African Shaddock x Rubidoux Trifoliate

UCR identifies CRC 3969 / PI 539830 / VI 476 as African Shaddock × Rubidoux trifoliate. The Riverside collection records receiving the accession as budwood from the US Date and Citrus Station in 1988. The entry also mentions a move to Lindcove and Hybrid 15-1 budwood brought to Riverside, without dating or sequencing those transfers. UCR lists ripening from October to November at Riverside.^⁠[1]

Hall et al.’s March 2014 Ft. Pierce survey reports 0–3 mean psyllid density ratings for the seedling population CRC 3969; these are estimates, not actual egg or nymph counts, and do not establish orchard-level HLB control.^⁠[2] A separate Arizona greenhouse report lists “S-27. African Shaddock x Rubidoux Trifoliate” under P. parasitica; the 1994 and 1995 cells show “--” and “**”, which the report does not define. It gives no CRC number for this row, so no root-loss value or resistance category is assigned.^⁠[3]