United States Department of Agriculture

Animal and Plant Health Inspection Service

Plant Protection and Quarantine

Risk Management Document

Importation of Unshu Orange, Citrus reticulata var. unshu, 

Fruit from Japan into the Continental United States 

May 16, 2013

Plant Health Programs (PHP)

Regulations Permits and manuals (RPM)

Contact Person: Meredith C. Jones
Introduction

In response to the request from the Japanese national plant protection organization (NPPO) to 

reevaluate the existing conditions for the importation of Unshu orange from Japan into the 

continental United States, a Pest Risk Assessment (PRA) was developed by United States 

Department of Agriculture (USDA), Animal and Plant Health Inspection Service (APHIS), Plant 

Epidemiology and Risk Analysis laboratory (PERAL).

The PRA document, “Importation of Japanese Unshu Orange, Citrus reticulata Blanco var. 

unshu, fruit into the Continental United States (USDA, 2013), identified the pathogen

“Candidatus Liberobacter asiaticus" Jagoueix et al. 1994, as a quarantine pest that may follow 

the pathway, but rated the risk as “Negligible” since it is highly unlikely to be introduced into the 

United States via fruit for consumption. The PRA (USDA, 2013) analyzed one bacterium, 

Xanthomonas citri subsp. citri (ex Hasse 1915) Gabriel et al. 1989, as of quarantine significance 

associated with Japanese Unshu orange fruit and rated it as “Medium” pest risk potential.

History

APHIS developed a PRA titled ‘‘An Updated Evaluation of Citrus Fruit (Citrus spp.) as a 

Pathway for the Introduction of Citrus Canker Disease (Xanthomonas citri subsp. citri)’’ in 

March 2009 (USDA, 2009a). This PRA examines the information presented in Gottwald et al. 

(2009) and Shiotani et al. (2009) in the context of an earlier PRA. Based on the evidence 

presented in both the November 2007 PRA (USDA, 2007) and the two new publications, the 

updated PRA concludes that asymptomatic fruit (treated or untreated) is not epidemiologically 

significant as a pathway for introducing citrus canker. It further concludes that symptomatic 

fruit subjected to a packinghouse process that includes washing with disinfectants is also not 

epidemiologically significant as a pathway for introducing citrus canker. These conclusions led 

APHIS to prepare a supplemental Risk Management Analysis (RMA), titled ‘‘Movement of 

Commercially Packed Citrus Fruit from Citrus Canker Disease Quarantine Area; Supplemental 

Risk Management Analysis’’ (USDA, 2009b). The supplemental RMA takes into account the 

conclusions of the updated PRA as well as the evidence and discussion presented in the 

November 2007 RMA.

In the supplemental RMA, APHIS determined that currently available scientific evidence 

provides additional certainty that commercially packed and disinfected fresh citrus fruit is not an 

epidemiologically significant pathway for the spread of Xanthomonas citri subsp. citri. As a 

result of this research, APHIS amended its domestic citrus canker regulations on October 22, 

2009. Each lot of harvested domestic citrus fruit from canker quarantine areas can be shipped to 

all U.S. States provided it is treated with an approved disinfectant and packed in a commercial 

packinghouse that operates under a compliance agreement. Equivalent phytosanitary measures, 

treatment with an APHIS-approved disinfectant and packing in a commercial packing house are 

therefore appropriate for commercial consignments of Unshu oranges from Japan. The current 

regulations for the importation of Unshu oranges from Japan include more stringent conditions 

that were based on the domestic regulations that were in place before we decided that it was 

appropriate to reduce restrictions on the interstate movement of citrus fruit from citrus canker 
quarantined areas. These include requirements for production in citrus canker-free export areas 

and inspections of the Unshu oranges in the groves.

Risk Management Measures for Xanthomonas citri subsp. citri

Unshu oranges from Japan may be imported if all of the following conditions are met: 

* Unshu orange fruits may be imported only in commercial consignments. The fruit must be 

practically free of leaves, twigs and other plant parts, except for stems that are less than one inch 

long and attached to the fruit.

