive species in early successional communitiestested in Illinois and densities of this species were alwayshighest, except when Aster pilosus was present in thesystem (Perozzi and Bazzaz 1978). Of the 45 speciesfound in an old-field system in Ohio, S. faberi wasdominant, even after the application of amitrole plusammonium thiocynate (Wakefield and Barrett 1979).Endress et al. (1999) suggest that S. faberi is better suitedfor interspecific competition than intraspecific competi-tion due to giant foxtail’s ability to outcompete otherspecies under increasing atmospheric ozone concentra-tions and decreasing water availability. In a greenhouseexperiment where S. faberi was grown at different ratiosin mixture with the perennial grasses Andropogongerardii Vitman, and Sorghastrum nutans (L.) Nash;S. faberi always outcompeted these two species.


In an old-field community in New Jersey, S. faberialways out-competed other grasses such as Panicumdichotomiflorum (Facelli and Pickett 1991b). However,when growing in stands with common dicotyledonousannuals such as Abutilon theophrasti, Ambrosia artemi-siifolia, and Amaranthus retroflexus, S. faberi was theleast competitive species (Bazzaz and Garbutt 1988).The population density of S. faberi was reduced from100 plants m�2 to 10 plants m�2 by heavy leaf litterfrom Quercus spp. Facelli and Pickett (1991b) specu-lated that this effect was regulated primarily by intras-pecific competitive interactions among S. faberiindividuals. The net primary production (NPP) con-tribution of S. faberi was estimated to be B5% of thetotal NPP in an old-field successional system in Ohio(Sedlacek et al. 1988).

Densities of S. faberi range from 98 to 1040 plantsm�2 in corn fields throughout the Northeastern UnitedStates (Myers et al. 2005). In a soybean field inWisconsin comprised of 27 different weed species, S.faberi accounted for 62�75% of the weed density (147 to452 plants m�2) (Mulugeta and Boerboom 2000). Insoybean fields in Wisconsin, S. faberi was more compe-titive than Chenopodium album, and a S. faberi popula-tion density of 64 plants m�2 resulted in more than an86% soybean yield loss. In this same study, the criticalperiod of S. faberi competition in soybeans was deter-mined to be up to the V2 leaf stage of the crop (Conleyet al. 2003b). In a similar study, Conley et al. (2003a)demonstrated that S. faberi could cause up to 75% yieldloss in soybeans if allowed to germinate prior to the V2stage of the crop. Weed shoot biomasses of 2000 and3500 kg ha�1 reduced soybean yield by 21 and 32%,respectively. When S. faberi emerged in the field at theV3 or later stage of soybeans there was no yield loss. Atlow densities (B16 plants m�2), soybean yield wasreduced by only 5.1%; however, S. faberi produced upto 28 000 seeds per plant (Conley et al. 2003a).

The relative fitness of acetyl-coenzyme A carboxylase(ACCase)-resistant S. faberi individuals was not reducedrelative to ACCase-susceptible individuals when sub-jected to inter- and intra-specific competitive environ-ments (Wiederholt and Stoltenberg 1996).

11. Response to Herbicides and Other ChemicalsThe increased occurrence of S. faberi in corn andsoybean fields has provided valuable information withregards to herbicide efficacy and resistance. This reviewis by no means exhaustive, but does provide a summaryof major herbicides efficacies and known resistance. Itshould also be noted that in the scientific literature,there are sometimes no clear distinctions made betweenthe various Setaria spp. in relation to chemical controlefficacy (Steel et al. 1983).

Flufenacet was applied to conventionally grown cornand soybeans in Ontario and Quebec. When appliedalone pre-emergence (PRE) at a rate of 570 g a.i. ha�1,flufenacet provided 95.7% control of S. faberi. When

flufenacet was tank-mixed with atrazine, dicamba, ordicamba/atrazine there was no improvement in percen-tage control. However, tank mixtures with metribuzin orlinuron did improve percentage control to 98% (PMRA2000).

A model developed by Bussan and Boerboom (2001)for control of S. faberi in a corn/soybean rotationshowed that over the long term S. faberi populationscould be managed more economically when herbiciderates are reduced unless the initial seedbank populationswere high. Broadcast applications of alachlor (3.3 kg a.i.ha�1) plus glyphosate (0.4 kg a.e. ha�1) and bromox-ynil (0.4 kg a.i. ha�1) provided 100% control of S.faberi populations in conventionally grown corn inMinnesota (Buhler 1998). Mesotrione (240 g a.i. ha�1)applied alone (PRE or POST) provided less than 33%control of S. faberi in conventional corn grown inVirginia (Armel et al. 2003b, c). Percentage control wasincreased to greater than 84% when mesotrione (240 ga.i. ha�1) was tank-mixed with acetochlor (1800 g a.i.ha�1), or imazethapyr (70 g a.i. ha�1). When applied toglyphosate-resistant corn, a tank mixture of mesotrione(70, 105, or 140 g a.i. ha�1) plus glyphosate (560 g a.i.ha�1) provided up to 75% control compared with B25% with using mesotrione (70, 105, and 140 g a.i.ha�1) alone (Armel et al. 2003d). All PRE and mid-POST applications of glyphosate (1100 g a.i. ha�1),acetochlor (2000 g a.i. ha�1), atrazine (1100 g a.i. ha�1),metolachlor (2200 g a.i. ha�1), dimethenamid (1500 ga.i. ha�1) alone and in tank-mix combinations providedgreater than 95% control of S. faberi in Kentucky(Ferrell and Witt 2002). At least 90% control wasobtained for plants 23 to 30 cm in height whensequential (2 or more) applications of glyphosate (800g a.i. ha�1) were applied to glyphosate-resistant corn inOhio (Gower et al. 2002). In glufosinate-resistant cornin Missouri, control levels of 90% were obtained whenacetochlor (1120 g a.i. ha�1) PRE followed by atrazine(1120 g a.i. ha�1) plus glufosinate (290 g a.i. ha�1)POST was applied. Glufosinate alone provided less than80% control (Bradley et al. 2000). Trifluralin (1.12 to1.40 kg a.i. ha�1) applied PRE in a conservation tillage(fall chisel plowed) rotation of corn and wheat inIndiana and Kansas provided greater than 90% controlof S. faberi (Regan 1995). Applications of halosulfuron-methyl (36 g a.i. ha�1), nicosulfuron (18 g a.i. ha�1), ordicamba (280 g a.i. ha�1) all provided at least 89%control in Delaware (Isaacs et al. 2002). Sethoxydim(213 g a.i. ha�1) alone provided 96% control and tankmixtures of sethoxydim (213 g a.i. ha�1) plus bentazon(1120 g a.i. ha�1), dicamba (280 g a.i. ha�1), dicamba(280 g a.i. ha�1) plus atrazine (588 g a.i. ha�1), andsethoxydim (213 g a.i. ha�1) plus bentazon (1120 g a.i.ha�1) plus atrazine (1166 g a.i. ha�1) reduced the levelsof control to between 60 and 89% in sethoxydim-resistant corn in Delaware (Isaacs et al. 2003).

In no-till corn in Illinois, herbicides applied PREprovided more consistent control (90 to 98%) than the


same herbicides applied early pre-plant (0 to 92%)(Krausz et al. 2000). Ninety-five percent control wasobtained after an application of metolachlor (3400 g a.i.ha�1) and flufenacet (920 g a.i. ha�1) plus metribuzin(230 g a.i. ha�1) and 87% control was obtained withacetochlor (2700 g a.i. ha�1) or dimethenamid (1600 ga.i. ha�1) in Illinois (Bunting et al. 2003). A burndownapplication of glyphosate (630 g a.e. ha�1) plus a fulllabel rate of the residual herbicides acetochlor (2240 ga.i. ha�1) and atrazine (2240 g a.i. ha�1) applied earlypreplant provided less than 80% control in Missouri(Hellwig et al. 2003). An imazethapyr (470 g a.i. ha�1)application provided better residual control (�96%control) (Hellwig et al. 2003). Percentage control 110 dafter no-till corn planting was only 73% after an earlypreplant treatment of atrazine (2.2 kg a.i. ha�1)compared with 99% control when the same amount ofherbicide was evenly divided between early preplant andpreemergence applications in Wisconsin (Buhler 1991).In Virginia, PRE or POST applications of mesotrione(70, 105, and 140 g a.i. ha�1) did not adequately controlS. faberi (Armel et al. 2003a; Armel et al. 2003b). Thebest season long control of S. faberi in Pennsylvania waswith metolachlor (2.2 kg a.i. ha�1), microencapsulatedalachlor (2.8 kg a.i. ha�1), or EPTC (4.5 kg a.i. ha�1)(Ritter et al. 1989).

In glyphosate-tolerant soybeans in Wisconsin, gly-phosate applied at rates as low as 210 g a.i. ha�1 to S.faberi plants up to 28 cm in height resulted in �90%control (Ateh and Harvey 1999). Glyphosate (420, 630,and 840 g a.i. ha�1) applied at the V2, V4, and R1stages of glyphosate-tolerant soybean gave excellentcontrol of S. faberi in both 18 cm and 76 cm rowsoybean (Mulugeta and Boerboom 2000). When gly-phosate was preceded by a residual herbicide in no-tillglyphosate-tolerant soybeans, populations of S. faberiwere reduced by 90% in Wisconsin (Corrigan andHarvey 2000). In glufosinate-tolerant soybeans in Mis-souri, glufosinate applied at 290 and 400 g a.i. ha�1

provided greater than 85% S. faberi control. However,two applications of glufosinate (290 g a.i. ha�1 followedby 290 g a.i. ha�1) during the cropping season providedfollowed by 90% control (Beyers et al. 2002). A 28-g a.i.ha�1 rate of quizalofop with 1.5% petroleum oilconcentrate (POC) resulted in up to 99% control of S.faberi, while a 56 g a.i. ha�1 rate of sethoxydim with1.5% POC resulted in up to 79% control in soybeanfields in Illinois (Beckett et al. 1992).

A PRE application of (metolachlor at 2220 g a.i.ha�1�metribuzin at 314 g a.i. ha�1�chlorimuron at54 g a.i. ha�1) and POST application of (quizalofop at62 g a.i. ha�1�thifensulfuron at 4 g a.i. ha�1�chlorimuron at 4 g a.i. ha�1) resulted in 95% controlof S. faberi in no-till soybeans in Illinois (Bradley et al.2001). Imazethapyr (55 g a.i. ha�1) applied early pre-plant reduced S. faberi population by 90% in no-tillsoybean in Wisconsin (Buhler and Proost 1992). Gly-phosate (840 g a.i. ha�1) early preplant followed by

glyphosate (840 g a.i. ha�1) POST resulted in 80 to100% control of S. faberi in no-till narrow-row glypho-sate-tolerant soybean in Missouri (Dirks et al. 2000a). Ifglyphosate was applied at planting at a rate of 430 g a.i.ha�1�sulfentrazone (220 g a.i. ha�1), S. faberi popula-tions were reduced more than if glyphosate was appliedalone at a rate of 430 g a.i. ha�1 in no-till narrow-rowglyphosate-tolerant soybeans in Missouri (Dirks et al.2000b). Flumioxazin applied at a rate of 70 g a.i. ha�1

in no-till soybeans in Missouri resulted in variablecontrol of S. faberi ranging from 18 to 81% control(Niekamp and Johnson 2001). In the same study,percentage control was also variable and ranged from65 to 93% if sulfentrazone was applied at a rate of 280 ga.i. ha�1. The addition of clomazone (840 g a.i. ha�1)alone, clomazone (840 g a.i. ha�1)�chlorimuron (60 ga.i. ha�1), or pendimethalin (1350 g a.i. ha�1)�chlorimuron (60 g a.i. ha�1) into a tank-mix with eitherherbicide provided substantially more effective S. fabericontrol.

