Chironja grapefruit hybrid (CRC 3909)

Citrus paradisi Macfadyen

CRC 3909

PI 539498

VI 438

Photos by Toni Siebert and David Karp, CVC, 5/22/2008. Photo rights. 25 year old trees. 

Source: Received as budwood from Puerto Rico via Glenn Dale  at the request of W.P. Bitters, 1983.

Parentage/origins:  Parent unknown.

Rootstocks of accession: Carrizo citrange, C-35 citrange

Season of ripeness at Riverside: January to May

Notes and observations:

3/10/1988, EMN: Dr. Bitters suggests that this might be a pummelo-orange hybrid instead of a grapefruit-orange hybrid; but he is not sure, so we will keep it in the grapefruit hybrid group for now.

3/11/1988, EMN: The reason Dr. Bitters thinks this may not be a grapefruit- sweet orange hybrid is because it is monoembryonic and both grapefruit and sweet orange are highly polyembryonic; therefore: Chironja should be more likely a pummelo-orange hybrid, maybe, perhaps, etc. etc.

2/26/1990, EMN: Only a very few fruits-small & still mostly green- off-bloom?--EMN

6/10/2009, DK & TS: Oblong; fine, tender orange flesh; medium seedy; sweet and juicy, with flavor more like orange than grapefruit.

Description from The Citrus Industry Vol. 1 (1967):

Fruit large (grapefruit size), broadly obovoid to pyriform: low neck or broad somewhat furrowed collar; few-seeded, seeds strongly polyembryonic.  Rind medium-thin, smooth, moderately adherent but readily peelable; color bright yellow at maturity.  Segments about 10; axis medium-large and semi-open.  Flesh color yellowish-orange; tender, very juicy; flavor mild, lacking the bitterness of the grapefruit.  Midseason in maturity and fruit holds well on tree.
      Tree vigorous, large, and grapefruit-like; leaves broadly winged, somewhat cupped, and margins irregularly undulate.  Fruits usually borne singly rather than in clusters characteristic of grapefruit.
      Chironja recently came to notice in Puerto Rico and exhibits resemblances to both the orange and grapefruit, particularly to the latter.  The name represents a combination of Chi(na), the local term used for the sweet orange, and (to)ronja, the Spanish word for grapefruit.
      According to Moscoso (1958), from whom the characterization above is adapted, this fruit first came to his attention in 1956 as a wild seedling tree in the mountainous Angeles and Caguanas rural section of Utuado municipality.  Subsequently, however, other seedling trees were found in isolated areas of the coffee zone.  The parentage of Chironja is unknown, but it is thought to be a natural orangelo of local origin.  The fruit has attracted interest and limited quantities are available in the principal local market.
      

Availability: available in California through the Citrus Clonal Protection Program.

USDA Germplasm Resources Information Network page for Chironja grapefruit hybrid (CRC 3909)