[Federal Register Volume 65, Number 116 (Thursday, June 15, 2000)]
[Rules and Regulations]
[Pages 37608-37669]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-14851]



[[Page 37607]]

-----------------------------------------------------------------------

Part II





Department of Agriculture





-----------------------------------------------------------------------



Animal and Plant Health Inspection Service



-----------------------------------------------------------------------



7 CFR Parts 300 and 319



Importation of Grapefruit, Lemons, and Oranges From Argentina; Final 
Rule

Federal Register / Vol. 65, No. 116 / Thursday, June 15, 2000 / Rules 
and Regulations

[[Page 37608]]


-----------------------------------------------------------------------

DEPARTMENT OF AGRICULTURE

Animal and Plant Health Inspection Service

7 CFR Parts 300 and 319

[Docket No. 97-110-5]
RIN 0579-AA92


Importation of Grapefruit, Lemons, and Oranges From Argentina

AGENCY: Animal and Plant Health Inspection Service, USDA.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: We are amending the citrus fruit regulations by recognizing a 
citrus-growing area within Argentina as being free from citrus canker. 
Surveys conducted by Argentine plant health authorities in that area of 
Argentina since 1992 have shown the area to be free from citrus canker, 
and Argentine authorities are enforcing restrictions designed to 
protect the area from the introduction of that disease. We are also 
amending the fruits and vegetables regulations to allow the importation 
of grapefruit, lemons, and oranges from the citrus canker-free area of 
Argentina under conditions designed to prevent the introduction into 
the United States of two other diseases of citrus, sweet orange scab 
and citrus black spot, and other plant pests. These changes will allow 
grapefruit, lemons, and oranges to be imported into the continental 
United States from Argentina subject to certain conditions.

EFFECTIVE DATE: June 15, 2000. The incorporation by reference provided 
for by this rule is approved by the Director of the Federal Register as 
of June 15, 2000.

FOR FURTHER INFORMATION CONTACT: Mr. Wayne D. Burnett, Import 
Specialist, Phytosanitary Issues Management Team, PPQ, APHIS, 4700 
River Road Unit 140, Riverdale, MD 20737-1236; (301) 734-6799.

SUPPLEMENTARY INFORMATION:

Background

    The regulations in ``Subpart--Fruits and Vegetables'' (7 CFR 319.56 
through 319.56-8, referred to below as the fruits and vegetables 
regulations) prohibit or restrict the importation of fruits and 
vegetables into the United States from certain parts of the world to 
prevent the introduction and dissemination of plant pests, including 
fruit flies, that are new to or not widely distributed within the 
United States.
    The regulations in ``Subpart--Citrus Fruit'' (7 CFR 319.28, 
referred to below as the citrus fruit regulations), restrict the 
importation of the fruit and peel of all genera, species, and varieties 
of the subfamilies Aurantioideae, Rutoideae, and Toddalioideae of the 
family Rutaceae into the United States from specified countries in 
order to prevent the introduction of citrus canker disease (Xanthomonas 
campestris pv. citri (Hasse) Dye). The citrus fruit regulations also 
restrict the importation of the fruit and peel of all species and 
varieties of the genus Citrus into the United States from specified 
countries, including Argentina, in order to prevent the introduction of 
the citrus diseases sweet orange scab (Elsinoe australis Bitanc. and 
Jenkins) and the B strain of citrus canker, which is referred to in the 
citrus fruit regulations as ``Cancrosis B.''
    On August 12, 1998, we published a proposed rule in the Federal 
Register (63 FR 43117-43125, Docket No. 97-110-1) to amend the citrus 
fruit regulations by recognizing a citrus-growing area within Argentina 
as being free from citrus canker. In that document, we also proposed to 
amend the fruits and vegetables regulations to allow the importation of 
grapefruit, lemons, and oranges from the citrus canker-free area of 
Argentina under conditions designed to prevent the introduction into 
the United States of two other diseases of citrus, sweet orange scab 
and citrus black spot, and other plant pests.
    The proposed rule was followed by three notices regarding the 
comment period and public hearings for the proposed rule. Specifically, 
on October 16, 1998, we published in the Federal Register (63 FR 55559, 
Docket No. 97-110-2) a notice advising the public that we were 
extending the comment period for the proposed rule by 120 days and that 
we had scheduled a public hearing in Thousand Oaks, CA, to give 
interested persons the opportunity for the oral presentation of data, 
views, and arguments regarding the proposed rule. On December 4, 1998, 
we published in the Federal Register (63 FR 67011, Docket No. 97-110-3) 
a notice advising the public that we had changed the date and location 
of the public hearing in Thousand Oaks, CA. Finally, on January 13, 
1999, we published in the Federal Register (64 FR 2151, Docket No. 97-
110-4) a notice advising the public that we had scheduled an additional 
public hearing to be held in Orlando, FL.
    With the extension granted in the October 16, 1998, notice, we 
solicited comments for a total of 180 days ending on February 11, 1999. 
We received 332 comments by that date, including 63 comments received 
at the public hearings held in Orlando, FL, and Thousand Oaks, CA. The 
comments were from foreign and domestic producers, handlers, packers, 
and processors of citrus fruit; Members of the U.S. Congress and 
elected representatives of State and local governments; State plant 
protection officials and officials from Argentine's national plant 
protection organization, the Servicio Nacional de Sanidad y Calidad 
Agroalimentaria (SENASA); and representatives of the U.S. Citrus 
Science Council (USCSC), a group formed specifically to respond to the 
proposed rule.
    Seventeen of the comments were letters requesting that we extend 
the comment period for the proposed rule, and 3 comments simply stated 
that any decision should be based on sound science. Two hundred and 
fifty comments, 148 of which were form letters offering support for the 
position of the USCSC, raised concerns or made suggestions regarding 
the proposed rule. Those comments are addressed in detail later in this 
document. The remaining 62 comments offered support for the proposed 
rule as it was written. Those commenters who supported the proposed 
rule noted the mutual benefits of trade, recognized the scientific 
basis of the proposed rule, stated that Argentine imports would provide 
competition for citrus imports from other countries, saw an opportunity 
to increase citrus exports to Argentina, noted that Argentine citrus 
has been exported to markets in other countries--including citrus-
producing countries--without incident, and noted the positive economic 
effects that Argentine citrus imports would have on consumers, 
wholesalers, distributors, and ports of entry.
    The comments that we received in opposition to the proposed rule 
focused largely on the scientific basis and support for the proposed 
mitigation measures and on the execution and conclusions of the risk 
assessment that was used by the Animal and Plant Health Inspection 
Service (APHIS) in reaching the decision to initiate the proposed rule. 
These comments, as well as the numerous comments that we received on 
other particular aspects of the proposed rule and its supporting 
documentation, are reported and addressed in this final rule.
    With regard to the proposed mitigation measures, several commenters 
questioned whether the systems approach to phytosanitary security 
explained in the proposed rule would provide an adequate measure of 
protection against the introduction of the diseases and insect pests of 
concern, especially given their understanding that APHIS had never 
before used a

[[Page 37609]]

systems approach to mitigate the risks presented by a pest complex that 
included both insects and pathogens. Other commenters questioned the 
volume, adequacy, and accuracy of the scientific data provided by 
Argentina to support the efficacy of the proposed mitigation measures 
contained in the systems approach. As we discuss in detail below in 
response to specific comments, we believe that the information 
furnished by Argentina, when considered in conjunction with the body of 
information available in the scientific literature regarding the 
insects and diseases of concern, provides the necessary rational basis 
for our determination that individual and cumulative mitigative effects 
of the systems approach serve to reduce the risks presented by 
Argentine grapefruit, lemons, and oranges produced and imported in 
accordance with this rule to a negligible level.
    With regard to the pest risk assessment prepared by APHIS, several 
commenters disagreed with the manner in which we prepared the risk 
assessment, questioning basic choices made by the risk assessors 
concerning issues such as independence in the model and our use of a 
shipping box as the risk unit. Other commenters questioned whether 
APHIS offered sufficient justification for the estimates used in 
section II.8 (Likelihood of Introduction) of the risk assessment. In 
this final rule, we discuss, in our responses to specific comments on 
these and other related issues, the manner in which we prepared the 
risk assessment and how we arrived at our estimates. Our experience in 
examining the risks presented by agricultural commodities produced 
around the world has led us to select the model that we used as the 
framework for estimating those risks. This model has proven itself over 
the years and for several commodity/pest combinations to be an 
efficient means of estimating phytosanitary risk, and we (and others, 
including the Harvard Center for Risk Analysis) believe our guidelines 
are valid. While we acknowledge that there are alternative ways of 
estimating this type of risk, we do not believe that using a different 
model would result in a substantively different outcome.

Distribution Limitations

    In the proposed rule, we discussed the importation of grapefruit, 
lemons, and oranges into the entire United States. However, the risk 
assessment that was prepared prior to the preparation of the proposed 
rule only examined the risks presented by the importation of that fruit 
into the continental United States (the 48 contiguous States, Alaska, 
and the District of Columbia). Although we have no reason to believe 
that the risk associated with importing Argentine citrus into Hawaii, 
Guam, the Northern Mariana Islands, Puerto Rico, or the U.S. Virgin 
Islands would differ in any significant way from the risks associated 
with the importation of that fruit into the continental United States, 
the fact remains that the risk assessment did not consider the risks 
associated with the importation of Argentine citrus into destinations 
outside the continental United States. Therefore, in this final rule we 
have narrowed the area into which the grapefruit, lemons, and oranges 
may be imported by limiting the distribution of the fruit to the 
continental United States. If we were requested to do so by Argentina 
or other interested parties, we would undertake to assess the risks 
associated with the entry of Argentine citrus into areas outside the 
continental United States and initiate rulemaking to provide for the 
entry of the fruit into those additional areas if our risk assessment 
supported such an action.
    We continue to have confidence in the efficacy of the systems 
approach for Argentine citrus and in the conclusions of our pest risk 
assessment, which found that the risk presented by grapefruit, lemons, 
and oranges imported in accordance with that systems approach is 
negligible. However, in response to comments from the domestic citrus 
industry and others voicing concern over the use of a systems approach 
in a situation where both diseases and insect pests exist in a foreign 
production area, we will institute a limited distribution plan that 
will delay the entry of Argentine citrus into citrus-producing areas in 
the continental United States until 2004. This delay will provide an 
opportunity for the efficacy of the systems approach to be demonstrated 
under actual production and distribution conditions before Argentine 
citrus imports are allowed to enter citrus-producing areas of the 
continental United States. The limited distribution plan would involve 
a three-stage phase-in of Argentine citrus imports:
    <bullet> Stage 1 (the 2000 and 2001 shipping seasons). Upon the 
effective date of this final rule, fruit that meets the requirements of 
the export program will be eligible for entry into 34 States in the 
continental United States that are neither buffer States nor commercial 
citrus-producing States.
    <bullet> Stage 2 (the 2002 and 2003 shipping seasons). When 
Argentina begins shipping fruit in May or June of 2002, the fruit will 
be eligible for entry into the 34 ``Stage 1'' States as well as the 10 
buffer States (Alabama, Arkansas, Colorado, Georgia, Mississippi, 
Nevada, New Mexico, Oklahoma, Oregon, and Utah) that share borders with 
one or more commercial citrus-producing States, leaving only 5 
commercial citrus-producing States (Arizona, California, Florida, 
Louisiana, and Texas) as prohibited destinations in the continental 
United States.
    <bullet> Stage 3 (the 2004 shipping season). When Argentina begins 
shipping fruit in May or June of 2004, the fruit will be eligible for 
entry into all areas of the continental United States.
    These ``rolling effective dates'' are built into the final rule, 
which precludes the need for APHIS to initiate rulemaking in 2002 and 
2004 to expand the area into which the fruit may be imported. If it is 
determined that the requirements of the export program are not being 
observed routinely or uniformly, APHIS will be able to act quickly to 
suspend the rolling effective dates or even the entire program, if 
warranted. The export program provides for the detection of diseased 
fruit at any point in the pathway, with that detection leading to the 
rejection of the shipment containing the diseased fruit and the removal 
of the grove that produced the fruit from the export program for the 
remainder of the shipping season. Thus, the detection of diseased fruit 
will not, by itself, result in the suspension of all or part of the 
export program.
    To determine whether the requirements of the export program are 
being observed routinely or uniformly and to ensure that the 
distribution restrictions of this rule are being observed, APHIS 
personnel will be involved in monitoring activities in both the United 
States and Argentina:
    Monitoring--United States. To help ensure that importers and 
distributors of Argentine citrus are aware of the distribution 
limitations of this rule, those limitations will be included as one of 
the conditions of the permit that importers must obtain in order to 
import grapefruit, lemons, or oranges from Argentina. APHIS personnel, 
as well as personnel with State regulatory agencies and the 
Department's Agricultural Marketing Service, will be enlisted to 
enforce the distribution limitations of the rule. This will be 
accomplished through market visits, inspections, and outreach efforts 
directed at importers, shippers, distributors, and retailers. The 
infrastructure needed to support these efforts is already in place.
    Monitoring Argentina. The rule does not require direct APHIS 
involvement in

[[Page 37610]]

the supervision of the export program in Argentina; that direct 
supervision is the responsibility of SENASA, Argentina's national plant 
protection organization, which is regarded by APHIS (and 
internationally) as an efficient and capable organization. A recent 
(April 24 to 28, 2000) site visit to citrus groves and packinghouses in 
Argentina by APHIS bears out this perception. In order to evaluate 
whether it is appropriate to allow each stage of the phased-in 
distribution plan to occur as scheduled, and to provide for the ongoing 
evaluation of the export program, APHIS will be conducting inspection 
visits to the Argentine production area and will maintain contact with 
SENASA throughout each year to monitor their administration of the 
export program. Further, APHIS and SENASA are currently finalizing the 
details of the annual operational work plan that will address the 
administration of the program during the current season and that will 
serve as the basis for future annual work plans. That work plan will 
include provisions for active and direct monitoring of the export 
program by APHIS personnel who will conduct frequent oversight visits 
to the growing areas and packinghouses. APHIS' monitoring activities 
will include:
    <bullet> Inspections of groves following the removal of leaves and 
other litter,
    <bullet> Review of the timing and application of fungicidal sprays,
    <bullet> Accompanying SENASA inspectors as they conduct preharvest 
grove inspections and collect samples of fruit for laboratory 
examination,
    <bullet> Visits to the SENASA-approved laboratories that will be 
examining the sampled fruit to review the procedures for, and results 
of, the fruit incubation protocol,
    <bullet> Observing the harvesting of fruit, its transport to the 
packinghouses, and the entry control systems in place at the 
packinghouses, and
    <bullet> Ensuring that the required handling, treatment, 
inspection, identification, and packing requirements of this rule are 
being observed in the packinghouses.
    These monitoring activities carried out by APHIS and SENASA 
personnel will provide us with a clear confirmation of the 
practicability of the systems approach under actual production 
conditions, its efficacy in preventing disease in export groves, and 
the ability of the required inspections and laboratory examinations to 
detect diseased fruit. Additional evidence of the success or failure of 
the export program will be gained through the inspections that will be 
conducted at U.S. ports of entry following the arrival of the fruit and 
the application of any required cold treatments. Should APHIS, as a 
result of these activities or any other assessments of the program, 
conclude that the requirements of the export program are not being 
observed uniformly and routinely, the program will be reviewed; should 
APHIS determine that there are deficiencies in the program that cannot 
be remedied, the phased-in expansion of distribution, or even the 
export program itself, may then be suspended or terminated.

Specific Regulatory Changes Regarding Limited Distribution

    To implement the limited distribution plan, we have made several 
changes to this final rule. These changes are explained below and 
pertain to the distribution limitations themselves, box marking, 
stickering, and ports of entry.

Limitations on Distribution.

    We have added a new Sec. 319.56-2f(g) to this final rule to 
incorporate the distribution limitations into the requirements of the 
rule. That paragraph states that the distribution of the grapefruit, 
lemons, and oranges is limited to the continental United States (the 48 
contiguous States, Alaska, and the District of Columbia.). That 
paragraph also states that during the 2000 through 2003 shipping 
seasons, the distribution of the grapefruit, lemons, and oranges is 
further limited as follows:
    <bullet> During the 2000 and 2001 shipping seasons, the fruit may 
be distributed in all areas of the continental United States except 
Alabama, Arizona, Arkansas, California, Colorado, Florida, Georgia, 
Louisiana, Mississippi, Nevada, New Mexico, Oklahoma, Oregon, Texas, 
and Utah.
    <bullet> During the 2002 and 2003 shipping seasons, the fruit may 
be distributed in all areas of the continental United States except 
Arizona, California, Florida, Louisiana, and Texas.
    For the 2004 shipping season and beyond, the fruit may be 
distributed in all areas of the continental United States.

Box Marking

    As was presented in the proposed rule, Sec. 319.56-2f(c)(6) of this 
final rule requires the boxes in which the fruit is packed to be marked 
with the SENASA registration number of the grove that produced the 
fruit. This final rule requires that the boxes also be marked with a 
statement indicating that the fruit may not be distributed in Hawaii, 
Guam, the Northern Mariana Islands, Puerto Rico the U.S. Virgin Islands 
(i.e., destinations outside the continental United States), or in any 
State (each of which must be individually listed) into which the 
distribution of the fruit is prohibited under the limited distribution 
plan. To account for the possibility that the fruit might have to be 
repackaged following its entry into the United States, new paragraph 
Sec. 319.56-2f(i) states that any new boxes in which the fruit is 
packed must also be marked with the limited distribution statement 
required under Sec. 319.56-2f(c)(6).

Stickering

    APHIS has found that the marking of individual fruit is necessary 
for the limited distribution scheme to be enforceable; otherwise it 
would be difficult to distinguish Argentine grapefruit, lemons, or 
oranges from domestically produced fruit or fruit imported from other 
sources. Therefore, we have amended Sec. 319.56-2f(c)(5) in this final 
rule to require that the grapefruit, lemons, and oranges be 
individually labeled with a sticker that identifies the packinghouse in 
which they were packed. We understand that Argentina's citrus producers 
routinely label their fruit with stickers identifying the packinghouses 
in which the fruit was prepared for distribution, and we believe that 
those packinghouse labels would serve to adequately identify the fruit 
since we would be able to provide examples of each packinghouse's 
sticker to our inspectors and cooperators. Therefore, we do not believe 
that this stickering requirement will impose a significant additional 
burden on Argentine growers, packers, or exporters.

Ports of Entry

    New Sec. 319.56-2f(h) states that the grapefruit, lemons, and 
oranges may enter the United States only through a port of entry 
located in a State where the distribution of the fruit is authorized 
under Sec. 319.56-2f(g), which, as explained above, is the section of 
the regulations that provides for the limitations on the distribution 
of the fruit. The port-of-entry restrictions of Sec. 319.56-2f(h) apply 
to both the limited distribution plan's staged phase-in of imports into 
the continental United States and the prohibition on the distribution 
of the fruit outside the continental United States.
    As noted above, we believe that this limited distribution plan will 
provide an opportunity for the efficacy of the systems approach to be 
demonstrated under actual production and distribution conditions before 
Argentine citrus imports are allowed to enter

[[Page 37611]]

citrus-producing areas of the continental United States.

