Four New SuperSour Rootstocks for Improved Production of Sweet Orange in a Huanglongbing Environment

Abstract

US SuperSour 2, US SuperSour 3, US SuperSour 4, and US SuperSour 5 are new citrus rootstock cultivars released during 2018 to 2023 (Bowman 2018a, 2018b, 2023a, 2023b) by the Agricultural Research Service (ARS) of the US Department of Agriculture (USDA). The major positive attributes of these new citrus rootstocks are superior field performance with sweet orange scion in huanglongbing (HLB)-endemic regions affected by Candidatus Liberibacter asiaticus (CLas). Superior performance included superior canopy health and fruit production. All four of these new rootstocks can be easily propagated by stem cuttings or micropropagation, and one of them is also uniformly and efficiently propagated by apomictic seed.

Keywords

• breeding
• citrus
• cultivar
• fruit drop
• genetics
• incompatibility
• rootstock
• single sequence repeats
• sour orange
• yield