* Unshu orange fruits must be packed in a commercial packinghouse that is approved by and 

registered with the Japanese NPPO.

* Unshu orange fruits must be surface disinfected in accordance with 7 CFR part 305, and 

according to treatment schedules listed in the PPQ Treatment Manual, at the packinghouses.

* The consignment must have a Phytosanitary Certificate (PC) with an Additional Declaration 

(AD) issued by the Japanese NPPO stating that the Unshu oranges were treated in accordance 

with 7 CFR part 305.

* APHIS will inspect Unshu orange fruit consignments at the port of entry to the United States.

Summary

APHIS believes that the risk management measures discussed in this document will provide an 

appropriate level of phytosanitary protection against the bacterium Xanthomonas citri subsp. citri

associated with Unshu orange fruit imported from Japan into the Continental United States.

APHIS requires fruit moved from an area where citrus canker exists to be treated with an 

approved disinfectant and to be packed in approved commercial packinghouses. The 

product may be imported in commercial consignments only after treatment with a 

disinfectant, only if it is free of leaves, twigs, and other plant parts, except for stems that 

are less than 1 inch long and attached to the fruit.

Author

José R. Hernández Ph.D.

Senior Risk Manager – Plant Pathology.
References

APHIS, 2000. Guidelines for Pathway-Initiated Pest Risk Assessments. Version 5.02. Plant 

Protection and Quarantine, Riverdale, Maryland.

Gottwald, T., Graham, J., Bock, C., Bonn, G., Civerolo, E., Irey, M., Leite, R., López, M. M., 

McCollum, G., Parker, P., Ramallo, J., Riley, T., Schubert, T., Stein, B., and Taylor, E. 

2009. The epidemiological significance of post packinghouse survival of Xanthomonas 

citri subsp. citri for dissemination of Asiatic citrus canker via infected fruit. Crop 

Protection 28:508-524.

Shiotani, H., Uematsu, H., Tsukamoto, T., Shimizu, Y., Ueda, K., Mizuno, A. & Sato, S. 2009. 

Survival and dispersal of Xanthomonas citri pv. citri from infected Satsuma mandarin fruit. 

Crop Protection 28:19-23.

USDA. 2007. Movement of Commercially Packed Citrus Fruit from Citrus Canker Disease 

Quarantine Area. Revised Risk Management Analysis. United States Department of 

Agriculture, Animal and Plant Health Inspection Service, Plant Protection and Quarantine, 

Center for Plant Health Science and Technology, Plant Epidemiology and Risk Analysis 

laboratory. 123 pp.

USDA, 2009a. An Updated Evaluation of Citrus Fruit (Citrus spp.) as a Pathway for the 

Introduction of Citrus Canker Disease (Xanthomonas citri subsp. citri). United States 

Department of Agriculture, Animal and Plant Health Inspection Service, Plant Protection 

and Quarantine, Center for Plant Health Science and Technology, Plant Epidemiology and 

Risk Analysis laboratory. 11 pp.

USDA, 2009b. Movement of Commercially Packed Citrus Fruit from Citrus Canker Disease 

Quarantine Area, Supplemental Risk Management Analyses. United States Department of 

Agriculture, Animal and Plant Health Inspection Service, Plant Protection and Quarantine, 

Center for Plant Health Science and Technology, Plant Epidemiology and Risk Analysis 

laboratory. 28 pp.

USDA, 2013. Importation of Japanese Unshu Orange, Citrus reticulata Blanco var. unshu, fruit 

into the Continental United States. A Pathway-Initiated Risk Analysis. Version 5. United 

States Department of Agriculture, Animal and Plant Health Inspection Service, Plant 

Protection and Quarantine, Center for Plant Health Science and Technology, Plant 

Epidemiology and Risk Analysis laboratory. 97 pp.