Miscellaneous Comments

    Comment: In 1995, APHIS denied Argentina's petition to export 
citrus to the United States due to the risks that were posed by the 
fruit. The proposed rule does not set forth the information and 
experimentation that transpired between 1995 and 1996 that led APHIS to 
reverse its position. It is only appropriate that the U.S. citrus 
industry have the opportunity to evaluate the basis for APHIS' decision 
to reverse its position.
    Response: In our proposed rules, we usually focus on describing and 
justifying the specific regulatory changes or additions that we are 
proposing, so we do not routinely provide the sorts of historical or 
evolutionary details that the commenter mentions. In the case of the 
Argentine citrus proposed rule, we concentrated on explaining the 
proposed citrus export program set forth in the regulatory text of the 
proposed rule; we did not believe it was necessary to examine the 
differences between that program and any earlier Argentine petitions 
that we had rejected. However, the process of data gathering, 
experimentation, and negotiation that led to the proposed rule is 
documented in the material contained in the rulemaking record, and we 
provided that material to several interested parties who requested it, 
including representatives of the U.S. citrus industry.
    Comment: Two documents in the rulemaking record--a trip report 
prepared after APHIS' 1994 trip to northwestern Argentina and a 
memorandum dated May 27, 1994, that discusses the status of Argentina's 
request to export citrus both raise questions and concerns regarding 
the Argentine petition. The May 1994 memorandum recommended two 
actions: (1) That the Government of Argentina request a thorough risk 
assessment be completed, and (2) that an expert group of pathologists 
from APHIS and the Agricultural Research Service determine what 
research was needed before a regulatory decision was made, establish 
tolerances for diseased fruit in an export program and how these can be 
measured, and make an assessment of Argentina's citrus canker survey. 
While the call for a risk assessment in point number one may have been 
addressed by APHIS' original 1995 risk assessment, the recommendations 
on point number two appear to have gone unaddressed. We believe that 
all those questions must be answered before APHIS takes any further 
action on Argentina's petition. To that end, the proposed rule should 
be withdrawn to allow for a full scientific discussion of the questions 
found in those documents.
    Response: Both of the actions recommended in the May 1994 
memorandum were completed prior to the development of the proposed 
rule. As noted by the commenter, APHIS did prepare a preliminary 
qualitative pest risk assessment in 1995, and that 1995 assessment was 
followed up by the 1997 quantitative pest risk assessment used as 
support for the proposed rule.
    In September 1994, our expert group of pathologists identified to 
Argentina the areas in which we believed additional research was needed 
and requested another year's worth of data to substantiate their 
proposed mitigation measures; that data was received in the spring of 
1996. Further, as evidenced by the provisions of the proposed rule and 
this final rule, we established tolerances for diseased fruit in the 
export program (i.e., the detection of a single diseased fruit will 
result in the grove in which the fruit was grown being removed from the 
export program, and the fruit from that grove being prohibited entry 
into the United States, for the remainder of that year's growing and 
harvest season). We have also included inspection provisions to detect 
diseased fruit and prevent its entry into the United States. Finally, 
we completed our review of Argentina's citrus canker survey program and 
have full confidence in the efficacy of its methodology and the 
accuracy of its findings. Given that all the issues raised in the May 
1994 memorandum were addressed prior to the preparation of the proposed 
rule, we do not believe it is necessary to withdraw the proposed rule 
for the reasons stated by the commenter.
    Comment: In 1994, Argentina proposed a systems approach to suppress 
citrus black spot and sweet orange scab that was based on individual 
farms performing the suppression treatment. At the time, APHIS stated 
that individual farms were too small a unit for sufficient disease 
suppression and that a larger area with clearly defined geographic 
boundaries encompassing all citrus grown in the region would be 
necessary. Why is APHIS now proposing a system based on individual 
farms performing the suppression treatment?
    Response: The original Argentine proposal did not include several 
of the aspects of the systems approach required by this rule, such as 
the preharvest surveys, laboratory analysis of sampled fruit, and post-
harvest treatments. When those aspects of the systems approach were 
included in later proposals and data were made available to support 
their efficacy, we concluded that a grove-level approach to the plant 
pests of concern would be appropriate.
    Comment: The 1994 trip report posits that one possible step that 
could be taken in order to permit Argentine citrus to enter the United 
States would be to limit exports to Northeastern ports. A limited 
distribution requirement similar to the restrictions on the importation 
of avocados from Mexico would not be a sufficient or enforceable 
mitigation measure for Argentine citrus. If the market provides an 
economic reason to ship the citrus to other States, parties with an 
economic motivation to do so will find a way to make that happen. It is 
not realistic to say that APHIS has sufficient resources to ``police'' 
this requirement. The result would be the spread of devastating 
diseases to citrus growing regions. Indeed, APHIS has had recent 
experience in dealing with illegal shipments of Mexican avocados by a 
large retailer. Once Argentine citrus enters the United States, it must 
be assumed that the fruit will reach every market in the continental 
United States. Thus, any potential restriction on where the fruit can 
be shipped is unrealistic.
    Response: That suggestion was indeed offered during discussions 
that preceded the preparation of the proposed rule, but the proposed 
rule did not include limitations on distribution. This final rule does, 
however, limit the importation of the fruit to the continental United 
States and incorporates a three-stage phase-in of imports that limits 
the distribution of the fruit during the 2000 through 2003 shipping 
seasons. These aspects of this final rule are explained above under the 
heading ``Distribution Limitations.'' As noted in that section, we 
continue to have faith in the efficacy of the systems approach and in 
the findings of the risk assessment, thus we continue to believe that 
citrus fruit imported from Argentina in accordance with this rule 
presents a negligible risk of introducing diseases or insect pests into 
any area of the continental United States.
    APHIS personnel, as well as personnel with State regulatory 
agencies and the Department's Agricultural Marketing Service, will be 
enlisted to enforce the distribution limitations of the rule. This will 
be accomplished through market visits, inspections, and outreach 
efforts directed at importers, shippers, distributors, and retailers, 
and the infrastructure and resources needed to support these efforts 
are already in place. Given the experience we have gained through the 
Mexican avocado

[[Page 37612]]

program and through the implementation of our expanded smuggling 
interdiction program, we believe that we have the ability to enforce 
the distribution restrictions of this rule.
    Comment: We requested a 1-year extension of the comment period for 
the proposed rule, then shortened the requested length of the extension 
to 6 months. By granting only a 4-month comment period extension and 
subsequently denying our request for a 2-month postponement of the 
scheduled public hearing, APHIS has denied the affected public a fair 
opportunity to comment on the proposed rule.
    Response: With the original 60-day comment period and the 120-day 
extension noted by the commenter, the proposed rule was open for public 
comment from August 12, 1998, through February 11, 1999, a total of 6 
months. We believe that this 180-day comment period afforded the 
affected public a fair opportunity to comment on the proposed rule. 
Further, in denying the commenter's request for a 2-month postponement 
of the California public hearing, which we had already postponed once, 
the Department made it clear that it was willing to review any new 
information that might surface following the close of the comment 
period. Specifically, the APHIS hearing officer at the Thousand Oaks, 
CA, hearing--which was attended by the commenter--read the following 
statement from Deputy Secretary Richard Rominger: ``Following the close 
of the comment period, we will thoroughly analyze and review the 
available material and all comments in the record to determine how best 
to proceed in the rulemaking process. However, if any new scientific 
information comes to light after the close of the comment period on 
February 11, 1999, which has a material and significant bearing on this 
rulemaking proceeding, such information will be thoroughly considered 
by the Department, and the Department will take such further action as 
is appropriate.''
    Comment: We informed APHIS on October 2, 1998, that our group was 
organizing to comment on the proposed rule and had selected a 
delegation of university scientists from California, Texas, and Florida 
to travel to Argentina in order to gather information. By failing to 
provide timely assistance to our group in arranging that trip, APHIS 
has denied our group and other interested parties a meaningful 
opportunity to conduct critical scientific analysis.
    Response: We believe that the correspondence exchanged between 
APHIS and the commenter concerning a site visit indicates that APHIS 
cooperated with the commenter's group in its efforts to arrange a visit 
to Argentina:
    <bullet> After receiving the commenter's letter dated October 2, 
1998, APHIS informed the Argentine Ministry of Agriculture of the 
commenter's desire for a site visit by university scientists. Argentine 
officials responded by requesting APHIS' endorsement of the visit prior 
to granting their consent for a site visit.
    <bullet> In a letter dated November 6, 1998, APHIS informed the 
commenter of Argentina's response. In that letter, we stated that we 
were prepared to endorse the visit and asked for a specific description 
of its objectives so that we could pass that information along to 
Argentina.
    <bullet> In a letter dated December 1, 1998, the commenter 
responded with the requested information and indicated its eagerness to 
work with APHIS to arrange the trip.
    <bullet> In a letter dated December 7, 1998, we informed the 
commenter that we would endorse the visit and attempt to arrange a 
visit in the second week of January 1999.
    <bullet> In a letter dated December 17, 1998, the commenter 
rejected the idea of a January visit, stating that the notice was too 
short and that January was not a ``biologically relevant'' time for a 
visit. In that letter, the commenter's group informed APHIS that it 
wished to make a visit in April or May, and perhaps make another visit 
in July or August.
    <bullet> No further progress was made on the issue of a site visit 
following that December 17, 1998, letter. In subsequent correspondence, 
the commenter's group informed us that they would attempt to ensure 
that the comment period was extended or the record otherwise held open 
in order to provide for APHIS' consideration of any information 
collected during possible future site visits by their scientists.
    We believe that the timeline provided above shows that APHIS did in 
fact provide timely assistance to the commenter, and we disagree with 
the commenter's assertion that APHIS denied interested parties a 
meaningful opportunity to conduct critical scientific analysis.
    Comment: On September 22, 1998, we filed a Freedom of Information 
Act (FOIA) request with APHIS in which we asked for any background 
materials and correspondence relating to the 1997 risk assessment. 
APHIS' FOIA office acknowledged that request on September 29, 1998, but 
did not provide any material or acknowledge our follow-up request 
before the end of the comment period. APHIS has, therefore, withheld or 
failed to disclose relevant information that would allow the public to 
interpret and understand the findings in the risk assessment.
    Response: Due to our FOIA staff's large workload, we were unable to 
fulfill the commenter's FOIA request before the February 11, 1999, 
close of the comment period. However, we did forward the requested 
documents to the commenter shortly after the close of the comment 
period. As indicated in the response to a previous comment, we informed 
the commenter prior to the close of the comment period that we are 
willing to thoroughly consider, and address as appropriate, any new 
scientific information that comes to light that has a material and 
significant bearing on this rulemaking proceeding.
    Comment: At the February 5, 1999, public hearing, a member of the 
APHIS panel stated that APHIS was relying on a 1986 Plant Protection 
and Quarantine (PPQ) study to support its position that it was highly 
unlikely that citrus black spot would become established by the spores 
produced on infected fruit. We believe that APHIS is using this PPQ 
study as the pivotal foundation for the proposed rule. APHIS' failure 
to disclose its reliance on this pivotal 1986 study until extremely 
late in the proposed rule's comment period is a violation of proper 
administrative procedures. APHIS has denied the affected public the 
opportunity to comment on the Agency's rationale for the proposal; the 
lack of disclosure of this one study, in and of itself, is a compelling 
reason why this proposal must be withdrawn by APHIS.
    Response: APHIS did not use the cited 1986 study as ``the pivotal 
foundation for the proposed rule.'' Most of the APHIS employees 
involved in the preparation of the proposed rule were either unaware of 
or had forgotten the 1986 study. It was not until the panel that 
represented APHIS at the two public hearings was preparing for the 
February 5, 1999, hearing in Orlando, FL, that one of the panel members 
recalled the existence of that study; this was more than 5 months after 
the proposed rule was published. Further, the official transcript of 
the February 5, 1999, hearing indicates that the APHIS panel member 
simply quoted from the 1986 study; she did not state that APHIS was 
``relying on'' the study. Because we did not rely on the study or its 
findings in the preparation of the proposed rule, we do not believe the 
fact that it was not mentioned until late in the comment period is 
grounds for the withdrawal of the proposed rule.

[[Page 37613]]

    Comment: APHIS did not comply with its obligations under Executive 
Order 12866 in developing the proposed rule. In particular, section 
6(a) of the Executive Order provides that each agency should engage the 
impacted public with an opportunity for informal dialogue prior to 
issuing a proposed rule. For this reason alone, APHIS should withdraw 
the proposed rule to permit the required consultations to begin.
    Response: The portion of the executive order cited by the commenter 
reads in part: ``Each agency shall (consistent with its own rules, 
regulations, or procedures) provide the public with meaningful 
participation in the regulatory process. In particular, before issuing 
a notice of proposed rulemaking, each agency should, where appropriate, 
seek the involvement of those who are intended to benefit from and 
those expected to be burdened by a regulation.'' Consistent with our 
standard procedures, APHIS did in fact informally contact 
representatives of the domestic citrus industry regarding the Argentine 
proposal in October 1997, and indications at that time were that the 
domestic citrus industry supported the concept of Argentine citrus 
imports. Further, a new pest list based on the 1995 risk assessment and 
updated with information provided by Argentina was sent for comment to 
the State plant regulatory officials (SPRO's) in the citrus-producing 
States of Florida, Louisiana, Texas, Arizona, and California in the 
fall of 1996, and a draft of the 1997 quantitative pest risk assessment 
was sent to those SPRO's in the spring of 1997. Each of the SPRO's was 
encouraged by APHIS to circulate those documents as they saw fit. We do 
not believe, therefore, that the proposed rule must be withdrawn in 
order to comply with Executive Order 12866.
    Comment: If APHIS allows Argentine citrus to enter the United 
States without adequate protective measures in place, and the U.S. 
citrus industry is then economically injured, APHIS' actions would rise 
to the level of a ``taking'' of private property by an arm of the U.S. 
Government.
    Response: Because this rule places no limitations or restrictions 
whatsoever on the U.S. citrus industry or individual U.S. growers or 
their property, we do not believe that this rule constitutes a 
regulatory taking.
    Comment: In failing to establish quarantine-level treatments for 
citrus black spot and sweet orange scab in the proposed rule, APHIS is 
failing to meet its responsibilities for pest exclusion under the Plant 
Quarantine Act and the Federal Plant Pest Act, which clearly charge the 
Secretary of Agriculture with the responsibility for preventing the 
entry of pests that are new to or not widely established in the United 
States.
    Response: Neither the Plant Quarantine Act nor the Federal Plant 
Pest Act state that quarantine-level treatments are the only means 
through which the Secretary may meet his responsibilities for pest 
exclusion under those acts. Rather, 106 of the Federal Plant Pest Act 
(7 U.S.C. 150ee) authorizes the Secretary to promulgate regulations 
requiring the inspection of articles imported into the United States 
and may impose ``other conditions upon such movement, as he deems 
necessary to prevent the dissemination into the United States, or 
interstate, of plant pests * * *.'' Quarantine-level treatments are not 
available for all commodity/pest combinations; in the absence of such 
treatments, we must consider whether alternative measures are available 
that will provide a comparable level of quarantine security, and we 
expect other nations to do the same with respect to U.S. agricultural 
exports. In this rule, we require the use of tiered and overlapping 
measures that, when combined with specified cold treatments or host 
resistance, will reduce the pest risks associated with the importation 
of Argentine citrus to a negligible level. We believe, therefore, that 
we have met our responsibilities under the acts cited by the commenter.
    Comment: APHIS' fruits and vegetables regulations only address the 
importation of fruits and vegetables from countries where insect pests 
are present; diseases are not addressed. It appears that APHIS does not 
have the authority under its regulations to permit the entry of fruits 
or vegetables from countries where one or more diseases exist. 
Therefore, given that citrus diseases exist in Argentina, it appears 
that APHIS does not have the authority under its regulations to 
promulgate a regulation that allows the importation of grapefruit, 
lemons, and oranges from that country.
    Response: Our regulations are not the source of our authority to 
regulate the importation of fruits and vegetables; rather, they are a 
means through which we exercise the authority derived from statutes 
such as the Federal Plant Pest Act and the Plant Quarantine Act. The 
Secretary of Agriculture is provided with the authority in the Plant 
Quarantine Act to restrict the importation of fruits and vegetables 
because of ``injurious plant diseases or insect pests'' or to prohibit 
such importation because of any ``disease or of any injurious insect'' 
(7 U.S.C. 159, 160). Therefore, we have clear statutory authority to 
regulate the importation of fruits and vegetables because of diseases 
as well as insect pests. With respect to our regulations implementing 
the Secretary's authority under those acts, the commenter is correct in 
noting that the fruits and vegetables regulations contain no general 
provisions regarding diseases. However, the regulations in ``Subpart--
Citrus Fruit'' (Sec. 319.28), which we are amending in this rule and 
which was discussed in the proposed rule, do in fact contain specific 
restrictions on the importation of fruit of citrus and citrus relatives 
from specified countries due to the presence of citrus diseases in 
those countries.
    Comment: The April 1992 pest risk analysis that APHIS completed for 
its rulemaking regarding the importation of citrus from South Africa 
states that ``[i]mportation of all plant parts, except seed, of Citrus 
spp. should be prohibited from countries where the disease [black spot] 
occurs'' (Pest Data Sheet on Black Spot of Citrus, p. 62). Yet, neither 
the risk assessment nor the proposed rule for Argentine citrus mentions 
that serious concern that the Agency had so recently expressed about 
citrus black spot. It appears that APHIS is now proposing to make an 
abrupt change in its position regarding this disease and the danger 
that it poses without either articulating the reasons for this change 
or including in the record substantial evidence that could support such 
a divergence from longstanding agency policy.
    Response: We disagree with the commenter's contention that we are 
making an abrupt change in policy with regard to the risks presented by 
citrus black spot. More importantly, our position regarding the 
phytosanitary significance of citrus black spot has not changed as 
drastically as the commenter suggests. We still consider citrus nursery 
stock and plant parts other than fruit to pose a high risk as pathways 
for the introduction of citrus black spot. It is only our position 
relative to citrus fruit--specifically, citrus fruit that has been 
subjected to the measures required by this rule--that has changed since 
the April 1992 pest risk analysis for South African citrus. The pest 
data sheet cited by the commenter was completed more than 5 years 
before we prepared the Argentine citrus analysis and did not consider 
the tiered and overlapping measures used in the systems approach to 
mitigate the risk of citrus black spot; thus, the data sheet's 
recommendations were made in the context of an importation scenario in 
which no measures short of prohibition were offered to mitigate the 
risk of citrus black spot.

