Pacific Island Ecosystems at Risk (PIER)


Helianthus annuus


RISK ASSESSMENT RESULTS: High risk, score: 10.5


Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i.
Information on Risk Assessments
Original risk assessment

Helianthus annuus L. Family - Asteraceae. Common Names(s) - sunflower. Synonym(s) - Helianthus aridus Rydb..

Answer

Score

1.01

Is the species highly domesticated?

y=-3, n=0

y

-3

1.02

Has the species become naturalized where grown?

y=1, n=-1

y

1

1.03

Does the species have weedy races?

y=1, n=-1

y

1

2.01

Species suited to tropical or subtropical climate(s) (0-low; 1-intermediate; 2-high) – If island is primarily wet habitat, then substitute “wet tropical” for “tropical or subtropical”

See Append 2

1

2.02

Quality of climate match data (0-low; 1-intermediate; 2-high) see appendix 2

1

2.03

Broad climate suitability (environmental versatility)

y=1, n=0

y

1

2.04

Native or naturalized in regions with tropical or subtropical climates

y=1, n=0

y

1

2.05

Does the species have a history of repeated introductions outside its natural range?

y=-2, ?=-1, n=0

y

3.01

Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05

y

1

3.02

Garden/amenity/disturbance weed y = 1*multiplier (see Append 2)

n=0

y

1.5

3.03

Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2)

n=0

y

2.5

3.04

Environmental weed y = 2*multiplier (see Append 2)

n=0

3.05

Congeneric weed y = 1*multiplier (see Append 2)

n=0

y

1.5

4.01

Produces spines, thorns or burrs

y=1, n=0

n

0

4.02

Allelopathic

y=1, n=0

y

1

4.03

Parasitic

y=1, n=0

n

0

4.04

Unpalatable to grazing animals

y=1, n=-1

n

-1

4.05

Toxic to animals

y=1, n=0

4.06

Host for recognized pests and pathogens

y=1, n=0

4.07

Causes allergies or is otherwise toxic to humans

y=1, n=0

4.08

Creates a fire hazard in natural ecosystems

y=1, n=0

n

0

4.09

Is a shade tolerant plant at some stage of its life cycle

y=1, n=0

n

0

4.10

Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)

y=1, n=0

n

0

4.11

Climbing or smothering growth habit

y=1, n=0

n

0

4.12

Forms dense thickets

y=1, n=0

y

1

5.01

Aquatic

y=5, n=0

n

0

5.02

Grass

y=1, n=0

n

0

5.03

Nitrogen fixing woody plant

y=1, n=0

n

0

5.04

Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers)

y=1, n=0

n

0

6.01

Evidence of substantial reproductive failure in native habitat

y=1, n=0

n

0

6.02

Produces viable seed.

y=1, n=-1

y

1

6.03

Hybridizes naturally

y=1, n=-1

y

1

6.04

Self-compatible or apomictic

y=1, n=-1

n

-1

6.05

Requires specialist pollinators

y=-1, n=0

n

0

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

n

-1

6.07

Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1

See left

1

1

7.01

Propagates likely to be dispersed unintentionally (plants growing in heavily trafficked areas)

y=1, n=-1

n

-1

7.02

Propagules dispersed intentionally by people

y=1, n=-1

y

1

7.03

Propagules likely to disperse as a produce contaminant

y=1, n=-1

y

1

7.04

Propagules adapted to wind dispersal

y=1, n=-1

n

-1

7.05

Propagules water dispersed

y=1, n=-1

y

1

7.06

Propagules bird dispersed

y=1, n=-1

y

1

7.07

Propagules dispersed by other animals (externally)

y=1, n=-1

y

1

7.08

Propagules survive passage through the gut

y=1, n=-1

n

-1

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

y

1

8.02

Evidence that a persistent propagule bank is formed (>1 yr)

y=1, n=-1

8.03

Well controlled by herbicides

y=-1, n=1

8.04

Tolerates, or benefits from, mutilation, cultivation, or fire

y=1, n=-1

n

-1

8.05

Effective natural enemies present locally (e.g. introduced biocontrol agents)

y=-1, n=1

y

-1

Total score:

