Citrus Canker; Movement of Fruit From Quarantined Areas, 65172-65204 [E7-22549]

Agencies

• DEPARTMENT OF AGRICULTURE
• Animal and Plant Health Inspection Service

[Federal Register Volume 72, Number 222 (Monday, November 19, 2007)]
[Rules and Regulations]
[Pages 65172-65204]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-22549]



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Part III





Department of Agriculture





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Animal and Plant Health Inspection Service



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7 CFR Parts 301 and 305



 Citrus Canker; Movement of Fruit From Quarantined Areas; Final Rule

Federal Register / Vol. 72, No. 222 / Monday, November 19, 2007 / 
Rules and Regulations

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DEPARTMENT OF AGRICULTURE

Animal and Plant Health Inspection Service

7 CFR Parts 301 and 305

[Docket No. APHIS-2007-0022]
RIN 0579-AC34


Citrus Canker; Movement of Fruit From Quarantined Areas

AGENCY: Animal and Plant Health Inspection Service, USDA.

ACTION: Final rule.

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SUMMARY: We are amending the citrus canker regulations to modify the 
conditions under which fruit may be moved interstate from a quarantined 
area. We are eliminating the requirement that the groves in which the 
fruit is produced be inspected and found free of citrus canker, and 
instead are requiring that every lot of fruit produced in the 
quarantined area be inspected by the Animal and Plant Health Inspection 
Service at a packinghouse operating under a compliance agreement and 
found to be free of visible symptoms of citrus canker. We are retaining 
the requirement that the fruit be treated with a surface disinfectant 
and the prohibition on the movement of fruit from a quarantined area 
into commercial citrus-producing States. These changes will relieve 
some restrictions on the interstate movement of fresh citrus fruit from 
Florida while maintaining conditions that will help prevent the 
artificial spread of citrus canker.

DATES: Effective Date: November 19, 2007.

FOR FURTHER INFORMATION CONTACT: Mr. Stephen Poe, Senior Operations 
Officer, Emergency and Domestic Programs, Plant Protection and 
Quarantine, APHIS, 4700 River Road Unit 137, Riverdale, MD 20737-1231; 
(301) 734-4387.

SUPPLEMENTARY INFORMATION:

Background

    Citrus canker is a plant disease caused by the bacterium 
Xanthomonas axonopodis pv. citri (referred to below as Xac) that 
affects plants and plant parts, including fresh fruit, of citrus and 
citrus relatives (Family Rutaceae). Citrus canker can cause defoliation 
and other serious damage to the leaves and twigs of susceptible plants. 
It can also cause lesions on the fruit of infected plants, which render 
the fruit unmarketable, and cause infected fruit to drop from the trees 
before reaching maturity. The aggressive A (Asiatic) strain of citrus 
canker can infect susceptible plants rapidly and lead to extensive 
economic losses in commercial citrus-producing areas. Citrus canker is 
only known to be present in the United States in the State of Florida.
    The regulations to prevent the interstate spread of citrus canker 
are contained in Sec. Sec.  301.75-1 through 301.75-14 of ``Subpart--
Citrus Canker'' (7 CFR 301.75-1 through 301.75-17, referred to below as 
the regulations). The regulations restrict the interstate movement of 
regulated articles from and through areas quarantined because of citrus 
canker and provide, among other things, conditions under which 
regulated fruit may be moved into, through, and from quarantined areas 
for packing. These regulations are promulgated pursuant to the Plant 
Protection Act (7 U.S.C. 7701 et seq.).
    On June 21, 2007, we published in the Federal Register (72 FR 
34180-34191, Docket No. APHIS-2007-0022) a proposal \1\ to amend the 
citrus canker regulations by modifying the conditions under which fruit 
may be moved interstate from quarantined areas. We proposed to 
eliminate the requirement that the groves in which the fruit is 
produced be inspected and found free of citrus canker, and instead 
proposed to require that every lot of fruit produced in the quarantined 
area be inspected by the Animal and Plant Health Inspection Service 
(APHIS) at a packinghouse operating under a compliance agreement and 
found to be free of visible symptoms of citrus canker. We proposed to 
retain the requirement that the fruit be treated with a surface 
disinfectant and the prohibition on the movement of fruit from a 
quarantined area into commercial citrus-producing States.
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    \1\ To view the proposed rule, the supporting analyses, and the 
comments we received, go to https://www.regulations.gov/fdmspublic/
component/main?main=DocketDetail&d=APHIS-2007-0022.
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    We solicited comments concerning our proposal for 30 days ending 
July 23, 2007. We subsequently reopened and extended the deadline for 
comments until August 7, 2007, in a document published in the Federal 
Register on July 27, 2007 (Docket No. APHIS-2007-0022, 72 FR 41239). We 
received 72 comments by the close of the comment period. They were from 
producers, exporters, researchers, and representatives of State 
governments. They are discussed below by topic.

Pest Risk Assessment and Risk Management Analysis

    To inform the deliberations that led to the proposed rule, we 
prepared two documents that addressed the risk associated with the 
interstate movement of citrus fruit from a quarantined area: A pest 
risk assessment (PRA) and a risk management analysis (RMA). The PRA, 
which was titled ``Evaluation of asymptomatic citrus fruit (Citrus 
spp.) as a pathway for the introduction of citrus canker disease 
(Xanthomonas axonopodis pv. citri),'' considered all available evidence 
associated with asymptomatic citrus fruit as a pathway for the 
introduction of citrus canker. The PRA concluded that asymptomatic, 
commercially produced citrus fruit treated with a surface disinfectant 
and subject to other mitigations is not epidemiologically significant 
\2\ as a pathway for the introduction and spread of citrus canker. We 
first made this document available for comment on April 6, 2006, when 
we published a notice in the Federal Register (71 FR 17434-17435, 
Docket No. APHIS-2006-0045), announcing its availability for comment 
for 60 days; the comment period was subsequently extended to 90 days. 
We also submitted it for peer review in accordance with the U.S. 
Department of Agriculture (USDA) guidelines for peer review developed 
in response to the Office of Management and Budget's peer review 
bulletin. We received 19 comments by the end of the comment period, 
which we also submitted to the peer review panel members for their 
consideration.\3\ We carefully considered the comments of the public 
and peer reviewers, and made revisions to the analysis based on 
concerns they raised. The revisions did not change the conclusions of 
the PRA; the revised version of the PRA was provided with the proposed 
rule.
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    \2\ We use the term ``epidemiologically significant'' to refer 
to minimum conditions required for disease transmission.
    \3\ The original PRA and the comments we received on it can be 
viewed at https://www.regulations.gov/fdmspublic/component/
main?main=DocketDetail&d=APHIS-2006-0045.
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    In light of the comments by the public and peer reviewers, it 
became clear that additional analysis was necessary to apply the 
conclusions of the PRA to the situation in Florida. In order to apply 
the conclusions of the PRA, we needed to extend its application to 
evaluate methods by which fruit \4\ could be produced, treated, 
inspected, packaged, and shipped without resulting in the

