Citrus vulgaris sour orange hybrid

"Japanese orange"

CRC 760

PI 539177 

Photos by David Karp, CVC,  2/11/2008. Photo rights. 

Source: Received as seed from P.J. Webster, Lamao, Bataan, Philippine Islands, 1916.

Parentage/origins: Parents unknown. Thought to be a hybrid with citron.

Rootstocks of accession: Carrizo citrange, C-35 citrange

Season of ripeness at Riverside: January to March.

Notes and observations:

1928, Tanaka: This is not known as "Japanese Orange."

RGL: Japanese orange must be a name given to this fruit in the Philippines.

1986, EMN: This appears to be a sour orange. This accession had seedling yellows, removed by thermotherapy. Citrus vulgaris does not appear in TCI, Vol. I.

2/26/1988, EMN: No fruit on trees but one fruit on ground (presumably from this cultivar) indicates possible citron hybrid. Young flush is dark purple.

1/20/1989, EMN: Probably not a sour orange. Externally, fruit resembles a Palestine sweet lime, but is not sweet. Greenish yellow flesh is VERY sour. Moderately thick rind, moderately seedy. Young fruits are purple. Is this a lemon or citron hybrid?

2/11/2008, OJB, TS & DK: Fruit round, yellow; flesh light green and slightly firm; both tree and aroma like citron; tree has dieback. 

Availability: Not commercially available in California.

USDA Germplasm Resources Information Network page for Japanese orange sour orange hybrid