Citrus sinensis (Linnaeus) Osbeck. Family - Rutaceae. Common Names:Navel Orange, Kona Orange, Sweet Orange, Waialua Orange, Cheng, Ju Zi. Synonym: C. aurantium Linnaeus var. sinensis Linnaeus

Answer

Score

1.01

Is the species highly domesticated?

y

-3

1.02

Has the species become naturalized where grown?

n

-1

1.03

Does the species have weedy races?

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”

2.02

Quality of climate match data (0-low; 1-intermediate; 2-high) see appendix 3

2.03

Broad climate suitability (environmental versatility)

n

0

2.04

Native or naturalized in regions with tropical or subtropical climates

y

1

2.05

Does the species have a history of repeated introductions outside its natural range? y=-3

y

3.01

Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.06

n

-2

3.02

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

n

0

3.03

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

n

0

3.04

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

n

0

3.05

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

4.01

Produces spines, thorns or burrs

y

1

4.02

Allelopathic

4.03

Parasitic

n

0

4.04

Unpalatable to grazing animals

n

-1

4.05

Toxic to animals

4.06

Host for recognized pests and pathogens

y

1

4.07

Causes allergies or is otherwise toxic to humans

n

0

4.08

Creates a fire hazard in natural ecosystems

n

0

4.09

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

y

1

4.1

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

y

1

4.11

Climbing or smothering growth habit

n

0

4.12

Forms dense thickets

n

0

5.01

Aquatic

n

0

5.02

Grass

n

0

5.03

Nitrogen fixing woody plant

n

0

5.04

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

n

0

6.01

Evidence of substantial reproductive failure in native habitat

n

0

6.02

Produces viable seed.

y

1

6.03

Hybridizes naturally

y

1

6.04

Self-compatible or apomictic

6.05

Requires specialist pollinators

n

0

6.06

Reproduction by vegetative fragmentation

n

0

6.07

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

3

0

7.01

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

7.02

Propagules dispersed intentionally by people

y

1

7.03

Propagules likely to disperse as a produce contaminant

y

1

7.04

Propagules adapted to wind dispersal

n

-1

7.05

Propagules water dispersed

n

-1

7.06

Propagules bird dispersed

7.07

Propagules dispersed by other animals (externally)

7.08

Propagules survive passage through the gut

8.01

Prolific seed production (>1000/m2)

n

-1

8.02

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

8.03

Well controlled by herbicides

8.04

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

8.05

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

y

-1

Total score:

Notes

Source

1.01

(1) Since sweet orange is so popular, and because it has been cultivated for so many centuries, there are a multitude of cultivars. (2) It is probably native to northwestern India, Myanmar (Burma), and southern China, but is no longer found in the wild.

(1) Staples, G.W. and D.R.Herbst. 2005. A Tropical Garden Flora: Plants Cultivated in Hawaii and Other Tropical Places. Bishop Museum Press, Honolulu, Hawaii. 908 pp. (2) Riffle, R.L. 1998. The Tropical Look: An Encyclopedia of Dramatic Landscape Plants. Timber Press, Portland, Oregon. 428 pp.

1.02

The following references are not sufficient evidence of naturalization. (1)Moist foothills and mountains; more than 1000 plants (2)DISTRIBUTION: Escape from cultivation; Kermadec Is (Raoul). (3)Citrus sinensis (L.) Osbeck; exotic, occasional, persistent, valley forests (Axelrod 8805).

(1) Francis, J.K. and H.A. Liogier. 1991. Naturalized exotic tree species in Puerto Rico. USDA Forest Service. Southern Forest Experiment Station. New Orleans, Louisiana. General Technical Report SO-82. (2) Sykes, W.R. 1982. Checklist of dicotyledons naturalised in New Zealand 15. Annonales, Berberidales, Cactales, Fagales, some Geraniales, Juglandales, Laurales, Rutales, Salicales, Sapindales, Tiliales, Nyctaginaceae, and Zygophyllaceae. New Zealand Journal of Botany 20 : 333-341. (3). Acevedo-Rodriguez, P. and F.S. Axelrod. 1999. Annotated Checklist for the Tracheophytes of Rı´o Abajo Forest Reserve, Puerto Rico. Caribbean Journal of Science 35(3-4): 265-285

1.03

(1) Listed as an Environmental Weed, but no specifics or impacts mentioned.