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spread of citrus canker to commercial citrus-producing areas. 
(Commercial citrus-producing areas are listed in Sec.  301.75-5 of the 
regulations and are referred to in this document as commercial citrus-
producing States. Those States, listed in Sec.  301.75-5(a), are: 
American Samoa, Arizona, California, Florida, Guam, Hawaii, Louisiana, 
Northern Mariana Islands, Puerto Rico, Texas, and the U.S. Virgin 
Islands.)
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    \4\ Given the practical difficulties in ensuring that only 
asymptomatic fruit enters interstate commerce under any regulatory 
strategy, we refer here to host fruit in general.
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    To address the considerations described above, APHIS prepared the 
RMA, which was titled ``Movement of commercially packed fresh citrus 
fruit (Citrus spp.) from citrus canker (Xanthomonas axonopodis pv. 
citri) disease quarantine areas, March 2007.'' We made the RMA 
available for comment along with the proposed rule.\5\ The RMA was also 
submitted for peer review, which occurred concurrently with the public 
comment period for the proposed rule.\6\ The RMA analyzed the potential 
of fresh commercially packed citrus fruit and associated packing 
material to serve as a pathway for the introduction and spread of 
citrus canker into new areas. It also identified and evaluated options 
for regulating the interstate movement of citrus fruit from quarantined 
areas with the goal of reducing the potential for citrus canker 
introduction and spread. The recommendations in the RMA served as the 
basis for the proposed rule.
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    \5\ The RMA is available on the Regulations.gov Web site and in 
our reading room (see ADDRESSES above) and may be obtained from the 
person listed under FOR FURTHER INFORMATION CONTACT.
    \6\ The peer review materials for the RMA may be viewed at 
https://www.aphis.usda.gov/peer_review/peer_review_agenda.shtml.
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    To develop the RMA, we reviewed available evidence regarding the 
biology and epidemiology of Xac and the management of citrus canker 
disease. The RMA concluded that the introduction and spread of Xac into 
other commercial citrus-producing States through the movement of 
commercially packed fresh citrus fruit from quarantined areas is 
unlikely because:
     Fresh citrus fruit is produced and harvested using 
techniques that reduce the prevalence of Xac-infected fruit;
     Citrus fruit is commercially packed using techniques that 
reduce the prevalence of infected or contaminated fruit, including 
disinfectant treatment for epiphytic contamination;
     For a successful Xac infection that results in disease 
outbreaks to occur, an unlikely sequence of events would have to occur;
     Reports of citrus canker disease outbreaks linked to fresh 
fruit are absent; and
     Large quantities of fresh citrus fruit shipped from 
regions with Xac have not resulted in any known outbreaks of citrus 
canker disease.
    Nevertheless, the RMA concluded that the evidence is not currently 
sufficient to support a determination that fresh citrus fruit produced 
in a Xac-infested grove cannot serve as a pathway for the introduction 
of Xac into new areas. Therefore, the RMA evaluated several 
packinghouse-centered risk management options for the interstate 
movement of fresh commercially packed citrus fruit from regions 
infested with citrus canker to regions without the disease. These 
packinghouse-centered risk management options were evaluated to 
determine whether they provide an appropriate level of phytosanitary 
protection without the resource constraints and other practical 
considerations that make it difficult to maintain the grove-centered 
regulatory approach in Florida. The risk management options evaluated 
were:
     Option 1: Allow unrestricted distribution of all types and 
varieties of commercially packed citrus fruit to all U.S. States.
     Option 2: Allow distribution of all types and varieties of 
commercially packed citrus fruit to all U.S. States, subject to 
packinghouse treatment with APHIS-approved disinfectant and APHIS 
inspection of finished fruit that has completed the packinghouse 
culling, washing, disinfection, and grading processes.
     Option 3: Allow distribution of all types and varieties of 
commercially packed citrus fruit (except tangerines) in U.S. States 
except commercial citrus-producing States. Allow distribution of 
commercially packed tangerines to all U.S. States, including commercial 
citrus-producing States. Require packinghouse treatment of all such 
citrus fruit with APHIS-approved disinfectant and APHIS inspection of 
finished fruit (all types and varieties) for citrus canker disease 
symptoms.
     Option 4: Allow distribution of all types and varieties of 
commercially packed citrus fruit in U.S. States except commercial 
citrus-producing States and require packinghouse treatment of citrus 
fruit with APHIS-approved disinfectant and APHIS inspection of finished 
fruit (all types and varieties) for citrus canker disease symptoms.
     Option 5: Leave the current regulations for the interstate 
movement of citrus fruit from citrus canker quarantined areas in place 
and unchanged.
    We proposed to implement Option 4. This option would have limited 
distribution of all types and varieties of citrus fruit to States other 
than commercial citrus-producing States, with mitigations conducted at 
packinghouses operating under compliance agreements. Those mitigations 
are the use of an approved disinfectant for all fruit and APHIS 
phytosanitary inspection.
    We received several comments on the overall level of risk 
associated with the movement of commercially packed citrus from a 
citrus canker quarantined area, as well as our selection of Option 4. 
These comments have not led us to change our determination that Option 
4 is the most appropriate option to implement. The RMA that we are 
making available with this final rule contains revisions based on the 
comments we received on the proposed rule and the comments we received 
through the peer review process, but its overall conclusion is the 
same. Accordingly, this final rule implements Option 4. (We are making 
some changes to the regulatory requirements associated with the 
implementation of Option 4. These changes are discussed later in this 
document.)
    Some commenters believed that the evidence presented in the RMA 
warranted the selection of Option 2, which would have allowed the 
distribution of citrus fruit to all States, subject to packinghouse 
treatment with APHIS-approved disinfectant and APHIS inspection of 
finished fruit. These commenters stated that it was extremely unlikely 
that the circumstances necessary for the movement of commercially 
packed fresh citrus fruit to result in the introduction and spread of 
Xac into other commercial citrus-producing States would ever occur.
    One commenter stated that the decision to allow the movement of 
regulated fruit from a citrus canker quarantined area only into States 
other than commercial citrus-producing States, rather than into all 
States, was based on politics rather than on science.
    One commenter stated that no Florida citrus fruit infected with 
citrus canker has ever been found in a commercial citrus-producing 
State under the current regulations and that, at the commenter's 
packinghouse, not a single piece of fruit with citrus canker had been 
found by any inspectors or employees during the last growing season.
    One commenter noted more generally that citrus canker has not been 
found outside Florida since the disease was first detected there, and 
stated that more certainty than uncertainty exists regarding the risk 
of commercially