10.5

Supporting data:

Notes

Source

1.01

(1)Ethnobotanic: The sunflower is a native domesticated crop. During the last 3,000 years, Indians increased the seed size approximately 1,000 percent. They gradually changed the genetic composition of the plant by repeatedly selecting the largest seeds [larger seeds likely reduce dispersibility] (2)Reported from the North American (and secondarily, the Eurosiberian) Center of Diversity, sunflower, or cvs thereof, is reported to tolerate disease, drought, frost, fungi, high pH, laterite, limestone, low pH, mycobacteria, photoperiod, poor soil, rust, salt, sand, smog, virus, weeds, and waterlogging (Duke, 1978). Botanically, the sunflower is treated as the following subspecies: ssp. lenticularis in the wild sunflower; ssp. annuus is the weedy wild sunflower; and ssp. macrocarpus is cultivated for edible seeds. Cultivars are divided into several types: Giant types: 1.8–4.2 m tall, late maturing, heads 30–50 cm diam., seeds large, white or gray, or with black stripes; oil content rather low; ex. 'Mammoth Russian'. Semi-dwarf types: 1.3–1.8 m tall, early maturing, heads 17–23 cm diam., seeds smaller, black, gray or striped; oil content higher; ex. 'Pole Star' and 'Jupiter'. Dwarf types: 0.6–1.4 m tall, early maturing, heads 14–16 cm diam., seeds small, oil content highest; ex., 'Advance' and 'Sunset'. Gene centers are in the Americas, with genuine resources for resistance in southern United States and Mexico. Two types of male sterility are known.

(1)http://plants.usda.gov/plantguide/pdf/cs_hean3.pdf [Accessed 17 July 2008] (2)http://www.hort.purdue.edu/newcrop/duke_energy/Helianthus_annuus.html [Accessed 17 July 2008]

1.02

(1)Helianthus annuus L. Status: Naturalized Distribution: H (between Manua Loa and Manua Kea) (2)Sunflower, originally from America, is cultivated in many places in East Africa for its seeds, as an oil crop.Occasionally it seems to escape and become naturalised, as in T 6, Uzaramo District: Dar es Salaam on airport road, Apr. 1977, Wingfield 3392a! and T 8, Songea District: Mkaku River SW of Kitai, Mar. 1956, Milne-Redhead & Taylor 9075! These escapes are small annual herbs, 20–120 cm high. (3)Two wild annual sunflower species, Helianthus annuus and H. petiolaris, were introduced in Argentina about 50 years ago and they became naturalized.

(1)http://botany.si.edu/pacificislandbiodiversity/hawaiianflora/result2.cfm [Accessed 17 July 2008] (2)http://www.aluka.org/action/showCompilationPage?doi=10.5555/AL.AP.COMPILATION.PLANT-NAME-SPECIES.HELIANTHUS.ANNUUS&cookieSet=1 [Accessed 17 July 2008] (3)Poverene M., Cantamutto M.A., Carrera A., Ureta S., Alvarez D., Alonso Roldán V., Presotto A., Gutiérrez A., Luis S., and Hernández A. 2006. WILD SUNFLOWERS RESEARCH IN ARGENTINA. HELIA 29(44): 65-76.

1.03

(1)It grows in prairies and dry, open areas, and is sometimes a weed in cultivated fields and pastures. (2)Helianthus annuus and H. petiolaris sometimes invade summer crops although not as frequently as in North America. (3)The common sunflower Helianthus annuus is an interesting case of a native, disturbance-adapted annual plant in which some populations have evolved many typical traits of agricultural weeds, including resistance to some of the most commonly used herbicides (Zelaya & Owen 2004; Massinga et al. 2005). The species H. annuus contains weedy, wild, and domesticated forms (Heiser et al. 1969). Weed and wild forms are self-incompatible, while domesticated varieties are typically self-compatible. The weed form is listed as a noxious weed in the states of Iowa, Minnesota and Alaska, and is known to be a problematic weed in corn, soybeans, and other species (Irons & Burnside 1982; Mesbah et al. 2004). It has been found to decrease yields of corn by up to 64% (Deines et al. 2004) and yields of soybean by as much as 97% (Geier et al. 1996).

