United States Department of Agriculture Animal and Plant Health Inspection Service Plant Protection and Quarantine



## Risk Management Document



## Importation of Unshu Orange Fruit, Citrus reticulata

Blanco var. unshu Swingle , from Korea into the

Continental United States

December 28

, 2009

Plant Health Programs (PHP) Regula tions Permits and manuals ( RPM )

Contact Person: Meredith C. JonesRisk Management Document: Unshu orange fruit ( Citrus reticulata var. unshu ) from Republic of Korea

2

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 of Unshu

orange from Cheju Island of the Republic of Korea into the United States.

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

unshu Swingle, from Korea into the Continental United States (USDA, 2009 a ), identified

two pest s
, Xanthomonas citri subsp. citri (ex Hasse 1915) Gabriel et al . 1989 (ex Hasse 1915) Gabriel et al. 1989 a nd Elsinoë australis Bit anc . & Jenkins 1936 , of quarantine significance associated with Unshu o range fruit.

Citrus can k er (

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

w ere rated as medium Pest Risk Po tential in the PRA (USDA, 200 9 a ), and a ccording to

the APHIS Guidelines for Pathway

- Initiated Pest Risk Assessments Version 5.02 (APHIS, 2000), pests receiving a rating within the m edium range may require specific phytosanitary measures in addition to standard port of entry inspec tion.

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, 2009b )

. This PRA examines the informatio n presented in

Gottwald et al . (2009) and Shiotani et al . (2009) in the context of an ea rlier 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 (t reated 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 sig nificant 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 M anagement Analysis’’ ( USDA, 2009c ). 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 sc ientific 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 amend ed its do mestic 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. S tates provided it is treated with an approved disinfectant and packed in a commercial packinghouse t hat operates under a compliance agreement

.Risk Management Document: Unshu orange fruit ( Citrus reticulata var. unshu ) from Republic of Korea

3

Equivalent phytosanitary m easures, treatment with an APHIS

- approved disinfectant a nd packing in a commercial packing house

, are therefore necessary for commercial consignments of Unshu oranges from Cheju Island o f the Republic of Korea

.

Recently

, the 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, 2009a )

.

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

Unshu oranges produced in Che ju Island of the Republic of Korea may be imported if all of the following conditions are met:

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

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

a nd registered with the Korean NPPO

.

* Unshu orange fruits must be treated with a disinfectant i n accordance with 7 CFR part
305

, and the consignment must have a P hytosanitary C ertificate (PC) with an A dditional

D eclaration (AD) issued by the Korean NPPO stating that the oranges 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 s of quarantine

concern associated with Unshu o range f ruit from Republic of Kor ea int o the Continental

United States.

Two pest s of quarantine concern, the bacterium Xanthomonas citri subsp. citri and the fungus Elsinoë australis could reasonably be expected to follow the pathway on Unshu

o range f ruit

.

APHIS requires fruit moved f rom a n area where citrus canker exists to be treated with an approved disinfectant and to be packed in approved commercial packinghouse

. The product may be imported in commercial consignments only

after treatment with a disinfectant

, only if it is free of leaves, twigs, and otherRisk Management Document: Unshu orange fruit ( Citrus reticulata var. unshu ) from Republic of Korea

4

plant parts, except for stems that are less than 1 inch long and attached to the fruit

, and it must be inspected an d found free of sweet orange scab

.

The phytosanitary certificate with the additional declaration will require the K orean NPPO to inspect the fruit for sym ptoms of s weet 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 th e disease ( USDA, 2009a ).

Author

José R. Hernández Ph.D.

Refer ences

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., P arker, 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 Protecti on 28:508

- 524.

Hyun, J.W., S.H. Yi, S.J. MacKenzie, L.W. Timmer, K.S. Kim, S. K. Ka ng, 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 Pack ed Citrus Fruit from Citrus Canker Disease Quarantine Area. Revised Risk Management Analysis. United States Department of Agriculture , Animal and Plant H ealth Inspection Service , Plant Protection and Quarantine , Center for Plant Healt h Science and Technolo gy , Plant Epidemiology and Risk Ana lysis laboratory. 123 pp.

USDA, 2009 a

. Importation of Unshu Orange Fruit, Citrus reticulata Blanco var. unshu Swingle, from Korea into the Continental United States. A Qualitative, Pathway

Initiated Risk Analysis. Rev. 0 03. United States Department of Agriculture , Animal

and Plant H ealth Inspection Service , Plant Protection and Quarantine , Center for

Plant Healt h Science and Technology , Plant Epidemiology and Risk Ana lysis laboratory

. 56 pp.Risk Management Document: Unshu orange fruit ( Citrus reticulata var. unshu ) from Republic of Korea

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USDA, 2009 b. An Updated Evalu ation 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 H ealth Inspection Service

, Plant Protection and Quarantine , Center fo r Plant Healt h Science and Technology

, Plant Epidemiology and Risk Ana lysis laboratory. 11 pp.

USDA, 2009 c. Movement of Commercially Packed Citrus Fruit from Citrus Canker Disease Quarantine Area, Supplemental Risk Management Analyses. United States Depar tment of Agriculture , Animal and Plant H ealth Inspection Service , Plant Protection and Quarantine , Center for Plant Healt h Science and Technology , Plant Epidemiology and Risk Ana lysis laboratory. 28 pp.