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packed citrus fruit as a viable pathway for citrus canker.
    Another commenter noted that the PRA stated the following in its 
executive summary: ``The combination of conditions necessary for 
introduction are so difficult to achieve that the likelihood of such 
occurrence is greater than the baseline exposure represented by 
unregulated pathways. The conclusions of the evaluation are reinforced 
by a strong record of empirical data from experience and 
interceptions.''
    We acknowledge the efforts of the Florida citrus industry to put 
safeguards in place against citrus canker infestation. The proposed 
rule recognized the effectiveness of those safeguards by providing for 
the interstate movement to States other than commercial citrus-
producing States of any lot of citrus fruit that is commercially 
packed, treated with APHIS-approved disinfectant, and inspected by 
APHIS and found to be free of visible canker lesions.
    The RMA concludes that commercially packed fresh citrus fruit is an 
unlikely pathway for the introduction and spread of Xac and that a 
phytosanitary inspection ensures, with high confidence, that few 
shipped fruit would have symptoms of citrus canker disease. However, 
the model in Appendix 1 to the RMA indicates the potential for some 
commercially packed fruit with visible canker lesions to be shipped to 
commercial citrus-producing States. That potential for such fruit to 
reach commercial citrus-producing States, coupled with the 
aforementioned uncertainty regarding fruit as a pathway, led to the 
determination that the additional mitigation of prohibiting 
distribution to commercial citrus-producing States was required. If, in 
the future, evidence is developed to support a determination that 
commercially packed citrus fruit (both symptomatic and asymptomatic) is 
not an epidemiologically significant pathway for the introduction and 
spread of citrus canker, we would undertake rulemaking to amend our 
regulations accordingly.
    Under section 412(a) of the Plant Protection Act (7 U.S.C. 
7712(a)), the Secretary of Agriculture may prohibit or restrict the 
movement in interstate commerce of any plant or plant product if the 
Secretary determines that the prohibition or restriction is necessary 
to prevent the dissemination of a plant pest or noxious weed within the 
United States. Based on information provided in the PRA and RMA, we 
have determined that it is not necessary to prohibit the interstate 
movement of citrus fruit from a quarantined area into States other than 
commercial citrus-producing States under the conditions described in 
the proposed rule. While APHIS has concluded that commercially packed 
citrus fruit is an unlikely pathway for the introduction and spread of 
citrus canker, the remaining uncertainty about the level of risk 
associated with the movement of citrus fruit from a quarantined area 
has led us to maintain the prohibition on the movement of citrus fruit 
into commercial citrus-producing States.
    One commenter supplied a report that provided initial data 
demonstrating that transmission of Xac from infected fruit placed 
directly under highly susceptible grapefruit seedlings does not occur.
    The research (which can be viewed at https://www.regulations.gov/
fdmspublic/component/main?main=DocumentDetail&d=APHIS-2007-0022-0053) 
is suggestive; when it is completed, it will help better determine 
whether citrus fruit can serve as a pathway for the introduction of 
citrus canker to commercial citrus-producing States outside the 
quarantined area. We encourage interested parties to make research on 
this issue available to us.
    Two commenters stated that APHIS' treatment of the risk associated 
with citrus canker was inconsistent with its treatment of the risk 
associated with other plant pests. For example, one of the commenters 
stated, the evidence is clear that the interstate movement of nursery 
stock is a pathway for the long-distance spread of P. ramorum, but 
APHIS' regulations continue to allow high-risk nursery stock to move to 
all States, under specified conditions. The commenter cited APHIS' 
actions with respect to the light brown apple moth as another example.
    The provisions governing the movement of regulated articles for 
each pest for which APHIS maintains quarantine requirements are the 
result of separate considerations of the available science and the risk 
posed by the plant pest in question. We make our determinations of risk 
based on, among other things, the likelihood that a pest will follow a 
specific pathway, the economic and environmental value of resources 
that could be damaged by the pest, and the likelihood of introduction 
of the pest into an unaffected area. Our choice of regulatory approach 
is based on, among other things, the likelihood that the mitigations 
available to us will be sufficient to prevent the introduction or 
spread of a plant pest. We have determined that the level of protection 
against the interstate spread of citrus canker that will be provided by 
the regulations as amended by this final rule is appropriate.
    One commenter asked why APHIS allows fruit to be exported from the 
quarantined area into the citrus-producing areas of Europe, given that 
we proposed to prohibit the distribution of fruit from quarantined 
areas into commercial citrus-producing States. Other commenters asked 
that we allow the interstate movement of fruit from quarantined areas 
into commercial citrus-producing States under conditions similar to 
those required by the European Union (EU) for the importation of citrus 
fruit into the EU.
    APHIS certifies U.S. plant products for export according to the 
conditions set by the importing country for the exportation of those 
products from the United States. The EU's requirements for the 
importation of citrus fruit apply to all areas where citrus canker is 
present, not just in the United States but in other countries whose 
citrus production areas are affected by citrus canker.
    The EU import requirements involve certification of grove freedom 
from citrus canker and are similar to, but less restrictive than, the 
requirements that were in the regulations before the publication of 
this final rule. For reasons discussed in the RMA, we do not consider 
these requirements to be sufficient to allow the movement of fruit from 
citrus canker quarantined areas into commercial citrus-producing States 
at this time. We will continue to review the available science and will 
update the regulations if necessary.
    Two commenters stated that Option 3, which would have allowed the 
unlimited distribution of tangerines subject to treatment and APHIS 
inspection, should be implemented. One commenter stated that canker 
finds have been few and far between, if the disease has been found at 
all, on some varieties of tangerine. Another stated that mandarin 
varieties are the least susceptible to citrus canker, and that the 
commercial citrus-producing States of California and Texas are 
important markets for producers of this fruit.
    Tangerines are generally grouped in the species Citrus reticulata 
and are widely regarded as less susceptible to citrus canker disease 
than other commercially grown Citrus species. But many of the 
``tangerine'' varieties grown in Florida are hybrids of C. reticulata 
with other more susceptible Citrus species. Clearly, tangerines in 
Florida are not immune to citrus canker, as APHIS records indicate 
that, during the 2005-2006 growing season grove surveys, Xac was 
detected on 274 samples from tangerine, tangor, and tangelo groves. 
APHIS pest interception data indicate that between 1985 and