When metolachlor (2240 g a.i. ha�1) was applied withmetribuzin (425 g a.i. ha�1)�clomazone (280 g a.i.ha�1) PRE, flumiclorac (45 g a.i. ha�1) POST, ormetribuzin (425 g a.i. ha�1) PRE and flumiclorac (45 ga.i. ha�1) POST, S. faberi populations were reduced byat least 85% in soybean fields in Michigan (Fausey andRenner 2001). In Illinois, the addition of lactofen (146 ga.i. ha�1) to a tank-mix with imazethapyr (67 g a.i.ha�1) decreased S. faberi control in a soybean croprelative to an application of imazethapyr alone (Hart etal. 1997). In the same study, S. faberi control withsethoxydim (213 g a.i. ha�1) and fluazifop (190 g a.i.ha�1)�fenoxaprop (45 g a.i. ha�1) was equal to controlprovided by application of imazethapyr alone. Theapplication of sulfentrazone at a rate of 280 g a.i.ha�1 resulted in 97 to 100% control of S. faberi insoybean in Illinois (Krausz and Young 2003).Setaria faberi is also an important economic weed in

several other crops. In a Virginia potato crop, rimsul-furon at a rate of 35 g a.i. ha�1 PRE or POSTcontrolled 90% of S. faberi (Ackley et al. 1996).Oxyfluorfen at rates of 280, 414, 560, and 1120 g a.i.ha�1 resulted in 71, 85, 90, and 100% control of S.faberi, respectively, in comparison to a cultivatedcontrol in transplanted broccoli in Tennessee (Eaton etal. 1990). Isoxaben (840 g a.i. ha�1) provided less than70% control of S. faberi 12 wk after treatment (WAT)and pronamide (2200 g a.i. ha�1) did not providecontrol of S. faberi in landscape crops in Kentucky(Setyowati et al. 1995). In the same study, oxyfluorfen(1100 g a.i. ha�1) and dithiopyr (2200 g a.i. ha�1)provided adequate control. In Tennessee snap beanfields, sethoxydim (280 g a.i. ha�1) provided 96�100%control of S. faberi (Mullins et al. 1993).

When S. faberi was grown in a greenhouse or a cornfield, foramsulfuron alone (37 g a.i. ha�1), or foram-sulfuron (37 g a.i. ha�1)�a methylated seed oil (MSO)provided higher control of S. faberi in comparison with


when a crop oil concentrate (COC) was added instead ofthe MSO (Bunting et al. 2004a, b, 2005). Whenglufosinate (291 and 409 g a.i. ha�1), glyphosate(1120 g a.i. ha�1) or sulfosate (1120 g a.i. ha�1) wereapplied in fallow field areas, S. faberi populations werereduced by at least 90% in North Carolina (Corbett etal. 2004). Antagonism occurred when a tank-mix ofimazethapyr and glyphosate at a rate of 210 g a.i. ha�1

was applied on S. faberi grown in monoculture (Li et al.2002). Corn gluten meal applied at a rate of 490 g m�2

reduced weed cover in greenhouse-grown strawberryplots in Iowa from 80% (of which S. faberi wasincluded) to as low as 8% of a control. The efficacy ofcorn gluten meal to control S. faberi was not reported(Nonnecke and Christians 1993). Diclofop applied at560 g a.i. ha�1, 840 g a.i. ha�1, and 1120 g a.i. ha�1

controlled 75, 25.4, and 16.4% S. faberi, respectively, incucumber, soybean, sorghum and wheat (Schreiber et al.1979). Thiazopyr, a pre-emergence grass herbicide,inhibited the growth of S. faberi in a greenhouse studyby 50% when the herbicide was sprayed at a rate of 4 ga.i. ha�1. The addition of piperonyl butoxide (PBO)increased the efficacy of thiazopyr by a factor of 1.5(Rao et al. 1995). Alachlor (2.24 kg a.i. ha�1), atrazine(2.24 kg a.i. ha�1), butylate (3.36 kg a.i. ha�1), andcyanazine (2.24 kg a.i. ha�1) all provided acceptablecontrol (�95%) of S. faberi in Wisconsin (Harvey 1974)and haloxyfop-methyl gave better than 95% control atrates of 101 g a.i. ha�1 and 134 g a.i. ha�1 and showedno antagonism when tank mixed with broadleaf herbi-cides in several northern, and mid-western states (Han-son and Velovitch 1986).

When S. faberi was planted in non-crop stands theherbicides simazine (1.1 kg a.i. ha�1), atrazine (1.1 kga.i. ha�1), and propazine (1.1 kg a.i. ha�1) all yieldedbetter than 90% control (Oliver and Schreiber 1971). Inthe same study, the herbicide butylate only provided79% control at a 1.1 kg a.i. ha�1 rate and 94% controlat a 3.4 kg a.i. ha�1 rate. Normally about 30% ofatrazine applied penetrates into the leaves and ismetabolized (McCall 1989).

The control of S. faberi was antagonized whenlactofen (70 g a.i. ha�1) was tank-mixed with eitherimazamox (35 g a.i. ha�1) or imazethapyr (70 g a.i.ha�1), and when imazethapyr (70 g a.i. ha�1) was tank-mixed with clethodim (140 g a.i. ha�1) in soybeansgrown in Michigan (Nelson et al. 1998). In the samestudy, S. faberi control with imazamox (35 g a.i. ha�1)or imazethapyr (70 g a.i. ha�1) plus a non-ionicsurfactant (0.25% vol/vol) was improved when 28%urea ammonium nitrate (2.6% vol/vol) was added intothe tank mixture.

The sesquiterpene lactone, artemisinin that is pro-duced by the leaf tissue of Artemisia annua L. has beenshown to inhibit seed germination and seedling growthof S. faberi when applied at a concentration of 200 mgper 9-cm-diameter Petri dish (Chen and Leather 1990).The short chain fatty acid, caprylic acid has also been

shown to have phytotoxic effects on S. faberi (Colemanand Penner 2006). Pyridazocidin, a microbial phyto-toxin, showed rapid (within 1 to 2 d) chlorosis andnecrosis of S. faberi leaf tissue at a rate of 1400 g a.i.ha�1 (Gerwick et al. 1997). Ferulic acid, catechol,salicylic acid and caffeic acid all showed some allelo-pathic potential in preventing the germination of S.faberi seeds; however, in field situations adsorption tosoil particles may reduce their activity (Vidal et al.1998). Water-soluble substances found in alfalfa inhib-ited seed germination, but stimulated plant height, leafarea, and dry weight of S. faberi plants (Chung andMiller 1995).

In Saskatoon, a potential bioherbicide, Pyriculariasetariae Niskada was tested and found to have lowpathogenicity on S. faberi. When the fungus was pairedwith 0.25� the labelled rate of sethoxydim (label rate�200 g a.i. ha�1) there was a 10-fold increase in thepathogenic infection of S. faberi, and a 100% increase inweed control in comparison to the pathogen alone (Pengand Byer 2004).

Herbicide ResistanceSetaria faberi resistance has been reported in Ontario[ALS inhibitors (B/2)], Spain [Photosystem II inhibitors(C1/5)], Iowa [Photosystem II inhibitors (C1/5) andACCase inhibitors (A/1)], Maryland [(Photosystem IIinhibitors (C1/5)], Wisconsin [ACCase inhibitors (A/1)and (ALS inhibitors (B/2))], and Minnesota [ALSinhibitors (B/2)] (Heap 2007).

Triazine resistance in S. faberi was also identified inPennsylvania (Ritter et al. 1989) and Iowa (Thornhilland Dekker 1993). A resistant biotype tolerated atrazineat a rate of 9.0 kg a.i. ha�1, while a susceptible biotypewas injured by a rate of 2.2 kg a.i. ha�1 (Ritter et al.1989). The inadequate control of S. faberi by atrazineand other selective herbicides may be due to detoxifica-tion by glutathione-S-transferases (GSTs) (Hatton et al.1995). These GSTs may detoxify atrazine, metolachlor,alachlor, and fluorodifen. Atrazine may only be phyto-toxic to young S. faberi plants (B35 d old). Up to 80%of S. faberi plants were affected by atrazine application(400 g a.i. ha�1) at ages below 35 d old. Glutathione(GSH) content was higher (700 nmols g�1 FW) inyounger tissue than in older tissue (300 nmols g�1 FW).The GST activities of the whole plant remain un-changed. Setaria faberi may detoxify atrazine throughGSH conjugation (Hatton et al. 1996). The levels ofGST in S. faberi foliage are 20-fold lower than levelsfound in corn foliage. Low levels of GST may increasethe effectiveness of chemicals such as atrazine whenapplied at the seedling stage (Hatton et al. 1999). Twomechanisms of atrazine resistance were identified inS. faberi growing in corn fields in Spain (De Prado et al.2000). The resistant biotype of S. faberi was 10 timesmore resistant to atrazine than the susceptible biotype.Furthermore, the resistant biotype metabolized the


atrazine into the conjugate-atrazine faster than thesusceptible biotype. The authors concluded thatS. faberi may have two resistance mechanisms (1) amutation in the D1 protein leading to a lower affinityfor atrazine and (2) an enhanced detoxification ofatrazine to conjugate-atrazine.

In Wisconsin, S. faberi was shown to have resistanceto sethoxydim, an acetyl-coA carboxylase-inhibitor,after repeated applications. A bioassay of 10 mg L�1

sethoxydim easily discriminated between susceptible andresistant biotypes after a 6-d exposure (Retrum andForcella 2002). High-level resistance to sethoxydim in S.faberi may be due to an alteration in the target enzyme(ACCase) (Shukla et al. 1997). In the same study, theresistant biotype was also less sensitive to clethodim,fenoxaprop, and quizalofop. Resistance to fluazifop-Pand sethoxydim in a carrot, onion, and corn rotationwas reported in Wisconsin in 1991. When sprayed at thelabelled rates, fluazifop-P provided 42% control andsethoxydim provided 47% control of S. faberi. Whenthe same population was sprayed with imazethapyr,nicosulfuron or clethodim few to no plants survived(Stoltenberg and Wiederholt 1995). In a similar study, S.faberi cross resistance to fluazifop-P-butyl was identifiedin a vegetable cropping system in Wisconsin where theresistant biotype was 10.6- and 319- fold more resistantthan the susceptible biotype (Volenberg and Stoltenberg2002a). Greenhouse experiments have shown that theoutcrossing rates between ACCase susceptible andACCase resistant parent plants are low and rangefrom 0.24 to 0.73% (Volenberg and Stoltenberg 2002b).

