FOR INFORMATION 

DA-2012-14

April 18, 2012

SUBJECT: Restrictions on importation of Phytophthora ramorum (P. ramorum) host plants for 

planting into the United States

 

TO: STATE AND TERRITORY AGRICULTURAL REGULATORY OFFICIALS 

APHIS is issuing a Federal Order to restrict importation of plants for planting known to be hosts of P.

ramorum. Since 2003, APHIS has been working toward limiting the spread of P. ramorum within 

the United States. APHIS has also been requiring that plants from several European countries 

and the United Kingdom be accompanied by certification of inspection and testing to be free of 

P. ramorum; however, the certification does not provide details about the country’s pest 

exclusion plan. Also, APHIS has not been requiring certification from other countries about 

testing or their disease-free status. The genotypic diversity and expanding host range of P. 

ramorum is of increasing concern.

Therefore, APHIS is requiring specific countries to have in place an annual pest exclusion 

program that incorporates monitoring, sampling, testing and a validation process to verify the 

absence of P. ramorum in a place of production. APHIS will approve the country to export host 

material to the United States if the program is comparable to APHIS’ restrictions for interstate 

movement of P. ramorum hosts. The shipments must also be accompanied by a phytosanitary 

certificate with an additional declaration about the place of production. Plants for planting of P. 

ramorum host commodities from other countries will be allowed into the United States if 

accompanied by a phytosanitary certificate with an additional declaration stating that P. 

ramorum is not known to exist within the country.

The restrictions apply to host plants for planting and all plant parts intended for propagation 

except seed of the plant taxa. The current APHIS-regulated P. ramorum host plant list is 

available at: 

http://www.aphis.usda.gov/plant_health/plant_pest_info/pram/downloads/pdf_files/usdaprlist.pdf 

For questions on this Federal Oder, contact William Aley, Sr. Import Specialist, APHIS Plant 

Protection and Quarantine, Riverdale, MD at (301) 851-2130 or William.D.Aley@aphis.usda.gov.

/s/ Osama El-Lissy for

Rebecca A. Bech

Deputy Administrator

Plant Protection and Quarantine

Attachment:

 Federal Order
FEDERAL ORDER

Importations of Plants for Planting that are Hosts of Phytophthora ramorum

April 18, 2012

1. Background

The purpose of this Federal Order is to prevent the entry and spread of the fungal plant pathogen 

Phytophthora ramorum into the United States from countries where it is known to be present and 

from uninfested countries that trade plants for planting with infested countries. P. ramorum, 

which causes sudden oak death, ramorum leaf blight and ramorum dieback, has a broad range of 

hosts, including many hardwoods, softwoods, and landscape plants. Since 2003, the United 

States Department of Agriculture (USDA) has been actively working toward limiting the spread 

of P. ramorum within the United States. The Animal and Plant Health Inspection Service 

(APHIS) subsequently designated fourteen California counties and one county in Oregon as P. 

ramorum quarantine areas in 2007. APHIS has been requiring that plants from several European 

countries and the United Kingdom be accompanied by certification of inspection and testing to 

be free of P. ramorum; however, the certification does not provide details about the country’s 

pest exclusion plan. Also, APHIS has not been requiring certification from other countries about 

testing or their disease-free status. 

The genotypic diversity and expanding host range of P. ramorum is of concern. Three virulent 

genotypes of P. ramorum, EU-1, NA-1 and NA-2, have been identified, and sexual reproduction 

of P. ramorum may lead to other virulent genotypes. In March 2011, the United Kingdom

reported that P. ramorum associated with Japanese larch (Larix kaempferi), continues to spread 

and is causing severe disease symptoms 

This Federal Order is issued pursuant to the regulatory authority provided by the Plant Protection 

Act of June 20, 2000, as amended, Section 412(a), 7 U.S.C. 7712(a), which authorizes the 

Secretary of Agriculture to prohibit or restrict the importation, entry, exportation or movement in 

interstate commerce of any plant, plant product, biological control organism, noxious weed, 

article or means of conveyance. Additionally, the Secretary may determine that a prohibition or 

restriction is necessary to prevent the introduction into or the dissemination of a plant pest within 

the United States.

on both Japanese and European larch (Larix decidua). 

The APHIS Administrator has determined that introduction, establishment, and spread of 

existing and new genotypes of P. ramorum would pose a serious threat to economically 

important commodities and natural resources of the United States. To prevent this, APHIS will 

restrict otherwise admissible P. ramorum host plants for planting from all countries. The 

National Plant Protection Organization (NPPO) of countries listed in section 2 below must 

provide APHIS with information about their NPPO-monitored P. ramorum annual exclusion 

program that incorporates monitoring, sampling, testing and a validation process that is 
comparable to APHIS restrictions for interstate movement, as stated within this Federal Order. 

The shipments must also be accompanied by a foreign origin phytosanitary certificate with an 

additional declaration stating that the plants within the shipment originated from an area that is 

monitored as part of a P. ramorum exclusion program. Plants for planting of P. ramorum host 

commodities from countries not listed in section 2 will be allowed entry into the United States if 

accompanied by a foreign origin phytosanitary certificate with an additional declaration stating 

that P. ramorum is not known to exist within the country. All other conditions and requirements 

of 7 CFR 319 or a written USDA import permit, in addition to those stated in this Federal Order, 

will remain effective.

2. Foreign countries from which P. ramorum host material is regulated

European Union (Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, 

Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, 

Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Ukraine, 

and the United Kingdom), Norway, and Switzerland.