(1)http://www.floridata.com/ref/H/heli_ann.cfm [Accessed 17 July 2008] (2)Poverene M., Cantamutto M.A., Carrera A., Ureta S., Alvarez D., Alonso Roldán V., Presotto A., Gutiérrez A., Luis S., and Hernández A. 2006. WILD SUNFLOWERS RESEARCH IN ARGENTINA. HELIA 29(44): 65-76. (3)Kane, N. C. and L. H. Rieseberg. 2008. Genetics and evolution of weedy Helianthus annuus populations: adaptation of an agricultural weed. Molecular Ecology 17: 384–394.

2.01

Native range extends marginally into subtropical areas, and species grown in subtropical climates, typically at higher elevations (1)The wild sunflower from which all the cultivars have been derived grows naturally in almost all of North America from central Canada to northern Mexico. (2)Mexico has long been recognized as one of the world's cradles of domestication with evidence for squash (Cucurbita pepo) cultivation appearing as early as 8,000 cal B.C. followed by many other plants, such as maize (Zea mays), peppers (Capsicum annuum), common beans (Phaseolus vulgaris), and cotton (Gossypium hirsutum). We present archaeological, linguistic, ethnographic, and ethnohistoric data demonstrating that sunflower (Helianthus annuus) had entered the repertoire of Mexican domesticates by ca. 2600 cal B.C., that its cultivation was widespread in Mexico and extended as far south as El Salvador by the first millennium B.C., that it was well known to the Aztecs, and that it is still in use by traditional Mesoamerican cultures today. The sunflower's association with indigenous solar religion and warfare in Mexico may have led to its suppression after the Spanish Conquest. The discovery of ancient sunflower in Mexico refines our knowledge of domesticated Mesoamerican plants and adds complexity to our understanding of cultural evolution. (3)Sunflowers are grown from the Equator to 55° N Lat. In the tropics, they grow better at medium to high elevations, but tolerate the drier lowlands. They thrive wherever good crops of corn are grown, Young plants withstand mild freezing.

(1)http://www.floridata.com/ref/H/heli_ann.cfm [Accessed 17 July 2008] (2)Lentz, D.L., Mary DeLand Pohl, José Luis Alvarado, Somayeh Tarighat, and Robert Bye. 2008. Sunflower (Helianthus annuus L.) as a pre-Columbian domesticate in Mexico. PNAS 105(17): 6232-6237. (3)http://www.hort.purdue.edu/newcrop/duke_energy/Helianthus_annuus.html [Accessed 17 July 2008]

2.02

2.03

(1)Hardiness: Common sunflower is a warm season annual and some of the cultivars can complete their life cycles in as little as 60 days. Sunflowers are noted for their tolerance to heat and dry conditions. They perish after the first frost, though. (2)Zones : 3-10 (3)Ranging from Boreal Moist through Tropical Thorn to Wet Forest Life Zones, sunflower tolerates annual precipitation of 2–40 dm (mean of 195 cases 11.4), annual temperature of 6–28°C (mean of 194 cases = 19.6), and pH of 4.5–8.7 (mean of 121 cases = 6.6)

(1)http://www.floridata.com/ref/H/heli_ann.cfm [Accessed 17 July 2008] (2)http://www.americanmeadows.com/WildflowerSeeds/Species/WildSunflowerseeds.aspx [Accessed 17 July 2008] (3)http://www.hort.purdue.edu/newcrop/duke_energy/Helianthus_annuus.html [Accessed 17 July 2008]

2.04

(1)Helianthus annuus L. Status: Naturalized Distribution: H (between Manua Loa and Manua Kea) (2)Sunflower, originally from America, is cultivated in many places in East Africa for its seeds, as an oil crop. Occasionally it seems to escape and become naturalised, as in T 6, Uzaramo District: Dar es Salaam on airport road, Apr. 1977, Wingfield 3392a! and T 8, Songea District: Mkaku River SW of Kitai, Mar. 1956, Milne-Redhead & Taylor 9075! These escapes are small annual herbs, 20–120 cm high. (3)Two wild annual sunflower species, Helianthus annuus and H. petiolaris, were introduced in Argentina about 50 years ago and they became naturalized.