12. Response to Other Human ManipulationsWhen mowed close to the soil surface two or moretimes, populations of S. faberi were eliminated orsuppressed in Missouri soybean and corn fields (Donald2000a, b, 2006; Donald et al. 2001). Shading by the cropcanopy also reduced weed growth in these studies. In theabsence of shade, S. faberi re-grew from tillers and wasstill able to set seed. Mowing of S. faberi in late August,during its reproductive phase reduced populations tosuch an extent that it was replaced by Digitaria ciliaris(Retz.) Koeler as the most dominant species in a whiteclover field in Osaka, Japan (Asai et al. 1995).

The addition of sludge (6-2-0, N-P-K) or fertilizer (34-11-0, N-P-K) to old-field plant communities whereS. faberi was present caused the populations to increasein number and biomass, especially when moisture was alimiting factor (Bollinger et al. 1991).

13. Response to Herbivory, Disease and HigherPlant Parasites

(a) Herbivory(i) Mammals * In Minnesota, goats were given thechoice of 12 weed species versus alfalfa or oats forconsumption and S. faberi was deemed unpalatable(Marten and Andersen 1975). Cattle and several small

mammals consume seeds of S. faberi (McCormick andKay 1968).

Harvest mouse [Reithrodontomys megalotis (Baird)]populations in Indiana were higher in grassy areas (thatincluded S. faberi) compared with areas that weredominated by dicot species (Ford 1977). Studies byBirkenholz (1967) and Pinkham and Mead (1970)suggested that the optimal habitat of the harvest mousewas in dense stands of Setaria spp.; however, Ford(1977) showed no direct correlation between Setaria spp.and harvest mouse population and that Setaria seedswere not used as a food source. The most importantfood source for the house mouse (Mus musculus L.) inIndiana was a mixture of Setaria seeds (Whitaker 1966).In the same study, the authors studied foraging habits ofthe prairie deer mouse (Peromyscus maniculatus bairdi-Wagner), which occupies the same habitat of the housemouse; however, Setaria seeds did not make up animportant component of the diet of the prairie deermouse.

Spencer and Barrett (1980) found that owing to lowprotein content, S. faberi seeds failed to sustain bodyweight in meadow voles [Microtus pennsylvanicus (Ord.)]that were force-fed the seeds. In a study focusing on thefeeding preferences of the prairie vole (Microtus ochro-gasterWagner), S. faberi seed were preferentially chosenby the voles even though this foxtail species was notcommon in the study area (Pascarella and Gaines 1991).This finding was supported by Zimmerman (1965), whoshowed that prairie vole populations in Indiana prefer-entially chose S. faberi seeds as a food source eventhough the seeds only accounted for 1.4% of their diet.Haken and Batzli (1996) found that S. faberi seeds werethe lowest ranking food choice for the prairie vole, whilethe S. faberi seeds were not chosen at all by the meadowvole in Illinois.

(ii) Birds * McCormick and Kay (1968) reported thatbirds consumed seeds of S. faberi and Sylwester (1970)reported that geese consumed foliage of Setaria species.In Illinois, Kendeigh and West (1965) listed S. faberiseeds as a food source for the tree sparrow (SpizellaarboreaWilson). West (1967) further documented that amixture of S. faberi and S. viridis seeds made up 70% ofthe tree sparrow’s diet even though grass seeds onlyrepresented 39% of the total seeds available to the birds.Also in Illinois, cardinals (Richmondena cardinalis L.)and song sparrows (Melospiza melodia Wilson) wereboth shown to prefer S. faberi seeds as a food source,especially during the spring and summer when outdoorabient temperatures were approximately 258C (Willsonand Harmeson 1973).

Although S. faberi seeds accounted for up to 12% ofthe total seeds available in feeding areas for Bobwhitequails (Colinus virginianus L.) in southern Illinois, onlyseeds of S. pumila were found in the crops of capturedquail (Bookhout 1958). This was supported by findingsin Eastern Kansas where S. pumila and S. viridis, but not


S. faberi were found in the crops and stomachs ofbobwhite quail (Jennings 1941).(iii) Insects * Menalled et al. (2000) documented up to12% removal of S. faberi seeds in Michigan as a result ofnon-selective post-dispersal seed predation by birds andground beetles. In Iowa, invertebrate seed predators[mainly Gryllus pennsylvanicus Burmiester (Orthoptera:-Gryllidae)] removed 30 to 90% of seeds in corn andsoybean crops between the months of July and Septem-ber (O’Rourke et al. 2006). Westerman et al. (2006)found that up to 67 and 80% of seeds were removed bypost-dispersal soil predators when S. faberi grew in acorn or soybean field, respectively. Setaria faberi washighly preferred as an oviposition host and food sourcefor the moths Hydraecia immanis Guenee (Lepidoptera:Noctuidae) and Papaipema nebris Guenee (Lepidoptera:Noctuidae) in Illinois (Levine 1985, 1986) and as a hostfor P. nebris in Wisconsin (Alvarado et al. 1989).

In greenhouse studies, the western corn rootworm[Diabrotica virgifera virgifera LeConte (Coleoptera:Chrysomelidae)] had good survivorship on S. faberiand may have chosen this grass as an alternate host tocorn (Chege et al. 2005; Oyediran et al. 2005). Clark andHibbard (2004) tested 28 species of grasses for non-cornhost suitability for western corn rootworm and S. faberiranked 13th out of the 28 species, but was shown to be aless suitable host than S. viridis. In corn fields, S. faberimay also be a suitable host for the northern cornRootworm [Diabrotica barberi Smith & Lawrence (Co-leptera: Chrysomelidae)] (Oyediran et al. 2004).

Potato leafhopper [Empoasca fabae (Harris) (Homo-ptera: Cicadellidae)] nymphs did not survive on S. faberiin Illinois (Lamp et al. 1984). Similarily, the Hessian fly[Mayetiola destructor Say (Diptera: Cecidomyiidae)] wasunable to reproduce when S. faberi was presented as apossible host (Zeiss et al. 1993).

(iv) Nematodes and/or Other Non-vertebrates * Wongand Tylka (1994) showed that S. faberi was not a hostfor the soybean cyst nematode (Heterodera glycinesIchinohe) in Iowa.

(b) Diseases(i) Fungi * Farr et al. (undated) give referencesreporting Bipolaris setariae (Sawada) Shoemaker [�Cochliobolus setariae (S. Ito & Kurib.) Dastur], Colleto-trichum graminicola (Ces.) G.W. Wilson (� Glomerellagraminicola D.J. Politis), Curvularia lunata (Wakker)Boedijn (� Cochliobolus lunatus R.R. Nelson & Haa-sis), Fusarium equiseti (Corda) Sacc. (� Gibberellaintricans Wollenw.), Nigrospora oryzae (Berk. &Broome) Petch (� Khuskia oryzae H.J. Huds.), Nigros-pora sphaerica (Sacc.) E.W. Mason (� K. oryzae),Phaeosphaeria luctuosa (Sacc.) Otani & Mikawa, Phomasorghina (Sacc.) Boerema, Dorenb. & Kesteren (�Leptosphaeria sacchari Breda de Haan), Pyriculariagrisea Sacc. [� Magnaporthe grisea (T.T. Hebert)

M.E. Barr], and Tilletia zundelii Hirschh. on S. faberiin the United States, as well as Ustilaginoidea virens(Cooke) Takah., Ustilago crameri Korn. and Ustilagoneglecta Niessl [� Macalpinomyces neglectus (Niessl)Vanky] in China.

In Iowa, seed-borne fungi were studied in S. faberiand S. viridis from fields in corn-soybean rotation byPitty et al. (1987). Fungal colonization of seeds wasinvestigated under conventional tillage and reducedtillage systems when harvested by hand from theinflorescences compared with seeds recovered fromvarious soil depths. Extent of colonization under alltreatments was greater in S. faberi than S. viridis,although it was not determined whether this wasattributable to differential susceptibility or correlationwith seed size. More than nine species of fungi wereisolated from colonized seeds (22%) on the inflores-cences, the most common of which were Cochlioboluscarbonum R.R. Nelson, Epicoccum nigrum Link (� E.purpurascens Ehrenb.) and Fusarium arthrosporioidesSherb. More than 16 species of fungi were isolatedfrom buried seeds, the most common of which wereAlternaria alternata (Fr.) Keissl., E. nigrum and severalunidentified sterile strains. At shallow soil depths (0�7.5cm) S. faberi seeds showed greater colonization in thereduced tillage system (60% vs. 32%), while in theconventional tillage system colonization increased withsoil depth (63% at 7.5�15 cm, 70.8% at 15�22.5 cm).The authors speculated that these colonization patternsare related to different moisture and organic matterprofiles in the two systems. An Endogone spp. found inIndiana cultivated fields was found to colonize on and inthe seeds of several plant species; however, the funguswas not found on any S. faberi seeds that were examined(Houtcooper 1972). Davis and Renner (2007) documen-ted that fatal germination caused by soil-borne patho-genic fungi was non-existent for S. faberi seedsin Michigan soil that was inoculated with Pythiumultimum.

Cropping system was shown to influence S. faberiseed mortality due to fungal community changes (Daviset al. 2006). The authors showed that seed mortality washighest in crop rotations that were conventionallymanaged versus those where a reduced input approachto weed management was adopted.

In Saskatoon, a potential bioherbicide, Pyriculariasetariae Niskada was tested and found to have lowpathogenicity on S. faberi. When the fungus was pairedwith 0.25� the labelled rate of the herbicide sethoxydim(labelled rate�200 g a.i. ha�1) there was a 10-foldincrease in the pathogenic infection of S. faberi, and a100% increase in weed control in comparison to thepathogen alone (Peng and Byer 2004).

(ii) Bacteria *The deleterious rhizobacteria strainsAeromonas hydrophila, Aeromonas caviae, Agrobacter-ium radiobacter, Chromobacterium violaceum, Chryseo-monas luteola, Pseudomonas aureofaciens, Pseudomonas


putida, Pseudomonas fluorescens, and Xanthomonusmaltophilia were isolated from S. faberi roots inMissouri (Li and Kremer 2000, 2006). Li and Kremer(2000) reported that the deleterious effects of theaforementioned isolates were similar for both S. faberiand S. viridis and Li and Kremer (2006) showed that therhizobacteria caused reductions of up to 77.2 and 79.1%for root and shoot mass, respectively.

(iii) Viruses * Brunt et al. (1996) refer to studiesreporting susceptibility of S. faberi to cereal northernmosaic cytorhabdovirus, maize chlorotic dwarf waika-virus, maize streak monogeminivirus and maize whiteline mosaic virus, but not susceptible to cereal northernmosaic cytorhabdovirus. Setaria faberi was reported tobe a suitable host for wheat streak mosaic virus inKansas (Christian and Willis 1993).

(c)Higher Plant Parasites*No information was found.