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2006, Xac was intercepted 632 times on C. reticulata fruit. The level 
of susceptibility was expressed as a continuum across ``tangerine'' 
varieties rather than as a discrete immunity for all varieties. This 
creates a regulatory problem when an overlap occurs in the level of 
susceptibility expressed by, for example, a more susceptible tangerine 
variety and a more resistant nontangerine citrus variety. Sufficient 
evidence does not exist to exclude tangerines from regulations 
applicable to other Florida citrus varieties. We are making no changes 
to the proposed rule in response to these comments.
    Several commenters supported Option 4 but asked APHIS to continue 
to examine the scientific evidence with a view toward allowing 
unlimited distribution of fruit moved interstate from areas quarantined 
for citrus canker at some future time.
    We will continue to examine scientific evidence regarding whether 
commercially packed citrus fruit (both with and without visible canker 
lesions) is an epidemiologically significant pathway for the 
introduction and spread of citrus canker. If, in the future, evidence 
is developed to support a determination that commercially packed citrus 
fruit is not an epidemiologically significant pathway for the 
introduction and spread of citrus canker, we would undertake rulemaking 
to amend our regulations accordingly.
    Some commenters proposed other options to allow the movement of 
fruit from quarantined areas. One commenter stated that fruit from 
groves that are free of citrus canker and that are 1,500 feet or 
farther from an affected grove should be allowed to move fruit to 
commercial citrus-producing States.
    It has been our experience in the State of Florida that citrus 
canker can spread more than 1,500 feet in stormy conditions. We 
recognize that citrus canker-free areas may exist adjacent to infected 
areas, but implementing the commenter's suggestion would require grove 
certification programs similar to those in place prior to the 
publication of this final rule. We have determined that certification 
of fruit for interstate movement at the packinghouse level rather than 
at the grove level will ensure an appropriate level of phytosanitary 
security; would be more reliable and less easily circumvented than the 
preharvest grove survey required by Option 5; would be consistent with 
the risk associated with citrus canker and commercially packed fruit 
from Florida; and would be easier and potentially less costly to 
implement and enforce than a grove-centered system of mitigations.
    Some commenters disagreed with our determination that prohibiting 
the distribution of citrus fruit from a quarantined area into 
commercial citrus-producing States would be an effective mitigation. 
Commenters holding this view stated that the illegal movement of citrus 
fruit harboring citrus canker from a quarantined area to a commercial 
citrus-producing State may be expected through current commercial 
channels; they cited the movement of Spanish clementines from Georgia 
to Florida through retailer distribution when such movement was 
prohibited as one example of the potential for incorrect distribution. 
Another commenter cited the discovery of Florida fruit in commercial 
citrus-producing States as a result of distribution mistakes.
    These commenters also stated that the potential for the movement of 
Florida citrus by tourists and visitors from nearby States into 
commercial citrus-producing States should also be taken into account, 
and that excluding shipments to buffer States would reduce the risk 
that this movement poses to commercial citrus-producing States. One 
commenter stated that the history of citrus disease movement such as 
citrus canker and citrus greening into Florida shows the high risk of 
movement by plant or by fruit from other citrus-growing countries. In 
these cases the initial infections were in urban areas, but movement to 
production areas was undetected until an epidemic was finally observed.
    One commenter also stated that we had not addressed mail-order 
shipment or gift-pack movement of citrus from Florida.
    These commenters proposed that we limit the distribution of fruit 
from citrus canker quarantined areas to other States in addition to the 
commercial citrus-producing States, thus creating a ``buffer zone'' 
around the commercial citrus-producing States. The buffer zones 
proposed by the commenters varied:
     One commenter suggested that only States east of the 
Mississippi River should be eligible to receive fruit moved interstate 
from quarantined areas.
     Two commenters suggested that only States in the northern 
tier of the United States and east of the Mississippi River should be 
eligible to receive such fruit.
     Two others suggested a buffer zone of all the States 
surrounding the commercial citrus-producing States.
    We do not agree that a buffer zone, such as these commenters 
suggest, is appropriate or necessary. Due to the geographic separation 
between Florida and other commercial citrus-producing States, citrus 
canker is not likely to spread through natural means (such as through 
storms) from Florida to a State that is not a commercial citrus-
producing State and then to a commercial citrus-producing State. While 
it is correct that the movement of plants for planting presents a high 
risk of spreading citrus canker from a quarantined area, the 
regulations already contain a prohibition on the movement of plants for 
planting; currently, only calamondin and kumquat plants are allowed to 
move interstate from the quarantined area, and those plants must be 
produced under conditions designed to prevent their infection with 
citrus canker. As mentioned earlier, we have determined that it is 
unlikely that the movement of commercially packed citrus fruit is an 
epidemiologically significant pathway for the spread of citrus canker.
    The proposed rule included requirements that boxes or other 
containers of fruit moving interstate from a quarantined area include a 
limited permit mark as well as the statement indicating that the fruit 
is not to be distributed into a commercial citrus-producing State. This 
requirement (which applies to mail-order and gift-pack shipments as 
well as truck shipments) will help to prevent inadvertent movement of 
citrus from quarantined areas into a commercial citrus-producing State. 
To strengthen the protection provided by the limited permit 
requirement, we are also adding a requirement in this final rule that 
the limited permit mark and the distribution statement appear on any 
shipping documents accompanying boxes or other containers in which 
fruit is moved interstate.
    To ensure that regulated parties comply with distribution 
restrictions, APHIS routinely monitors wholesalers and fresh fruit 
markets in commercial citrus-producing States and monitors distribution 
routes that are bound for commercial citrus-producing States to ensure 
that Florida citrus fruit does not unlawfully enter those States. This 
monitoring is conducted primarily by APHIS' Smuggling, Interdiction, 
and Trade Compliance program.
    If we find Florida citrus in a commercial citrus-producing State, 
we will trace the product back to its distributor and its origin in 
Florida. We will investigate violations (through APHIS' Investigative 
and Enforcement Services) and may seek penalties against any 
distributor that moves Florida citrus to commercial citrus-producing 
States. We may seize the prohibited products and destroy them or ensure 
they are moved from the area of concern. We