[[Page 37614]]

    APHIS' reading of the relative risks presented by citrus plants, 
fruit, and other plant parts is consistent with the current research 
into the epidemiology and control of citrus black spot and the evolving 
scientific understanding of the disease. For example, Professor J.M. 
Kotze of the University of Pretoria (South Africa) reports in a 
Department of Microbiology and Plant Pathology summary of plant 
pathology research focus areas that: ``We have shown that the disease 
[citrus black spot] spreads to new areas through leaves of nursery 
trees. The importance of the inoculum sources was already demonstrated, 
especially the fact that fruit presents no danger to importers of 
citrus in Europe.'' Fruit has been shown to be a poor pathway for the 
introduction of citrus black spot, and, as explained in the proposed 
rule, the required systems approach acts to reduce any remaining risk 
to a negligible level.

Trade-Related Issues

    Comment: In the proposed rule, APHIS stated: ``Maintaining a 
prohibition on the importation of grapefruit, lemons, and oranges from 
the Argentine States of Catamarca, Jujuy, Salta, and Tucuman in light 
of those State's [sic] demonstrated freedom from citrus canker would 
run counter to the United States' obligations under international trade 
agreements and would likely be challenged through the World Trade 
Organization'' (WTO). This is simply not true. Even if the four 
involved Argentine States are free from citrus canker, there are other 
potentially devastating citrus diseases and pests present. Under the 
Uruguay Round WTO agreement, the United States has no obligation to 
permit the introduction and spread of quarantine diseases and pests in 
this country. Any country is free to adopt a ``zero risk'' standard as 
its appropriate level of protection; we submit that the current U.S. 
prohibition on fruit that is infected with sweet orange scab and citrus 
black spot is entirely consistent with the Uruguay Round's ``Agreement 
on the Application of Sanitary and Phytosanitary Measures'' (the ``S&P 
Agreement''). Argentina has not shown that the importation of fruit 
from an indisputably infected region poses no risk that sweet orange 
scab, citrus black spot, or both, may be introduced into the United 
States.
    Response: We understand that we are not required to allow diseased 
or infested fruit to be imported into the United States; indeed, this 
rule does nothing to alter the ``current U.S. prohibition on fruit that 
is infected with sweet orange scab and citrus black spot'' noted by the 
commenter. However, we also recognize that we are obliged to use health 
requirements only to the extent necessary to meet our ``appropriate 
level of protection.'' In the case of grapefruit, lemons, and oranges 
from Argentina, we believe that the tiered and overlapping safeguards 
contained in this final rule will reduce the pest risk associated with 
their importation to a negligible level. If the United States had 
deemed ``zero risk'' to be its appropriate level of protection, then it 
is unlikely that Argentine citrus--and many other commodities, for that 
matter--would ever be approved for importation into the United States. 
There will always be some degree of pest risk associated with the 
movement of agricultural products; APHIS' goal is to reduce that risk 
to a negligible level.
    While the one sentence quoted by the commenter from the proposed 
rule mentioned only citrus canker, we believe that it is evident from 
the content of the entire proposed rule that we did indeed consider the 
presence of other diseases and insect pests in Argentina. It should be 
noted that the sentence quoted by the commenter was preceded by another 
sentence in the proposed rule: ``We have rejected that alternative 
[i.e., to make no changes in the regulations and continue to prohibit 
the importation of grapefruit, lemons, and oranges from Argentina] 
because we believe that Argentina has demonstrated that the citrus-
growing areas of the States of Catamarca, Jujuy, Salta, and Tucuman are 
free from citrus canker and because we believe that the systems 
approach offered by Argentina to prevent the introduction of other 
plant pests reduces the risks posed by the importation of grapefruit, 
lemons, and oranges to a negligible level.''
    Comment: We submit that APHIS should consult with the U.S. Congress 
on the issue of the ``appropriate level of protection'' in this 
situation, especially given that the world trading community has yet to 
settle the issue of what constitutes an appropriate level of 
protection. The citrus industry is far too important to the United 
States economy and trade interests for APHIS to make critical economic 
and foreign policy decisions on its own, particularly when no 
international standard dictates a particular result.
    Response: The provisions of the WTO SPS Agreement provide that it 
is the sovereign right of each member to set its own level of 
protection, thus it would be inappropriate for the ``world trading 
community'' to make such a determination. In this instance, APHIS, as 
the recognized regulatory authority, is establishing a system of 
phytosanitary measures that reflect the level of protection deemed 
appropriate. It is our intent to allow fresh grapefruit, lemons, and 
oranges to be imported into the continental United States from 
Argentina only if they are grown, packed, and shipped under specified 
phytosanitary conditions designed to mitigate the risk of plant pest 
introduction. We are confident that the phytosanitary measures required 
by this rule will mitigate the risk presented by Argentine citrus. 
Given that confidence, we do not believe that the level of protection 
afforded by this rule is a departure from the level of protection we 
demand in other commodity import situations.
    Comment: Article 6 of the S&P Agreement recognizes that countries 
can have regions that are pest- or disease-free or have areas of low 
pest or disease prevalence. However, it is envisioned that each country 
claiming to have such regions has the burden of proving that such areas 
have no pests or diseases or have low levels of pests or disease. 
Argentina has not provided any information to APHIS as to the levels of 
pests or diseases that are present in the four States that are proposed 
for export.
    Response: Argentina claims that the citrus-growing regions 
identified in this rule are free from citrus canker, and we believe 
that they have provided sufficient documentation to support that claim. 
We also believe that Argentina submitted sufficient documentation to 
support its position that the remaining pests and diseases were of low 
enough prevalence that the chemical, cultural, and other controls of 
the systems approach would prevent their introduction into the United 
States on fruit imported under the requirements of this rule.
    Comment: APHIS' regulations in Sec. 319.56-2 refer to ``without 
risk,'' yet the proposed rule seems to have a standard on ``negligible 
risk.'' Even if APHIS does have the statutory authority to adopt a 
``negligible risk'' standard, the standard is undefined and impossible 
to determine. This is not acceptable. The standard should be capable of 
being independently validated and should be set only after rigorous 
peer review, in accord with standards and guidelines adopted by WTO 
with the advice of International Plant Protection Convention (IPPC).
    Response: The ``without risk'' provision selected by the commenter 
is found in Sec. 319.56-2(e) and is used in the context of importing a 
fruit or vegetable from a definite area or district of a country that 
is free from some or all of the injurious insects that attack the fruit 
or vegetable when that area or

[[Page 37615]]

district meets the criteria for pest freedom found in Sec. 319.56-2(f). 
Section 319.56-2(e) is not applicable to this rulemaking because the 
Argentine Government has made no claims with regard to the freedom of 
northwestern Argentina with regard to injurious insects i.e., fruit 
flies in this case. The risk of diseases is addressed under the 
regulations in Sec. 319.28 (Subpart--Citrus Fruit), which contains no 
such ``without risk'' standard. In any event, we do not believe that a 
policy of requiring imports to be ``without risk'' or to present ``zero 
risk'' could be sustained by any country that wishes to engage in 
international trade. There will always be some degree of pest risk 
associated with the movement of agricultural products; APHIS' goal is, 
and always has been, to reduce that risk to a negligible level. This 
goal is entirely consistent with the standards and guidelines of the 
WTO and the IPPC.
    Comment: In the proposed rule, APHIS does not offer any ``reasoned 
analysis'' for departing from its longstanding policy of not permitting 
the importation of fruit from diseased regions. In its two recent 
rulemakings regarding the importation of citrus from South Africa and 
Australia, APHIS stated that it would deny the entry of citrus from 
each of those countries if the citrus was found to be infected with 
citrus black spot. It appears that it was clear to APHIS in those cases 
that citrus black spot was so troubling and dangerous that the only way 
to protect the United States against importation of this disease was to 
disallow the importation of any fruit from diseased areas. The 
inconsistency of APHIS' proposed approach to Argentine fruit with its 
prior, recent positions regarding fruit from South Africa and Australia 
is never mentioned or explained in the proposed rule or the risk 
assessment. Further, the differences in the approaches applied to 
Argentine citrus on one hand, and Australian and South African citrus 
on the other, leaves the United States open to challenges from 
Australia and South Africa under article 2.3 of the S&P Agreement, 
which requires that member countries do not discriminate with respect 
to other member countries where ``similar conditions prevail.''
    Response: In the two rulemakings cited by the commenter regarding 
the importation of citrus from Australia and South Africa, the freedom 
of the production areas from citrus black spot formed part of the basis 
for allowing the importation of citrus from those countries. Because 
the importation protocols were based largely on that area freedom, it 
follows that we would prohibit the importation of citrus from either 
country if it was found to be infected with citrus black spot. In the 
case of Argentine citrus, no such claim of area freedom is made, which 
is why this rule requires control and detection measures for citrus 
black spot. Because of these differences in the bases for the three 
rules in question, we do not believe that this final rule arbitrarily 
or unjustifiably discriminates between countries where similar or 
identical conditions prevail. Further, it is important to note that 
this final rule, like the Australian and South African citrus fruit 
regulations, prohibits the importation of any fruit found to be 
infected with citrus black spot.
    Comment: The rate of importation of fruit into the United States 
should be consistent with the rate of production of a normal lemon farm 
as if trees were planted today. If I planted a lemon tree today, I 
wouldn't receive any production for 3 years, and then production would 
increase gradually through the tenth year. Regardless of current 
Argentine production available for importation, no lemons should be 
allowed into the United States during the first 3 years, and then only 
15 percent the fourth year, 30 percent in the fifth year, etc., until 
full production is allowed.
    Response: APHIS has no authority to impose the quotas suggested by 
the commenter.
    Comment: APHIS should calculate the cost per field box to the 
American farmer of the cost of U.S. Government regulation and adopt a 
temporary tariff in that amount on all imported Argentine fruit. The 
amount collected by the temporary tariff would be distributed to the 
American lemon farmer based on each farmer's field box production until 
Argentina adopts the same laws and regulations that the American farmer 
must obey. The minimum-wage law, Labor Standards Act, and all 
environmental and health safety laws are examples of such laws and 
regulations.
    Response: APHIS has no authority to impose the tariff suggested by 
the commenter.
    Comment: APHIS has no regulations that govern the procedure and 
standards for consideration of import petitions filed by foreign 
governments. Nor does the website maintained by APHIS provide any 
information on the process for, or standards which are applied to, such 
petitions. We submit that APHIS has an obligation to establish its 
procedures and standards when dealing with plant diseases in such a way 
as to provide the affected industry with confidence that agency 
decisionmaking is being conducted in a ``reasoned'' way based upon 
substantial evidence in the record and meaningful opportunity for 
public comment.
    Response: Foreign governments most often broach the subject of 
exporting new fruits or vegetables to the United States through formal 
negotiations or informal contacts with APHIS officials. These requests 
and any subsequent detailed proposals are reviewed by APHIS staff 
experts. After that review, APHIS staff may either recommend approval 
of the petition or contact the petitioning government with a request 
for additional research, proposed safeguards, etc. As noted by the 
commenter, this government-to-government contact is not the subject of 
any procedural regulations in part 319. However, the public is provided 
the opportunity to review the Agency's basis for any change in the 
regulations proposed as a result of a foreign government's import 
petition. Each time we propose to amend our regulations to address an 
import request that involves a new commodity/region combination, we 
prepare a proposed rule that is commented upon by the public. In each 
case, the proposed import program, including mitigation measures, is 
clearly described in the proposed rule, and the rationale underlying 
the proposed import program is explained. The public, which includes 
any potentially affected industry, then has the opportunity to review 
the proposed rule and its supporting information and may provide 
comments that must be considered and addressed by APHIS before any 
final action on a foreign government's import petition may be taken.

Systems Approach

    Comment: APHIS' regulations contain no discussion, definition, or 
description of what constitutes a ``systems approach,'' or what 
treatment or treatments will qualify as an acceptable systems approach. 
There are no standards in APHIS regulations that permit affected 
parties to understand or judge the Agency's actions to approve or 
disapprove such an approach. This is unacceptable. An agency is 
obligated to set forth the standard the agency is applying or how it is 
applying that standard to the factual situation.
    Response: The standard that we apply to any potential import 
situation is clear and has been well-established over the course of 
numerous APHIS rulemakings dealing with the importation of agricultural 
commodities: Does the importation of a particular commodity from a 
particular region present a risk of introducing pests into the United 
States,

[[Page 37616]]

and, if so, can that risk be reduced to a negligible level through the 
application of phytosanitary measures? These considerations are 
addressed each time we propose to amend our regulations to address an 
import request that involves a new commodity/region combination. In 
each case, the proposed mitigation measures, which can range from 
something as basic as inspection at the port of entry to a more 
complicated systems approach of tiered and overlapping measures, are 
clearly stated in the proposed rule, and the rationale for their 
proposed use is explained. So, while the general provisions of our 
regulations do not discuss, define, or describe what constitutes a 
systems approach or what treatment or treatments qualify as an 
acceptable systems approach, we do not believe that the lack of such a 
discussion in the regulations detracts from the public's ability to 
understand, assess, and comment upon the mitigation measures proposed 
for a particular commodity/region combination.
    Comment: Applying a systems approach to disease suppression for the 
purpose of allowing imports from a region with a disease that does not 
exist in the United States is a fundamental change in APHIS policy. 
Previously, APHIS has always demanded that the area in which the crop 
is grown be completely free of disease and geographically separated 
from regions with the disease. This principle is applied to citrus 
canker in the northwestern region of Argentina, but is not the case 
with sweet orange scab or citrus black spot. There has not been a full 
scientific discussion of the principles that need to be fulfilled 
before moving forward with such a fundamental change in the standards 
for U.S. quarantine pest protection. Therefore:
    <bullet> APHIS should identify and cite the studies that have been 
used to determine that a systems approach provides sufficient safety 
from all kinds of plant pests when importing fresh produce into the 
United States;
    <bullet> APHIS should establish basic standards for the kind of 
data and experiments that are needed to provide confidence in applying 
the systems approach to disease control;
    <bullet> APHIS should establish standards by which the information 
used to determine the effectiveness and practicality of the systems 
approach are to be judged; and
    <bullet> There needs to be a public discussion of what level of 
risk is appropriate.
    Response: We believe that the commenter is incorrect in asserting 
that APHIS is fundamentally changing its policy by not demanding that a 
growing area be completely free of disease and geographically separated 
from regions where disease exists. A long-standing precedent for the 
local freedom concept is found in the citrus fruit regulations in 
Sec. 319.28(b)(1), which allow Unshu variety oranges to be imported 
into certain areas of the United States from Japan and South Korea if 
the oranges are grown in citrus-canker-free export areas that are 
surrounded by 400-meter buffer zones. While the Unshu orange program 
differs from the Argentine citrus program in many respects, the fact 
remains that the Unshu orange program stands as an example of a 
successful approach to importing fruit from regions where a disease 
exists.
    As noted in the response to the previous comment, it is true that 
the general provisions of our regulations do not discuss, define, or 
describe what constitutes a systems approach or what treatment or 
treatments qualify as an acceptable systems approach. However, we do 
not believe that the lack of such a discussion in the regulations 
detracts from the public's ability to understand, assess, and comment 
upon the mitigation measures proposed for a particular commodity/region 
combination because, in each case where we propose to allow the entry 
of a new commodity, we explain the proposed mitigation measures and 
provide the scientific rationale underlying their proposed use. Thus, 
the public has the opportunity to judge each proposed importation 
according to the criteria suggested by this commenter.
    The commenter states that ``APHIS should identify and cite the 
studies that have been used to determine that a systems approach 
provides sufficient safety from all kinds of plant pests when importing 
fresh produce into the United States.'' We are unaware of any studies 
that examine the use of systems approaches as broadly or definitively 
as the commenter suggests; there are simply too many possible 
combinations of pests and hosts on one hand, and biological, physical 
and operational factors that could be integrated into a systems 
approach on the other, to allow for such a conclusive determination. 
Thus, while it is acknowledged that systems of practices and procedures 
can be assembled to provide quarantine security in many cases, each 
proposed use of a systems approach must be evaluated individually. We 
will, however, consider the commenter's suggestion that we establish, 
to the extent possible, general standards for the preparation and 
evaluation of data that serve to support the establishment of systems 
approaches. Finally, the commenter states that there needs to be a 
public discussion of what level of risk is appropriate; we believe that 
the comments received in response to our proposed rule are one 
indication that such a discussion of the level of risk that APHIS has 
determined to be approporiate is already open and ongoing. Given the 
numerous, evolving, and unpredictable factors affecting the perception 
of, and tolerance for, risk, it appears that the ``public discussion of 
what level of risk is appropriate'' will, by necessity, be an ongoing 
exchange rather than a discrete deliberation.
    Comment: APHIS has never before proposed using a systems approach 
for a combination of diseases and insect pests. What is particularly 
troubling about the approach APHIS is proposing in the Argentine rule 
is that the Agency has issued this proposal with no specific discussion 
of its rationale; its only stated justification is the previous use of 
system approaches. However, previous systems approaches are similar in 
only the most remote of ways and are not at all similar in execution or 
in impact. Thus, the Agency must set forth a detailed justification 
supported by sound scientific evidence for this fundamental shift in 
regulatory approach. Further, we submit that APHIS should have adopted 
this expanded use of a systems approach only after conducting a notice 
and comment process, with rigorous scientific peer review to determine 
whether a systems approach can be an effective tool when addressing 
diseases.
    Response: It is not true that we sought to justify the use of a 
systems approach for Argentine citrus by pointing to previous uses of 
systems approaches; indeed, the proposed rule did not mention the use 
of a systems approach in any context other than that of Argentine 
citrus. Further, we disagree with the commenter's contention that we 
issued the proposed rule ``with no specific discussion of its 
rationale.'' Our rationale for the use of a systems approach for 
Argentine citrus was stated early in the proposed rule, at the end of 
the first paragraph under the heading ``Importation of Grapefruit, 
Lemons, and Oranges,'' where we stated ``To prevent the introduction 
into the United States of those diseases [i.e., sweet orange scab and 
citrus black spot] and fruit flies, the Government of Argentina, with 
the cooperation of APHIS, has formulated a systems approach of tiered 
and overlapping measures that, when combined with specified cold 
treatments, would reduce the risks presented by those pests to a 
negligible