ACKNOWLEDGEMENTSThe authors thank Lorraine Smith and Lisa Boughnerat AAFC (Harrow) for their help locating articles forthe literature review. Barry Flahey of Agriculture andAgri-Food Canada produced the drawings in Fig. 1and 2. We acknowledge the generous assistance of theherbarium curators who provided loans of specimens forstudy and distribution mapping (see caption toFig. 3).

Abul-Fatih, H. A. and Bazzaz, F. A. 1979. The biology ofAmbrosia trifida L. I. Influence of species removal on theorganization of the plant community. New Phytol. 83: 813�816.Ackley, J. A., Wilson, H. P. and Hines, T. E. 1996. Efficacy ofrimsulfuron and metribuzin in potato (Solanum tuberosum).Weed Technol. 10: 475�480.Agriculture Canada. 1986. Weed Seeds Order. 1986 CanadaGazette Part II. 120(17): 3382�3385.Allard, H. A. 1941. Some plants found in Virginia and WestVirginia. Va. J. Sci. 2: 119.Alvarado, L. J., Hogg, D. B. and Wedberg, J. L. 1989. Effectsof corn and selected weed species on feeding behaviour of thestalk borer, Papaipema nebris (Lepidoptera: Noctuidae). GreatLakes Entomol. 22: 65�69.Anonymous. 2003. Summary information for plants in WF4153/6153. Department of Wildlife and Fisheries, College ofForest Resources, Mississippi State University, Starkville, MS.[Online] Available: http://www.cfr.msstate.edu/courses/wf4153/planttable.htm [2007 Aug. 02].Armel, G. R., Wilson, H. P., Richardson, R. J. and Hines, T. E.2003a. Mesotrione combinations in no-till corn (Zea mays).Weed Technol. 17: 111�116.Armel, G. R., Wilson, H. P., Richardson, R. J. and Hines, T. E.

2003b. Mesotrione, acetochlor, and atrazine for weed manage-ment in corn (Zea mays). Weed Technol. 17: 284�290.Armel, G. R., Wilson, H. P., Richardson, R. J. and Hines, T. E.

2003c. Use of mixtures of mesotrione, imazethapyr, andimazethapyr plus imazapyr in imidazolinone-resistant corn(Zea mays). Weed Technol. 17: 674�679.

Armel, G. R., Wilson, H. P., Richardson, R. J. and Hines, T. E.

2003d. Mesotrione alone and in mixtures with glyphosate inglyphosate-resistant corn (Zea mays). Weed Technol. 17: 680�685.Asai, M., Ito, M. and Kusanagi, T. 1995. Effects of mowingregimes on the growth and vegetation dynamics of establishedwhite clover (Trifolium repens L.) cover for weed suppression.Weed Res. (Japan) 40: 194�202.Ateh, C. M. and Harvey, R. G. 1999. Annual weed control byglyphoste in glyphosate-resistant soybean (Glycine max). WeedTechnol. 13: 394�398.Baskin, C. C. and Baskin, J. M. 1998. Seeds: Ecology,biogeography, and evolution of dormancy and germination.Academic Press, New York, NY. 666 pp.Bazzaz, F. A. and Garbutt, K. 1988. The response of annuals incompetitive neighborhoods: effects of elevated CO2. Ecology69: 937�946.Beckett, T. H., Stoller, E. W. and Bode, L. E. 1992. Quizalofopand sethoxydim activity as affected by adjuvants and ammo-nium fertilizers. Weed Sci. 40: 12�19.Bell, D. T. and Koeppe, D. E. 1972. Non competitive effects ofgiant foxtail on the growth of corn. Agron. J. 64: 321�325.Benabdelmouna, A., Abirached-Darmency, M. and Darmency,

H. 2001a. Phylogenetic and genomic relationships in Setariaitalica and its close relatives based on the molecular diversityand chromosomal organization of 5S and 18S-5.8S rDNAgenes. Theor. Appl. Genet. 103: 668�677.Benabdelmouna, A., Shi, Y., Abirached-Darmency, M. and

Darmency, H. 2001b. Genomic in situ hybridization (GISH)discriminates between the A and the B genomes in diploid andtetraploid Setaria species. Genome 44: 685�690.Beyers, J. T., Smeda, R. J. and Johnson, W. G. 2002. Weedmanagement programs in glufosinate-resistant soybean (Gly-cine max). Weed Technol. 16: 267�273.Bigwood, D. W. and Inouye, D. W. 1988. Spatial patternanalysis of seed banks: an improved method and optimizedsampling. Ecology 69: 497�507.Biniak, B. M. and Aldrich, R. J. 1986. Reducing velvetleaf(Abutilon theophrasti) and giant foxtail (Setaria faberi) seedproduction with simulated roller herbicide application. WeedSci. 34: 256�259.Birkenholz, D. E. 1967. The harvest mouse (Reithrodontomysmegalotis) in central Illinois. Trans Ill. State Acad. Sci. 60:49�53.Bollinger, E. K., Harper, D. J. and Barrett, G. W. 1991. Effectsof seasonal drought on old-field plant communities. Am. Midl.Nat. 125: 114�125.Bookhout, T. A. 1958. The availability of plant seeds toBobwhite Quail in Southern Illinois. Ecology 39: 671�681.Bouchard, C. J. and Neron, R. 1991. Atlas des mauvaisesherbes, Feuillet no M-9. Ministere de l’Agriculture desPecheries et de l’Alimentation, Quebec, QC. Publ. no.06-91-05.Bradley, C. A., Wax, L. M., Ebelhar, S. A., G. A. Bollero and

Pedersen, W. L. 2001. The effect of fungicide seed protectants,seeding rates, and reduced rates of herbicides on no-tillsoybean. Crop Prot. 20: 615�622.Bradley, P. R., Johnson, W. G., Hart, S. E., Buesinger, M. L.

and Massey R. E. 2000. Economics of weed management inglufosinate-resistant corn (Zea mays L.). Weed Technol. 14:495�501.Brown, W. V. and Emery, W. H. P. 1958. Apomixis in theGramineae: Panicoideae. Am. J. Bot. 45: 253�263.


Brunt, A. A., Crabtree, K., Dallwitz, M. J., Gibbs, A. J.,

Watson, L. and Zurcher, E. J. (eds.) 1996 onwards. Plantviruses online: Descriptions and lists from the VIDE database.Version: 20th August 1996. [Online] Available: http://image.f-s.uidaho.edu/vide/refs.htm [2007 Aug. 02].Bryan, G. C. and Best, L. B. 1991. Bird abundance and speciesrichness in grassed waterways in Iowa rowcrop fields. Am.Midl. Nat. 126: 90�102.Buckelew, L. D., Pedigo, L. P., Mero, H. M., Owen, M. D. K.

and Tylka, G. L. 2000. Effects of weed management systems oncanopy insects in herbicide-resistant soybeans. J. Econ.Entomol. 93: 1437�1443.Buhler, D. D. 1991. Early preplant atrazine and metolachlor inconservation tillage corn (Zea mays). Weed Technol. 5: 66�71.Buhler, D. D. 1998. Effect of ridge truncation on weedpopulations and control in ridge-tillage corn (Zea mays).Weed Sci. 46: 225�230.Buhler, D. D. 1999. Weed population responses to weedcontrol practices. I. Seed bank, weed populations, and cropyields. Weed Sci. 47: 416�422.Buhler, D. D. and Hartzler, R. G. 2001. Emergence andpersistence of seed of velvetleaf, common waterhemp, woollycupgrass, and giant foxtail. Weed Sci. 49: 230�235.Buhler, D. D. and Mester, T. C. 1991. Effect of tillage systemson the emergence depth of giant (Setaria faberi) and greenfoxtail (Setaria viridis). Weed Sci. 39: 200�203.Buhler, D. D. and Oplinger, E. S. 1990. Influence of tillagesystems on annual weed densities and control in solid-seededsoybean (Glycine max). Weed Sci. 38: 158�165.Buhler, D. D. and Proost, R. T. 1992. Influence of applicationtime on bioactivity of imazethapyr in no-tillage soybean(Glycine max). Weed Sci. 40: 122�126.Buhler, D. D., Hartzler, R. G., Forcella, F. and Gunsolus, J. L.

1997. Relative emergence sequence for weeds of corn andsoybean. Iowa State University, Ames, IA. Extension Publica-tion SA�11.Buhler, D. D., Mester, T. C. and Kohler, K. A. 1996. The effectof maize residues and tillage on emergence of Setaria faberi,Abutilon theophrasti, Amaranthus retroflexus, and Chenopo-dium album. Weed Res. 36: 153�165.Bunting, J. A., Simmons, F. W. and Wax, L. M. 2003. Earlypreplant application timing effects on acetamide efficiency inno-till corn (Zea mays). Weed Technol. 17: 291�296.Bunting, J. A., Sprague, C. L. and Riechers, D. E. 2004a.

Absorption and activity of foramsulfuron in giant foxtail(Setaria faberi) and woolly cupgrass (Eriochloa villosa) withvarious adjuvants. Weed Sci. 52: 513�517.Bunting, J. A., Sprague, C. L. and Riechers, D. E. 2004b.

Proper adjuvant selection for foramsulfuron activity. CropProt. 23: 361�366.Bunting, J. A., Sprague, C. L. and Riechers, D. E. 2005.

Incorporating foramsulfuron into annual weed control systemsfor corn. Weed Technol. 19: 160�167.Bussan, A. J. and Boerboom, C. M. 2001. Modelling theintegrated management of giant foxtail in corn-soybean. WeedSci. 49: 675�684.Bussan, A. J., Boerboom, C. M. and Stoltenberg, D. E. 2000.

Response of Setaria faberi demographic processes to herbiciderates. Weed Sci. 48: 445�453.Cardina, J., Herms, C. P. and Doohan, D. J. 2002. Croprotation and tillage system effects on weed seedbanks. WeedSci. 50: 448�460.

Cardina, J., Herms, C. P., Herms, D. A. and Forcella, F. 2007.

Evaluating phenological indicators for predicting Giant Fox-tail (Setaria faberi) emergence. Weed Sci. 55:455�464.Cardina, J., Webster, T. M. and Herms. 1998. Long-termtillage and rotation effects on soil seedbank characteristics.Asp. Appl. Biol. 51: 213�220.Catling, P. M., Reznicek, A. A. and Riley, J. L. 1977 [1978].

