Discovered
A bud sport with much deeper red flesh was found on the irradiated A&I 1-48 selection and became Rio Red.
Sources: [3]
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World of CitrusWorld of CitrusRio Red Grapefruit
A bud sport with much deeper red flesh was found on the irradiated A&I 1-48 selection and became Rio Red.
Sources: [3]
Rio Red grapefruit was released in 1984.
Rouse, Wutscher, and Youtsey (2001, printed p. 3) explicitly state that A&I-1-48S was released by Texas A&I Citrus Center as Rio Red in 1984, supporting this existing Releasing Organization attribution. The 2004 origins paper remains the selected source for the recognized 1976/1984 chronology; the 2001 account is cited as corroboration.
The 2002 Citrus Australia fact sheet reports that Rio Red was imported from California and released from Australian plant quarantine in 1992.
Sources: [7]