[[Page 37617]]

level.'' The proposed rule then explains in detail each of the 
phytosanitary measures that would be required in order for citrus to be 
exported to the United States from Argentina. That explanation, we 
believe, constitutes the ``detailed justification'' requested by the 
commenter. We do not believe that our application of systems approach 
principles to the importation of Argentine citrus is in any way a 
departure from our policy of allowing the importation of fruits and 
vegetables when the risks presented by those commodities can be 
mitigated to a negligible level.
    Comment: The systems approach is premised upon the layering of 
several risk reduction measures. An effective verification and 
enforcement system is essential for the layering of risk reduction 
measures to result in the desired outcome. What will be done when one 
or more of these layers beaks down? APHIS should have a response plan 
for action when a risk reduction measure fails.
    Response: The systems approach contained in this rule, as is the 
case with all systems approaches contained in APHIS' regulations, is 
indeed premised upon the layering of several risk reduction measures. 
The tiered and overlapping nature of any systems approach ensures that 
even if any one of the elements of the systems approach is omitted or 
fails, and that omission or failure remains undetected, adequate 
measures will remain to provide the necessary level of phytosanitary 
security. Further, we agree that an effective verification and 
enforcement system is essential to the success of any systems approach. 
To achieve that success, this rule requires that SENASA actively 
participate in or supervise each step of the process in Argentina to 
verify and document each step's successful completion or application, 
and the required documentation must be made available to APHIS. 
Further, as discussed earlier in this document in the paragraph titled 
``Monitoring--Argentina,'' the operational work plan that addresses the 
administration of the export program will include provisions for active 
and direct monitoring of the program by APHIS personnel who will 
conduct frequent oversight visits to the growing areas and 
packinghouses in order to observe each step of the program in 
Argentina. Further, each shipment of fruit must be accompanied by a 
phytosanitary certificate issued by SENASA that verifies that the fruit 
was produced and handled in accordance with the requirements of 
Sec. 319.56-2f(a) through (c) and that the fruit is apparently free 
from citrus black spot and sweet orange scab. Fruit that fails to meet 
those requirements will not be eligible for importation into the United 
States. At the port of entry in the United States, APHIS will inspect 
the fruit and its accompanying phytosanitary certificate and will 
confirm that any required cold treatment has been properly applied. 
Finally, the detection of citrus black spot or sweet orange scab on any 
grapefruit, lemons, or oranges at any time in Argentina, during 
transport, or in the United States will result in the grove in which 
the fruit was grown or is being grown being removed from the SENASA 
citrus export program for the remainder of that year's growing and 
harvest season, and the fruit harvested from that grove being 
ineligible for importation into the United States from the time of 
detection through the remainder of that shipping season.
    Comment: For a systems approach to be effective, it is essential to 
know the biological interactions between the pest and its host to 
understand how these interactions affect production, shipment, and 
marketing of commodities. There is very little current knowledge about 
citrus black spot or sweet orange scab, and virtually no work has been 
done on the question of how the diseases would respond if brought into 
the United States. Thus, there is a substantial threshold question of 
whether a systems approach can even be designed to deal with citrus 
black spot or sweet orange scab.
    Response: As neither of those diseases is present in the United 
States, it is not unusual that most researchers in this country who 
study citrus crops and their pests have directed their efforts to 
other, more immediate concerns. However, in countries where citrus 
black spot or sweet orange scab is present and where citrus is an 
economically important crop, those diseases have been, and continue to 
be, the subject of focused research. We believe that the information on 
the prevention, control, and detection of these diseases that has been 
collected over the years, combined with the results of the field trials 
conducted in Argentina, provides the necessary degree of scientific 
support for the systems approach described in this rule.
    Comment: APHIS has not used a systems approach previously in a 
situation where the intended result of the treatments is simply 
suppression of the symptoms of the disease(s) in a proposed export 
area. Thus, proposing to rely on an approach which admittedly only 
results in suppression of the symptoms of the diseases is a fundamental 
policy shift by APHIS. The proposal also stands in stark contrast to 
the goal of complete eradication of a disease, which has been and 
remains the objective in every situation in the United States where a 
plant disease or pest does exist. As such, any contemplated use of such 
an approach should be subjected to the most rigorous, exhaustive, and 
comprehensive level of scientific peer review.
    Response: The intended result of the treatments, particularly the 
oil-copper oxychloride sprays during the growing season, as well as 
measures such as grove cleaning to remove inoculum, is the prevention 
of infection, and not simply the suppression of symptoms as stated by 
the commenter. Other required measures are specifically designed to 
detect the presence of diseased fruit and prevent its importation into 
the United States. Given that the goal of this rule is to provide for 
the importation of disease--free and not simply asymptomatic--
grapefruit, lemons, and oranges, we do not believe that this rule 
represents a departure from our policy of allowing the importation of 
fruits and vegetables when the risks presented by those commodities can 
be mitigated to a negligible level.
    Comment: A publication titled Quarantine Treatment for Pests of 
Food Plants (edited by Jennifer L. Sharp and Guy J. Hallman, Westview 
Press, 1994), includes a discussion of systems approaches that stresses 
the importance of determining the level at which a pest or disease 
exists in order to design an effective systems approach. Nothing on the 
record of the Argentine proposed rule indicates the ``level of 
infestation'' of the host fruit by any of the diseases or pests at 
issue. This infestation information must be known before APHIS can even 
consider the possibility of designing a systems approach. Only when 
this infestation level is known can the efficacy of the proposed system 
be judged. Without this information, interested parties are unable to 
conduct any meaningful review of the proposed systems approach.
    Response: The ``level of infestation'' passage noted by the 
commenter is found on page 226 of the cited publication and states ``* 
* * [S]ystems recognize that the commodity in question is a host, the 
level of infestation in the host being the key component in the design 
of the overall system. Systems rely on knowledge of the infestation 
level of the host and measure the impact of the various operational 
procedures on removing infested hosts, thereby reducing the risks that 
infested hosts will be shipped.''

[[Page 37618]]

    For the fruit flies of concern in Argentina, a single quarantine 
treatment--cold treatment--is available and is required by this rule, 
which leaves citrus black spot and sweet orange scab as the ``diseases 
or pests at issue.'' Surveys produced by Argentina show that disease 
incidence--i.e., the ``level of infestation'' referred to in the cited 
publication--varies from season to season, depending on the prevailing 
environmental conditions, and can be high in untreated groves. The 
results of those surveys were reported in the risk assessment that 
accompanied the proposed rule, so there is in fact information on the 
record indicating our knowledge of disease incidence in Argentina. 
Because of the known seasonal variations in disease incidence, the 
design of the systems approach for Argentine citrus began with the 
assumption of a potentially high ``level of infestation'' and set out, 
through biological and operational factors such as buffer zones, 
inoculum removal, inspections, testing, and treatments, to reduce the 
risks of infected fruit being shipped to the United States.
    Comment: It is not possible to properly assess the adequacy of a 
systems approach in preventing the introduction of pests into an 
importing nation without detailed knowledge of the circumstances under 
which a pest occurs, and the frequency with which it occurs, in the 
export region. APHIS' current risk assessment is based on a poor body 
of knowledge of insect species present or potentially present in 
Argentina, particularly the Anastrepha species present in northwestern 
Argentina. Further, the level of pesticide use there could be masking 
the presence of lesser-known pests that could emerge as a problem if 
newer, more specific pesticides are used in Argentina. Therefore, 
extensive taxonomic research and population surveys on fruit flies and 
other insect species present in northwestern Argentina, as well as data 
on other potential hosts in that region, are necessary in order for a 
proper risk assessment to be completed on Argentine citrus and for the 
systems approach to be fully evaluated.
    Response: Citrus is an economically important crop in Argentina, 
and as such has been, and continues to be, the subject of well-
supported and vigorously pursued research into its production and 
factors affecting that production, including pests. We are confident, 
therefore, that the pest list produced by SENASA, which was reviewed by 
APHIS and by agricultural officials in the four main citrus-producing 
States of this country and compared against reports from various 
international sources and the scientific literature, accurately 
addressed the range of citrus pests present in Argentina. Further, we 
believe that the risks posed by those pests were adequately considered 
in the risk assessment and addressed by the provisions of this rule.
    Comment: What is the goal of the systems approach for citrus black 
spot and sweet orange scab? Some of the statements in the rulemaking 
record imply that the goal is to have disease-free groves, while the 
proposed rule seems to seek the suppression of disease symptoms in 
export groves. Recent statements by APHIS imply that it would be 
acceptable for diseased fruit to enter the United States.
    Response: The goal of the systems approach is to reduce the plant 
pest risks associated with the importation of Argentine citrus to a 
negligible level. With regard to citrus black spot and sweet orange 
scab, the systems approach is designed to accomplish that goal through 
both prevention and detection; the grove cleaning and growing season 
spraying requirements are designed specifically to prevent fruit from 
becoming infected in the first place, and subsequent surveys, 
inspections, and testing provide multiple opportunities for the 
detection of infected fruit. If a single infected fruit is found at any 
point in the process, including inspections conducted after the fruit 
has arrived in the United States, the grove in which that fruit was 
grown will be removed from the SENASA citrus export program and the 
fruit harvested from that grove may not be imported into the United 
States from the time of detection through the remainder of the shipping 
season. Thus, the commenter's impression that we would find it 
acceptable for diseased fruit to enter the United States is incorrect.
    Comment: The record of data supplied by Argentina, as provided to 
the public by APHIS, is completely inadequate to assess the efficacy of 
the individual measures, let alone the systems approach, for citrus 
black spot and sweet orange scab. Either APHIS has not maintained a 
complete record of the information Argentina supplied, or the Agency is 
basing its risk estimates on ambiguous data because of inadequate 
reporting by Argentina.
    Response: We have, in fact, maintained a complete record of the 
information supplied by Argentina, and we did share that information 
with the commenter, although we were unable to provide the information 
that was the subject of the commenter's FOIA request until after the 
close of the comment period. Further, it is important to note that our 
assessment of the risks presented by Argentine citrus and of the 
efficacy of specific measures was not based solely on the material 
provided by Argentina; information gathered from other sources and the 
expert judgment of subject matter specialists also played a role. This 
is the norm when conducting probabilistic assessments to inform 
decisions regarding importation of agricultural commodities. When data 
that represent ``direct evidence'' do not exist, which is often the 
case in probabilistic risk assessments, available information is 
reviewed and applied through the use of professional judgment. APHIS 
bases the estimates needed for its probabilistic commodity risk 
assessments on pest interception records, the known biology of the 
organism being assessed (or the known biology of related taxa) as 
represented in the scientific literature, expert judgment based on 
laboratory experience with the pest or related organisms, expert 
judgment based on field experience with the pest or related organisms, 
expert judgment based on experience conducting commodity inspections at 
ports of entry or in the exporting country, and experience working with 
export programs and export-quality commodities. Thus, we believe that 
the entire body of information available is, in fact, sufficient to 
support the efficacy of the measures required by this rule and our 
analysis of the risks associated with Argentine citrus.
    Comment: The following items are examples of the type of data or 
information that appear to be missing from the rulemaking record. No 
information is provided as to what the climatic conditions were in the 
tested groves during the spraying program. Similarly, no information is 
provided on how the spraying program would be affected by different 
climatic conditions in different growing areas, such as the 
northwestern versus the southern part of Tucuman, and Tucuman as 
compared to Salta, etc. Accordingly, it was impossible to answer many 
critical questions: Was it a year of light incidence of the disease, 
and thus the spraying was very effective? What would happen in a year 
of heavy incidence? What were the ages and varieties of the trees in 
the program? What was the protocol that was followed? How would 
different climatic conditions affect the spraying program? Would the 
same results have been achieved if the trees had been 10 years older? 
Neither the risk assessment nor the rulemaking record addresses or 
answers any of these questions. APHIS must require much more extensive 
tests

[[Page 37619]]

covering multiple variables before further considering the Argentine 
petition. Variables that should have been included in tests before 
approving the Argentine petition would include, but are not limited to: 
Multiple and differing climatic situations (i.e., drier versus more 
humid areas; more humid years versus drier years); differing ages of 
trees, since citrus black spot is more often seen in older trees and in 
ripe fruit; differing sizes of groves; whether the grove was virtually 
surrounded by untreated groves; whether the trees had been under any 
type of stress; etc.
    Response: The bioecological factors affecting citrus black spot 
development that were considered in the design of the field testing 
conducted in Argentina, the protocols for the field tests, and the 
results of those tests are among the material provided to the commenter 
in Note S.P. 338 of December 5, 1995, and its three annexes 
(``Bioecology of Black Spot in Citrus,'' ``Field Assays for the Control 
of Black Spot in Citrus,'' and ``Results of the Postharvest Assays 
Carried Out up to the Present''). These documents demonstrate that 
Argentina recognized, and took into account, that factors such as 
climate, humidity, fruit susceptibility, and the presence of inoculum 
have an effect on the presence of the disease. The Argentine field 
tests were conducted during growing seasons marked by both dry 
conditions with light disease incidence in control trees and prolonged 
rainy conditions with a heavy incidence of disease in control trees. 
This information, which was used in the design of the systems approach, 
was also considered by the experts who prepared the risk assessment. As 
noted elsewhere in this document, the systems approach is designed to 
mitigate the risk of citrus black spot during years in which the 
disease is likely, which is why this rule requires in part that the 
timing of the fungicidal sprays be determined by SENASA using an expert 
system that takes climatic data, as well as fruit susceptibility and 
the presence of disease inoculum, into account. We believe that the 
body of information contained in the rulemaking record, including the 
research and testing data provided by Argentina, provides the necessary 
scientific and rational basis for our regulatory decisionmaking.
    Comment: The evidence that APHIS has made available to date is 
inadequate to support the proposed rule. The Secretary should appoint 
an independent scientific team to travel to the proposed Argentine 
production area when climatic conditions are appropriate, and that team 
should be given access to the production and packing facilities, as 
well as to the transportation and port operations that would be 
utilized for the export program. The Secretary should direct that team 
to report its findings to the Department and Congress.
    Response: APHIS, under the authority of the Plant Quarantine Act 
and the Federal Plant Pest Act, has reviewed the Argentine petition and 
has made the determination that phytosanitary measures that comprise 
the systems approach reduce the pest risk to a negligible level. The 
systems approach that is the subject of this rule was developed in 
Argentina by that country's plant health officials and citrus interests 
and was presented, along with its supporting data, to APHIS for review. 
APHIS rejected Argentina's initial proposal on the grounds that it did 
not sufficiently mitigate the pest risk presented by Argentine citrus. 
It was only after Argentina included additional phytosanitary measures 
in its systems approach and provided what we determined to be an 
adequate amount of additional efficacy data that APHIS accepted the 
Argentine proposal. The Secretary is not required to appoint an 
independent scientific team as suggested by the commenter, nor do we 
believe that one is needed in light of the review already conducted by 
APHIS.
    Comment: The 1997 risk assessment states that the level of visible 
incidence of citrus black spot can be extremely high in Argentina--as 
high as 82 percent and can vary greatly year to year. This level of 
disease incidence is disturbingly high. Further, this data does not 
address the phenomenon of symptoms that remain latent. Based on the 
current state of science, we submit that no fruit from such highly 
diseased areas should be allowed to enter the United States.
    Response: The section of the risk assessment cited by the commenter 
stated that in untreated export-area orange groves, field surveys for 
citrus black spot in 1994 and 1995 found 14 percent and 82 percent, 
respectively, of sampled fruit were infected with the citrus black spot 
fungus, and a similar 1996 survey found that 56 percent of the sampled 
trees in an untreated lemon grove bore fruit with citrus black spot 
symptoms. The risk assessment further states, however, that in the 1994 
survey, citrus black spot incidence was reduced from 14 percent in 
control groves to 0 percent in treated orange groves; in the 1995 
survey, citrus black spot incidence was reduced from 82 percent to 11 
percent; and in the 1996 lemon survey, none of the trees sampled in 
treated groves bore fruit with citrus black spot symptoms. These tests 
show that the incidence of citrus black spot can be significantly 
reduced by orchard treatments, which is just one aspect of the systems 
approach, even when the level of disease in the area is high. The issue 
of asymptomatic, latently infected fruit is addressed by the rule's 
requirement that a sample of fruit collected according to a 
statistically valid sampling protocol be held for 20 days under 
conditions that are ideal for producing symptoms in infected fruit. We 
believe that this rule provides an array of effective measures to 
reduce to a negligible level the risk of introducing citrus black spot 
into the United States.

APHIS Involvement

    Comment:  The proposed rule does not provide for APHIS personnel to 
perform any of the required inspections in Argentina. APHIS personnel 
should inspect all groves according to a detailed protocol, and the 
Argentines should pay all costs associated with such inspections.
    Response: APHIS routinely relies upon the national plant protection 
organizations of exporting countries to provide the supervision or 
certification of phytosanitary measures that might be required for 
specific agricultural commodities, just as other countries rely upon 
APHIS to provide such services. We have had the opportunity to work 
with SENASA on numerous phytosanitary issues in the past and, as a 
result, we have every confidence in SENASA's ability to administer and 
supervise the citrus export program established by this rule. SENASA, 
as the national plant protection organization of Argentina, has a well-
established infrastructure in place throughout the country. Also, 
SENASA personnel were involved at every step in the development of the 
systems approach, so they are as familiar as APHIS with its 
requirements. Further, SENASA personnel possess a level of familiarity 
with Argentine groves, growers, and citrus production that APHIS 
personnel do not. Given these considerations, we do not believe that 
any appreciable advantage would be gained, from a plant protection/risk 
reduction perspective, by requiring Argentina to pay for APHIS to 
establish a new operational presence in that country. However, as 
discussed earlier in this document in the paragraph titled 
``Monitoring--Argentina,'' the operational work plan that addresses the 
administration of the export program will include provisions for active 
and direct monitoring of the program by APHIS personnel who will 
conduct frequent oversight visits to the growing areas and 
packinghouses in order to observe each step of the program in 
Argentina.

[[Page 37620]]

    Comment:  APHIS does not have a sufficient number of employees 
stationed in Argentina to provide an adequate level of monitoring for 
the proposed export program.
    Response: As noted in the response to the previous comment, we have 
every confidence in SENASA's ability to administer and supervise the 
citrus export program established by this rule. Accordingly, this rule 
does not require direct APHIS supervision of the activities of the 
citrus export program carried out in Argentina, so APHIS staffing in 
that country is not an issue. While APHIS personnel will travel to the 
production areas in order to monitor the progress of the export 
program, especially during the first season, this rule provides for the 
direct supervision of the measures required in Argentina to be carried 
out by SENASA.