Some new and interesting grass records from southernOntario. Can. Field-Nat. 91: 350�359.Chase, A. 1948. The meek that inherit the earth. US Dep.Agric. Yearbook Agric. 1948: 8�15.Chege, P. G., Clark, T. L. and Hibbard, B. E. 2005. Alternatehost phenology affects survivorship, growth, and developmentof Western Corn Rootworm (Coleoptera: Chrysomelidae)larvae. Environ. Entomol. 34: 1441�1447.Chen, P. K. and Leather, G. R. 1990. Plant growth regulatoryactivities of artemisinin and its related compounds. J. Chem.Ecol. 16: 1867�1876.Christian, M. L. and Willis, W. G. 1993. Survival of wheatstreak mosaic virus in grass hosts in Kansas from wheat to fallwheat emergence. Plant Dis. 77: 239�242.Chung, I. and Miller, D. A. 1995. Natural herbicide potential ofalfalfa residue on selected weed species. Agron. J. 87: 920�925.Clark, T. L. and Hibbard, B. E. 2004. Comparison of nonmaizehosts to support Western Corn rootworm (Coleoptera: Chry-somelidae) larval biology. Environ. Entomol. 33: 681�689.Coleman, R. and Penner, D. 2006. Desiccant activity of shortchain fatty acids. Weed Technol. 20: 410�415.Conley, S. P., Binning, L. K., Boerboom, C. M. and Stoltenberg,

D. E. 2002. Estimating giant foxtail cohort productivity insoybean based on weed density, leaf area, or volume. WeedSci. 50: 72�78.Conley, S. P., Binning, L. K., Boerboom, C. M. and Stoltenberg,

D. E. 2003a. Parameters for predicting giant foxtail cohorteffect on soybean yield loss. Agron. J. 95: 1226�1232.Conley, S. P., Stoltenberg, D. E., Boerboom, C. M. and

Binning, L. K. 2003b. Predicting soybean yield loss in giantfoxtail (Setaria faberi) and common lambsquarters (Chenopo-dium album) communities. Weed Sci. 51: 402�407.Corbett, J. L., Askew, S. D., Thomas, W. E. and Wilcut, J. W.

2004. Weed efficacy evaluations for bromoxynil, glufosinate,glyphosate, pyrithiobac, and sulfosate. Weed Technol. 18:443�453.Corrigan, K. A. and Harvey, R. G. 2000. Glyphosate with andwithout residual herbicides in no-till glyphosate-resistantsoybean (Glycine max). Weed Technol. 14: 569�577.Crowner, A. W. and Barrett, G. W. 1979. Effects of fire on thesmall mammal component of an experimental grasslandcommunity. J. Mammal. 60: 803�813.Cruden, R. W. 1977. Pollen-ovule ratios: A conservativeindicator of breeding systems in flowering plants. Evolution31: 32�46.Cybulski, W. J., III and Peterjohn, W. T. 1999. Effects ofambient UV-B radiation on the above-ground biomass ofseven temperate-zone plant species. Plant Ecol. 145: 175�181.Darbyshire, S. J. 2003. Inventory of Canadian agriculturalweeds. Agriculture and Agri-Food Canada, Ottawa. [Online]Available: http://dsp-psd.pwgsc.gc.ca/collection/A42-100-2003E.pdf [2007 Mar. 06].Davis, A. S. and Liebman, M. 2003. Cropping system effectson Setaria faberi seedbank dynamics. Asp. Appl. Biol. 69:83�91.


Davis, A.S. and Renner, K. A. 2007. Influence of seed depthand pathogens on fatal germination of velvetleaf (Abutilontheophrasti) and giant foxtail (Setaria faberi). Weed Sci. 55:30�35.Davis, A. S., Anderson, K. I., Hallett, S. G. and Renner, K. A.

2006. Weed seed mortality in soils with contrasting agriculturalmanagement histories. Weed Sci. 54: 291�297.Davis, A. S., Cardina, J., Forcella, F., Johnson, G. A., Kegode,

Lindquist, J. L., Luschei, E. C., Renner, K. A., Sprague, C. L.

and Williams, M. M., II 2005. Environmental factors affectingseed persistence of annual weeds across the U.S. corn belt.Weed Sci. 53: 860�868.DeFelice, M. S., Brown, W. B., Aldrich, R. J., Sims, B. D.,

Judy, D. T. and Guethle, D. R. 1989. Weed control in soybeans(Glycine max) with reduced rates of postemergence herbicides.Weed Sci. 37: 365�374.Dekker, J. 2003a. The foxtail (Setaria) species-group. WeedSci. 51: 641�656.Dekker, J. 2003b. Evolutionary biology of the foxtail (Setaria)species group. Pages 65�114 in Inderjit, ed. Weed biology andmanagement. Kluwer Academic Publishers, Dordrecht, theNetherlands.Dekker, J. and Hargrove, M. 2002. Weedy adaptation inSetaria spp. V. Effects of gaseous environment on giant foxtail(Setaria faberii) (Poaceae) seed germination. Am. J. Bot. 89:410�416.De Prado, R., Lopez-Martinez, N. and Gonzalez-Gutierrez, J.

2000. Identification of two mechanisms of atrazine resistancein Setaria faberi and Setaria viridis biotypes. Pestic. Biochem.Physiol. 67: 114�124.Dirks, J. T., Johnson, W. G., Smeda, R. J., Wiebold, W. J. and

Massey, R. E. 2000a. Reduced rates of sulfentrazone pluschlorimuron and glyphosate in no-till, narrow-row, glypho-sate-resistant Glycine max. Weed Sci. 48: 618�627.Dirks, J. T., Johnson, W. G., Smeda, R. J., Wiebold, W. J. and

Massey, R. E. 2000b. Use of preplant sulfentrazone in no-till,narrow-row, glyphosate-resistant Glycine max. Weed Sci. 48:628�639.DiTommaso, A. and Nurse, R. E. 2004. Impact of sodiumhypochlorite concentration and exposure period on germina-tion and radicle elongation of three annual weed species. SeedSci. Technol. 32: 377�391.Donald, W. W. 2000a. Between-row mowing�in-row band-applied herbicide for weed control in Glycine max. Weed Sci.48: 487�500.Donald, W. W. 2000b. Timing and frequency of between-rowmowing and band-applied herbicide for annual weed control insoybean. Agron. J. 92: 1013�1019.Donald, W. W. 2006. Preemergence banded herbicides fol-lowed by only one between-row mowing controls weeds incorn. Weed Technol. 20: 143�149.Donald, W. W. and Johnson, W. G. 2003. Interference effects ofweed-infested bands in or between crop rows on field corn(Zea mays) yield. Weed Technol. 17: 755�763.Donald, W. W., Kitchen, N. R. and Sudduth, K. A. 2001.

Between-row mowing�banded herbicide to control annualweeds and reduce herbicide use in no-till soybean (Glycinemax) and corn (Zea mays). Weed Technol. 15: 576�584.Doyon, D., Bouchard, C. J. and Neron, R. 1988. Extension de larepartition geographique de Setaria faberii au Quebec. Nat.Can. (Que.) 115: 125�129.

Eaton, W., Coffey, D. L., Mullins, C. A. and Rhodes, G. N., Jr.

1990. Weed control with oxyfluorfen in transplanted broccoli.Tenn. Farm Home Sci. 154: 17�21.Emery, W. H. P. 1957. A study of reproduction in Setariamacrostachya and its relatives in the southwestern UnitedStates and northern Mexico. Bull. Torrey Bot. Club 84: 106�121.Endress, G. A., Endress, A. G. and Iverson, L. R. 1999. Droughtand ozone stress effects on competition among selected prairiegrass species and giant foxtail. HortTechnology 9: 227�234.Evers, R. A. 1949. Setaria faberii in Illinois. Rhodora 51:391�392.Facelli, J. M. and Pickett, S. T. A. 1991a. Indirect effects oflitter on woody seedlings subject to herb competition. Oikos62: 129�138.Facelli, J. M. and Pickett, S. T. A. 1991b. Plant litter: lightinterception and effects on an old-field plant community.Ecology 72: 1024�1031.Fairbrothers, D. E. 1959. Morphological variation of Setariafaberii and S. viridis. Brittonia 11: 44�48.Farr, D. F., Rossman, A. Y., Palm, M. E. and McCray, E. B.

undated. Fungal Databases. Systematic Botany and MycologyLaboratory, Agricultural Research Service, US Dep. Agric.[Online] Available: http://nt.ars-grin.gov/fungaldatabases/[2007 Aug. 02].Fausey, J. C. and Renner, K. A. 1997. Germination, emergence,and growth of giant foxtail (Setaria faberi) and fall panicum(Panicum dichotomiflorum). Weed Sci. 45: 423�425.Fausey, J. C. and Renner, K. A. 2001. Incorporating CGA�248757 and flumiclorac into annual weed control programs forcorn (Zea mays) and soybean (Glycine max). Weed Technol.15: 148�154.Fausey, J. C., Kells, J. J., Swinton, S. M. and Renner, K. A.

1997. Giant foxtail (Setaria faberi) interference in nonirrigatedcorn (Zea mays). Weed Sci. 45: 256�260.Fernald, M. L. 1944. Setaria faberii in eastern America.Rhodora 46: 57�58.Ferrell, J. A. and Witt, W. W. 2002. Comparison of glyphosatewith other herbicides for weed control in corn (Zea mays):Efficacy and economics. Weed Technol. 16: 701�706.Forcella, F., Colbach, N. and Kegode, G. O. 2000. Estimatingseed production of three Setaria species in row crops. WeedSci. 48: 436�444.Forcella, F., Wilson, R. G., Dekker, J., Kremer, R. J., Cardina,

J., Anderson, R. L., Alm, D., Renner, K. A., Harvey, R. G.,

Clay, S. and Buhler, D. D. 1997. Weed seed bank emergenceacross the Corn Belt. Weed Sci. 45: 67�76.Ford, S. D. 1977. Range, distribution and habitat of thewestern harvest mouse, Reithrodontomys megalotis, in Indiana.Am. Midl. Nat. 98: 422�432.Gallagher, R. S. and Cardina, J. 1998. The effect of lightenvironment during tillage on the recruitment of varioussummer annuals. Weed Sci. 46: 214�216.Garbutt, K., Williams, W. E. and Bazzaz, F. A. 1990. Analysisof the differential response of five annuals to elevated CO2

during growth. Ecology 71: 1185�1194.Gilmore, A. R. 1980. Phytotoxic effects of giant foxtail onloblolly pine seedlings. Comp. Physiol. Ecol. 5: 183�192.Gerwick, B. C., Fields, S. S., Graupner, P. R., Gray, J. A.,

Chapin, E. L., Cleveland, J. A. and Heim, D. R. 1997.

Pyridazocidin, a new microbial phytotoxin with activity inthe Mehler reaction. Weed Sci. 45: 654�657.


Gower, S. A., Loux, M. M., Cardina, J. and Harrison, S. K.

2002. Effect of planting date, residual herbicide, and post-emergence application timing on weed control and grain yieldin glyphosate-tolerant corn (Zea mays). Weed Technol. 16:488�494.Gutierrez, M., Gracen, V. E. and Edwards, G. E. 1974.

Biochemical and cytological relationships in C4 plants. Planta119: 279�300.Haflinger, E. and Scholz, H. 1980. Grass weeds 1. Weeds of thesubfamily Panicoideae. Ciba-Geigy, Basle, Switzerland. 142pp.�plates.Haken, A. E. and Batzli, G. O. 1996. Effects of availability offood and interspecific competition on diets of prairie voles(Microtus ochrogaster). J. Mammal. 77: 315�324.Hamill, A. S., Weaver, S. E., Sikkema, P. H., Swanton, C. J.,

Tardif, F. J. and Ferguson, G. M. 2004. Benefits and risks ofeconomic vs. efficacious approaches to weed management incorn and soybean. Weed Technol. 18: 723�732.Hanson, C. L. and Velovitch, J. J. 1986. Performance of verdictherbicide with broadleaf herbicides in soybeans. Down toEarth 42: 14�17.Hart, S. E., Wax, L. M. and Hager, A. G. 1997. Comparison oftotal postemergence weed control programs in soybean. J.Prod. Agric. 10: 136�141.Hartzler, R. G., Buhler, D. D. and Stoltenberg, D. E. 1999.

