United States Department of Agriculture

Animal and Plant Health Inspection Service

Plant Protection and Quarantine

Risk Management Document

Importation of Two Fresh Fruit Hybrids of Unshu, Sweet, and 

Mandarin Oranges, Citrus spp., from Korea into the 

Continental United States 

May 22, 2013

Plant Health Programs (PHP)

Regulations Permits and manuals (RPM)

Contact Person: Marc E. Phillips
Risk Management Document for Two Tangerine, Unshu, and Sweet from Korea

Introduction

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) in response to the request from the 

Korean national plant protection organization (NPPO) to allow the importation into the 

continental United States from Cheju Island of the Republic of Korea of two hybrids of 

Unshu, sweet, and mandarin oranges:

• Shiranuhi [(C. reticulata ssp. unshiu × (C. × sinensis)) × C. reticulata]

• Setoka [(C. reticulata ssp. unshiu × (C.× sinensis)) × C. reticulata] × C. 

reticulata]

The PRA document, “Importation of Two Fresh Fruit Hybrids of Unshu, Sweet, and 

Mandarin Oranges, Citrus spp., from Korea into the Continental United States

(USDA, 2013), identified two pests, Xanthomonas citri subsp. citri (ex Hasse 1915) 

Gabriel et al. 1989 (ex Hasse 1915) Gabriel et al. 1989 and Elsinoë australis Bitanc. &

Jenkins 1936, of quarantine significance associated with the above mention commodity.

Citrus cancer (Xanthomonas citri subsp. citri) and sweet orange scab (Elsinoë australis)

were rated as medium Pest Risk Potential in the PRA (USDA, 2013).

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 

newer 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 (USDA, 2009b). Each lot of harvested domestic citrus fruit from 

2
Risk Management Document for Two Tangerine, Unshu, and Sweet from Korea

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 APHISapproved disinfectant and packing in a commercial packing house are therefore necessary

for commercial consignments of the two fresh fruit hybrids of unshu, sweet, and 

mandarin oranges, Citrus spp., from Korea into the Continental United States.

Elsinoë australis pathotype natsudaidai was characterized from Citrus natsudaidai

Hayata (Hyn et al., 2009); research needs to be performed to confirm susceptibility of 

different species of citrus (Hyn et al., 2009). We consider this pathotype a quarantine 

pest, however, at this time we have no evidence this pathotype attacks Unshu oranges

(USDA, 2013).

Risk Management Measures for Xanthomonas citri subsp. citri and Elsinoë australis.

Citrus produced in Cheju Island of the Republic of Korea may be imported if all of the 

following conditions are met: 

* Citrus fruits may be imported in commercial consignments only.

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

registered with the Korean NPPO. 

* Citrus fruits must be treated with a disinfectant in accordance with 7 CFR part 305, and 

the consignment must be accompanied by a Phytosanitary Certificate (PC) with an 

Additional Declaration (AD) issued by the Korean NPPO stating that the citrus were 

treated in accordance with 7 CFR part 305, inspected and found free of sweet orange 

scab.

* The regulated fruit is free of leaves, twigs, and other plant parts, except for stems that 

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

Summary

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

provide an appropriate level of phytosanitary protection against the pest of quarantine 

concern associated with the two fresh fruit hybrids of unshu, sweet, and mandarin 

oranges, Citrus spp., from Korea into the Continental United States.

Two pests of quarantine concern, the bacterium Xanthomonas citri subsp. citri and the 

fungus Elsinoë australis, could reasonably be expected to follow the pathway on citrus 

fruits in the absence of risk management measures. 

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

3
Risk Management Document for Two Tangerine, Unshu, and Sweet from Korea

packinghouse. 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, 

and be inspected and found free of sweet orange scab.

The phytosanitary certificate with the additional declaration will require the Korean 

NPPO to inspect the fruit for symptoms of Sweet orange scab. This disease can be 

detected if present, and if the symptoms are not present the fruit are unlikely to be a 

pathway for the disease (USDA, 2009a).

Author

José R. Hernández Ph.D.

References

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.

Hyun, J.W., S.H. Yi, S.J. MacKenzie, L.W. Timmer, K.S. Kim, S.K. Kang, H.M. Kwon, 

and H.C. Lim. 2009. Pathotypes and genetic relationship of worldwide collections 

of Elsinoë spp. causing scab diseases of citrus. Phytopathology 99:721-728.

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.

4
Risk Management Document for Two Tangerine, Unshu, and Sweet from Korea

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 Two Fresh Fruit Hybrids of Unshu, Sweet, and Mandarin 

Oranges, Citrus spp., from Korea into the Continental United States. A Qualitative, 

Pathway-Initiated Risk Analysis. Ver. 1. 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. 77 pp.

5