(1)http://botany.si.edu/pacificislandbiodiversity/hawaiianflora/result2.cfm [Accessed 17 July 2008] (2)http://www.aluka.org/action/showCompilationPage?doi=10.5555/AL.AP.COMPILATION.PLANT-NAME-SPECIES.HELIANTHUS.ANNUUS&cookieSet=1 [Accessed 17 July 2008] (3)Poverene M., Cantamutto M.A., Carrera A., Ureta S., Alvarez D., Alonso Roldán V., Presotto A., Gutiérrez A., Luis S., and Hernández A. 2006. WILD SUNFLOWERS RESEARCH IN ARGENTINA. HELIA 29(44): 65-76.

2.05

(1)Sunflowers are grown from the Equator to 55° N Lat. In the tropics

http://www.hort.purdue.edu/newcrop/duke_energy/Helianthus_annuus.html [Accessed 17 July 2008]

3.01

(1)Helianthus annuus L. Status: Naturalized Distribution: H (between Manua Loa and Manua Kea) (2)Sunflower, originally from America, is cultivated in many places in East Africa for its seeds, as an oil crop. Occasionally it seems to escape and become naturalised, as in T 6, Uzaramo District: Dar es Salaam on airport road, Apr. 1977, Wingfield 3392a! and T 8, Songea District: Mkaku River SW of Kitai, Mar. 1956, Milne-Redhead & Taylor 9075! These escapes are small annual herbs, 20–120 cm high. (3)Two wild annual sunflower species, Helianthus annuus and H. petiolaris, were introduced in Argentina about 50 years ago and they became naturalized.

(1)http://botany.si.edu/pacificislandbiodiversity/hawaiianflora/result2.cfm [Accessed 17 July 2008] (2)http://www.aluka.org/action/showCompilationPage?doi=10.5555/AL.AP.COMPILATION.PLANT-NAME-SPECIES.HELIANTHUS.ANNUUS&cookieSet=1 [Accessed 17 July 2008] (3)Poverene M., Cantamutto M.A., Carrera A., Ureta S., Alvarez D., Alonso Roldán V., Presotto A., Gutiérrez A., Luis S., and Hernández A. 2006. WILD SUNFLOWERS RESEARCH IN ARGENTINA. HELIA 29(44): 65-76.

3.02

(1)The sunflower (Helianthus annuus) is a common and widespread roadside weed.

(1)http://plants.usda.gov/plantguide/pdf/cs_hean3.pdf [Accessed 17 July 2008]

3.03

(1)It grows in prairies and dry, open areas, and is sometimes a weed in cultivated fields and pastures. (2)Helianthus annuus and H. petiolaris sometimes invade summer crops although not as frequently as in North America. (3)The common sunflower Helianthus annuus is an interesting case of a native, disturbance-adapted annual plant in which some populations have evolved many typical traits of agricultural weeds, including resistance to some of the most commonly used herbicides (Zelaya & Owen 2004; Massinga et al. 2005). The species H. annuus contains weedy, wild, and domesticated forms (Heiser et al. 1969). Weed and wild forms are self-incompatible, while domesticated varieties are typically self-compatible. The weed form is listed as a noxious weed in the states of Iowa, Minnesota and Alaska, and is known to be a problematic weed in corn, soybeans, and other species (Irons & Burnside 1982; Mesbah et al. 2004). It has been found to decrease yields of corn by up to 64% (Deines et al. 2004) and yields of soybean by as much as 97% (Geier et al. 1996).

(1)http://www.floridata.com/ref/H/heli_ann.cfm [Accessed 17 July 2008] (2)Poverene M., Cantamutto M.A., Carrera A., Ureta S., Alvarez D., Alonso Roldán V., Presotto A., Gutiérrez A., Luis S., and Hernández A. 2006. WILD SUNFLOWERS RESEARCH IN ARGENTINA. HELIA 29(44): 65-76. (3)Kane, N. C. and L. H. Rieseberg. 2008. Genetics and evolution of weedy Helianthus annuus populations: adaptation of an agricultural weed. Molecular Ecology 17: 384–394.