Origin Requirement

    Comment:  The proposed rule does not provide for annual surveys on 
citrus canker. Such surveys should be made, records should be kept, and 
audits should be required.
    Response: Argentina has an ongoing monitoring program, as well as 
quarantine protection systems, for citrus canker that have been in 
place since 1992. Because Argentina's monitoring program is conducted 
in accordance with United Nations' Food and Agriculture Organization 
(FAO) standards, which include reporting and recordkeeping 
requirements, we do not believe that it is necessary for this rule to 
impose additional or redundant requirements regarding citrus canker 
surveys.
    Comment:  If APHIS allows the importation of Argentine citrus, it 
should impose movement restrictions on Argentine citrus similar to 
those of its domestic citrus canker regulations.
    Response: Our domestic citrus canker regulations apply to fruit 
grown or packed in areas that are quarantined due to the presence of 
citrus canker. Because it has been established in accordance with 
international standards that northwestern Argentina is free of citrus 
canker, such movement restrictions are neither necessary nor 
justifiable.
    Comment: According to the risk assessment, the median chance of 
citrus canker becoming established in the United States with no pest 
mitigation program is estimated as 1 chance in 4 trillion per year. The 
extremely low value for this risk estimate can partially be attributed 
to the fact that northwestern Argentina is assumed to be free of citrus 
canker. However, even if it is assumed that 100 percent of the boxes of 
fruit were initially infected (instead of the average of 0.05 percent 
assumed in the risk assessment), the likelihood of citrus canker 
establishing itself in the United States would be 1 in 2 billion per 
year, according to the analysis performed by APHIS. If it is really 
this improbable that citrus canker will become established in the 
United States, why does the risk assessment even address citrus canker? 
Why does the United States currently prohibit the importation of citrus 
fruit from countries where citrus canker occurs and regulate the 
interstate movement of citrus fruit from infested areas of the United 
States? On the one hand, APHIS states that no outbreak of citrus canker 
has ever been traced to the importation of fruit, and hence estimates a 
very low probability that citrus canker will occur. In contrast, the 
risk assessment's pest data sheet indicates that citrus canker can 
potentially move long distances on diseased fruit, that at least three 
outbreaks of citrus canker have occurred in the United States within 
the past 100 years, and that there is currently citrus canker in 
Florida. This information seems to indicate a risk greater than 1 in 2 
billion per year, and suggests that the quantitative estimate is 
incorrect.
    Response: The fact that northwestern Argentina has been 
demonstrated to be free of citrus canker in accordance with 
international standards was an important factor in our assigning an 
``extremely low value for this risk estimate.'' Another important 
factor in that risk estimate is the evidence that the long-distance 
spread of citrus canker has occurred primarily through the movement of 
infected planting and propagating materials. The commenter reports that 
the pest data sheet indicates that the pathogen could potentially move 
long distances on diseased fruit, but omits the second half of the 
sentence in which that statement appears, wherein we report that there 
is no authenticated example of a disease outbreak that initiated from 
diseased fruit. Given the preponderance of evidence and expert opinion 
that long-distance spread occurs primarily through the movement of 
infected planting and propagating materials, and given the absence of 
documented cases of citrus canker outbreaks attributable to the 
movement of infected fruit, we believe that the probability calculated 
by the commenter is actually not unreasonable and our assessment of the 
risk posed by citrus fruit from the citrus-canker-free States of 
northwestern Argentina is appropriate. The larger question of whether 
citrus canker may be spread long distances on diseased fruit has not 
been answered to the satisfaction of some in the citrus production and 
research communities, which accounts for our continuing restrictions on 
the importation and interstate movement of citrus fruit from areas 
where the disease occurs.
    Comment: If the fruit from northwestern Argentina passes through 
that country's eastern regions, which are not free from citrus canker, 
it is possible that the fruit could be contaminated by airborne citrus 
canker bacteria during transport.
    Response: As stated in the pest data sheet for citrus canker 
provided in the risk assessment, short-distance dispersal of the 
pathogen in groves occurs primarily by wind-driven rain (rain and wind 
in excess of 6--8 m/sec) that causes the water soaking in leaves 
necessary for infection and causes entrance wounds when shoots are 
injured by wind whipping. The pest data sheet also notes that overhead 
irrigation may also play a role in short distance spread, as may 
mechanical equipment used in grove maintenance (Ferguson, et al., 1985; 
Swings & Civerolo, 1993). Given that citrus fruit traveling from the 
packinghouses in the production areas will be boxed, with those boxes 
being protected from the elements to prevent damage, we do not believe 
that there is any appreciable risk of the fruit being contaminated by 
airborne citrus canker bacteria during transport.
    Comment: In a 1994 report that is part of the rulemaking record, 
APHIS personnel who visited Argentina stated that they had concerns 
regarding an apparent lack of inspection at the local airports with 
regard to citrus canker. Has this issue been satisfactorily addressed?
    Response: This issue was addressed following APHIS' 1994 trip. 
Argentina has established quarantine control stations at all main 
entrances to the citrus-canker-free States, including quarantine 
checkpoints at local airports.
    Comment: Although it is claimed that the four States of 
northwestern Argentina listed in the proposed rule are free from citrus 
canker, it may be that citrus canker does actually exist in those 
States but is inhibited by warm temperatures and dry climate.
    Response: Argentina's monitoring system for citrus canker consists 
of inspections and systematic sampling carried out annually in all 
production areas as well as in urban areas and nurseries. The collected 
samples are analyzed at university and research center laboratories 
using a high-sensitivity immunofluorescence serologic technique. Since 
this monitoring system was implemented in

[[Page 37621]]

1992, no evidence of citrus canker has been found. We are, therefore, 
confident that citrus canker is not present in the four northwestern 
Argentine States.

Grove Requirements

    Comment: The 150-meter buffer zone appears to be inadequate for 
mitigating the spread of citrus black spot spores dispersed long 
distances by the wind.
    Response: The buffer zone is designed to reduce to an insignificant 
level the possibility that ascospores from an infected grove would 
reach a grove producing fruit for the U.S. market. The ascospores are 
the only wind-dispersed propagule of black spot and are produced in 
leaves on the ground, usually under the tree canopy. Environmental 
conditions must be correct for ascospores to be dispersed (i.e., rain 
to promote the release of the ascospores followed by sufficient wind to 
move the ascospores from under the overhanging canopy of the tree). The 
combination of the prevention of long-distance movement by the canopy 
itself and the presence of a 150-meter buffer that, like the export 
area of the grove, must be cleaned of all fallen leaves and other 
debris before blossom, will significantly reduce the unlikely 
possibility that ascospores from outside the area of production will 
reach the production area. Additionally, because environmental 
conditions are monitored and control methods are utilized during 
periods when the developing fruit is susceptible to infection, the 
likelihood of successful infection is negligible.
    Comment: The risk assessment claims all new citrus stock in the 
canker-free area must originate within the zone (which we assume to 
mean the canker-free area) or be tissue culture that has passed through 
quarantine, whereas the proposed rule only requires new citrus stock 
planted within the export groves to meet those requirements. Does the 
risk assessment therefore overestimate the protection offered by this 
measure?
    Response: The citrus stock origin requirements referred to by the 
commenter as being in the risk assessment are existing requirements 
established and enforced by SENASA as part of that agency's program to 
maintain the citrus-canker-free status of the northwestern Argentine 
States. SENASA's citrus stock origin requirements apply to all groves 
in the citrus-canker-free area of Argentina; therefore, the risk 
assessment's characterization of those requirements is correct and does 
not overestimate the protection offered by those requirements. Because 
the requirements of this rule pertain only to groves that produce fruit 
for export to the United States, the rule does not extend those 
requirements to other groves producing fruit for other export markets 
or for domestic consumption within Argentina.
    Comment: The proposed rule provides that any new citrus planting 
stock used in a certified grove must originate from one of the four 
States or from a SENASA-approved propagation center (Sec. 319.56-
2f(b)(3)). It is not clear whether this requirement goes only to citrus 
canker, or whether it also applies to citrus black spot and sweet 
orange scab. If it does not apply to citrus black spot and sweet orange 
scab, what precautions will be taken to insure that planting stock does 
not carry these diseases from within the approved areas? Evidence must 
be included in the record that such precautions will be effective.
    Response: As explained in the response to the previous comment, the 
citrus stock origin requirements are part of SENASA's program to 
maintain the citrus-canker-free status of northwestern Argentina. Thus, 
those requirements apply only to citrus canker, and not to citrus black 
spot or sweet orange scab. Because this rule is not based on the four 
northwestern Argentine States being a free area for citrus black spot 
or sweet orange scab, it was not necessary to include provisions for 
the freedom of planting stock from those two diseases.
    Comment: The preamble to the proposed rule states that domestic-
origin citrus plants must meet ``strict phytosanitary requirements'' 
before they may enter the four States that will be allowed to export. 
Is this reference to the SENASA requirements for a propagation center?
    Response: Yes. The requirements referred to in the preamble of the 
proposed rule pertain to the testing and grow-out regimen conducted at 
SENASA-approved citrus stock propagation centers for citrus stock that 
has been imported into Argentina and for any domestic-origin citrus 
plants from outside the four citrus-canker-free States. As stated in 
the proposed rule, citrus plants from sources outside the citrus-
canker-free area ``must meet strict phytosanitary requirements before 
they may enter the States of Catamarca, Jujuy, Salta, or Tucuman. Under 
SENASA supervision, such citrus plants are officially tested to ensure 
their freedom from quarantine pests and diseases, and are grown in 
quarantine before being released for use in the citrus canker-free area 
of Argentina.''
    Comment: The preamble implies that nursery stock will be 
``tested.'' However, citrus black spot is a latent disease. Can it be 
successfully detected years in advance of when it appears? If tests 
cannot be carried out, what precautions will be taken to ensure that 
stock that may be from groves infected with sweet orange scab or citrus 
black spot is not planted in noninfested groves? Answers to these 
questions do not appear in the rulemaking record. Without such answers, 
APHIS should not proceed with the proposed rule.
    Response: As noted previously, SENASA's requirements, and the 
requirements of this rule, pertaining to planting stock are intended to 
prevent the introduction of citrus canker into the citrus-canker-free 
area of northwestern Argentina; because the four Argentine States are 
not a free area for citrus black spot or sweet orange scab, those 
measures are not intended to provide protection against citrus black 
spot or sweet orange scab introduction via nursery stock. The risks 
presented by those two diseases are instead mitigated by the pre-and 
post-harvest treatment and inspection requirements of this rule.
    Comment: The risk assessment speaks only of the removal of fallen 
fruit and leaves in the grove, but implies immediate and continuous 
removal. The proposed rule considers fallen fruit, leaves, and branches 
in both grove and buffer zone, but specifies removal only before 
blossoming in the grove (but not necessarily before blossoming in the 
buffer zone, or in any regions outside the buffer zone). If the buffer 
zone contains fruit blossoming earlier than the grove, the fruit is 
more likely to become infected if there is contaminated material 
remaining on the ground, but such infection is less likely to be 
observed/reported.
    Response: The buffer zone immediately surrounds the grove--indeed, 
it would be part of the grove if the owner was not producing fruit for 
export to the United States--so it is not likely that the trees in the 
buffer area will be blossoming any earlier or later than the trees in 
the export portion of the grove.
    Comment: The proposed requirement for the removal of all fallen 
fruit, leaves, and branches from the orchard floor and the buffer area 
is not a biological, well-justified safeguard. Research on attempts to 
decrease incidence in other, similarly dispersed diseases through 
cleaning of groves indicated that, while leaf and fruit removal could 
remove about 90 percent of the inoculum, the 10 percent of inoculum 
still present was more than sufficient to maintain the presence of the 
disease. It is very likely that ascospore inoculum will remain in the 
ground and any out-of-season or

[[Page 37622]]

late-hanging fruit will supply additional inoculum.
    Response: The removal of fruit, leaves, and branches from the 
orchard floor and buffer area is a biologically justified safeguard. 
Because the ascospores of citrus black spot are produced only in fallen 
leaves, the removal of this debris will significantly reduce the 
inoculum level. This is a part of a control strategy that is used by 
plant pathologists for diseases for which inoculum is produced in 
fallen debris. Because this is only one part of a systems approach, it 
is designed to reduce the likelihood of infection, not prevent it 
entirely. Therefore, we have taken into account in the risk analysis 
the possibility that debris may remain on the ground or in late season 
fruit.
    Comment: The proposed rule requires that export groves be cleaned 
of debris, leaves, and fallen fruit before bloom to remove the main 
sources of disease inoculum. Argentine researchers monitored leaf fall 
during a whole season and found that for all three citrus species in 
Salta, the majority of leaves fell between August and November, while 
fruit set occurred from September to October. Thus, the maximum leaf 
fall is occurring during bloom and fruit set. Furthermore, the summer 
rains, which are needed for development of citrus black spot on the 
dead leaves, tend to start in October. If decreasing inoculum through 
removal of fallen leaves is the goal to protect the developing fruit, 
then there must be continuous cleaning of the grove throughout the 
maximum leaf fall period, otherwise fruit will be developing in the 
presence of leaf litter as a potential source of inoculum.
    Response: A thorough cleaning of the grove and buffer area prior to 
blossom will remove a significant amount of potential inoculum. Any 
ascospores on leaves that fall after the cleaning of the grove will not 
form ascocarps until 40 to 180 days after blossom, depending on the 
frequency of wetting; by that time, the preventive oil-copper 
oxychloride sprays will be in use to protect the developing fruit from 
infection. If the removal of fallen fruit, leaves, and branches was the 
only measure employed to reduce the risk of citrus black spot infection 
during the growing season, additional cleaning would likely be 
advisable, but given the additional requirements of this rule, we do 
not believe that is necessary.
    Comment: The proposed requirement for the removal of all fallen 
fruit, leaves, and branches from the orchard floor and the buffer area 
would be difficult, if not impossible, to satisfy. We suggest that the 
word ``substantially'' be inserted before the word ``all'' to make this 
requirement more realistic.
    Response: Although the grove/buffer sanitation requirement may be 
difficult to meet, SENASA and the growers in northwestern Argentina 
have indicated their willingness to comply with that requirement. 
Further, it would likely prove difficult to establish a standard for 
what is meant by ``substantially all.''
    Comment: The proposed grove-cleaning would be a difficult, if not 
impossible, task to complete. The proposed rule does not explain what 
criteria will be used to verify the orchard floor cleaning and how it 
can be verified at a later date.
    Response: The proposed rule and this final rule state that SENASA 
must inspect the grove and buffer area before blossom to verify that 
all fallen fruit, leaves, and branches have been removed from the 
ground. In the phytosanitary certificate required by paragraph (d) of 
the regulations, SENASA must confirm that the fruit was produced in 
accordance with the requirements of the regulations; the grove and 
buffer area sanitation measures are one of those requirements. SENASA 
will keep records regarding its inspection of each export grove and 
buffer area, and APHIS may request to review those records. Further, as 
noted previously in this final rule, the operational work plan 
governing the administration of the export program will provide for the 
active and direct monitoring of the export program by APHIS personnel; 
that monitoring will include verification of the required grove 
sanitation measures.
    Comment: The risk assessment states that groves are inspected for 
disease symptoms prior to fungicide applications, and fruit with 
possible disease symptoms is sent to a laboratory for analysis. The 
timing of fungicide applications is determined by ``an expert system.'' 
In section 8.f. P1 of the risk assessment, it indicates that the export 
groves would have a ``minimum of two or three additional applications'' 
of fungicide, as opposed to the total of at least two specified in 
section 8.a. of the risk assessment and in the proposed rule. The 
proposed rule states that SENASA will determine timing of fungicide 
applications ``during the growing season,'' based on monitoring of 
climatic data, fruit susceptibility, and the presence of disease 
inoculum, and will monitor for correct fungicide application. There is 
no requirement in the proposed rule for inspection of the groves for 
pests at times of fungicide application, nor for laboratory analysis of 
suspect fruit at this time (if there is any fruit at the times of spray 
application). There is no discussion of what is meant by ``presence of 
disease inoculum.'' There is no requirement that the fungicide 
treatment include any fruit, leaves, or branches on the ground that 
have not been removed. It is not required by the proposed rule that 
SENASA use an expert system to determine fungicide application times.
    Response: After the risk assessment was prepared, and before the 
provisions that formed the basis of the proposed rule were fully 
developed, SENASA suggested that the inspections be conducted after the 
fungicide treatments, when there is a better chance of detecting the 
disease; this accounts for the difference between the risk assessment 
(which speaks to inspection before fungicide treatment) and the 
proposed rule on this subject. The oil-copper-oxychloride treatments 
will be applied during the period of greatest susceptibility of the 
fruit to infection (i.e., from the time that three quarters of the 
petals have fallen to the time the fruit have reach 3 cm in diameter). 
Given that disease symptoms are unlikely to be manifested at that stage 
of fruit development, the proposed rule did not, and this final rule 
does not, call for inspections prior to the application of those 
treatments or the laboratory inspection of suspect fruit at that time.
    With regard to the number of oil-copper-oxychloride applications, 
section 8.f P1 of the risk assessment did, as noted by the commenter, 
state that groves would receive ``a minimum of two or three additional 
applications of fungicide,'' while elsewhere in the risk assessment and 
in the proposed rule the number of applications was characterized as 
``two or more'' and ``at least twice.'' However, the way in which the 
number of applications was characterized did not have any effect on our 
estimation of the mitigation value of the fungicidal sprays. Our 
estimates were not based on any finite, predetermined number of sprays; 
rather, the risk assessment assumed that the timing and number of 
sprays would be determined using SENASA's expert system, with the 
optimal number of sprays being applied to prevent infection.
    With regard to the term ``expert system,'' which was used in the 
risk assessment, we chose to describe the components of the system in 
the proposed rule (i.e., monitoring of climatic data, fruit 
susceptibility, and the presence of disease inoculum) rather than 
simply use the term itself. The risk assessment and the proposed rule 
are, therefore, referring to the same thing. We have included the term 
``expert