3. Regulated Hosts and Plants Proven or Associated with Phytophthora ramorum

This Federal Order identifies APHIS-regulated P. ramorum host plants and applies to all plant 

parts intended for propagation, except seed. The P. ramorum hosts list is available at the 

following APHIS URL: 

http://www.aphis.usda.gov/plant_health/plant_pest_info/pram/downloads/pdf_files/usdaprlist.pdf

4. Requirements for P. ramorum hosts for export into the United States

A. From countries identified in section 2 

The following criteria will apply to plants for planting exports from the countries 

identified in section 2 for the hosts identified in section 3.

I. NPPO-monitored P. ramorum annual exclusion program

The NPPO must provide APHIS with their national or regional monitoring P. 

ramorum exclusion program plan that meets the criteria in section 5 of this 

Federal Order. The plan should include methods and procedures to monitor, 

sample, test, and validate freedom from evidence of P. ramorum within a place of 

production on an annual basis. The NPPO shall provide to APHIS on an annual 

basis a list of the approved places of production.

II. P. ramorum host plant export documentation
P. ramorum host plants must originate from an NPPO approved place of 

production that meets the criteria in section 5 below. The exporting country must 

certify the export is authorized by a USDA issued import permit and accompanied 

by a NPPO issued phytosanitary certificate with an additional declaration stating:

“All life stages of the plants for planting in this shipment meet the requirements of 

USDA import Permit (insert permit number) and were solely grown in [insert 

name of country], within the approved place of production identified as [Name of 

the NPPO approved place of production]. The plants are determined to be free of 

symptoms of Phytophthora ramorum through an annual monitoring, sampling, 

testing, and validation program.”

B. From all other countries, excluding Canada

Any plants for planting hosts identified in section 3 and not from a country designated in 

section 2 above must be imported to the United States as authorized by a USDA import 

permit. The exporting country must certify the export with a NPPO authorized 

phytosanitary certificate with an additional declaration stating:

“All life stages of the plants for planting in this shipment meet the requirements of USDA 

import Permit (insert permit number) and were grown solely in [insert name of country]. 

Phytophthora ramorum is not known to occur in (insert name of country).”

C. Importation of P. ramorum host plants from Canada

Any plants for planting hosts identified in Section 3 above that are solely from Canada as 

defined in 7 CFR 319.37-1 may be imported to the United States if accompanied by a 

Canadian phytosanitary certificate.

Any plants for planting hosts identified in Section 3 that are from a third country and 

grown in Canada for less than one year may be imported to the United States if 

accompanied by a Canadian re-export phytosanitary certificate with a copy of the 

phytosanitary certificate from the country of origin attached with the appropriate 

additional declaration as listed in Sections 4A and 4B above.

5. P. ramorum Annual Exclusion Program from countries identified in Section 2

A. Monitoring

Any place of production exporting P. ramorum host plants to the United States should be

inspected for signs or symptoms of P. ramorum on host plants. Host plants should be 

sampled for the presence of P. ramorum with a process that meets the requirements as
listed below. Symptomatic host plants should be tested to verify the absence of P. 

ramorum.

B. Sampling 

A minimum sample size consisting of 40 leaf samples from genera of representative P. 

ramorum host plants within each place of production should be collected. The 

representative sample may contain more than one leaf, and may come from one or more 

plants, but all plants in the sample must be from the same place of production. Sampling 

must be conducted at times when greatest potential for the expression of P. ramorum

symptoms is anticipated in the local environment and should avoid times when applied 

chemical fungicide treatments might mask the presence of P. ramorum.

C. Testing

Samples from a place of production should be tested utilizing an immunologically-based 

assay such as an ELISA test that is designed to detect any species of Phytophthora. The 

testing must be comparable to the procedure used in the United States, which is posted on 

the following website: 

http://www.aphis.usda.gov/plant_health/plant_pest_info/pram/downloads/pdf_files/ELIS

A.pdf

a. Negative immunological test results for host plant genera at the place of 

production:

If all samples from a place of production are found to be negative through 

immunological testing, no additional confirmation is required. The place of 

production may be considered free of evidence of P. ramorum, and host plants in 

the place of production are eligible for export to the United States following the 

requirements as described in section 4(A) above.

b. Positive immunological test results for host plant genera at the place of 

production:

Should immunological testing indicate the presence of Phytophthora spp., each 

sample must be analyzed using PCR or other molecular tests. They do not require 

confirmatory culture tests, nor do positive culture tests require confirmatory PCR 

or other molecular tests; however, if culture tests return other than positive results, 

a PCR or other molecular test must be conducted.

D. Validation protocol to verify the place of production’s host plants are free from 

P. ramorum

a. PCR or culture test or other molecular tests with negative results:
If the results of PCR or culture test or other molecular tests are negative for all 

samples in a place of production, no further testing is required and it will be 

considered free of evidence of P. ramorum. Plants from that place of production 

are eligible for export to the United States following the requirements as 

described in section 4(A) above.

b. PCR or culture test or other molecular tests with positive results:

Any PCR or culture test or other molecular tests with a positive result for P. 

ramorum will make the place of production ineligible to export P. ramorum host 

plants for planting to the United States.

E. Annual Certification to verify the place of production’s host plants are free from 

P. ramorum 

A place of production within a country or an area known to have P. ramorum and/or a 

place of production once known to have P. ramorum is eligible to export P. ramorum

host plants to the United States when the NPPO verifies annually that the specific place 

of production has been monitored, sampled, tested, and validated to be free from 

evidence of P. ramorum using the protocol described above and provides APHIS with the 

name of the place of production.

F. Place of production with confirmed presence of P. ramorum and re-testing

Any place of production found to have P. ramorum will remain ineligible for export of P. 

ramorum host plants for planting into the United States until the NPPO determines the 

place of production has corrected problems and that plants subsequently produced in that 

place of production are free of evidence of P. ramorum as prescribed within this Federal 

Order.

This Federal Order is effective on May 21, 2012.