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will conduct surveillance on other methods of sale such as Internet 
sales and gift-pack shipments to ensure that the fruit is not 
advertised as being available for delivery to commercial citrus-
producing States. We will also provide outreach to retailers and 
wholesalers who are moving products to help prevent any inadvertent 
movement of citrus from a quarantined area into a commercial citrus-
producing State.
    The packinghouse measures of disinfection and APHIS inspection 
ensure that even if a given shipment were illegally moved to a 
commercial citrus-producing State, the shipment would have a low 
likelihood of containing fruit with the potential to cause an outbreak 
of citrus canker disease.
    As mentioned earlier, the RMA examined four options for allowing 
the interstate movement of citrus fruit from a citrus canker 
quarantined area under a packinghouse-centered approach. Of those four 
options, we determined that Option 4 was most appropriate, based on the 
available scientific evidence, which indicates that fruit subject to 
commercial packing, treatment, and APHIS inspection will be unlikely to 
serve as a pathway for the introduction or spread of citrus canker.
    We recognize that individual consumers may move fruit from Florida 
into States other than commercial citrus-producing States and then 
subsequently move that fruit into commercial citrus-producing States. 
However, such movement could have occurred under the regulations in 
place before the publication of this final rule as well; APHIS does not 
have the regulatory infrastructure to monitor interstate movement of 
fruit by individual consumers. Additionally, even with a buffer zone in 
place, tourists and visitors would often travel across multiple States 
to reach their destinations, meaning that a buffer zone would not be 
highly effective at eliminating this consumer movement. For tourists 
and visitors, as well as for local residents who routinely move between 
commercial citrus-producing States and other States, the distance 
between the borders of commercial citrus-producing States and the 
citrus-producing areas within those States acts as a buffer as well, 
further decreasing the risk associated with such movement. Finally, the 
volume of such movement is extremely low when compared with the volume 
of commercial movement of fruit, making the risk of citrus canker 
establishment in commercial citrus-producing States through this 
scenario highly unlikely. These factors, combined with our 
determination that the introduction and spread of Xac into other 
commercial citrus-producing States through the movement of commercially 
packed fresh citrus fruit is unlikely and that the mitigations of 
treatment and APHIS inspection are highly effective, have led us to 
determine that a buffer zone to address such movement is unnecessary.

Scientific Evidence Used in the PRA and RMA

    We received several general comments on the scientific evidence we 
used to make our determinations in the PRA and RMA. One commenter 
stated that the conclusion reached by the RMA is in part based on the 
lack of evidence that citrus fruit could play a role in the 
introduction of citrus canker in new areas, but that this lack of 
evidence is a consequence of the lack of scientific studies and is not 
based on scientific data; this commenter suggested that we evaluate the 
risks further using fruit produced subject to the regulations that were 
in place before the publication of this final rule. Another commenter 
suggested an extensive list of experimental data that the commenter 
believed were necessary to prove that the introduction and spread of 
Xac into other commercial citrus-producing States through the 
interstate movement of commercially packed fresh citrus fruit from a 
quarantined area is unlikely. One commenter stated that this program, 
which the commenter characterized as precedent-setting, requires a much 
more solid foundation of science and process affirmation than has been 
developed to date. Other commenters stated that not enough of the 
evidence we used in developing the RMA had been published in peer-
reviewed scientific journals and that we had relied too much on 
preliminary research in making our determinations.
    We used the best scientific evidence available to develop the PRA 
and the RMA, and we have detailed extensively how this evidence 
supports the conclusions we present in those documents. It is important 
to note that, based on the available evidence, we did not conclude that 
commercially packed citrus fruit could not serve as a pathway for the 
introduction and spread of Xac, but rather that it was unlikely that 
commercially packed citrus fruit serves as an epidemiologically 
significant pathway. That is why this final rule prohibits the 
distribution of such fruit to commercial citrus-producing States.
    The Plant Protection Act charges us with ensuring that our 
decisions affecting imports, exports, and interstate movement of plants 
and plant products that we regulate under the Act are based on sound 
science. To fulfill this mission, we use all the scientific evidence 
that may be brought to bear on an issue, not just studies published in 
peer-reviewed journals. Observations based on APHIS' experience, survey 
and pest detection data, and preliminary experimental results can all 
provide valuable information to inform a regulatory decision, and we 
have used them in the PRA and RMA when appropriate. Having said that, 
the vast majority of the sources cited in the PRA and RMA have been 
peer-reviewed, as have both the PRA and RMA themselves.
    Comments on specific studies we cited in the RMA and PRA are 
discussed later in this document.
    The peer review for the RMA was conducted concurrently with the 
comment period for the proposed rule. One commenter stated that 
stakeholders should have the opportunity to review the peer reviewers' 
comments when submitting their own comments on this document.
    We appreciate the commenter's concerns. APHIS had already provided 
for peer review of and public comment on the PRA, which informed the 
development of the RMA. In accordance with the Office of Management and 
Budget's bulletin on peer review, we are also making all the materials 
associated with the peer review, including the peer reviewers' 
comments, available at https://www.aphis.usda.gov/peer_review/peer_
review_agenda.shtml. The conclusion of the RMA did not change as a 
result of the peer review, which was generally favorable.
    One commenter included a late comment on the PRA as a reference, 
stating that APHIS had not made appropriate changes to the PRA based on 
the comment.
    We reviewed the comment that the commenter included when we 
developed the revised version of the PRA. We addressed all the 
substantive points raised by that comment in the revised version of the 
PRA published with the proposed rule. Many of the points raised by that 
comment had been previously raised in other comments submitted on the 
PRA during the comment period.
    As discussed earlier, the PRA concluded that asymptomatic, 
commercially produced citrus fruit treated with a surface disinfectant 
and subject to other mitigations is not epidemiologically significant 
as a pathway for the introduction and spread of citrus canker. However, 
in order to apply the conclusions of the PRA, we determined that we 
needed to extend its application to evaluate methods by

[[Page 65177]]

which fruit could be produced, treated, inspected, packaged, and 
shipped without resulting in the spread of citrus canker to commercial 
citrus-producing areas. Accordingly, the RMA addresses the risk 
associated with all commercially packed fruit; the RMA's 
recommendations have served as the basis for the Secretary's 
determination that it is not necessary to prohibit the interstate 
movement of citrus fruit from a quarantined area into States other than 
commercial citrus-producing States under the conditions described in 
the proposed rule. Therefore, specifically addressing comments on the 
PRA is unnecessary for the purposes of this rulemaking.

