Duncan

Synonyms

Bowen (sec. Cottin 2002)

Cultivar or taxon

Citrus x aurantium L., pro sp. [Grapefruit Group] (sensu Mabberley 1997, Bayer et al. 2009); Citrus paradisi Macfad. (sensu Swingle and Reece 1967; sensu Tanaka sec. Cottin 2002)

Origin

Hodgson (1967) noted that:

"This variety represents the oldest grapefruit clone grown in Florida, though it was not named and introduced until about 1892. As near as can be determined, the parent seedling tree was planted around 1830 near Safety Harbor, on the Pinellas Peninsula, Florida. The seed came from a tree in the original planting made by Count Odette Phillippe, who is credited with having brought the grapefruit to Florida from the West Indies. It was named for the introducer, A. L. Duncan of nearby Dunedin.

Since the grapefruits are highly polyembryonic and all varieties and seedlings in Florida trace back to the planting which contained the seed parent of Duncan, the probability is good that many, if not most, of them represent the same clone. Certainly many of the early named varieties are indistinguishable from Duncan and have been marketed under that name. It has recently been established (Cooper, Reece and Furr 1962) that the Bowen variety used in some of the early citrus breeding work in Florida was in reality Duncan."

The Chiefland Budwood Facility (2010) provided the following notes on the cultivar (clone F-56-33/F-57-19): "Open pollinated nucellar selections made by Dr. Mort Cohen with the Florida State Plant Board (SPB/DPI) in the citrus grove near Century Tower, on the campus of UF....Planted in DPI Foundation Grove in 1960 (SPB-43). Origin: 1830 near Safety Harbor, FL, introduced by A.L. Ducan, commercial by 1892."

Description

Crown compact or dense, not weeping. First-year twig surface glabrous; second- or third-year twig surface striate; thorns absent or not persistent; prickles absent or not persistent. Petiole glabrous, length short; wings medium, adjoining the blade. Leaflets one, margin entire (by misinterpretation) or bluntly toothed, shade leaflet blades flat or weakly conduplicate, sun leaflet blades flat or weakly conduplicate. Scent of crushed leaflets sweetly orange-like. Fruit as broad as long or longer than broad; rind green-yellow (6), yellow (7-10), yellow-orange (11), or orange (12); rind texture smooth (1-3) or slightly rough (4-5); firmness leathery; navel absent; flesh yellow; taste grapefruit-like.

 

Hodgson (1967) provided the following additional notes on the cultivar:

 

"Fruit large, oblate to globose or broadly obovate; basal furrows short and radiating; areolar ring faint; seedy. Color pale to light yellow. Rind medium-thick and surface smooth and even. Flesh color buff to chamois-colored; tender, very juicy; flavor pronounced and excellent. Medium-early in maturity.

 

Tree vigorous, large, very productive, and reputed to be probably the most cold-resistant."

 

The Chiefland Budwood Facility (2010) provided the following additional notes on the cultivar (clone F-56-33/F-57-19): "Description: white fleshed, large, 30-70 seeds, clusters. Season: November-May"

Notes

The Chiefland Budwood Facility (2010) provided the following notes on the cultivar (clone F-56-33/F-57-19): "Yields are good with normal Duncan grapefruit traits."

References

Bayer, R.J., D.J. Mabberley, C. Morton, C.H. Miller, I.K. Sharma, B.E. Pfeil, S. Rich, R. Hitchcock, and S. Sykes. 2009. A molecular phylogeny of the orange subfamily (Rutaceae: Aurantioideae) using nine cpDNA sequences. American Journal of Botany 96: 668–685.

Chiefland Budwood Facility. 2010. 2010 Annual report July 1, 2009 - June 30, 2010. Bureau of Citrus Budwood Registration, Florida Department of Agriculture & Consumer Services, Winter Haven.

Cottin, R. 2002. Citrus of the World: A citrus directory. Version 2.0. France: SRA INRA-CIRAD.

Mabberley, D.J. 1997. A classification for edible Citrus (Rutaceae). Telopea 7: 167–172.

Swingle, W.T. and P.C. Reece. 1967. The botany of Citrus and its wild relatives. In: Reuther, W., H.J. Webber, and L.D. Batchelor (eds.). The Citrus industry. Ed. 2. Vol. I. University of California, Riverside. http://lib.ucr.edu/agnic/webber/Vol1/Chapter3.html .

Resources

Search for this cultivar in NCBI Entrez, NCBI Nucleotide, or NCBI Expressed Sequence Tags

Additional information on this cultivar at University of California: Riverside Citrus Variety Collection

           Habit (Winter Haven, FL)

Habit (Winter Haven, FL)

           Habit (Riverside, CA)

Habit (Riverside, CA)

           Bark (Riverside, CA)

Bark (Riverside, CA)

           First year twig (Riverside, CA)

First year twig (Riverside, CA)

             Second - third year twig (Riverside, CA)

Second - third year twig (Riverside, CA)

             Petiole (Riverside, CA)

Petiole (Riverside, CA)

             Unifoliolate leaf (Riverside, CA)

Unifoliolate leaf (Riverside, CA)

             Unifoliolate leaf (Riverside, CA)

Unifoliolate leaf (Riverside, CA)

             Unifoliolate leaf (Riverside, CA)

Unifoliolate leaf (Riverside, CA)

             Margin (Riverside, CA)

Margin (Riverside, CA)

             Shade leaves (Riverside, CA)

Shade leaves (Riverside, CA)

             Shade leaves (Riverside, CA)

Shade leaves (Riverside, CA)

             Sun leaves (Riverside, CA)

Sun leaves (Riverside, CA)

           Immature fruit (Riverside, CA)

Immature fruit (Riverside, CA)

             Fruit (Riverside, CA)

Fruit (Riverside, CA)

             Fruit (Riverside, CA)

Fruit (Riverside, CA)

             Fruit cross-section (Riverside, CA)

Fruit cross-section (Riverside, CA)