Emergence characteristics of four annual weed species. WeedSci. 47: 578�584.Harvey, R. G. 1974. Susceptibility of seven annual grasses toherbicides. Weed Res. 14: 51�55.Hatterman-Valenti, H. M., Pitty, A. and Owen, M. D. K. 2006.

Effect of environment on giant foxtail (Setaria faberi) leaf waxand fluzifop-P absorption. Weed Sci. 54: 607�614.Hatton, P., Cole, D. J. and Edwards, R. 1996. Influence ofplant age on glutathione levels and glutathione transferasesinvolved in herbicide detoxification in corn (Zea mays L.) andgiant foxtail (Setaria faberi Herrm). Pestic. Biochem. Physiol.54: 199�209.Hatton, P. J., Cummins, I., Cole, D. J. and Edwards, R. 1999.

Glutathione transferases involved in herbicide detoxification inthe leaves of Setaria faberi (giant foxtail). Physiol. Plant. 105:9�16.Hatton, P. J., Edwards, R. and Cole, D. J. 1995. Glutathionetransferases in major weed species. Pestic. Sci. 43: 173�175.He, J. S., Bazzaz, F. A. and Schmid, B. 2002. Interactive effectsof diversity, nutrients and elevated CO2 on experimental plantcommunities. Oikos 97: 337�348.Heap, I. 2007. The International Survey of Herbicide ResistantWeeds. [Online] Available: http://www.weedscience.org/in.asp[2007 Aug. 02].Heggenstaller, A. H. and Liebman, M. 2005. Demography ofAbutilon theophrasti and Setaria faberi in three crop rotationsystems. Weed Res. 46: 138�151.Hellwig, K. B., Johnson, W. G and Massey, R. E. 2003. Weedmanagement and economic returns in no-tillage herbicide-resistant corn (Zea mays). Weed Technol. 17: 239�248.Hitchcock, A. S. 1950 [1951]. Manual of the grasses of theUnited States. ed. 2, revised by A. Chase. US Dep. Agric.Misc. Publ. 200. 1051 p.Hoagland, D. R. and Arnon, D. I. 1938. The water-culturemethod for growing plants without soil. Univ. CaliforniaAgric. Exp. Stn. Circ. 374 pp.

Hoffman, M. L., Owen, M. D. K. and Buhler, D. D. 1998.

Effects of crop and weed management on density and verticaldistribution of weed seeds in soil. Agron. J. 90: 793�799.Holm, L. G., Plucknett, D. L., Pancho, J. V. and Herberger, J.

P. 1977. The world’s worst weeds � distribution and biology.The East-West Food Institute, Honolulu, HI. 609 pp.Holmgren, P. K., Holmgren, N. H. and Barnett, L. C. 1990.

Index herbarorium. Part 1. The herbaria of the world. 8th ed.New York Botanical Garden, Bronx, NY. 693 pp.Houtcopper, W. C. 1972. Notes on the occurrence of Endogonein soils and seeds from cultivated fields in Vigo County,Indiana. Am. Midl. Nat. 88: 497�499.Hunt, M. E., Floyd, G. L. and Stout, B. B. 1979. Soil algae infield and forest environments. Ecology 60: 362�375.Isaacs, M. A., Wilson, H. P. and Toler, J. E. 2002. Rimsul-furon plus thifensulfuron-methyl combinations with selectedpostemergence broadleaf herbicides in corn (Zea mays). WeedTechnol. 16: 664�668.Isaacs, M. A., Wilson, H. P. and Toler, J. E. 2003. Combina-tions of sethoxydim with postemergence broadleaf herbicidesin sethoxydim-resistant corn (Zea mays). Weed Technol. 17:224�228.Jennings, D. 1941. Fall food habits of the bobwhite quail ineastern Kansas. Trans. Kansas Acad. Sci. 44: 420�426.Kane, R. P. 1998. Ozone depletion, related UV-B changes andincreased skin cancer incidence. Int. J. Climatol. 18: 457�472.Kegode, G. O. and Pearce, R. B. 1998. Influence of environ-ment during maternal plant growth on dormancy of shatter-cane (Sorghum bicolor) and giant foxtail (Setaria faberi) seed.Weed Sci. 46: 322�329.Kemp, J. C. and Barrett, G. W. 1989. Spatial patterning:Impact of uncultivated corridors on arthropod populationswithin soybean agroecosystems. Ecology 70: 114�128.Kendeigh, S. C. and West, G. C. 1965. Caloric values of plantseeds eaten by birds. Ecology 46: 553�555.King, L. J. 1952. Germination and chemical control of thegiant foxtail grass. Contrib. Boyce Thompson Inst. 16:469�487.Kishimoto, E. 1938. Chromosomenzahlen in den gattungenPanicum und Setaria. I. Chromosomenzahlen einiger Setaria-Arten. Cytologia 9: 23�27.Knake, E. L. 1972. Effect of shade on giant foxtail. Weed Sci.20: 588�592.Knake, E. L. 1977. Giant foxtail: The most serious annualgrass weed in the Midwest. Weeds Today 9: 19�20.Knake, E. L. 1987. Foxtail: Of questionable parentage. CropsSoils Mag. 39: 7�9.Knake, E. L. 1990. Giant foxtail (Setaria faberi Herrm.). Univ.Illinois, Champaign, IL. Agric. Exp. Sta. Bull. No. 803. 22 p.Knake, E. L. and Slife, F. W. 1961. Competition of Setariafaberi with corn and soybean. Weeds 10: 26�29.Knake, E. L. and Slife, F. W. 1969. Effect of time of giantfoxtail removal from corn and soybeans. Weed Sci. 17: 281�283.Koeppe, D. E. and Bell, D. T. 1972. Chemical warfare in thecornfield: phytotoxic compounds released by weeds may beone cause of reduced yields. Illinois Research Bulletin. pp. 3�4.Krausz, R. F. and Young, B. G. 2003. Sulfentrazone enhancesweed control of glyphosate in glyphosate-resistant soybean(Glycine max). Weed Technol. 17: 249�255.Krausz, R. F., Young, B. G., Kapusta, G. and Matthews, J. L.

2000. Application timing determines giant foxtail (Setaria


faberi) and barnyardgrass (Echinochloa crus-galli) control inno-till corn (Zea mays). Weed Technol. 14: 161�166.Lamp, W. O., Morris, M. J. and Armbrust, E. J. 1984.

Suitability of common weed species as host plants for thepotato leafhopper, Empoasca fabae. Entomol. Exp. Appl. 36:125�131.Leck, M. A. and Leck, C. F. 1998. A ten-year seed bank studyof old field succession in central New Jersey. J. Torrey Bot.Soc. 125: 11�32.Leon, R. G. and Owen, M. D. K. 2003. Regulation of weed seeddormancy through light and temperature interactions. WeedSci. 51: 752�758.Leon, R. G. and Owen, M. D. K. 2004. Artificial and naturalseed banks differ in seedling emergence patterns. Weed Sci. 52:531�537.Leon, R. G., Knapp, A. D. and Owen, M. D. K. 2004. Effect oftemperature on the germination of common waterhemp(Amaranthus tuberculatus), giant foxtail (Setaria faberi), andvelvetleaf (Abutilon theophrasti). Weed Sci. 52: 67�73.Levine, E. 1985. Oviposition by the stalk borer, Papaipemanebris (Lepidoptera: Noctuidae), on weeds, plant debris, andcover crops in cage tests. J. Econ. Entomol. 78: 65�68.Levine, E. 1986. Oviposition preference of Hydraecia immanis(Lepidoptera: Noctuidae) in cage tests. J. Econ. Entomol. 79:1544�1547.Levine, M. B., Hall, A. T., Barrett, G. W. and Taylor, D. H.

1989. Heavy metal concentrations during ten years of sludgetreatment to an old-field community. J. Environ. Qual. 18:411�418.Li, C. H., Pao, W. K. and Li, H. W. 1942. Interspecific crossesin Setaria. II. Cytological studies of interspecific hybridsinvolving: 1, S. faberii and S. italica, and 2, a three way cross,F2 of S. italica�S. viridis and S. faberii. J. Hered. 33: 351�355.Li, J. and Kremer, R. J. 2000. Rhizobacteria associated withweed seedlings in different cropping systems. Weed Sci. 48:734�741.Li, J. and Kremer, R. J. 2006. Growth response of weed andcrop seedlings to deleterious rhizobacteria. Biol. Control 39:58�65.Li, J., Johnson, W. G. and Smeda R. J. 2002. Interactionsbetween glyphosate and imazethapyr on four annual weeds.Crop Prot. 21: 1087�1092.Liebman, M., Menalled, F. D., Buhler, D. D., Richard, T. L.,

Sundberg, D. N., Cambardella, C. A. and Kohler, K. A. 2004.

Impacts of composted swine manure on weed and cornnutrient uptake, growth, and seed production. Weed Sci. 52:

365�375.Lindquist, J. L., Mortensen, D. A., Westra, P., Lambert, W. J.,

Bauman, T. T., Fausey, J. C., Kells, J. J., Langton, S. J.,

Harvey, R. G., Bussler, B. H., Banken, K., Clay, S. and

Forcella, F. 1999. Stability of corn (Zea mays)-foxtail (Setariaspp.) interference relationships. Weed Sci. 47: 195�200.Maly, M. S. and Barrett, G. W. 1984. Effects of two types ofnutrient enrichment on the structure and function of contrast-ing old-field communities. Am. Midl. Nat. 111: 342�357.Marten, G. C. and Andersen, R. N. 1975. Forage nutritive valueand palatability of 12 common annual weeds. Crop Sci. 15:821�827.Martin, L. D. and Smith, A. E. 1994. Allelopathic potential ofsome warm-season grasses. Crop Prot. 13: 388�392.McCall, P. J. 1989. Quantitative modelling of the effects ofphysical and chemical parameters on the foliar penetration of

pesticides and its potential for predicting field behaviour. Asp.Appl. Biol. 21: 185�201.McCall, P. J., Stafford, L. E., Zorner, P. S. and Gavit, P. D.

1986. Modeling the foliar behaviour of atrazine with andwithout crop oil concentrate on giant foxtail and the effect oftridiphane on the model rate constants. J. Agric. Food Chem.34: 235�238.McConnaughay, K. D. M., Berntson, G. M. and Bazzaz, F. A.

1993. Limitations to CO2-induced growth enhancement in potstudies. Oecologia 94: 550�557.McCormick, J. and Kay, H. 1968. Setaria faberi Herrmann inNorth America: Introduction, spread, and contemporarydistribution. (Preliminary report to cooperating scientists.).Unpublished Report. Hitchcock and Chase Library, Smithso-nian Institution, Washington, DC. 12 pp.Menalled, F. D., Buhler, D. D. and Liebman, M. 2005.

