Citrus x insitorum Mabb.
Received as budwood from Florida DPI clone DPI-814-A at F/E 19-18. CTV status 'NTF'. DPI source from original USDA parent FF-1-132-46. Bureau of Citrus Budwood Registration, Florida, 2002.
Hybrid of C. reticulata 'Sunki' X P. trifoliata 'Benecke', Joe Furr, USDCS, 1965.
Rootstocks of accession
Season of ripeness at Riverside
Notes and observations
RRK, 9/2006: "Although this accession originated at the US Date and Citrus Station in Indio, California. its release was made possible by development work by Florida USDA personnel in 1980's and 1990's. According to the Release Notice (dated 05/2001), "In some Florida trials, performance of US-812 was outstanding in comparison to common commercial rootstocks in yield and fruit quality over multiple years. In all Florida trials US-812 performance was good, and trees on US-812 grew, survived well, and produced good crops of excellent quality fruit. The major attributes of this new rootstock are ease of seed propagation, resistance to severla important diseases, and favorable effects on scion tree size, health, fruit quality, and productivity...[In a trial in Polk County, Florida] Trees on US-812 rootstock...were generally of good health and medium stature, similar to trees on Carrizo...Preliminary test data suggests that US-812 is resistant to...citrus tristeza virus (CTV), citrus nemataode (Tylenchulus semipenetrans), and Phytophthora nicotianae foot and root rot. A low incidence of blight-like decline has been observed [in comparison to other rootstocks used in various trials]. This suggests that US-812 is resistant but not immune to citrus blight. Greenhouse tests with Diaprepes abbreviatus weevil indicate that US-812 is equal to Swingle in susceptibility to Diaprepes larvae feeding. US-812 rootstock is expected to be sensitive to exocortis...Meaningful evaluations of US-812 resistance to other potential biotic and abiotic problems have not yet been completed."