3.04

(1)Listed as an environmental weed, but mostly of disturbed places

(1)http://www.hear.org/gcw/species/helianthus_annuus/ [Accessed 17 July 2008]

3.05

(1)Helianthus ciliaris. Noxious weed of several states

(1)http://www.hear.org/gcw/species/helianthus_ciliaris/ [Accessed 17 July 2008]

4.01

4.02

(1)Sunflowers are supposedly allelopathic: their roots give off a chemical that inhibits the growth of other, nearby plants (2)The first stage of succession in abandoned fields in central Oklahoma and southeastern Kansas is the weed stage in which Helianthus annuus is an important dominant. The causative factors involved in the short duration of this stage, 2 to 3 years, and its passage into the annual grass stage consisting of one dominant, Aristida oligantha, have long been sought. The present study was undertaken to ascertain the allelopathic effects of Helianthus annuus on species with which it is associated in abandoned fields. Field studies indicated that certain associated species exhibit reduced growth around the sunflower plants, and preliminary experiments indicated that the reduced growth was not due to competition. Extracts of various organs of sunflower plants, decaying leaves, root exudate, leaf leachate, and soils collected from around sunflowers inhibited the seed germination and seedling growth of Helianthus annuus and many associated species, with the exception of Aristida oligantha and Croton glandulosus. Strong correlations were evident between the species with reduced growth in the field and those inhibited through various laboratory tests. Chlorogenic acid and isochlorogenic acid, present in all extracts of the various sunflower organs, and a suspected α-naphthol derivative and scopolin from the leaf leachate were the major phytotoxins identified from the sunflower plants. The phytotoxins of the extracts, leaf leachate, root exudate, and soil extracts are not the same compounds and this indicates that there is probably an additive effect with each group of toxins, thus accentuating the allelopathic effects of sunflower. The present results which indicate that Helianthus annuus is allelopathic to many of the early weeds including its own seedlings, but not to Aristida oligantha, complements the findings of others and may help in explaining the short duration of the weed stage and its replacement by Aristida oligantha in old-field succession of this region.

(1)http://www.floridata.com/ref/H/heli_ann.cfm [Accessed 17 July 2008] (2)Wilson, R.E. and Elroy L. Rice. 1968. Allelopathy as Expressed by Helianthus annuus and Its Role in Old-Field Succession. Bulletin of the Torrey Botanical Club 95(5): 432-448.

4.03

No evidence

4.04

(1)Muskrats eat the stems and foliage. Antelope, deer, and moose browse on the plants.

(1)http://plants.usda.gov/plantguide/pdf/cs_hean3.pdf [Accessed 17 July 2008]

4.05

(1)Cattle have been poisoned in Europe after ingesting plants that did not have mature seeds. This is a result of nitrate toxicity, which has caused sickness and death

(1)http://www.scib.gc.ca/pls/pp/ppack.info?p_psn=225&p_type=all&p_sci=sci&p_x=px [Accessed 17 July 2008]