[[Page 37623]]

system'' in Sec. 319.56-2f(b)(5) of this final rule to make that clear.
    With regard to what is meant by ``presence of disease inoculum,'' 
SENASA's monitoring of the presence of disease inoculum considers both 
the presence of fallen leaves within the grove, as leaves have been 
identified as the primary source of inoculum, as well as the incidence 
of disease in the area surrounding each grove.
    We did not include provisions for the spraying of fruit, leaves, or 
branches that may be on the ground because the oil-copper-oxychloride 
treatment is intended to prevent infection in the developing fruit 
itself and because the required grove sanitation measures are intended 
to leave the ground in the grove free of such debris.
    Comment: Eureka-type lemons, which are commonly planted in 
Argentina, do not have a very distinct start and finish of flowering, 
depending on climatic conditions. Under mild winter conditions, 
flowering can occur year round; indeed, some reports indicate that 
lemons are harvested year round in Tucuman province. In one report, 
Argentine researchers observed both immature and mature lemons on the 
sampled trees at the same time in Salta and noted that the presence of 
different aged fruit provides for an additional risk of fruit 
infection. How can a grove be certified as having been cleaned prior to 
bloom when bloom is not specifically seasonal?
    Response: While there may be multiple blooms in a year under mild 
winter conditions, Argentina reports that there is, as occurs in the 
United States, a main spring flush during which most of the trees will 
bloom, and it is the fruit from those trees that will be exported to 
the United States. Therefore, the blossoming period in the Argentine 
production areas is distinct enough to allow for the cleaning and 
inspection of the groves and buffer areas prior to blossom.
    Comment: The timing of flowering in not necessarily distinct in 
some common lemon varieties, and it is not clear how the timing of the 
oil-copper-oxychloride treatments will be determined when flowering and 
fruit set occur over several months. The efficacy studies of the 
fungicide treatments need to provide for careful testing of timing of 
the treatments to deal with the different bloom lengths, fruit set, 
rainfall patterns, and disease incidence in the different citrus 
species and the different regions.
    Response: The timing of each treatment application will be 
determined by SENASA using an expert system that considers climatic 
data (including temperature and rainfall patterns), fruit 
susceptibility (which is dictated in part by the timing and length of 
bloom, when fruit set occurred, and the relative disease susceptibility 
of each species), and the presence of disease inoculum (which takes 
into account both the presence of fallen leaves within the grove, as 
leaves have been identified as the primary source of inoculum, and the 
incidence of disease in the area surrounding each grove). The goal of 
the expert system is to maximize the effectiveness of the oil-copper-
oxychloride treatments in preventing the fruit from becoming infected. 
Whether or not that goal has been met will become apparent during the 
laboratory incubation and examination of the 20-day preharvest sample, 
as well as through the grove and packinghouse inspections.
    Comment: The proposed rule fails to require that certified groves 
keep detailed records of the various blooms and required program steps 
(e.g., when the spraying and debris-clearing programs are carried out). 
Any program which APHIS develops should be subject to further public 
comment.
    Response: There is no need for APHIS to develop a recordkeeping 
program as suggested by the commenter. As stated in the proposed rule 
and in this final rule, SENASA is responsible for inspecting the 
registered groves prior to blossom to ensure that the required 
sanitation measures have been accomplished, as well as for determining 
the timing of the oil-copper-oxychloride treatments and monitoring 
their application. SENASA will maintain records of these activities as 
part of its citrus fruit export program, and will make those records 
available to APHIS during program reviews or when otherwise necessary.
    Comment: From the APHIS-SENASA correspondence, it is clear that 
APHIS had wanted an inspection of the orchard prior to the fungicide 
treatments. However, SENASA requested that the inspection for disease 
occur after the treatments. APHIS must explain its reasoning for why 
the inspection of a grove for disease before fungicide applications was 
not included in the proposed rule.
    Response: Until the fruit has matured somewhat and has begun to 
color, the symptoms of citrus black spot will not be apparent. Since 
the fruit would be too small and would not have colored yet prior to 
the fungicide applications, we concurred with SENASA's suggestion that 
the inspections be conducted after the treatments, when there is a 
better chance of detecting the disease.
    Comment: No specific rate for the copper oxychloride sprays is 
provided in the proposed rule. It appears that the Argentine 
researchers found that a rate of 0.36 percent was more effective in 
preventing the disease, but SENASA has stated that a rate of 0.18 
percent would be used for the export program, which may be ineffective 
at least some of the time or on some fruit, according to the 
information in the record. APHIS should determine why the lower copper 
oxychloride rate was chosen by SENASA, even though the data showed the 
higher rate to be more effective.
    Response: The lower oil-copper-oxychloride application rate was 
recommended by SENASA based on its studies that showed that the 0.36 
and 0.18 percent application rates were both effective in preventing 
disease in test plots when the disease was evident in the control 
plots. Given that the 0.18 percent application rate was shown to be 
effective in preventing disease, and given that this rule requires at 
least two applications of the fungicide during the growing season, we 
have accepted SENASA's recommendation that the 0.18 percent application 
rate be used.
    Comment: It appears that Argentine researchers performed only one 
test to assess the effectiveness of the in-season fungicide treatments 
for sweet orange scab and that only one test was conducted using both 
in-season fungicide treatments and post-harvest chemical treatments. 
This limited testing is not sufficient to determine the effectiveness 
of the proposed measures. APHIS should provide or cite efficacy data 
for the proposed copper oxychloride sprays on the incidence of sweet 
orange scab.
    Response: The American Phytopathological Society's Citrus 
Compendium (Whiteside et al., 1988), which was cited in the body of the 
risk assessment (p. 57) and in the pest data sheet for sweet orange 
scab (p. 101), indicates that copper sprays are effective protectants 
to prevent the infection of susceptible fruit by sweet orange scab.
    Comment: While the risk that sweet orange scab might be introduced 
into the United States may be reduced by timely, reliable, and negative 
surveys, there are still some unresolved taxonomic issues surrounding 
the Elsinoe species complex. The less than distinct differentiation 
between possible strains/biotypes strongly suggests that additional 
systematic research is needed to fully understand this pest complex.
    Response: While there may be room for additional systematic 
research in order to fully differentiate between possible strains/
biotypes of Elsinoe spp.,

[[Page 37624]]

we do not believe that any of those taxonomic issues need to be 
resolved in order for the survey, inspection, and treatment provisions 
of this rule to be effective in reducing the risk of sweet orange scab 
being introduced into the United States.
    Comment: A more detailed description of how an orchard will be 
inspected or sampled (location in grove, timing, etc.) for sweet orange 
scab is necessary.
    Response: The freedom of the fruit from sweet orange scab will be 
verified through the inspections required by this rule, i.e., the 
visual inspection of the grove and buffer area required by Sec. 319.56-
2f(b)(6) and the packinghouse inspections required by Sec. 319.56-
2f(c)(4) and (c)(5). Given that the symptoms of sweet orange scab are 
readily detectable on infected fruit, and given that the detection of 
the disease in a single fruit will result in a grove's losing its 
ability to export fruit to the United States for the remainder of the 
current growing and shipping season, we believe that the 20-day 
preharvest survey and the subsequent packinghouse inspections will 
effectively mitigate the risk of fruit infected with sweet orange scab 
being imported into the United States.
    Comment: Copper-based fungicides are preventative, i.e., they only 
prevent new infections and do not stop already established infections. 
Thus, timing is extremely critical to ensure that developing fruit is 
continuously protected from infections. Other fungicides, such as 
preharvest applications of Benomyl (benlate), not only prevent, but 
also stop infections that are already present, and newer chemistry 
fungicides (triazoles, strobilurins, etc.) may provide better control 
of already infected fruit and allow rotation of fungicides.
    Response: Copper oxychloride is a well-established preventative 
treatment for citrus black spot and sweet orange scab, and its efficacy 
has been demonstrated in a variety of studies on the control of these 
diseases (for example, as referenced in Whiteside et al., 1988, as 
cited in the risk assessment). We would, however, certainly consider 
allowing the use of other fungicides if the Argentine growers or SENASA 
were to request that we do so and were to provide information 
supporting the efficacy of the alternative treatments.
    Comment: Since the packinghouse treatments have little or no impact 
on citrus black spot infections, any citrus black spot present in the 
fruit must have been prevented or detected by the time of harvest. The 
keys to the proposed program for Argentina are successful prevention 
and successful detection of any infection. The proposed preventative 
fungicide treatments are not 100 percent effective, so the successful 
detection of treatment failures is critical, but the latency of citrus 
black spot makes that detection very difficult. Given that difficulty, 
it appears there is a near certainty that latently infected fruit will 
be imported into the United States.
    Response: As explained in detail later in this document, we have 
modified the protocol for sampling the grove and buffer area in 
response to comments on the subject. This final rule requires the 
sampling of 4 fruit from each of 298 randomly selected trees in each 
800 hectares of grove and buffer area, which yields at least a 95 
percent confidence level of detecting an infection rate of 1 percent or 
greater. In addition, the modified sampling protocol requires that the 
fruit be chosen from the portion of the tree most likely to have 
infected fruit. Given those requirements, there is almost no chance 
that infection could exist in a grove without infected fruit being 
included in the sample subjected to laboratory examination. Further, 
during the required 20-day sample holding period, the fruit will be 
held under conditions that are ideal for the expression of symptoms in 
any infected fruit (i.e., 27  deg.C, 80 percent relative humidity, and 
permanent light). Finally, this rule requires that the detection of 
symptoms in a single fruit will result in a grove being removed from 
the export program and all fruit from that grove being prohibited from 
entering the United States. Given those considerations, we believe that 
the risk of latently infected fruit being imported into the United 
States is negligible.
    Comment: The risk assessment claims the buffer zone receives the 
same ``treatment, inspections, sanitation, etc.'' as the grove, but the 
proposed rule only calls for full inspections of fruit from the grove, 
not from the buffer zone. Thus if citrus black spot or sweet orange 
scab is detected on fruit from the buffer zone at or after harvest, 
there is strictly no requirement to remove that grove from the program. 
Indeed, there are no requirements in the proposed rule for any 
inspection or reporting on diseases in the buffer zone after the 20 
days preharvest inspection.
    Response: This final rule, as did the proposed rule, calls for the 
removal of fallen fruit, leaves, and branches from both the grove and 
the buffer area, inspection of both the grove and the buffer area to 
ensure the cleaning requirements have been met, spraying of oil-copper 
oxychloride in both the grove and the buffer area, and a visual 
inspection of both the grove and the buffer area 20 days before 
harvest. While the proposed regulations did not specifically state 
where the sample of fruit for laboratory examination was to be 
collected, the samples must be taken from both the grove and the buffer 
area. (This is made clear in Sec. 319.56-2f(b)(6)(ii) in the regulatory 
text of this final rule.) This is consistent with the risk assessment's 
statement that the buffer zone will receive the same ``treatment, 
inspections, sanitation, etc.'' as the grove. After harvest, the 
packinghouse treatments and inspections are limited to the fruit from 
the grove itself because, as stated in Sec. 319.56-2f(b)(2), no fruit 
from the buffer zone may be offered for importation to the United 
States.
    Comment: There is no definition of ``laboratory,'' or any 
requirement for certification of such laboratories, nor is there any 
requirement that the laboratory examination be certified or carried out 
by SENASA.
    Response: The laboratory testing required by Sec. 319.56-
2f(b)(6)(ii), as is the case with the other surveys and inspections 
that must be conducted in Argentina under this rule, must be conducted 
under the direct supervision of SENASA, and records relating to testing 
and test results will be available for review by APHIS.

Post-harvest Requirements

    Comment: The risk assessment (8.a.) claims that packinghouses will 
be used for export to the United States only. The preamble of the 
proposed rule states that packinghouses cannot accept fruit from 
``nonregistered export groves during the time that fruit intended for 
export to the United States is being handled in the packinghouse.'' The 
proposed rule requires that ``[d]uring the time that a packinghouse is 
used to prepare grapefruit, lemons, or oranges for export to the United 
States, the packinghouse may accept fruit only from groves that meet 
the requirements of paragraph (b) of this section.'' The risk 
assessment (8.a.) requirement is stricter than the proposed rule, and 
the preamble of the proposed rule indicates that packinghouses could 
accept nonregistered, nonexport fruit. The proposed rule allows for 
some possibility of admixture, since no time-scale is specified; one 
could alternately process nonexport and export fruit in separate 
batches.
    Response: While the risk assessment's narrative description of the 
systems approach and the proposed rule's description of packinghouse 
requirements differed in their approach,

[[Page 37625]]

we do not believe that the two documents contradict one another. The 
statement in the risk assessment that packinghouses in the program will 
only be used for export to the United States reflected the risk 
assessors' understanding that there would be no commingling of fruit 
from registered and nonregistered groves in the packinghouses. This is 
entirely consistent with our statement in the preamble of the proposed 
rule that ``[b]arring the entry of fruit from nonregistered groves into 
the packinghouse would ensure that the fruit intended for export is not 
commingled with or potentially infected by fruit that was grown in a 
grove that has not been subject to the same sanitation, inspection, and 
treatment measures that would be required for export groves.'' This 
statement from the proposed rule's preamble also makes it clear that we 
were not indicating, as the commenter asserts, that packinghouses would 
be able to accept fruit from nonregistered groves during the time that 
fruit was being prepared for export to the United States.
    To address the commenter's concerns that ``no time-scale is 
specified'' with regard to when batches of export fruit and nonexport 
fruit could be processed, we have modified the wording in Sec. 319.56-
2f(c)(2) to reflect our intent that there be no commingling of fruit 
from registered and nonregistered groves in the packinghouse. That 
paragraph now states: ``During the time that any grapefruit, lemons, or 
oranges from groves meeting the requirements of paragraph (b) of this 
section are in the packinghouse, no fruit from groves that do not meet 
the requirements of paragraph (b) of this section may enter the 
packinghouse.'' To support this requirement, and to prevent the 
``possibility of admixture'' raised by the commenter, a SENASA-
registered technician will be present at each packinghouse to verify 
the origin of all fruit entering the packinghouse. In its 
correspondence with APHIS during the development of the proposed rule, 
SENASA had stated that a registered technician would be present at each 
packinghouse for that purpose, but this consideration was not 
explicitly set forth in the text of the proposed rule. We also are 
amending Sec. 319.56-2f(c)(2) to make it clear that a packinghouse 
technician registered with SENASA must verify the origin of all fruit 
entering the packinghouse.
    Comment: What steps will be taken to ensure there is no commingling 
of fruit from certified and uncertified groves at the packinghouse? For 
example, records would have to be kept of the arrival of each load. 
These records would have to be available for auditing.
    Response: As noted in the response to the previous comment, a 
technician responsible for the packinghouse, who will be approved by 
and registered with SENASA, will be on hand to verify the origin of all 
lots of fruit entering the packinghouse. These technicians are required 
by SENASA to maintain accurate records, and SENASA will make those 
records available to APHIS upon request.
    Comment: The proposed rule and risk assessment do not mention the 
need for measures to prevent the contamination of export groves, 
packinghouses, or storage facilities by workers or equipment that have 
been in untreated groves or that have been in contact with untreated 
fruit. Such measures are necessary to prevent the artificial spread of 
disease inoculum. APHIS should consider establishing sanitation 
measures for workers and equipment moving between nonregistered groves 
and those producing fruit destined for export to the United States. The 
requirements would have to be set forth in detail in the regulation, 
and strict audit and inspection procedures would have to be implemented 
to ensure that disease is not transmitted to export groves. If such 
requirements are not established, APHIS should discuss why such 
measures are not needed, given the characteristics of the two diseases 
of concern. Similarly, APHIS should establish sanitation measures for 
packinghouses and storage facilities to use between runs of U.S.-bound 
citrus and fruit bound for other markets.
    Response: The spores produced in fruit infected with sweet orange 
scab and citrus black spot are nonpigmented and are thus short-lived 
when removed from their host tissue. It is, therefore, unlikely that 
any ``free'' spores that might be found on workers or equipment moving 
from an untreated grove into an export grove, packinghouse, or storage 
facility would remain viable long enough to cause infection. Similarly, 
because of the short-lived nature of ``free'' spores, there is little 
risk that export fruit would become contaminated during processing at a 
packinghouse that had previously handled fruit from nonregistered 
groves. In any event, that export fruit will be mature fruit, and thus 
not susceptible to infection. Furthermore, that fruit will be surface-
sterilized and waxed in the final processing steps before being packed 
in boxes, thereby rendering nonviable any spores contaminating the 
surface of the fruit. That surface-sterilization and waxing is a 
routine measure applied to all fruit in Argentine packinghouses, 
including nonexport fruit, so it is unlikely that export fruit would be 
contaminated after packing even if it was stored with nonexport fruit.
    Comment: The proposed rule does not specify what happens to other 
fruit in the packinghouse if infected fruit from some other grove that 
simultaneously or recently went through the same packinghouse is 
detected.
    Response: We believe that it is unlikely that infected fruit would 
proceed undetected as far as the packinghouse, given this rule's 
requirements for the removal of potential sources of inoculum from the 
groves, the treatment of developing fruit, and the sampling and testing 
of mature fruit prior to harvest. However, if infected fruit was 
identified in the packinghouse or at a later time, we believe that the 
non-susceptibility of the mature fruit that will be handled in the 
packinghouses, when combined with the short-lived nature of ``free'' 
spores and the required surface-sterilization and waxing, make it 
unlikely that fruit will be contaminated as a result of contaminated 
fruit having recently passed though the same packinghouse. This rule's 
requirement that the identity of the origin of the fruit be maintained 
during its time in the packinghouse will prevent fruit from two 
different groves being processed simultaneously.
    Comment: The risk assessment claims that at the prepacking 
inspection stage, any blemished fruit are culled. There is no 
requirement in the proposed rule for culling of blemished fruit, 
although that presumably would be a commercial necessity; the proposed 
rule only requires SENASA to examine fruit for any evidence of disease.
    Response: The commenter is correct in presuming that the culling of 
blemished fruit is a commercial consideration. As such, our proposed 
rule did not include a requirement for the culling of blemished fruit, 
per se, but instead focused on SENASA inspecting the fruit prior to 
packing to verify its freedom from citrus black spot and sweet orange 
scab. However, as explained in the response to the next comment, we 
have included the culling of blemished fruit in the provisions of this 
rule set forth in Sec. 319.56-2f(c)(4) relating to the 4-day 
packinghouse holding period.
    Comment: The proposed rule called for the holding of all harvested 
fruit for 4 days at room temperature before sorting and packing, but 
there is no evidence in the record that this is an adequate time for 
latent citrus black spot symptoms to develop. The Argentine researchers 
stated that they held sampled fruit for 20 days at 27  deg.C,

[[Page 37626]]