(1)http://www.hear.org/gcw/species/citrus_sinensis/ (Accessed 25 Oct 2007).

2.01

(1) The orange is subtropical, not tropical. During the growing period, the temperature should range from 55º to 100º F (12.78º-37.78º C). (2) Citrus sinensis and its cultivars are hardy in zones 9b through 11 and marginal in zone 9a…The navel oranges are not completely adapted to the humid subtropical regions like Florida and the Gulf Coast

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL. (2) Riffle, R.L. 1998. The Tropical Look: An Encyclopedia of Dramatic Landscape Plants. Timber Press, Portland, Oregon. 428 pp.

2.02

2.03

(1) The orange is subtropical, not tropical. During the growing period, the temperature should range from 55º to 100º F (12.78º-37.78º C). (2) Citrus sinensis and its cultivars are hardy in zones 9b through 11 and marginal in zone 9a…The navel oranges are not completely adapted to the humid subtropical regions like Florida and the Gulf Coast (3) Orange cultivation in the Hawaiian Islands succeeds best below 1500' elevation, where sunny, warm, low-humidity conditions prevail.

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL. (2) Riffle, R.L. 1998. The Tropical Look: An Encyclopedia of Dramatic Landscape Plants. Timber Press, Portland, Oregon. 428 pp. (3) Staples, G.W. and D.R.Herbst. 2005. A Tropical Garden Flora: Plants Cultivated in Hawaii and Other Tropical Places. Bishop Museum Press, Honolulu, Hawaii. 908 pp.

2.04

(1) The orange is unknown in the wild state; is assumed to have originated in southern China, northeastern India, and perhaps southeastern Asia (formerly Indochina).

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL.

2.05

(1) The orange has become the most commonly grown tree fruit in the world. It is an important crop in the Far East, the Union of South Africa, Australia, throughout the Mediterranean area, and subtropical areas of South America and the Caribbean.

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL.

3.01

The following references are not sufficient evidence of naturalization. (1)Moist foothills and mountains; more than 1000 plants (2)DISTRIBUTION: Escape from cultivation; Kermadec Is (Raoul). (3)Citrus sinensis (L.) Osbeck; exotic, occasional, persistent, valley forests (Axelrod 8805).

(1) Francis, J.K. and H.A. Liogier. 1991. Naturalized exotic tree species in Puerto Rico. USDA Forest Service. Southern Forest Experiment Station. New Orleans, Louisiana. General Technical Report SO-82. (2) Sykes, W.R. 1982. Checklist of dicotyledons naturalised in New Zealand 15. Annonales, Berberidales, Cactales, Fagales, some Geraniales, Juglandales, Laurales, Rutales, Salicales, Sapindales, Tiliales, Nyctaginaceae, and Zygophyllaceae. New Zealand Journal of Botany 20 : 333-341. (3). Acevedo-Rodriguez, P. and F.S. Axelrod. 1999. Annotated Checklist for the Tracheophytes of Rı´o Abajo Forest Reserve, Puerto Rico. Caribbean Journal of Science 35(3-4): 265-285

3.02

(1) Not listed as a garden weed

(1) http://www.hear.org/gcw/species/citrus_sinensis/ (Accessed 25 Oct 2007)

3.03

(1) Not listed as an agricultural weed

(1) http://www.hear.org/gcw/species/citrus_sinensis/ (Accessed 25 Oct 2007)

3.04

(1) Listed as an Environmental Weed, but no specifics or impacts mentioned and the cited data sources have already proven to be unreliable [this species have not even been shown to be naturalized]

(1)http://www.hear.org/gcw/species/citrus_sinensis/ (Accessed 25 Oct 2007).

3.05

(1) Numerous references to other Citrus spp. as "weed" or "environmental weed" but no specifics given on impacts or problems caused.

(1) http://www.hear.org/gcw/scientificnames/scinamec.htm (Accessed 25 Oct 2007)

4.01

(1) The twigs are twisted and angled when young and may bear slender, semi-flexible, bluntish spines in the leaf axils.