4.06

(1)Gophers dig up seeds; birds eat tremendous amounts of seeds from the maturing crop. Insects can be destructive to seeds not stored properly. The following fungi are known to cause diseases in sunflowers: Albugo tragopogonis, Alternaria tenuis, Alternaria zinniae, Armillaria mellea, Ascochyta helianthi, Botrytis cinerea, Cercospora bidentis, Cercospora helianthi, Cercospora helianthicola, Cercospora pachypus, Corticium rolfsii, Cystopus cubicus, Cystopus tragopogonis, Diaporthe arctii, Diplodina helianthi, Entyloma polysporum, Erysiphe chicoracearum, Fusarium acuminatum, Fusarium conglutinans, Fusarium culmorum, Fusarium equiseti, Fusarium javanicum, Fusarium oxysporum, Fusarium sambucinum, Fusarium scirpi, Fusarium semitecum, Fusarium solani, Helminthosporium helianthi, Leptosphaeria helianthi, Leveillula compositarum, Leveillula taurica, Macrophomina phaseoli, Oidium helianthi, Ophiobolus helianthi, Phialea cynthoides, Phoma oleracea, Phymatotrichum omnivorum, Plasmopara halstedii, Puccinia helianthi, Pythium debaryanum, Pythium irregulare, Pythium splendens, Pythium ultimum, Rhabdospora helianthicola, Rhizoctonia rocorum, Rhizoctonia solani, Rhizoctonia bataticola, Rhizopus nodosus, Sclerotinia fuckeliana, Sclerotinia libertiana, Sclerotinia minor, Sclerotinia sclerotiorum, Sclerotium rolfsii, Septoria helianthi, Sphaerotheca fulginea, Sphaerotheca humuli, Uromyces junci, Verticillium albo-atrum, Verticillium dahliae. Bacteria reported as infecting sunflowers are the following: Agrobacterium tumefaciens, Bacterium melleum, Erwinia aroides, Pseudomonas cichorii, Pseudomonas helianthi, and Pseudomonas solanacearum. Virus diseases reported from sunflowers are: Apple mosaic, Argentine sunflower, Aster yellows, Brazilian tobacco streak, Cucumber mosaic, Tomato spotted wilt, Peach ringspot, Peach yellow-bud mosaic, Pelargonium leaf-curl, Tobacco necrosis, Tobacco ringspot, and Yellows. Sunflowers are parasitized by the following flowering plants: Cuscuta pentagona, Cuscuta arvensis, Orobanche aegyptiaca, Orobanche cumana, Orobanche muteli, Orobanche ramosa, Striga hermonthica, Striga asiatica, Striga lutea, Striga senegalensis. Sunflowers are attacked by many nematodes: Anguina balsamophila, Aphelenchoides ritzemabosi, Ditylenchus destructor, Ditylenchus dipsaci, Helicotylenchus cavenessi, Helicotylenchus microcephalus, Helicotylenchus microlobus, Helicotylenchus pesudorobustus, Heterodera schachtii, Longidorus maximus, Meloidogyne arenaria, Meloidogyne hapla, Meloidogyne incognita acrita, Meloidogyne javanica, Meloidogyne thamesi, Paratylenchus minutus, Pratylenchus penetrans, Rotylenchulus reniformis, Scutellonema clathricaudatum, Trichodorus christiei, and Xiphinema ifacolum.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Helianthus_annuus.html [Accessed 17 July 2008]

4.07

Yes, but only to susceptible individuals (1)Some individuals are allergic to sunflower foliage and may develop a skin rash from contact. (2)Sunflower (Helianthus annuus) causes allergic contact dermatitis in sensitive individuals after contact with the sesquiterpene lactones contained in fragile, multicellular, capitate glandular hairs

(1)http://www.floridata.com/ref/H/heli_ann.cfm [Accessed 17 July 2008] (2)http://www.scib.gc.ca/pls/pp/ppack.info?p_psn=225&p_type=all&p_sci=sci&p_x=px [Accessed 17 July 2008]

4.08

No evidence

4.09

(1)Light: True to their name, sunflowers prefer full sun. They are likely to stretch for the sun and fall over from their own weight if grown in partial shade.

(1)http://www.floridata.com/ref/H/heli_ann.cfm [Accessed 17 July 2008]

4.10

(1)Sunflowers are easy to grow in any well-drained, neutral to slightly alkaline soil. Add lime if your soil is acidic. Fertilize the bed with rotted manure or a balanced chemical fertilizer for maximum growth. (2)Crop may be grown on a wide range of soils, including poor soils, provided they are deep and well-drained. Plants are intolerant of acid or waterlogged soils.

(1)http://www.floridata.com/ref/H/heli_ann.cfm [Accessed 17 July 2008] (2)http://www.hort.purdue.edu/newcrop/duke_energy/Helianthus_annuus.html [Accessed 17 July 2008]

4.11

4.12

(1)Sunflowers can invade cultivated sites and pastures forming dense stands.