The Packinghouse-Centered Approach and the Current Regulations

    In evaluating the risk associated with asymptomatic fruit, the PRA 
assumed that the citrus fruit in question was commercially produced 
under a specific set of pest management measures. The RMA, while 
recognizing that effective pest management measures for Xac are 
available to private and commercial growers and are normal production 
practices for many of these growers, does not assume that measures in 
the grove are mandatory. Instead, the RMA focuses on treatment with an 
APHIS-approved disinfectant at the packinghouse and APHIS inspection of 
fruit to be moved interstate. The recommendations in the RMA served as 
the basis for the proposed rule.
    The regulations in place at the time the proposed rule was 
published required that fruit moved interstate originate in a grove 
that was found by an inspector to be free of citrus canker no more than 
30 days before harvest (with additional requirements for limes), in 
addition to treatment of vehicles, equipment, and other articles that 
are used on the grove and treatment of the fruit itself.
    Several commenters objected to APHIS moving away from the grove 
inspection approach and to the fact that we did not propose to require 
the use of the commercial production practices described in both the 
PRA and the RMA. These commenters stated that, under the proposed rule, 
measures such as copper sprays, designation and exclusion of infected 
trees, field culling of fruit, and packinghouse culling of fruit were 
all voluntary, and their effectiveness was unknown. The commenters 
expressed concern that not requiring these measures would increase the 
risk associated with citrus fruit moved interstate from a quarantined 
area.
    One commenter stated that in other countries such as Argentina that 
ship fruit to citrus-producing countries in Europe, strict guidelines 
are followed that include field inspections and the planting of wind 
breaks between orchards that minimize wind velocity and subsequent 
dispersal of inoculum. The commenter stated that these countries 
realize that inspection of ``finished'' fruit in the packinghouse alone 
is not enough to guarantee the shipment of disease-free fruit.
    One commenter stated that the objective of a rule addressing 
Florida's situation should be to prevent citrus canker from being 
introduced into disease-free areas in the United States; such a rule 
should not be designed with the primary objective of allowing shipments 
of fresh fruit from canker-affected areas. This commenter stated that 
the building blocks of premises and assumptions set forth in the 
proposed rule and the RMA create risk rather than develop protective 
barriers.
    The regulations promulgated in this final rule include protective 
barriers against the introduction of citrus canker into other citrus-
producing areas: Treatment with a surface disinfectant, APHIS 
inspection, and a prohibition of the movement of citrus fruit from a 
quarantined area into commercial citrus-producing States. We have 
determined that these barriers provide an appropriate level of 
protection with regard to the movement of citrus fruit from areas 
quarantined for citrus canker.
    The grove certification requirement in place prior to the 
publication of this final rule and the APHIS packinghouse inspection 
required under this final rule are not dissimilar in their approach to 
preventing the interstate movement of fruit with visible canker 
lesions. Under the regulations in place before the publication of this 
final rule, none of the grove-centered measures cited by the commenters 
(copper sprays, designation and exclusion of infected trees, and field 
culling of fruit) were required. Rather, growers were required to 
demonstrate that their groves were free from citrus canker, on the 
basis of an inspection. In order to be found free from citrus canker, 
and thus have fruit from their groves be eligible for the interstate 
market, growers had incentives to employ the grove-centered measures 
described in the PRA and RMA and mentioned by the commenters.
    Instead of a grove inspection, this final rule requires an 
inspection of the finished fruit at the packinghouse, which must 
operate under a compliance agreement and treat fruit with an approved 
surface disinfectant. Every lot of fruit must be inspected by an APHIS 
inspector for visible canker lesions. While growers are not required to 
practice measures that would reduce the prevalence of citrus canker in 
their fruit, and packinghouses are not required to perform their own 
culling process to remove fruit with visible canker lesions, the 
regulations promulgated in this final rule still provide them with a 
strong incentive to do so, since lots of fruit that fail APHIS 
inspection will not be eligible for interstate movement. Additionally, 
packinghouse culling for blemished fruit of any kind is already a 
standard business practice, and field management programs that include 
the use of copper sprays and field sanitation are already available to 
producers.
    The purpose of the APHIS inspection at the packinghouses is to 
ensure that fruit moved interstate is free of visible canker lesions, 
and to prohibit the interstate movement of fruit that is not free of 
those lesions. From each lot of fruit intended for interstate movement, 
APHIS will inspect a quantity that is sufficient to detect, with a 95 
percent level of confidence, any lot of fruit containing 0.38 percent 
or more fruit with visible canker lesions. Lots of fruit that fail 
inspection will not be allowed to enter interstate commerce.
    A packinghouse-based inspection can ensure an appropriate level of 
phytosanitary security and will be easier to implement and enforce than 
the grove certification system in place before the publication of this 
final rule. Because it focuses on the end product, a packinghouse-based 
inspection will be more reliable and less easily circumvented than the 
preharvest grove survey that has been required in the regulations. A 
packinghouse-based inspection is also consistent with the risk 
associated with citrus canker and commercially packed fruit from 
Florida. In addition, a phytosanitary packinghouse inspection creates a 
performance standard for packed fruit that allows citrus producers 
greater flexibility to determine the most efficient and effective means 
of producing a compliant product.
    Our choice of a packinghouse-based APHIS inspection as a means to 
prevent fruit with visible canker lesions from being moved interstate, 
rather than requiring specific grove and packinghouse practices to 
ensure the production of fruit free of visible canker lesions, is 
consistent with the recommendations of the 1997 Presidential/
Congressional Commission on Risk Assessment and Risk Management. The 
commission recommended that agencies use alternatives to command-and-
control

[[Page 65178]]

measures that dictate the use of specific technologies, where 
applicable (CRARM 1997), in order to encourage flexibility in the 
choice of risk management alternatives.
    One commenter characterized the approach of the proposed rule as a 
control point approach, and stated that in the past APHIS has applied 
control point approaches only to quarantine treatments that are able to 
demonstrate a probit 9 level of effectiveness.
    The probit 9 standard (99.997 percent mortality) applies to 
treatments for insect pests such as fruit flies, not to treatment of 
pathogens. In any case, the probit 9 standard is not applicable for the 
surface disinfectant treatment and packinghouse-based APHIS inspection 
that we are requiring. Scientific evidence indicates that both of these 
measures are highly effective.
    One commenter stated that the PRA and RMA appeared to imply that 
packinghouse studies conducted to date were based upon fruit with known 
levels of contamination with Xac. The commenter asked how the 
packinghouse inspection process would achieve the results described in 
the RMA without grove inspections and without the ability to determine 
the infection pressure. The commenter also asked how the proposed 
measures can be effective without knowing the magnitude of the hazard, 
as expressed by the proportion of infected fruit.
    Both of the packinghouse measures that we are requiring in this 
final rule are effective regardless of infection pressure. The surface 
disinfectant treatments approved by APHIS reduce numbers of Xac cells 
to low or undetectable levels. The APHIS packinghouse-based inspection 
is sufficient to detect, with a 95 percent level of confidence, any lot 
of fruit containing 0.38 percent or more fruit with visible canker 
lesions. In other words, if the infection pressure is higher than 0.38 
percent of the fruit, it is 95 percent likely that the lot will be 
rejected from interstate commerce.
    Two commenters cited findings of canker symptoms on fruit exported 
from Argentina and Uruguay to Spain in stating that symptomatic fruit 
will often pass through the packinghouse process. These commenters 
stated that the price growers and packers are receiving for citrus is 
what drives the quality of the citrus shipped, and that with low 
prices, low-quality fruit, such as those with canker, are more likely 
to be introduced into distribution channels.
    We agree that, in general, price helps to determine the quality of 
fruit supplied. However, under the regulations established by this 
final rule, the fruit will be subject to an additional APHIS inspection 
separate from any field inspection and culling or packinghouse culling 
that may occur. Any lot that fails APHIS inspection will not be 
approved to move for interstate commerce. Given that, if there is a 
financial advantage to being able to supply fresh citrus to the 
interstate market, producers and packinghouses in quarantined areas are 
likely to employ measures and processes that will allow them to supply 
fruit free of visible canker lesions for APHIS inspection.