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL.

4.02

No evidence for Citrus sinensis (1) AB: The involvement of allelopathy in citrus orchards was indicated by the discovery of a phenolic phytotoxin in citrus orchard soils and partly decomposed citrus root residues. The phytotoxin, tentatively identified as homovanillic acid, is produced by the anaerobic decomposition of citrus roots in the deeper soil horizons. It caused arrest in rough lemon seedling radicle elongation and a marked swelling of the root tip. (2) Aqueous methanol extracts of Citrus junos, C. unshiu and C. hassaku fruit peel inhibited the growth of the roots and hypocotyls of lettuce (Lactuca sativa L.) seedlings. (3) Known Allelopath: No

(1) Burger, W. P.; Small, J. G. C. (1982) Allelopathy in citrus orchards. Abstracts, XXIst International Horticultural Congress, 1982, No.Vol. I, p.Abstract No. 1359 (2) Kato-Noguchi, H. and Y. Tanaka. 2003. Allelopathic potential of citrus fruit peel and abscisic acid-glucose ester. Plant Growth Regulation 40(2): 117-120. (3) http://plants.usda.gov/java/charProfile?symbol=CISI&format=print (Accessed 25 Oct 2007) 

4.03

free living tree

4.04

(1) In and around old plantations, but until recently wild plants have usually been killed when young by feral goats.

(1) Webb, C.J., W.R. Sykes and P.J. Garnock-Jones. 1988. Flora of New Zealand Volume IV: Naturalised Pteridophytes, Gymnosperms, Dicotyledons. Botany Division, D.S.I.R., Christchurch, New Zealand. 1365 pp.

4.05

Unlikely, but see references (1) Animal studies are however recommended to determine at what level limonene becomes toxic to farm animals. (2) Citrus seed meal has been reported to contain limonene which is toxic to pig and especially to poultry

(1) Oluremi O I A, Ngi J and Andrew I A 2007: Phytonutrients in citrus fruit peel meal and nutritional implication for livestock production. Livestock Research for Rural Development. Volume 19, Article #89. Retrieved October 25, 2007, from http://www.cipav.org.co/lrrd/lrrd19/7/olur19089.htm (2) Serres, H. 1999. Manual of Pig production in the Tropics. CABS Publishing in Association with CTA. Biddles Ltd. Guild for Kings Lynn London: 101.

4.06

(1) Citrus canker is a disease that causes lesions on the leaves, stems, and fruit of citrus trees. While not harmful to humans, the disease affects the health and marketability of infected fruit. It is spread by wind and rain. Despite a 10-year monumental effort to eradicate the disease from Florida, an unprecedented series of storms in 2004 and 2005 spread the disease to the point where eradication was no longer possible. (2) Citrus greening, also called Huanglongbing or yellow dragon disease, is one of the more serious diseases of citrus. This bacterial disease is thought to have originated in China in the early 1900s. The disease is primarily spread by two species of psyllid insects. One species, the Asian citrus pysllid, Diaphorina citri, has been present in Florida since 1998. The bacteria itself is not harmful to humans but the disease has harmed trees in Asia, Africa, the Arabian Peninsula, and Brazil. There are three strains of the bacteria, an Asian, an African version, and a recently described American strain discovered in Brazil.

(1) http://www.aphis.usda.gov/newsroom/hot_issues/citrus_canker/citrus_canker.shtml (Accessed 25 Oct 2007). (2) http://www.aphis.usda.gov/plant_health/plant_pest_info/citrus_greening/index.shtml (Accessed 25 Oct 2007)

4.07

(1) rare event (2) Persons in close proximity to orange trees in bloom may have adverse respiratory reactions. Sawdust of the wood of orange trees, formerly used for polishing jewelry, has caused asthma. Excessive contact with the volatile oils in orange peel can produce dermatitis.

4.08

(1) The lack of fires during this period can be ascribed to a combination of fire suppression, conversion of adjacent lands to non-flammable citrus groves, and happenstance.