(1)http://el.erdc.usace.army.mil/pmis/plants/html/helianth.html [Accessed 17 July 2008]

5.01

Terrestrial

5.02

Asteraceae

5.03

Asteraceae

5.04

6.01

No evidence

6.02

(1)Propagation is always by seed.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Helianthus_annuus.html [Accessed 17 July 2008]

6.03

(1)Helianthus annuus is highly variable as a species, and hybridizes with several other species. (2)Gene flow between the two wild species and the cultivated sunflower is evidenced by intermediate forms often found in wild populations and tilled lands. Hybridization and introgression might have shifted genetic variation in Argentinean populations that may now differ from variation at the center of origin.

(1)http://plants.usda.gov/plantguide/pdf/cs_hean3.pdf [Accessed 17 July 2008] (2)Poverene M., Cantamutto M.A., Carrera A., Ureta S., Alvarez D., Alonso Roldán V., Presotto A., Gutiérrez A., Luis S., and Hernández A. 2006. WILD SUNFLOWERS RESEARCH IN ARGENTINA. HELIA 29(44): 65-76.

6.04

(1)Seed set low when selfed, as most cultivars seed set low when selfed, as most cultivars are self-incompatible. [incompatible for the most part] (2)The plant not is self-fertile.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Helianthus_annuus.html [Accessed 17 July 2008] (2)http://www.ibiblio.org/pfaf/cgi-bin/arr_html?Helianthus+annuus [Accessed 17 July 2008]

6.05

(1)Cross-pollination may be facilitated by 2–3 hives of honeybees per ha, the hives spaced in rows 300–400 m apart, as they need to be distributed to give coverage to all blooms.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Helianthus_annuus.html [Accessed 17 July 2008]

6.06

(1)The sunflower is an annual crop that is propagated by seed only

(1)http://www.agbios.com/docroot/decdocs/05-209-009.pdf [Accessed 17 July 2008]

6.07

(1)All the sunflower cultivars are fast-growing annuals

(1)http://www.floridata.com/ref/H/heli_ann.cfm [Accessed 17 July 2008]

7.01

Large seeds with no means of attachment

 

7.02

(1)Sunflowers are widely grown commercially for the oil that is extracted from the seeds. Russia is the world's largest producer, Argentina is second and the U.S. is third. Most production in North America is in the northern Great Plains, especially Minnesota, the Dakotas and Manitoba.

(1)http://www.floridata.com/ref/H/heli_ann.cfm [Accessed 17 July 2008]

7.03

(1)Many bird seed aliens easily germinate if exposed to water, even while still in the bird cage. Some of the better-known bird seed aliens include Panicum miliaceum (proso millet), Setaria italica (foxtail millet), and Helianthus annuus (sunflower), all common seed contaminants themselves.

(1)http://www.nescb.org/epublications/fall2001/invasives.html [Accessed 17 July 2008]

7.04

(1)sunflower seeds can disperse at least 3 m from their parent plants; thus our calculations of seed fall in natural populations (based on delimiting the area of natural patches by the outer edge of the adult plants) are likely to have led to an overabundance of added seed.

(1)Cummings, C.L. and H. M. Alexander. 2002. Population ecology of wild sunflowers: effects of seed density and post-dispersal vertebrate seed predators. Oecologia 130:274–280.

7.05

(1)The number of seeds which were transported at the surface of the river Eider was continuously analysed by four aquatic seed traps for a period of 20 weeks (July–December 2000). To test the capture rate of these traps, a recapture experiment with colour marked seeds of Helianthus annuus L. was carried out. During the investigation period approx. 9000 seeds of 76 species were captured by the four aquatic seed traps. The number of trapped seeds varied both spatially (across the river profile) and temporally. Considering this variation and the capture rate of the traps, the water-borne seed transport was estimated to be 3139 seeds per week and meter of the river profile. [seeds are buoyant]

(1)Vogta, K., L. Rasrana and K. Jensen. 2004. Water-borne seed transport and seed deposition during flooding in a small river-valley in Northern Germany. Flora - Morphology, Distribution, Functional Ecology of Plants 199(5): 377-388.