Treatments and Surface Contamination With Xac

    The regulations require all fruit moved interstate from an area 
quarantined for citrus canker to be treated in accordance with Sec.  
301.75-11(a). This paragraph has included two treatments: Thorough 
wetting for at least 2 minutes with a solution containing 200 parts per 
million (ppm) sodium hypochlorite, with the solution maintained at a pH 
of 6.0 to 7.5; or thorough wetting with a solution containing sodium-o-
phenyl phenate (SOPP) at a concentration of 1.86 to 2.0 percent of the 
total solution, for 45 seconds if the solution has sufficient soap or 
detergent to cause a visible foaming action or for 1 minute if the 
solution does not contain sufficient soap to cause a visible foaming 
action.
    One commenter noted that disinfectants are only effective if the 
active ingredient is not degraded. The commenter gave the example that 
sodium hypochlorite is degraded by sunlight and organic matter.
    We agree with the commenter's point that it is important to ensure 
that the treatment is conducted properly. APHIS regularly monitors the 
treatment of fruit to ensure that the disinfectant agent is at the 
proper concentration and, in the case of sodium hypochlorite, pH, thus 
ensuring the effectiveness of the treatment. Under this final rule, we 
will conduct monitoring under conditions specified in the compliance 
agreements with packinghouses.
    In this final rule, we are amending the treatment regulations to 
require fruit to be treated at a commercial packinghouse whose owner 
operates under a compliance agreement. Previously, the regulations had 
required that treatment be performed either in the presence of an 
inspector or at a facility whose owner operates under a compliance 
agreement under Sec.  301.75-7(a)(2); this change will reflect the fact 
that all fruit intended for interstate movement must be treated at a 
commercial packinghouse under this final rule.
    Several commenters stated that these surface disinfectant 
treatments may not be 100 percent effective, citing various reports 
that indicated that bacteria could be recovered from citrus fruit that 
had been treated with sodium hypochlorite or SOPP, including reports by 
Verdier (2006) and Golmohammadi (2007) and a newspaper article 
reporting on a lecture by Gottwald in which he presented unpublished 
preliminary results. With regard to the last of these, two commenters 
requested that we provide information about the followup studies 
mentioned in the article.
    As stated in the RMA, the surface disinfectant treatments approved 
by APHIS reduce numbers of Xac cells to low or undetectable levels, but 
do not necessarily provide complete eradication. The evidence cited by 
the RMA does demonstrate that the treatments allowed under the rule 
substantially reduce bacterial populations, including Xac, found on the 
surface of citrus fruit to the extent practicable using surface 
disinfectant treatments currently registered for use in the United 
States on raw fruits and vegetables.
    Recovery of Xac from fruit after surface disinfectant treatment 
does not demonstrate that the treatment is ineffective. Microbial 
detection or recovery tests simply measure the presence or absence of 
the organism in a sample and do not enumerate or measure the difference 
between the pre- and post-treatment bacteria population levels or 
infectivity. The treatments in the regulations are consistently 
reported as dramatically reducing Xac populations on the surface of 
fruit, if not eliminating them entirely. For example, Verdier (2006), 
cited by the commenters, measured the pre- and post-treatment levels in 
the wash solution and found that the bacteria population level was 
reduced 99.8 percent from an average of 39.4 colony-forming units 
(cfu)/mL on untreated controls to an average of 0.06 cfu/mL on treated 
fruit.
    The information from Gottwald (2006) the commenters cite has not 
been published, and the followup studies referred to in news reports 
are currently being completed. We are not able to obtain the 
unpublished data that have been collected to this point. We will review 
the Gottwald information when it becomes available in final form. It is 
important to note again that the recovery of some bacteria after 
treatment is not inconsistent with treatment being highly effective at 
reducing Xac population levels, as described earlier.
    Another commenter, referring to a study by Brown and Schubert 
(1987)

[[Page 65179]]