80 percent relative humidity, and in permanent light in order for 
latent citrus black spot infections to develop enough for detection. In 
addition, the risk assessment assumes that the fruit sampled from the 
orchard shortly before harvest will be held for 20 days at room 
temperature, which would allow latent citrus black spot infections to 
show up in the samples. However, the proposed regulations do not 
explicitly state a 20-day holding period at room temperature, nor do 
they define what constitutes ``room temperature.'' APHIS should conduct 
studies to determine the optimum time, temperature, and other 
environmental conditions for detection of the latent citrus black spot 
infections; if APHIS cannot provide data that demonstrates the 
effectiveness of the 4-day holding period, a longer holding period 
should be required. Further, steps must be taken to ensure that all 
packinghouses are able to hold the harvested fruit at the required 
temperatures for citrus black spot development in order to assess the 
practicability of this measure. Finally, the requirements for Argentine 
citrus should explicitly state that fruit sampled from the grove 20 
days before harvest must be held under conditions conducive to citrus 
black spot development.
    Response: We acknowledge that the proposed rule did not fully 
explain the procedure to be used during the 20-day laboratory 
examination period of the sampled fruit. We further acknowledge that 
the proposed rule incorrectly stated that the purpose of the 4-day 
holding period was to allow for symptom expression of citrus black spot 
in the event that latent infection exists in the fruit. We have 
corrected both of these issues in the text of the final rule.
    As noted by the commenter, the laboratory procedure to be used to 
promote the expression of symptoms in the fruit sampled 20 days prior 
to harvest will be to hold the fruit for 20 days at 27  deg.C, 80 
percent relative humidity, and in permanent light. These conditions 
have been shown to be ideal for latent citrus black spot infections to 
develop enough for detection. Although this protocol was omitted from 
the proposed rule, the protocol was, as evidenced by the commenter's 
remarks, explained fully in documents made available following the 
publication of the proposed rule.
    If none of the sampled fruit manifest symptoms of citrus black spot 
during the 20-day laboratory examination period, the remaining fruit in 
the grove will be harvested and taken to the packinghouse, where it 
will be held at room temperature--i.e., not refrigerated--for 4-days. 
This 4-day holding period is a standard practice in the Argentine 
citrus industry that provides sufficient time for bruises or other 
damage on the fruit to become plainly evident, thus providing an 
opportunity for that blemished fruit to be culled. For the purposes of 
this rule, that 4-day holding period will also provide an opportunity 
for SENASA inspectors to examine the harvested fruit for signs of 
infection.
    We have, therefore, amended the requirements set forth in the rule 
portion of this document in order to fully explain these requirements. 
The requirements pertaining to the laboratory examination are set forth 
in Sec. 319.56-2f(b)(6)(ii), and the provisions relating to the 4-day 
holding period and the culling of damaged fruit in the packinghouse are 
set forth in Sec. 319.56-2f(c)(3) and (c)(4).
    Comment: Section 8.a of the risk assessment claims 4-5 days holding 
time (for all fruit) to allow expression of citrus black spot. Section 
8.f P3 of the risk assessment claims a ``20-day preharvest sample and 
incubation period'' that may have been derived from the 20-day 
preharvest inspection, or may be a confusion between inspection and 
this packinghouse holding time. Section 8.f P3 of the risk assessment 
also confuses matters since it refers to a ``sample'' holding time, but 
then refers to the likelihood of packinghouse detection, but the fruit 
in the packinghouse would not have had the 20-day holding time. The 
preamble and proposed rule require just 4 days holding time at room 
temperature, followed by SENASA inspection.
    Response: The commenter has identified that, like the proposed 
rule, the risk assessment's narrative description of the systems 
approach (Section 8.a) incorrectly characterizes the purpose of the 4-
day holding period. The intended purpose of both the 4-day holding 
period and the 20-day laboratory examination period are explained in 
the response to the previous comment and in paragraphs (b)(6), (c)(3), 
and (c)(4) of Sec. 319.56-2f in this final rule. In light of that 
explanation, it can be seen that the reference to ``a 20-day preharvest 
sample and incubation period'' in section 8.f P3 of the risk assessment 
accurately portrays what is required by this rule. Section 8.f P3 of 
the risk assessment links the sample holding time and the likelihood of 
packinghouse detection (which the commenter states ``confuses 
matters'') because that node P3, ``Pathogen not detected at packing 
house inspection'' is the portion of the risk assessment where the 20-
day holding period is addressed. As stated in Section 8.f. P3: ``Also 
considered in making our estimates for this node in the mitigated 
scenario, was the orchard sampling 20 days prior to harvest and the 
incubation of this sample at room temperature to observe post harvest 
symptom development.''
    Comment: The risk assessment claims in section 8.a that blemished 
fruit are culled during harvest and claims in section 8.f. P2 that 
diseased fruit would be detected and culled at harvest; section 8.f P2 
also stated that this detection would be improved for citrus black spot 
``under the proposed workplan'' due to its ``more rigorous export 
standards and [the] reduced frequency of latent infection,'' although 
no specific measures are mentioned for harvest time. The preamble and 
proposed rule have no harvest requirements whatever, and it appears 
from the correspondence on the record that the Argentines do not know 
what ``blemished fruit'' means.
    Response: As noted in our response to a previous comment, the 
culling of blemished fruit was not specifically addressed in the 
proposed rule, but requirements for the culling of blemished fruit in 
the packinghouse have been added to this rule. While pickers can be 
expected to cull obviously blemished fruit during harvest, the best 
opportunity for the removal of blemished fruit will come after the 
fruit has been held for 4 days at room temperature. Given that the 4-
day holding period will provide an opportunity for bruises and other 
damage on the fruit to become more readily apparent, we consider this 
post-harvest culling to be an improvement over the reliance on pickers 
to cull blemished fruit that was envisioned in the risk assessment. 
Finally, we have explained to SENASA what we mean by the term 
``blemished fruit.''
    Comment: The proposed systems approach envisions chemical treatment 
after the 4-day holding period, followed by a further inspection before 
packing. Does APHIS believe such treatment will have any impact on 
citrus black spot? If so, what is the evidence? The literature on 
citrus black spot would indicate that such treatment would have no 
impact. We believe that the data provided by Argentina demonstrates the 
chemical treatment envisioned in the proposed systems approach, to be 
applied prior to packing of the fruit, will not have any impact on the 
virulence of the citrus black spot spores.
    Response: The post-harvest treatment is designed to render 
nonviable any spores contaminating the surface of the fruit, and these 
post-harvest treatments

[[Page 37627]]

are mainly to prevent post-harvest decay. In the risk assessment, our 
estimates took into account the fact that post-harvest treatments have 
little effect on citrus black spot infections (a reduction from 0.64 to 
0.50).
    Comment: The proposed rule does not specify any concentrations or 
other conditions for the immersion in orthophenilphenate of sodium, nor 
any application rate for the spray with imidazole or application of 2-4 
thiazalil benzimidazole and wax. Thus, it appears that any 
concentrations or application rates--including ineffective ones--would 
meet the requirements of the proposed rule.
    Response: Argentina's environmental protection authority, like our 
Environmental Protection Agency, requires that products such as those 
called for in this rule be applied in accordance with their label 
instructions. For orthophenilphenate of sodium, the concentration is 
200 L per 2,000 L of water; for imidazole, it is 200 cm\3\ per 100 L of 
water; and for 2-4 thiazalil benzimidazole, it is 0.5 L per 200 L of 
water. By not including these concentrations in the text of the rule 
itself, we avoid the need for future amendments to the rule should the 
label instructions change.
    Comment: The risk assessment (8.f. P4) states that the treatment 
program incorporates a dip in 200 parts per million sodium hypochlorite 
for 2 minutes. The preamble and rule portions of the proposed rule 
spell out the required chemical treatments, but do not include any 
mention of time for the sodium hypochlorite immersion.
    Response: The commenter is correct; the proposed rule should have 
stated that the immersion in sodium hypochlorite be for 2 minutes as 
described in the risk assessment. We have corrected that omission in 
Sec. 319.56-2f(c)(4)(i) of this final rule.
    Comment: There is no explicit mention that the packed boxes of 
fruit may not contain any plant parts other than the fruit to be 
exported. Leaves and twigs are suitable vectors for diseases and 
several insects pests (e.g., brown citrus aphid). While a prohibition 
on inclusion of leaves, twigs, or other plant parts in packing boxes is 
included as a general requirement for imported fruits and vegetables in 
7 CFR 319.56-2(a), the requirements for Argentine citrus should 
explicitly prohibit any plant parts other than the fruit itself.
    Response: The commenter is correct in noting that Sec. 319.56-2(a) 
requires that ``[a]ll importations of fruits and vegetables must be 
free from plants or portions of plants, as defined in Sec. 319.56-1.'' 
Plants or portions of plants is defined in Sec. 319.56-1 as ``[l]eaves, 
twigs, or other portions of plants, or plant litter or rubbish as 
distinguished from clean fruits and vegetables, or other commercial 
articles.'' We agree that this is an important requirement and have 
added language to the requirements in Sec. 319.56-2f(c)(5) to make it 
clear that SENASA inspectors must ensure that all stems, leaves, and 
other portions of plants have been removed from the fruit prior to 
packing.
    Comment: All packing boxes sent to commercial citrus-growing areas 
of the United States should be required to be destroyed upon reaching 
their destination, and records of such destruction should be kept.
    Response: We are unaware of any risks presented by packing boxes 
used to ship citrus fruit produced in accordance with this rule that 
would make it necessary to require their destruction, and we do not 
believe that any meaningful reduction in risk would be realized by 
imposing such a requirement.

Fruit Flies, Other Pests, and Treatments

    Note: On May 19, 2000, we received a letter from the California 
Citrus Research Board (CCRB) informing APHIS that the CCRB had 
contracted with U.S. Department of Agriculture's (USDA's) 
Agricultural Research Service (ARS) to conduct a research program to 
determine the suitability of lemons as a host of tephritid fruit 
flies. The CCRB letter reported that the preliminary results of the 
initial tests call into question the current regulatory assumption 
that lemons at any stage of maturity are not a viable fruit fly 
host. When contacted by APHIS for additional information, ARS 
reported that the preliminary results were similar to the results 
published in 1984 by ARS scientists (i.e., the Spitler, et al. 
research discussed below) in which a limited number of Medfly pupae 
were recovered in similarly conducted tests. ARS reports that, at 
the present time, it is reluctant to extend the findings of these 
preliminary laboratory cage studies to lemons in a commercial field 
setting where there might be other, more preferred fruit fly hosts 
present. Further, ARS points out, some species of fruit are known to 
be much more infestable after harvest than before as a result of a 
rapid ripening process initiated when the fruit is separated from 
the tree; ARS states that fruit that can be stored on the tree, such 
as citrus, may fall into this category. ARS has stated that they 
will provide APHIS with a full report upon the conclusion of the 
studies. If the results of the studies lead to a recommendation that 
quarantine measures such as cold treatment should be required for 
lemons, we will take action to amend both our foreign and domestic 
quarantine regulations to require that the appropriate treatment be 
applied to lemons as a condition of importation or interstate 
movement.

    Comment: APHIS should require a fruit fly trapping program in the 
export area and should require spraying of the groves if population 
levels exceed a set threshold. If the spraying proves ineffective at 
eradicating the fruit flies, exports should be cut off, even with cold 
treatment.
    Response: Argentina reports that populations of Medfly and the 
South American fruit fly (Anastrepha fraterculus) are not present at 
economically important levels and periodically confirms their low 
population levels through trapping. Further, Argentina maintains that 
A. obliqua and A. serpentina are not present in Argentina despite 
reports to the contrary, and that both species of fruit fly are 
considered quarantine pests in Argentina. Given the economic importance 
of the citrus industry in Argentina, it is in that country's best 
economic interests to ensure that fruit fly populations remain low. The 
lack of significant fruit fly population pressure, combined with the 
nonhost status of smooth-skinned lemons and this rule's requirement for 
a probit 9 level (99.997 percent mortality or 1 survivor per 33,333) 
cold treatment for grapefruit, oranges, and lemons other than smooth-
skinned lemons, has led us to conclude that trapping and spraying 
provisions are not a necessary element of the Argentine citrus export 
program.
    Comment: There is no discussion in the proposed rule of fruit fly 
detection in Argentina, nor what, if any, prevalence of fruit flies 
would be sufficient to prevent import. Thus, any analysis must take 
account of the possibility of very high prevalence of fruit flies.
    Response: Our risk assessment did take into account the presence of 
fruit flies in Argentina and concluded that the nonhost status of 
smooth-skinned lemons and the post-harvest cold treatments for other 
citrus fruit would reduce the risk of Argentine citrus introducing 
fruit flies into the United States to a negligible level.
    Comment: The proposed rule, the risk assessment, and the PPQ 
Treatment Manual (which is used by APHIS personnel as a guide for the 
application of quarantine treatments) do not consider the issue of 
``preconditioning phenomenon,'' which could render cold treatment 
ineffective in preventing the transmission of fruit fly pests into the 
United States via Argentine citrus. Research indicates that fruit fly 
larvae and eggs can develop increased tolerance to quarantine cold 
treatment if the infested fruit is exposed to sublethal temperatures in 
the field or in storage prior to the initiation of an approved cold 
treatment. In order to preclude the possibility of preconditioning

[[Page 37628]]

phenomenon, the PPQ Treatment Manual should explicitly state that the 
fruit should not be held at sublethal chilling temperatures prior to 
initiation of cold treatment. In addition, further research should be 
conducted to determine whether it may be necessary to require fruit 
subjected to cold field or storage conditions to undergo longer 
quarantine chilling periods.
    Response: In a publication titled Temperature Sensitivity in 
Insects and Application in Integrated Pest Management (edited by Guy J. 
Hallman and David L. Denlinger, Westview Press, 1998), it is noted that 
any technique used to reduce chilling injury (e.g., holding the fruit 
for several days at temperatures several degrees above the quarantine 
treatment temperature, which is referred to as ``pretreatment'' or 
``preconditioning'') can also be suspected of favoring the survival of 
the pest inside the fruit. However, Dr. Guy Hallman, one of the editors 
of that publication, indicated to APHIS that no references in the 
literature were found for this ``preconditioning phenomenon'' with 
regard to quarantine pests, although it has been demonstrated with 
flesh flies, house flies, Drosophila, and other laboratory species. It 
was Dr. Hallman's opinion that because cold treatments are so extreme 
and infestation rates in commercial fruit are so low, the issue of 
``preconditioning phenomenon'' is not likely to be a serious practical 
concern. This opinion is borne out by the consistently successful use 
of quarantine cold treatments around the world over many years on 
numerous commodity/pest combinations.
    Comment: APHIS's position that lemons cannot be a host to 
Mediterranean fruit fly is not consistent with published scientific 
literature on the subject, which demonstrates clearly that lemons can 
become a host to this pest in certain circumstances. While lemons are 
not a preferred host to the Medfly, they have been found to be a host 
when insect pressure is applied to ripe or damaged fruit. If tree-ripe 
fruit is shipped to the United States, this increases the risk of 
Medfly introduction into the United States dramatically. The studies 
APHIS cites to support the nonhost status of lemons (Spitler et al. 
1984) are based on lemons picked green to partially ripe, which is how 
lemons are picked in commercial production in the United States. It is 
not clear from the proposed rule at what stage the Argentine lemons 
will be picked for export to the United States, but we believe the 
Argentines pick lemons by maturity, since much of their fruit goes to 
processing and currently they do not have the ``curing'' facilities to 
ripen lemons during storage. APHIS should establish maximum maturity 
standards for lemons for export, in the absence of cold treatments. If 
the maturity standard is exceeded, then either a cold treatment should 
be required or the shipment of ripe lemons should be rejected for 
export. Further, APHIS needs to consider the impact of harvesting 
lemons at earlier stages on the ability to detect any citrus black spot 
infections.
    Response: While the commenter refers to lemons in general, it is 
only smooth-skinned lemons that are exempted from the cold treatment 
requirements of this rule. In the research conducted by Spitler et al. 
(J. Econ. Entomol. 77: 1441-1444, 1984), both green and yellow Eureka 
and Lisbon variety smooth-skinned lemons were used. In their discussion 
of the results of the study, the researchers report: ``Although 
maturity of the lemon (green or yellow) had no noticeable effect on the 
number of flies collecting on the fruit, more punctures (707 green vs. 
805 yellow per 10 fruit) and eggs (23 [green] vs. 46 [yellow]) per egg 
cavity were found in the more mature yellow fruit. Even in a thin-
skinned lemon with 57 ovipositor wounds, no larvae or pupae (i.e., our 
criterion of survival) were recovered.'' So, while the researchers did 
observe that oviposition was more likely in the more mature yellow 
fruit, they found that in only one case--in which the ripest fruit used 
in the study was left in the infestation cage for 3 days in an attempt 
to have egg survival--did any larvae or pupae survive (5 survivors out 
of a very conservatively estimated population of 31,800). In the other 
12 lots tested, in which the percentage of yellow lemons ranged from 50 
to 100 percent in all lots but 1 (which was 100 percent green lemons), 
there were no survivors out of a very conservatively estimated 
population of 484,182. The results of this study, coupled with our 
experience with both domestically produced and imported lemons, has led 
us to conclude that the probability of a Medfly infestation resulting 
from the importation of commercial shipments of smooth-skinned lemons 
is extremely low. Thus, because we do not believe that it is necessary 
to establish maximum maturity standards for smooth-skinned lemons 
imported under this rule, we do not believe that it is necessary to 
consider the impact of harvesting lemons at earlier stages on the 
ability to detect any citrus black spot infection.
    Comment: APHIS must consider the effects that fruit fly population 
pressure and environmental stress on fruit trees may have on the 
nonhost status of lemons. The existence of a large fruit fly population 
in any given year or at any particular time of year substantially 
increases the likelihood that the fruit flies will infest citrus fruit, 
especially if other hosts are not available at that time, even if the 
fruit is considered a poor host for fruit flies. Similarly, the effect 
of plant stress on host resistance must be taken into account. 
Therefore, APHIS should integrate on-site field inspections, trapping 
programs, and/or possible field control programs for all species of 
fruit flies into the systems approach for Argentine citrus, and should 
require monitoring to ensure that no conditions arise that overwhelm 
the lemons' resistance to fruit flies. Further, the effect of citrus 
tree health on susceptibility should be included in the risk 
assessment.
    Response: In the research conducted by Spitler et al. discussed in 
the previous comment, Eureka and Lisbon variety smooth-skinned lemons 
were exposed to a high population pressure of 7,500 adult medflies per 
3.6 m \3\ in the infestation cage, a population level unlikely to be 
attained in the field. With that high population pressure in the 
infestation cage, the researchers estimated that a total of 516,000 
eggs were laid in the 13 lots of lemons used in the study, with only 5 
pupae surviving, a mortality rate that exceeds the probit 9 security 
level of 99.997 percent mortality (i.e., 1 survivor per 33,333). In the 
last of the 13 lots tested, a total of 34 yellow lemons were placed in 
the infestation cage for 1 day, after which the eggs in each lemon were 
counted (rather than estimated). These 34 lemons yielded a total of 
126,997 eggs, an average of 3,735 eggs per lemon. Despite this 
exceedingly high per-fruit egg population, no larvae or pupae were 
recovered from the lemons. The commenter further suggests that we 
assess the effect of citrus tree health on host resistance. Official 
records reflecting the host resistance of commercial smooth-skinned 
lemons date back as far as 1914 (Quayle, H.J., ``Citrus fruit insects 
in Mediterranean countries,'' USDA Bulletin 134, 1914), yet we have 
been unable to find any records or other published material documenting 
cases in which plant stress or other environmental conditions led to a 
breakdown in that resistance.
    Comment: Fruit flies in many cases prefer other hosts that are not 
limited to subtropical or Mediterranean climates. For example, the 
South American fruit fly and Medfly will lay eggs in stone fruit, 
apples, or pears, which are grown commercially in many areas of the 
United States. While it is unlikely that