7.06

(1)Birds (especially finches and cardinals) and squirrels will help themselves to the seeds. [birds possibly disperse seeds occasionally by dropping them accidentally] (2)These attractive weedy plants are of outstanding value to wildlife in the prairies and other parts of the West. Birds eating the seeds include Wilson snipes, doves, grouse, ring-necked pheasants, quail, blackbirds, bobolinks, lazuli buntings, black-capped chickadees, cowbirds, white-winged crossbills, crows, house finches, goldfinches, purple grackles, horned larks, longspurs, meadowlarks, white-breasted nuthatches, pyrrhuloxias, ravens, sparrows, and tufted titmice.

(1)http://www.floridata.com/ref/H/heli_ann.cfm [Accessed 17 July 2008] (2)http://plants.usda.gov/plantguide/pdf/cs_hean3.pdf [Accessed 17 July 2008]

7.07

(1)Birds (especially finches and cardinals) and squirrels will help themselves to the seeds. [dispersal likely occurs when animals cache or drop seeds they intend to eat] (2)Small mammals who relish the seeds include the least chipmunk, eastern pocket gopher, ground squirrels, lemmings, meadow mice, pocket mice, white-footed mice, prairie dogs, and kangaroo rats.

(1)http://www.floridata.com/ref/H/heli_ann.cfm [Accessed 17 July 2008] (2)http://plants.usda.gov/plantguide/pdf/cs_hean3.pdf [Accessed 17 July 2008]

7.08

Mostly depredated by birds and other animals

 

8.01

(1)Average yields range from 900–1,575 kg/ha of seed; however, yields of over 3,375 kg/ha have been reported. Heads may contain 1,000–4,000 florets, with the potential of as many seeds.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Helianthus_annuus.html [Accessed 17 July 2008]

8.02

Possible (1)Storage Behaviour: Orthodox

Storage Conditions: Seeds not damaged from exposure to liquid nitrogen (Stanwood & Bass, 1981); seeds maintained for 2-5 years in commercial storage conditions (Priestley, 1986); p50= 5.4 years for seeds stored under open storage in a temperate climate (Priestley, 1986); no problem for long- term storage under IPGRI preferred conditions, seeds tolerate desiccation to 1.1% mc, LMCL= 2.04%, Cw= 4.16 (Ellis et al., 1988)

(1)Liu, K., Eastwood, R.J., Flynn, S., Turner, R.M., and Stuppy, W.H. 2008. Seed Information Database (release 7.1, May 2008) http://www.kew.org/data/sid [Accessed 17 July 2008]

8.03

Possibly not, depending on cultivar (1)Weed management techniques have been suggested as necessary to manage herbicide-tolerant populations of H. annuus (Burton et al. 2004), which have evolved in numerous distinct locales, including regions of Kansas, Missouri, South Dakota, and Iowa. Interestingly, in several of these cases, herbicide tolerance is almost nonexistent in nearby, unmanaged roadside populations, despite tolerance frequencies of up to 70% in adjacent agricultural fields (Massinga et al. 2003). This indicates the potential for differentiation between wild and weedy varieties of H. annuus, even in cases with the potential for relatively high levels of gene flow.

(1)Kane, N. C. and L. H. Rieseberg. 2008. Genetics and evolution of weedy Helianthus annuus populations: adaptation of an agricultural weed. Molecular Ecology 17: 384–394.

8.04

No evidence

8.05

(1)A major problem with sunflower production in Hawaii is the prevalence of birds that will consume a large portion of the desired seed. Birds will attack the cotyledon leaves of sunflower much as they feed on soybean plants. This activity can virtually destroy entire stands. Local growers who attempt to produce sunflower at a small scale for personal use have continually met with disappointing yields due to bird predation on the seeds (Osgood, 2006). One possible reason for such heavy bird predation is the need to ‘dry down’ the crop during cool weather, which Hawaii rarely experiences. The longer time to ‘dry down’ in the field allows for more bird damage. This factor likely makes sunflower unsuitable for proposed use as a biodiesel crop in Hawaii.

(1)Poteet, M.D. 2006. Biodiesel Crop Implementation in Hawaii. Prepared for: The State of Hawaii Department of Agriculture Under Contract Number HDOA-2006-2


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