Composted swine manure effects on germination and earlygrowth of crop and weed species under greenhouse conditions.Weed Technol. 19: 784�789.Menalled, F. D., Marino, P. C., Renner, K. A. and Landis, D. A.

2000. Post-dispersal weed seed predation in Michigan cropfields as a function of agricultural landscape structure. Agric.Ecosyst. Environ. 77: 193�202.Mester T. C. and Buhler, D. D. 1986. Effects of tillage on thedepth of giant foxtail germination and population densities.Proc. N. Cent. Weed Sci. Soc. 41: 4�5.Mester, T. C. and Buhler, D. D. 1991. Effects of soiltemperature, seed depth, and cyanazine on giant foxtail(Setaria faberi) and velvetleaf (Abutilon theophrasti) seedlingdevelopment. Weed Sci. 39: 204�209.Moechnig, M. J., Boerboom, C. M., Stoltenberg, D. E. and

Binning, L. K. 2003. Growth interactions in communities ofcommon lambsquarters (Chenopodium album), giant foxtail(Setaria faberi), and corn. Weed Sci. 51: 363�370.Monachino, J. 1959. Type of Setaria faberii. Rhodora 61: 220�223.Mulligan, G. A. and Findley, J. N. 1970. Reproductive systemsand colonization in Canadian weeds. Can. J. Bot. 48: 859�860.Mullins, C. A., Shamiyeh, N. B., Straw, R. A. and Roberts, C.

H. 1993. Effects of pesticides when used alone and incombinations on snap beans. Tenn. Farm Home Sci. 165:31�36.Mulugeta, D. and Boerboom, C. M. 2000. Critical time of weedremoval in glyphosate-resistant Glycine max. Weed Sci. 48: 35�42.Mulugeta, D. and Stoltenberg, D. E. 1997. Increased weedemergence and seed bank depletion by soil disturbance in a no-tillage system. Weed Sci. 45: 234�241.Myers, M. W., Curran, W. S., VanGessel, M. J., Calvin, D. D.,

Mortensen, D. A., Majek, B. A., Karsten, H. D. and Roth, G.

W. 2004. Predicting weed emergence for eight annual species inthe northeastern United States. Weed Sci. 52: 913�919.Myers, M. W., Curran, W. S., VanGessel, M. J., Majek, B. A.,

Mortensen, D. A., Calvin, D. D., Karsten, H. D. and Roth, G.

W. 2005. Effect of soil disturbance on annual weed emergencein the Northeastern United States. Weed Technol. 19: 274�282.Nelson, K. A., Renner, K. A. and Penner, D. 1998. Weedcontrol in soybean (Glycine max) with imazamox and im-azethapyr. Weed Sci. 46: 587�594.Niekamp, J. W. and Johnson, W. G. 2001. Weed managementwith sulfentrazone and flumioxazin in no-tillage soyabean(Glycine max). Crop Prot. 20: 215�220.


Nonnecke, G. R. and Christians, N. E. 1993. Evaluation of corngluten meal as a natural, weed control product in strawberry.Acta Hortic. 348: 315�320.Oliver, L. R. and Schreiber, M. M. 1971. Differential selectivityof herbicides on six Setaria taxa. Weed Sci. 19: 428�431.O’Rourke, M. E., Heggenstaller, A. H., Liebman, M. and

Rice, M. E. 2006. Post-dispersal weed seed predation byinvertebrates in conventional and low-external-input croprotation systems. Agric. Ecosyst. Environ. 116: 280�288.Orwick, P. L. and Schreiber, M. M. 1975. Differential rootgrowth of four Setaria taxa. Weed Sci. 23: 364�368.Oyediran, I. O., Hibbard, B. E. and Clark, T. L. 2005. Westerncorn rootworm (Coleoptera: Chrysomelidae) beetle emergencefrom weedy Cry3Bb1 rootworm-resistant transgenic corn.J. Econ. Entomol. 98: 1679�1684.Oyediran, I. O., Hibbard, B. E., Clark, T. L. and French, B. W.

2004. Selected grassy weeds as alternate hosts of northern cornrootworm (Coleoptera: Chrysomelidae). Environ. Entomol.33: 1497�1504.Parrish, J. A. D. and Bazzaz, F. A. 1976. Underground nicheseparation in successional plants. Ecology 57: 1281�1288.Parrish, J. A. D. and Bazzaz, F. A. 1982. Responses of plantsfrom three successional communities to a nutrient gradient. J.Ecol. 70: 233�248.Parrish, J. A. D. and Bazzaz, F. A. 1985. Ontogenetic nicheshifts in old-field annuals. Ecology 66: 1296�1302.Pascarella, J. B. and Gaines, M. S. 1991. Feeding preferencesof the Prairie vole (Microtus ochrogaster) for seeds and plantsfrom an old-field successional community. Trans. KansasAcad. Sci. 94: 3�11.Pavuk, D. M., Purrington, F. F., Williams, C. E. and Stinner, B.

R. 1997. Ground beetle (Coleoptera: Carabidae) activity,density and community composition in vegetationally diversecorn agroecosystems. Am. Midl. Nat. 138: 14�28.Peles, J. D., Brewer, S. R., Barrett, G. W. 1998. Heavy metalaccumulation by old-field plant species during recovery ofsludge-treated ecosystems. Am. Midl. Nat. 140: 245�251.Peng, G. and Byer, K. N. 2004. Potential enhancement ofpathogen virulence using low rate herbicides with Pyriculariasetariae. Can. J. Plant Pathol. 26: 419�420.Perozzi, R. E. and Bazzaz, F. A. 1978. The response of an earlysuccessional community to shortened growing season. Oikos31: 89�93.Pest Management Regulatory Agency. 2000. Regulatory note:Flufenacet. Reg 2000�11 pp. 73. [Online] Available: http://www.pmra-arla.gc.ca/english/pdf/reg/reg2000�11-e.pdf [2007Sep. 07].Peters, R. A., Meade, J. A. and Santelman, P. W. 1963. Lifehistory studies as related to weed control in the northeast. 2.Yellow foxtail and Giant foxtail. Univ. Rhode Island Agric.Exp. Stn. Bulletin 369.18 p.Pickett, S. T. A. and Bazzaz, F. A. 1978. Germination of co-occurring annual species on a soil moisture gradient. BullTorrey Bot. Club 105: 312�316.Pinkham, C. A. and Meade, S. 1970. The southeastwardmovement of the harvest mouse (Reithrodontomys megalotis)in Illinois. Trans. Ill. State Acad. Sci. 63: 339�340.Pitty, A., Staniforth, D. W. and Tiffany, L. H. 1987. Fungiassociated with caryopses of Setaria species from field-harvested seeds and from soil under two tillage systems.Weed Sci. 35: 319�323.Pohl, R. W. 1951. The genus Setaria in Iowa. Iowa State Coll.J. Sci. 25: 501�508.

Pohl, R. W. 1962. Notes on Setaria viridis and S. faberi(Gramineae). Brittonia 14: 210�213.Probatova, N. S. and Sokolovskaya, A. P. 1983. Chromosomenumbers in Adoxaceae, Chloranthaceae, Cupressaceae, Junca-ceae, Poaceae. Bot. Zh. (St. Petersbg.) 68: 1683. [In Russian].Rao, S. R., Feng, P. C. C. and Schafer, D. E. 1995.

Enhancement of thiazopyr bioefficacy by inhibitors of mono-oxygenases. Pestic. Sci. 45: 209�213.Raynal, D. J. and Bazzaz, F. A. 1973. Establishments of earlysuccessional plant populations on forest and prairie soil.Ecology 54: 1335�1341.Raynal, D. J. and Bazzaz, F. A. 1975. The contrasting life-cyclestrategies of three summer annuals found in abandoned fieldsin Illinois. J. Ecol. 63: 587�596.Regan, J. B. 1995. Natural resource stewardship � efficacy oftreflan and sonalan in conservation tillage. Down to Earth 50:6�12.Retrum, J. and Forcella, F. 2002. Giant foxtail (Setaria faberi)seedling assay for resistance to sethoxydim. Weed Technol. 16:464�466.Reuss, S. A., Buhler, D. D. and Gunsolus, J. L. 2001. Effects ofsoil depth and aggregate size on weed seed distribution andviability in a silt loam soil. Appl. Soil Ecol. 16: 209�217.Ritter, R. L., Kaufman, L. M., Monaco, T. J., Novitzky, W. P.

and Moreland, D. E. 1989. Characterization of triazine-resistant giant foxtail (Setaria faberi) and its control in no-tillage corn (Zea mays). Weed Sci. 37: 591�595.Rominger, J. M. 1962. Taxonomy of Setaria (Gramineae) inNorth America. Ill. Biol. Monogr. 29: 1�132.Rothrock, P. E., Squiers, E. R. and Sheeley, S. 1993. Hetero-geneity and size of a persistent seedbank of Ambrosiaartemisiifolia L. and Setaria faberi Herrm. Bull. Torrey Bot.Club 120: 417�422.Salas, M. L., Hickman, M. V., Huber, D. M. and Schreiber, M.

M. 1997. Influence of nitrate and ammonium nutrition on thegrowth of giant foxtail (Setaria faberi). Weed Sci. 45: 664�669.Santelmann, P. W. and Meade, J. A. 1961. Variation inmorphological characteristics and dalapon susceptibilitywithin species Setaria lutescens and S. faberii. Weeds 9: 406�410.Santelmann, P. W., Meade, J. A. and Peters, R. A. 1963.

Growth and development of yellow and giant foxtail. Weeds11: 139�142.Schmidt, A. A. and Johnson, W. G. 2004. Influence of early-season yield loss predictions from WeedSOFT and soybeanrow spacing on weed seed production from a mixed-weedcommunity. Weed Technol. 18: 412�418.Schreiber, M. M. 1965. Effect of date of planting and stage ofcutting on seed production of giant foxtail. Weeds 13: 60�62.Schreiber, M. M. 1977. Longevity of foxtail taxa in undis-turbed sites. Weed Sci. 25: 66�72.Schreiber, M. M. 1992. Influence of tillage, crop rotation, andweed management on giant foxtail (Setaria faberi) populationdynamics and corn yield. Weed Sci. 40: 645�653.Schreiber, M. M. and Williams, J. L. Jr. 1967. Toxicity of rootresidues of weedy grass species. Weed Sci. 15: 80�81.Schreiber, M. M. and Orwick, P. L. 1978. Influence of nitrogenfertility on growth of foxtail (Setaria) Taxa. Weed Sci. 26: 547�550.Schreiber, M. M., Warren, G. F. and Orwick, P. L. 1979.

Effects of wetting agent, stage of growth, and species on theselectivity of diclofop. Weed Sci. 27: 679�683.


Sedlacek, J. D., Barrett, G. W. and Shaw, D. R. 1988. Effectsof nutrient enrichment on the Auchenorrhyncha (Homoptera)in contrasting grassland communities. J. Appl. Ecol. 25: 537�550.Setyowati, N., Weston, L. A. and McNiel, R. E. 1995.