(1) Menges, E.S.; W. G. Abrahamson; K. T. Givens; N. P. Gallo and J. N. Layne. 1993. Twenty Years of Vegetation Change in Five Long-Unburned Florida Plant Communities. Journal of Vegetation Science 4( 3): 375-386.

4.09

(1) Light: Full sun for maximum production, but oranges do quite well in partial shade, or under the light, filtered shade of large pines or oaks.

(1) http://www.floridata.com/ref/C/citr_sin.cfm (Accessed 25 Oct 2007).

4.1

(1) Soil: The best soil for orange-growing in Florida is known as Lakeland fine sand, well-drained, and often identified as high hammock or high pineland soil. There must be adequate depth for good root development. Shallow soils of high water-holding ability are avoided. In Egypt, it has been found that where the water table is too high–30 in (78 cm) or less below the surface of the soil–root growth, vegetative vigor and fruit yield of orange trees are greatly reduced. In the alkaline soil of South Florida, neglected orange trees develop chlorosis and gradually decline. Many old groves planted in the southern part of the state to avoid cold have been totally lost. In California, the best soils for orange groves are deep loams. It is important to select the appropriate rootstock for particular soil conditions. (2) Soil type: Trees will grow in almost any soil type if well aerated. The optimum conditions for citrus orchards are fertile, light to medium, well-drained, deep, loose loams; soils with a high water table should be avoided. The species is sensitive to excess salts; pH range of 5-8 is preferred.

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL. (2) http://www.worldagroforestrycentre.org/SEA/Products/
AFDbases/AF/asp/SpeciesInfo.asp?SpID=537 (Accessed 25 Oct 2007)

4.11

(1) The orange tree, reaching 25 ft (7.5 m) or, with great age, up to 50 ft (15 m), has a rounded crown of slender branches.

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL.

4.12

(1) No evidence of dense stand formation in any mention of naturalization

(1) http://www.hear.org/gcw/species/citrus_sinensis/ (Accessed 25 Oct 2007).

5.01

(1) The orange tree, reaching 25 ft (7.5 m) or, with great age, up to 50 ft (15 m), has a rounded crown of slender branches.

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL.

5.02

(1) The orange tree, reaching 25 ft (7.5 m) or, with great age, up to 50 ft (15 m), has a rounded crown of slender branches.

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL.

5.03

(1) Rutaceae

(1) http://en.wikipedia.org/wiki/Nitrogen_fixation (Accessed 25 Oct 2007)

5.04

(1) A tree

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL.

6.01

(1) Reproduces in native and introduced habitats

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL.

6.02

(1) While the orange will often come true from seed because of nucellar embryos, the common means of assuring the reproduction of cultivars of known quality is by budding onto appropriate rootstocks.

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL.

6.03

(1) Among the variants of the common lemon, the oriental one, or Citrus meyeri, or Lemon Meyer, is a natural hybrid of the lemon (Citrus limon) and the sweet orange (Citrus sinensis) and comes from China.

(1) http://www.limmi.it/content/view/45/89/lang,en/ (Accessed 25 Oct 2007)

6.04

(1) ORANGES: A general statement about the pollination of oranges is difficult because of the variation among cultivars. Coit (1915) stated that certain oranges require pollination to set fruit, others will set fruit parthenocarpically without the stimulus of pollination, and some will not accept pollen from some other cultivars. (2) Oranges: A large variation between cultivars exists in oranges making any sort of general statement difficult. Studies on certain varieties, however, have been accomplished: Mandarin and Mandarin-Hybrid Complex: Many varieties of this complex are self-incompatible and require pollination. Pummelo: This variety appears to be grown commercially only in the Orient and is self-incompatible.

(1) http://www.beeculture.com/content/pollination_handbook/chap_5.html (Accessed 25 Oct 2007) (2) M.T. Sanford. 1992. Pollination of Citrus by Honey Bees. Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida.RFAA092.

6.05

(1) In summary it may be concluded that honey bees are unquestionably important in the pollination of citrus, though some varieties benefit more than others.

(1) M.T. Sanford. 1992. Pollination of Citrus by Honey Bees. Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida.RFAA092.

