US-802 Citrumelo

US-802 is a USDA citrus rootstock released in 2007. UCR records its parentage as a cross of Siamese pummelo and Gotha Road trifoliate orange, believed made around 1970; the maker and individual Siamese accession are not established. UCR also records its 2008 receipt as CRC 4266 and evaluation in some California trials.^{⁠[1]⁠[3]⁠[7]}

Citrus ID describes a compact or dense, nonweeping crown and fruit that are as broad as long or longer than broad, with yellow-to-red-orange, slightly rough to rough, leathery rind and orange flesh. Studies report propagation from stem cuttings and open-pollinated seedling production, with nursery results specific to their methods and samples.^{⁠[5]⁠[4]⁠[10]}

The release account describes vigorous grafted trees and resistance or tolerance to citrus tristeza virus, citrus blight, Phytophthora palmivora and Diaprepes root weevil in its field evaluations, while noting very large trees and intermediate or low soluble solids in scion fruit. Later Florida reports describe site-specific Hamlin and Valencia performance. A controlled greenhouse study classified US-802 as moderately tolerant to Las, not resistant; results varied and shoot mass was reduced. These findings concern particular release evaluations, grafted scions and experimental seedlings, not universal field performance or immunity.^{⁠[1]⁠[6]⁠[11]⁠[12]}