Evaluation of selected preemergence herbicides in field-grownlandscape crops in Kentucky. J. Environ. Hortic. 13: 196�202.Shukla, A., Leach, G. E. and Devine, M. D. 1997. High-levelresistance to sethoxydim conferred by an alteration in thetarget enzyme, acetyl-CoA carboxylase, in Setaria faberi andSetaria viridis. Plant Physiol. Biochem. (Paris) 35: 803�807.Sionit, N. and Patterson, D. T. 1984. Responses of C4 grassesto atmospheric CO2 enrichment. I. Effect of irradiance.Oecologia 65: 30�34.Spencer, S. R. and Barrett, G. W. 1980. Meadow volepopulation response to vegetational changes resulting from2,4-D application. Am. Midl. Nat. 103: 32�46.Spyreas, G., Gibson, D. J. and Middleton, B. A. 2001. Effects ofendophyte infection in tall fescue (Festuca arundinacea:Poaceae) on community diversity. Int. J. Plant Sci. 162:1237�1245.Squiers, E. R. 1989. The effects of seasonal timing ofdisturbance on species composition in a first-year oldfield.Bull. Torrey Bot. Club. 116: 356�363.Staniforth, D. W. 1965. Competitive effects of three foxtailspecies on soybeans. Weeds 13: 191�193.Stanway, V. 1971. Laboratory germination of giant foxtailSetaria faberii Herrm. at different stages of maturity. Proc.Assoc. Offic. Seed Anal. 61: 85�90.Steel, M. G., Cavers, P. B. and Lee, S. M. 1983. The biologyof Canadian weeds. 59. Setaria glauca (L.) Beauv. andS. verticillata (L.) Beauv. Can. J. Plant Sci. 63: 711�725.Stoltenberg, D. E. and Wiederholt, R. J. 1995. Giant foxtail(Setaria faberi) resistance to aryloxyphenoxypropionate andcyclohexanedione herbicides. Weed Sci. 43: 527�535.Sylwester, E. P. 1970. The ten worst weeds of field crops.Foxtails. Crops Soils Mag. June-July 1970: 11�13.Tateoka, T. 1955. Karyotaxonomy in Poaceae. III. Furtherstudies of somatic chromosomes. Cytologia 20: 296�306.Taylorson, R. B. 1972. Phytochrome controlled changes indormancy and germination of buried weed seeds. Weed Sci. 20:417�422.Taylorson, R. B. 1982. Anesthetic effects on secondarydormancy and phytochrome responses in Setaria faberi seeds.Plant Physiol. 70: 882�886.Taylorson, R. B. 1986. Water stress induced germination ofgiant foxtail (Setaria faberi) seeds. Weed Sci. 34: 871�875.Taylorson, R. B. and Brown, M. M. 1977. Accelerated after-ripening for overcoming seed dormancy in grass weeds. WeedSci. 25: 473�476.Teasdale, J. R., Pillai, P. and Collins, R. T. 2005. Synergismbetween cover crop residue and herbicide activity on emer-gence and early growth of weeds. Weed Sci. 53: 521�527.Thornhill, R. and Dekker, J. 1993. Mutant weeds of Iowa: V. S-triazine resistant Setaria faberi Herrm. J. Iowa Acad. Sci. 100:13�14.Tosserams, M., Magendans, E. and Rozema, J. 1997. Differ-ential effects of elevated ultraviolet-B radiation on plantspecies of a dune grassland ecosystem. Plant Ecol. 128: 266�281.Tosserams, M., Pais de Sa, A. and Rozema, J. 1996. The effectsof solar UV radiation on four plant species occurring in a

coastal grassland vegetation in the Netherlands. Physiol.Plantarium. 97: 731�739.USDA, NRCS. 2007. The PLANTS Database. National PlantData Center, Baton Rouge, LA. [Online] Available: http://plants.usda.gov [2007 Aug. 02].Vanasse, A. and Leroux, G. D. 2000. Floristic diversity, size,and vertical distribution of the weed seedbank in ridge andconventional tillage systems. Weed Sci. 48: 454�460.Vatovec, C., Jordan, N. and Huerd, S. 2005. Responsiveness ofcertain agronomic weed species to arbuscular mycorrhizalfungi. Renew. Agric. Food Syst. 20: 181�189.Vidal, R. A., Hickman, M. V. and Bauman, T. T. 1998.

Phenolics adsorption to soil reduces their allelochemicalactivity. Pesq. Agrop. Gaucha. 4: 125�129.Volenberg, D. and Stoltenberg, D. 2002a. Altered acetyl-coenzyme A carboxylase confers resistance to clethodim,fluazifop and sethoxydim in Setaria faberi and Digitariasanguinalis. Weed Res. 42: 342�350.Volenberg, D. and Stoltenberg, D. 2002b. Giant foxtail (Setariafaberi) outcrossing and inheritance of resistance to acetyl-coenzyme A carboxylase inhibitors. Weed Sci. 50: 622�627.Wakefield, N. G. and Barrett, G. W. 1979. Effects of positiveand negative nitrogen perturbations on an old-field ecosystem.Amer. Midl. Nat. 101: 159�169.Walker, K. L. and Williams, D. J. 1989. Annual grassinterference in container-grown bush cinquefoil (Potentillafruticosa). Weed Sci. 37: 73�75.Wang, R. L., Wendel, J. F. and Dekker, J. H. 1995. Weedyadaptation in Setaria spp. II. Genetic diversity and populationgenetic structure in S. glauca, S. geniculata, and S faberii(Poaceae). Am. J. Bot. 82: 1031�1039.Warwick, S. I., Thompson, B. K. and Black, L. D. 1987. Life-history and allozyme variation in populations of the weedspecies Setaria faberi. Can. J. Bot. 65: 1396�1402.Warwick, S. I., Crompton, C., Black, L. D. and Wotjas, W.

1997. IOPB chromosome data 11. Newslett. Int. Organ. Pl.Biosyst. (Oslo) 26/27: 25�26.West, G. C. 1967. Nutrition of Tree Sparrows during winter incentral Illinois. Ecology 48: 58�67.Westerman, P. R., Liebman, M., Heggenstaller, A. H. and

Forcella, F. 2006. Integrating measurements of seed availabil-ity and removal to estimate weed seed losses due to predation.Weed Sci. 54: 566�574.Whitaker, J. O. 1966. Food of Mus musculus, Peromyscusmaniculatus bairdi and Peromyscus leucopus in Vigo County,Indiana. J. Mammal. 47: 473�486.Wiederholt, R. J. and Stoltenberg, D. E. 1996. Absence ofdifferential fitness between giant foxtail (Setaria faberi)accessions resistant and susceptible to acetyl-coenzyme Acarboxylase inhibitors. Weed Sci. 44: 18�24.Wieland, N. K. and Bazzaz, F. A. 1975. Physiological ecologyof three codominant successional annuals. Ecology 56: 681�688.Willson, M. F. and Harmeson, J. C. 1973. Seed preferences anddigestive efficiency of cardinals and song sparrows. TheCondor 75: 225�234.Willweber-Kishimoto, E. 1962. Interspecific relationships in thegenus Setaria. Contrib. Biol. Lab. Kyoto Univ. pp. 1�41.Wood, C. E. J. 1956. Setaria faberii in North Carolina.Rhodora 48: 391�392.Wong, A. T. S. and Tylka, G. L. 1994. Eight nonhost weedspecies of Heterodera glycines in Iowa. Plant Dis. 78: 365�367.


Yoshioka, T., Ota, H., Segawa, K., Takeda, Y. and Esashi, Y.1995. Contrasted effects of CO2 on the regulation of dormancyand germination in Xanthium pennsylvanicum and Setariafaberi seeds. Ann. Bot. (Lond.) 76: 625�630.Zeiss, M. R., Brandenburg, R. L. and van Duyn, J. W. 1993.Suitability of seven grass weeds as Hessian fly (DipteraCecidomyiidae) hosts. J. Agric. Entomol. 10: 107�119.Zhang, J., Hamill, A. S., Gardiner, I. O. and Weaver, S. E.

1998. Dependence of weed flora on the active soil seedbank.Weed Res. 38: 143�152.Zimdahl, R. L. 1980. Weed crop competition: a review. OregonState University, Corvallis, OR. 220 pp.Zimmerman, E. G. 1965. A comparison of habitat and food oftwo species of Microtus. J. Mammal. 46: 605�612.Ziska, L. H. and Bunce, J. A. 1997. Influence of increasingcarbon dioxide concentrations on the photosynthetic andgrowth stimulation of selected C4 crops and weeds. Photo-synth. Res. 54: 199�208.

Appendix A

Key to the species of Setaria in Canada:

1. Bristles below each spikelet 5 or more, orangeor tawny; upper glume covering about half thecoarsely transversely wrinkled fertile lemma; uppersurface of leaf blade with a few long (greater than 4mm) hairs near the base, the hairs with swollenbases; leaf sheaths smooth on margins, keeled;spikelets (2)3�3.4 mm long . . . . . . . . . . S. pumila

1. Bristles below each spikelet 1�3 (sometimes to 6 inS. faberi), green or purplish; upper glume covering3/4 or more of the minutely transversely wrinkled orsmooth fertile lemma; upper surface of leaf bladesmooth or with shorter hairs (0.5�3.5 mm) through-

out, the hairs without swollen bases; leaf sheathmargins fringed with hairs, not keeled; spikelets1.9�3 mm long . . . . . . . . . . . . . . . . . . . . . . . . 2

2. Spikelets toward the base of panicle in spaced clustersor verticils, with the rachis visible in between; leafblades with a few hairs on upper surface; bristles4�7 mm long; bristles, rachis and upper culmwith downwardly (or rarely upwardly) pointingbarbs . . . . . . . . . . . . . . . . . . . . . . . S. verticillata

2. Spikelets not (or rarely) in spaced clusters on rachis;leaf blades hairy or hairless on upper surface; bristles5�12 mm long; bristles, rachis and upper culm withupwardly pointing barbs . . . . . . . . . . . . . . . . . 3

3. Fertile floret separating from glumes and sterilelemma at maturity; panicle (excluding bristles) 7�15mm diam., cylindrical but often lobed or interrupted;fertile lemmas smooth and shiny, occasionally ob-scurely transversely wrinkled . . . . . . . . . S. italica

3. Entire spikelet falling at maturity leaving a cup-likescar on the pedicel; panicle (excluding bristles) 4�8(10) mm diam., narrowly cylindrical; fertile lemmasfinely or coarsely transversely wrinkled, not shiny 4

4. Spikelets 1.9�2.2(2.4) mm long; upper glume almostcompletely covering the fertile lemma; leaf bladessmooth or scabrous . . . . . . . . . . . . . . . . S. viridis

4. Spikelets 2.4�3 mm long; upper glume covering aboutthree-quarters of the fertile lemma; leaf blades usuallyevenly covered with soft hairs at least on the uppersurface . . . . . . . . . . . . . . . . . . . . . . . . . S. faberi


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