that the RMA cited, stated that the study's use of Xanthomonas 
campestris pv. vesicatoria as a proxy for X. axonopodis pv. citri in 
assessing the efficacy of SOPP was not appropriate, because the 
behavior of closely related bacteria may be very different.
    The use of a proxy in efficacy testing is not unusual; for example, 
the Environmental Protection Agency (EPA) requirements for testing the 
efficacy of disinfectants allow the use of a proxy. A proxy organism 
was used in this study because the study was conducted in a model 
packinghouse. It is difficult to experiment with quarantine plant 
pathogens in the field because of the need to provide safeguards 
against their spread. While the bacteria in question are not identical, 
SOPP has a broad range of efficacy; there is no reason to believe that 
some feature of Xac would defeat the mechanism of SOPP. In addition, 
the RMA cited other studies establishing the efficacy of SOPP as a 
treatment against Xac itself.
    The PRA contained the following statement regarding treatment 
effectiveness: ``Studies performed in Argentina on the effectiveness of 
sodium hypochlorite on mature symptomless fruit artificially 
contaminated with Xac showed that sodium hypochlorite levels as low as 
8 ppm were effective in eliminating epiphytic or surface bacteria from 
the fruit (Canteros, undated).'' One commenter stated that there were 
no references about the viability of the bacteria, which is an 
important factor for risk assessment.
    This particular study was one of many studies cited in the PRA and 
RMA establishing the effectiveness of sodium hypochlorite as a 
treatment. Other studies we cited included references about the 
viability of the bacteria.
    Related to the presence of bacteria on the surface of treated fruit 
(also referred to as epiphytic bacteria or contamination), several 
commenters stated that fruit with such populations pose a risk of 
spreading citrus canker that was not addressed by the measures 
recommended in the RMA.
    While surface populations of Xac undoubtedly exist on some citrus 
fruit that is packed in a quarantined area, and commenters cited 
scientific evidence establishing this point, substantial evidence 
indicates that surface bacterial populations do not infect mature fruit 
or survive on mature fruit long enough to infect other hosts. The 
evidence cited in the RMA regarding epiphytic survival indicates that 
epiphytic populations on harvested, mature fruit decline rapidly. For 
example, researchers in Brazil sprayed asymptomatic fruit, picked from 
trees, with a bacterial suspension of 106 cfu/mL; no 
bacteria were recovered after 5 days at room temperature under 
laboratory conditions (Belasque and Rodriguez Neto 2000). Epiphytic 
bacteria do not multiply in water on leaf surfaces or on dry leaves 
(Timmer et al. 1996). Graham et al. (2000) found that Xac survived for 
48 to 72 hours on a variety of inanimate surfaces in sun or shade, 
respectively. Additionally, there is no authenticated record of 
movement of diseased fruit as the origin for a citrus canker disease 
outbreak, which is especially suggestive given the brisk global trade 
in such fruit and the likely presence of some level of epiphytic 
bacteria on many fruit that is exported from citrus canker-affected 
areas.
    Commenting on the PRA, one commenter noted that a low concentration 
of 8 cfu/mL (cited as a result of treatment by one study) may mean very 
high numbers of bacteria in tons of fruit.
    The commenter's assertion is correct. However, shipments of fruit 
are commercially packed in boxes or other approved containers and are 
dispersed through market channels all over the United States, greatly 
diluting the concentration of bacteria which are at the same time 
experiencing rapid mortality. Therefore, such bacterial concentrations 
would not occur in the real world. In any case, for the reasons stated 
above, we have determined that fruit with epiphytic bacterial 
populations is not an epidemiologically significant pathway for the 
spread of citrus canker.
    Some commenters were also concerned about the possible presence of 
Xac on other materials, citing reports of Xac survival for various 
periods on media like clean microscopic slides; leaf surfaces, plastic, 
wood, and other materials; cloth, sawdust and shavings, dried herbarium 
tissue, and sterile soil; and non-host weeds.
    While Xac undoubtedly persists on a number of surfaces, it does not 
multiply outside of hosts. Under the regulations, the interstate 
movement of any regulated article other than fruit, calamondin and 
kumquat plants, and seed is prohibited. Regulated articles include 
leaves and grass clippings. In addition, under paragraph (c) of Sec.  
301.75-3, an inspector may designate any other product, article, or 
means of conveyance, of any character whatsoever as a regulated article 
when it is determined by an inspector that it presents a risk of spread 
of citrus canker and the person in possession thereof has actual notice 
that the product, article, or means of conveyance is subject to the 
provisions of this subpart. We do not typically regulate the movement 
of the other articles cited by the commenters under the current 
regulations because populations of Xac on such articles are very 
unlikely to infect mature citrus fruit.
    Two commenters were concerned about the possibility that canker-
infected fruit could contaminate packinghouse equipment with Xac. One 
commenter stated that packinghouse equipment needs to be disinfected if 
citrus canker is found in a lot run on that equipment. The other 
expressed a specific concern about contamination of existing wounds in 
fruit and stated that surface disinfestation cannot be continuously 
done during the commercial packing of fruit where both diseased and 
healthy fruit are being packed. This commenter suggested that we amend 
the regulations to exclude fruit from being packed from orchards or 
harvested fruit lots with an incidence of citrus canker above some 
established threshold, in order to minimize contamination of packing 
lines.
    We acknowledge that infected fruit in a lot could contaminate the 
packing line with Xac, but, as stated above, substantial evidence 
indicates that the epiphytic bacterial populations that could be 
transferred from the packing line to the fruit do not infect mature 
fruit or survive on mature fruit long enough to infect other hosts. For 
that reason, we have determined that grove inspections are not 
necessary to mitigate the risk associated with such contamination, nor 
is disinfection of the packing line equipment necessary if canker is 
found during the inspection of a lot of fruit.
    The RMA stated that ``Bacteria within lesions may be more protected 
from the detrimental effects of washing, disinfection and drying. 
Viable Xac has been recovered by APHIS pathologists from citrus canker 
lesions on fruit culled from packinghouse lines after postharvest 
treatments (Riley 2007).'' A few commenters expressed concern relating 
to this statement. One stated that chlorine is well known as a surface 
sanitizer but has no ability to penetrate beyond the surface--for 
example, into lesions. Another commenter noted that none of the 
experiments mentioned in the PRA or RMA evaluate the effect of 
disinfectants on Xac within the fruit, either in visible lesions (of 
any size) or in circumstances where the effects of Xac are not visible 
to the naked eye. The third, reacting to the statement about recovery 
of viable Xac by APHIS pathologists after postharvest treatments, asked 
what treatment had been performed, what level of recovery

[[Page 65180]]

had occurred, what preharvest management the fruits were subject to, 
why the fruits were not culled on the packing line before treatment, 
and whether the postharvest treatment included wax.
    As stated earlier, the surface disinfectant treatments required in 
this final rule reduce numbers of Xac cells to low or undetectable 
levels. The RMA acknowledges that treatment with surface disinfectants 
is not effective on canker lesions, which is why this final rule also 
requires an APHIS inspection of each lot of fruit for canker lesions.
    The canker lesions referred to in Riley (2007) occurred in fruit 
produced under the regulations that were in place before the 
publication of this final rule, i.e., with certification of grove 
freedom and with surface disinfectant treatment. As the regulations in 
place before the publication of this final rule did not require 
specific canker management measures, we do not have records of what 
canker management measures the fruit may have been subject to beyond 
the measures required by the regulations.

Addition of Peroxyacetic Acid Treatment

    We proposed to add a new surface disinfectant treatment using 
peroxyacetic acid (PAA). The proposed rule would have required the 
regulated fruit to be thoroughly wetted for at least 1 minute with a 
solution containing 85 ppm peroxyacetic acid. At the request of growers 
in Florida, we evaluated the efficacy of this treatment and determined 
that the disinfectant is at least as efficacious as a surface 
disinfectant treatment as the currently approved disinfectants listed 
in the regulations. In the RMA, we described the tests that had been 
performed to confirm the efficacy of PAA. These tests were conducted on 
X. axonopodis pv. citrumelo (Xa citrumelo), which was used as a 
surrogate for X. axonopodis pv. citri (i.e., Xac).
    Two commenters stated that PAA should be tested on Xac itself 
rather than on a surrogate. One stated that Xa citrumelo does not 
infect fruit and does not survive in orchards, making it a poor 
surrogate, and asked that we make the data referred to in the RMA 
publicly available. Another stated that, while it seems highly likely 
that PAA may be effective against Xac, to allow its use without any 
testing against the particular organism of concern appears to be 
unnecessarily optimistic. The commenter recommended testing in field 
conditions for this application or at least to demand post-introduction 
testing to demonstrate efficacy in the field.
    We are making the data on PAA testing available on the 
Regulations.gov Web site with this final rule (see footnote 1 at the 
beginning of this final rule) or from the p