6.06

(1) Vegetative Spread Rate: Slow [not an indication of vegative fragmentation]

(1) http://plants.usda.gov/java/charProfile?symbol=CISI&format=print (Accessed 25 Oct 2007)

6.07

(1) C. sinensis starts flowering and bearing fruit after 3-5 years.

(1) http://www.worldagroforestrycentre.org/SEA/Products
/AFDbases/AF/asp/SpeciesInfo.asp?SpID=537 (Accessed 25 Oct 2007)

7.01

No evidence.

7.02

(1) The orange has become the most commonly grown tree fruit in the world. It is an important crop in the Far East, the Union of South Africa, Australia, throughout the Mediterranean area, and subtropical areas of South America and the Caribbean.

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL.

7.03

Propagules are inside product (fruit)

7.04

Large fruit (1) The fruit is globose, subglobose, oblate or somewhat oval, 2 1/2 to 3 3/4 in (6.5-9.5 cm) wide.

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL.

7.05

Large fruit (1) The fruit is globose, subglobose, oblate or somewhat oval, 2 1/2 to 3 3/4 in (6.5-9.5 cm) wide.

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL.

7.06

(1) AB: The damage caused by the blue-fronted amazon (Amazona aestiva )[a parrot] to oranges, lemons and grapefruits in an orchard in northeast Tucumán was assessed. The 1)damage caused was low (1% in total) and of little economic significance. Oranges suffered more damage (2%) than lemons or grapefruits. 2) many reports such as this one were found on damage to oranges, but nothing on significant bird visitation to lemons. In Hawaii, bird damage has not been observed.

(1) Navarro, J. L.; Martella, M. 1)B.; Chediack, A. (1991) Analysis of blue-fronted amazon damage to a citrus orchard in Tucumán, Argentina. AgriScientia, 1991, Vol.8, pp.75-78, 8 ref. 2) Manabe, K.; Ashizawa, M.1977 Studies on delayed harvesting of satsumas. The effects of covering materials and antitranspirants on fruit quality. Technical Bulletin of Faculty of Agriculture, Kagawa University, , Vol.28, No.60, pp.203-208

7.07

(1) POSSIBLY DISPERSED BY BATS? AB: A review and discussion on the damage caused by R. aegyptiacus to dates, figs, pears, apples, peaches, citrus fruits, strawberries, mulberries and other fruits.

(1) Madkour, G. (1977) Rousettus aegyptiacus (Megachiroptera) as a fruit eating bat in A.R. Egypt. Agricultural Research Review, 1977, Vol.55, No.1, pp.167-172, 14 ref. AB: A review and discussion on the damage caused by R. aegyptiacus to dates, figs, pears, apples, peaches, citrus fruits, strawberries, mulberries and other fruits.

7.08

possibly bird dispersed but little or no report of visitation or damage by birds

8.01

(1) In each segment there may be 2 to 4 irregular seeds, white externally and internally, though some types of oranges are seedless.

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL.

8.02

No evidence

8.03

No evidence

8.04

Don't know (1) Pruning: Orange trees are self-forming and do not need to be shaped by early pruning. Removal of water sprouts from young and older trees is important. Branches that are lower than 1 ft (30 cm) from the ground should be taken off. Deadwood from any cause–adverse soil conditions, pests or diseases, nutritional deficiencies, or cold injury–should be cut out and cut surfaces over 1 in (2.5 cm) in diameter should be sealed with pruning compound. Orange trees that are close-planted and hedged are being mechanically pruned by special equipment. Cuban experimenters claim that this procedure is beneficial in increasing the number of new shoots and that it decreases pest and disease problems.
In Israel, the old practice of girdling has been revived. If done in winter, it will enhance the sprouting of buds in the spring. Summer girdling increases the size of the fruits. [most cultivated trees are on grafted rootstock, so it is difficult to infer behavior from cultivated plants]

(1) Morton, J. 1987. Orange. p. 134–142. In: Fruits of warm climates. Julia F. Morton, Miami, FL.

8.05

in most parts of Hawai‘i active and frequent pest control is required for fruit production by Citrus. Many serious citrus pests are present.

http://www.extento.hawaii.edu/kbase/