[[Page 37629]]

the fruit flies would survive during the winter in northern regions of 
the United States and become established permanently in these regions, 
their introduction could still ruin local fruit crops for one season, 
and fruit from temporarily infested regions could be transported into 
more hospitable climates where the fruit flies could become 
established. Therefore, APHIS' risk assessment should consider the full 
range of environments in the risk assessment in which fruit flies, if 
introduced, can cause significant damage to agricultural crops and 
should develop confirming data on fruit fly distributions using insect 
phenology models, such as those developed by plant protection 
authorities in Australia (e.g., CLIMEX).
    Response: The remote chance of the occurrence suggested by the 
commenter is addressed in the risk assessment's node for ``pest finds 
suitable host.'' We believe that it would be exceedingly unlikely that 
fruit flies would be introduced in commercial shipments of Argentine 
citrus fruit in such numbers that their populations would reach 
outbreak levels in a matter of a few months. With regard to the use of 
CLIMEX, we have found that this computerized climate matching system 
can be overly conservative and often does not identify the full range 
of areas into which we know a pest could spread. What we do in most 
cases, and did do in the Argentine citrus risk assessment, is ask what 
are all the locations that have both suitable hosts (not part of 
CLIMEX) and suitable habitat (we consider additional factors not 
considered by CLIMEX). Our results typically indicate that a pest could 
spread to more areas than indicated by CLIMEX.
    Comment: Having gone through two Medfly quarantines in the last 10 
years because the USDA considers lemons a host to the Medfly, we find 
it difficult to understand why Argentina is exempt from the same rules 
that apply to our country. Similarly, California spends hundreds of 
thousands of dollars per year on Medfly trapping, survey, and exclusion 
activities, yet the proposed rule does not require any fruit fly 
trapping in Argentina.
    Response: Smooth-skinned lemons harvested for packing by commercial 
packinghouses are not regulated articles under our domestic Medfly 
regulations in Secs. 301.78-2, and it is those varieties of lemons that 
are exempted from the cold treatment requirements of this rule. Thus, 
there is no disparity between the provisions of this rule and our 
domestic Medfly regulations in this regard. Any Medfly-related measures 
that were applied to smooth-skinned lemons in California during Medfly 
quarantines in that State were not due to APHIS regulations, but were 
applied at the request of nations to which California growers sought to 
export their product. The Medfly survey and exclusion activities 
carried out by California are designed to maintain that State's freedom 
from Medfly; similar requirements were not made part of this rule for 
the export areas of northwestern Argentina because that region has not 
been represented as a Medfly-free area.
    Comment: Lemons have been stated to be nonhosts of fruit flies, but 
during the Medfly eradication program in Ventura County, CA, and other 
parts of California and in Hawaii, lemons have, in fact, been found 
that were infested with Medfly larvae.
    Response: Smooth-skinned lemons harvested for packing by commercial 
packinghouses are not regulated articles under our domestic Medfly 
regulations in Secs. 301.78-2, and this rule is consistent with our 
domestic Medfly regulations. Neither the risk assessment nor proposed 
rule stated that lemons in general were considered to be nonhosts of 
fruit flies. Instead, both documents, as well as the supporting 
research such as that conducted by Spitler et al. (1984), indicate that 
it is only smooth-skinned varieties of lemons that are considered 
nonhosts of fruit flies. Accordingly, this rule requires all lemons 
other than smooth-skinned varieties to undergo specified cold 
treatments to mitigate the risk presented by fruit flies, a 
consideration reflected in the risk assessment. Considerable research 
and investigations into anecdotal reports such as those cited by the 
commenter have not uncovered any documented cases of Medfly attacking 
smooth-skinned varieties of lemons.
    Comment: No information appears to be available on what pesticides 
are used or registered for use in Argentina. What assurances can the 
USDA give that pesticide residues on imported fruit will not threaten 
public health?
    Response: The U.S. Food and Drug Administration (FDA) samples and 
tests imported fruits and vegetables for pesticide residues. If residue 
of a pesticide unapproved in the United States is found in a shipment 
of imported fruit or vegetables, the shipment is denied entry into the 
United States by the FDA.
    Comment: APHIS has an obligation to the U.S. citrus grower 
community to assess whether Argentine growers currently use pesticides 
(for the control of pests or diseases) that cannot legally be used in 
the United States. Further, APHIS should assess whether there would be 
any substance that could be used in the United States to control a pest 
or disease, should such a pest or disease be brought in that is not 
currently present in the United States. If no substances are registered 
in the United States that would replace those used in Argentina, APHIS 
should not allow the citrus to be imported.
    Response: As noted in the response to the previous comment, the FDA 
samples and tests imported fruits and vegetables for pesticide 
residues. The U.S. Government does not have any control over what 
pesticides are approved for use in foreign countries. The Environmental 
Protection Agency has regulations that address the exportation from the 
United States of pesticides that are not registered for use in this 
country and works with foreign environmental protection agencies and 
agricultural producers to promote safer pesticide use and food 
production practices. In response to the second part of the commenter's 
remarks, there is a variety of fungicides and other pesticides 
available for use in the United States in the unlikely event that a 
plant pest is introduced into this country via citrus imported from 
Argentina in accordance with this rule.
    Comment: The proposed rule and risk assessment do not address the 
legitimate concern that a pest that exists in one U.S. citrus-growing 
region could be introduced by imported Argentine citrus into another 
U.S. citrus-growing region that is free of that pest. For example, 
brown citrus aphid (Toxoptera citricidus), a quarantine actionable pest 
that is a vector of the tristeza virus, is listed as existing in 
Florida in the 1997 Risk Assessment. Currently, Arizona and California, 
which have limited occurrences of tristeza, have measures in place to 
prevent the introduction of brown citrus aphid from Florida; Texas has 
not had any serious tristeza outbreaks due to the lack of good vectors 
for the virus. APHIS should address the possibility that pests 
established in one part of the United States could be introduced into 
free areas of this country via imported Argentine citrus. We suggest 
that APHIS should require country-of-origin/lot number labeling of 
individual fruit in order to address this concern and to allow for the 
tracking of Argentine fruit if it becomes necessary. Further, APHIS 
should develop an overall policy, consistent with WTO rules, for 
dealing with this situation.
    Response: The commenter raises the concern that pests established 
in one part of the United States could be introduced into free areas of 
this country via imported Argentine citrus,

[[Page 37630]]

and then suggests that country-of-origin/lot number labeling of 
individual fruit to allow for the tracking of Argentine fruit could be 
used to address that concern. To address the commenter's first concern, 
in preparing our risk assessment, we identified all pests of citrus 
known to be present in Argentina, examined the available information 
regarding those pests, then focused our analysis on any pests that were 
identified as quarantine actionable pests that could reasonably be 
expected to follow the pathway, i.e., be included in commercial 
shipments of citrus. With regard to the commenter's second concern, 
this rule, in Sec. 319.56-2f(c)(6), requires that Argentine fruit be 
packed in boxes that bear the SENASA registration number of the fruit's 
grove of origin, so we will have the ability to track shipments of 
imported Argentine fruit after they enter the United States. Although 
the requirement was not added in response to this commenter's 
suggestion, this final rule does, as explained earlier in this document 
under the heading ``Specific Regulatory Changes Regarding Limited 
Distribution,'' contain a requirement for the stickering of individual 
Argentine fruit.
    The commenter also urged APHIS to develop an overall policy, 
consistent with WTO rules, for dealing with the issue of pests of 
limited distribution. We believe that the new revised text of the IPPC, 
which was approved by the FAO Conference at its 29th Session in 
November 1997, provides the kind of overall policy sought by the 
commenter. (The WTO SPS Agreement identifies the IPPC as the 
organization providing international standards for measures implemented 
by governments to protect their plant resources from harmful pests.) 
Specifically, Article VI, ``Regulated pests,'' provides that: 
``Contracting parties may require phytosanitary measures for quarantine 
pests and regulated non-quarantine pests, provided that such measures 
are: (a) no more stringent than measures applied to the same pests, if 
present within the territory of the importing contracting party; and 
(b) limited to what is necessary to protect plant health and/or 
safeguard the intended use and can be technically justified by the 
contracting party concerned.'' Under the Federal Plant Pest Act and the 
Plant Quarantine Act, APHIS has the authority to take action against 
pests of limited distribution in the United States when such pests are 
found present in imported plants or plant products. Such action would 
be in accord with WTO rules.
    Comment: The risk assessment states that leprosis is found in 
Florida, but an expert states that leprosis has been eradicated in 
Florida since the early 1960's. Leprosis is not present in California 
or Arizona. False spider mites (Brevipalpus spp.) are present in 
Argentina and vector the virus for leprosis; these mites and their eggs 
are difficult to detect through visual inspection, and the usual post-
harvest treatments have no effect on their presence. Although several 
Brevipalpus spp. are present in the United States, the lack of leprosis 
has made them less of a threat to U.S. agriculture. If the vectoring 
mites and leprosis occur together in the northwest region of 
Argentina--and there is evidence that leprosis is a serious disease in 
Misiones Province in northern Argentina--then additional treatments of 
all the fruit for the mites is required. APHIS should consider the risk 
associated with Brevipalpus spp. remaining with the fruit through post-
harvest treatment and shipping and the risk of the mites carrying the 
leprosis virus. If a risk is identified, then measures need to be taken 
to prevent the mites from transmitting leprosis to the United States 
via citrus, even if that disease exists in Florida.
    Response: The expert mentioned by the commenter has not published 
his findings regarding leprosis, whereas Alfieri, et al. (1994) and 
Brunt, et al. (1996) both list leprosis as present in the United 
States. As both leprosis and Brevipalpus spp. mites occur in the United 
States and are not subject to official restrictions or regulations 
(i.e., they are not listed as actionable and are not under an official 
control program), these organisms do not meet the geographical and 
regulatory definition of a quarantine pest.
    Comment: The risk assessment does not account for the possibility 
that a number of insect and mite species may be transmitted under the 
calyx (button) of citrus fruits, thus allowing for the possibility of 
transmission of such pests into the United States via Argentine citrus. 
The calyx of citrus fruit can harbor a large number of insects and 
mites or their eggs. These contaminant species are not easily visible 
unless the button is removed (which leads to more rapid fruit decay) 
and are resistant to cold treatment, surface washes, and insecticide 
treatments. APHIS' risk assessment should address the issue of all 
types of insect pests that may inhabit the calyx of Argentine citrus, 
and calyx inspection should be a routine part of the inspection of 
Argentine citrus at the port of first arrival.
    Response: As indicated in an earlier response, in preparing our 
risk assessment, we identified all pests of citrus known to be present 
in Argentina, examined the available information regarding those pests, 
then focused our analysis on any pests that were identified as 
quarantine actionable pests that could reasonably be expected to follow 
the pathway, i.e., be included in commercial shipments of citrus. In 
examining the information regarding citrus pests present in Argentina, 
we did not identify any insect or mite species that could be 
transmitted under the calyx of citrus fruit that were quarantine 
actionable pests that could reasonably be expected to follow the 
pathway. Thus, we do not believe that it is necessary to include 
provisions in this rule to require the routine calyx inspection at the 
port of first arrival. However, this does not preclude our inspectors 
from conducting calyx inspections, even on a routine basis, when they 
believe such a measure might be necessary.

Disease Detection

    Comment: The proposed rule states: ``If, during the course of any 
inspection or testing required by this section or Sec. 319.56-6 of this 
subpart, citrus black spot or sweet orange scab is detected on any 
grapefruit, lemons, or oranges, the grove in which the fruit was grown 
or is being grown shall be removed from the SENASA citrus export 
program for the remainder of that year's growing and harvest season * * 
*.'' It is currently unclear how much disease detection is needed to 
cause SENASA to remove the grove from the export program. Does a single 
infection on a single fruit disqualify an orchard from the export 
program? The presence of the diseases can be detected in the litter and 
occasionally the tree without obvious fruit infections. Would that be 
grounds for the removal of a grove? A much clearer definition of when a 
grove must be removed from the export program, and an explanation of 
why that threshold for removal was chosen, needs to be established in 
order to minimize the risk that latently infected fruit will reach the 
United States. Further, the proposed rule contained no discussion of 
whether any special criteria or measures need to be met for a grove to 
re-enter the export program after it has been disqualified for a season 
due to disease incidence.
    Response: Paragraph (f) of Sec. 319.56-2f clearly states that if 
citrus black spot or sweet orange scab is detected on any grapefruit, 
lemons, or oranges, the grove will be removed from the export program. 
So, in response to the

[[Page 37631]]

commenter's first question, a single infection on a single fruit, will 
result in a grove's removal from the export program. That paragraph 
does not, however, call for the removal of a grove from the export 
program upon the detection of either disease in litter or in the tree 
if the infection is not detected in the fruit, since there are no 
requirements for the testing of litter or parts of the tree other than 
the fruit. The commenter`s statement that the presence of citrus black 
spot and sweet orange scab ``can be detected in the litter and 
occasionally the tree without obvious fruit infections'' is true to a 
certain extent; the fungi can be isolated from leaf litter and leaves 
on the tree. However, the presence of these diseases cannot be reliably 
detected through the visual inspection of plants or plant parts other 
than the fruit. So, while Sec. 319.56-2f(b)(6)(i) does provide that a 
grove's freedom from citrus black spot and sweet orange scab shall be 
verified through visual inspection of the grove and buffer area, that 
visual inspection will necessarily be limited to fruit on the trees. 
The diseased fruit threshold was chosen because it will be the fruit 
itself, and not any leaves, branches, or litter, that will be imported 
into the United States. We did not include any special criteria or 
measures for a previously disqualified grove to re-enter the export 
program because we believe that the testing, treatment, and inspection 
requirements that must be satisfied by any grove seeking to export 
fruit to the United States make such additional measures unnecessary.
    Comment: In the proposed rule, Sec. 319.56-2f(f) refers to 
``growing,'' ``harvest,'' and ``shipping'' seasons, with no definition 
of what is meant by such terms.
    Response: We regard the ``growing season'' as the period between 
bloom and fruit maturity, the ``harvest season'' as the period during 
which the mature fruit are picked, and the ``shipping season'' as 
beginning at roughly the same time as the harvest season and continuing 
until shortly after the harvest ends. As we are using those terms in 
their generally understood sense, we see no reason to specifically 
define them in the regulations.
    Comment: In Sec. 319.56-2f(f) of the proposed rule, it states that 
fruit must pass ``any inspection or testing required by this section or 
Sec. 319.56-6 of this subpart.'' Thus, if fruit is observed to be 
infected before fungicide application, or at some random time (but not 
during an inspection), or by non-SENASA personnel, there is strictly no 
requirement to remove the grove from the export program, since these 
inspections are not ``required.'' There is no overall catchall 
requirement that any detection is sufficient to remove a grove from the 
export program.
    Response: We believe that the official inspections and tests called 
for by this rule will be sufficient to detect the diseases of concern 
should they be present in a grove or in harvested fruit. However, in 
order to address the concerns raised by this commenter, we have added 
the words ``or at any other time'' to Sec. 319.56-2f(f).
    Comment: While the proposed rule specifies that any detection of 
sweet orange scab or citrus black spot during required inspections 
shall result in a grove's removal from the export program, it provides 
no mechanism by which this shall happen. For example, there is no 
requirement for SENASA to be notified, and no requirement for SENASA to 
notify APHIS.
    Response: In response to this comment, we have amended Sec. 319.56-
2f(f) in this final rule to require that both SENASA and APHIS be 
notified in the event that citrus black spot or sweet orange scab is 
detected.
    Comment: While the proposed rule specifies that any detection of 
sweet orange scab or citrus black spot during required inspections 
shall result in a grove's removal from the export program, it does not 
state what would occur if citrus canker was discovered in a grove or 
within a particular growing region.
    Response: As stated in the proposed rule, we believe that Argentina 
has demonstrated, in accordance with FAO guidelines for pest-free 
areas, that the citrus production areas in Catamarca, Jujuy, Salta, and 
Tucuman are free from citrus canker. Should citrus canker be detected 
in any of those States in the future, those same FAO guidelines require 
that Argentina report that detection. Because the citrus fruit 
regulations in Sec. 319.28 prohibit the importation of the fruits and 
unprocessed peel of all species and varieties of the genus Citrus from 
areas where citrus canker exists, the detection of citrus canker in an 
area within the citrus-canker-free region of northwestern Argentina 
would result in a prohibition on the importation into the United States 
of grapefruit, lemons, and oranges from that area.
    Comment: The proposed systems approach for citrus black spot and 
sweet orange scab provides only suppression of symptoms and reduction 
of the inoculum in the area proposed for export. So the question the 
risk assessment must answer is will this provide the United States with 
an appropriate level of protection against the introduction and 
establishment of one or both of these diseases when it is clear that 
infected, though symptomless, fruit will be certified for export to the 
United States?
    Response: The risk assessment provides the decisionmaker with the 
information he needs to determine whether certain phytosanitary 
measures provide ``an appropriate level of protection'' in a particular 
situation; it is not the purpose of the risk assessment itself to 
answer that question. In this case, the risk assessment examined the 
risk associated with the importation of Argentine citrus and estimated 
the likelihood of pest introduction. In any event, the systems approach 
for citrus black spot and sweet orange scab is not designed to suppress 
symptoms. It is designed to prevent infection. For that reason, part of 
the systems approach includes removal of debris to reduce inoculum and 
application of fungicides to prevent infection. As part of the entire 
systems approach, this prevention portion provides an appropriate level 
of protection against the introduction or establishment of either of 
these diseases. It is not ``clear'' that symptomless, infected fruit 
will be certified for export. In fact, using the systems approach makes 
it highly unlikely that symptomless, infected fruit will be certified 
for export.

Risk Assessment

    Note: In this section, as well as in the subsequent section 
titled ``Risk Assessment--`Principles of Good Practice' some of the 
comments state that the proposed rule's supporting risk assessment 
failed to establish a connection between certain of its conclusions 
and the data or information that was used as the basis for those 
conclusions. We have responded to those comments by explaining the 
role that expert judgment played in reaching those conclusions or by 
pointing to our use of the sources cited in section III 
(``References'') of the risk assessment. However, in order to more 
thoroughly document the sources of the risk assessment's 
conclusions, we have prepared an addendum to the risk assessment 
that provides, node-by-node, specific references to the information 
or data used as the basis for those conclusions. The addendum may be 
obtained from the person listed at the beginning of this final rule 
under the heading FOR FURTHER INFORMATION CONTACT.

    Comment: The consequences of introduction are addressed in the 
qualitative portion of the risk assessment via an estimation of the 
economic and/or environmental damage potential according to ratings 
applied to five risk elements. In these estimations, broad 
uncharacterized assumptions are used and the role of uncertainty is 
never discussed.

[[Page 37632]]

    Response: The objective criteria we use to rate the five risk 
elements are stated on pages 22 through 25 of the risk assessment, and 
our findings regarding the five risk elements are provided on page 26. 
Our findings are not based on ``broad uncharacterized assumptions,'' 
but on specific information available in the scientific literature. The 
information used in rating each pest is provided in the pest data 
sheets provided for each of the rated pests (Appendix I-IV for four 
species of fruit flies and Appendix V-VII for the three citrus 
diseases), which are supported by the scientific literature cited and 
listed in each pest data sheet.
    We did not discuss the role of uncertainty in the assignment of 
ratings for the five risk elements because uncertainty played an 
insignificant, if any, role in the assignment of those ratings. For 
each risk element, each pest received a qualitative ranking of high, 
medium, or low; the assignment of each ranking for each pest was 
dictated by the responses to specific and objective criteria. For 
example, the rankings assigned for Risk Element #2 (host range) were 
assigned as follows:
    <bullet> High--Pest attacks multiple species within multiple plant 
families.
    <bullet> Medium--Pest attacks multiple species within a single 
plant family.
    <bullet> Low--Pest attacks a single species or multiple species 
within a single genus.
    As can be seen in the pest data sheet included in the risk 
assessment for each of the pests examined, the host range of each pest 
has been established and documented, so there was no uncertainty 
involved in the assignment of a qualitative risk rating for each pest 
under this risk element. The same may be said for the other four risk 
elements as well, with the possible exception of Risk Element #5 
(environmental impact), in which three of the five factors considered 
involve expected impacts on the environment or on threatened/endangered 
species. Because those factors involve likely future impacts as opposed 
to documented past impacts, some degree of uncertainty is inevitable; 
however, we do not believe that the level of uncertainty is sufficient 
to have had any substantive impact on the assigned risk ratings.
    Comment: Climate-host interaction is estimated solely on the USDA s 
Plant Hardiness Zone Map. This map provides temperature zones for 
specified regions, and risk is calculated based on a pest's ability to 
exist in one to several temperature zones. Yet, rainfall and relative 
humidity play an equally critical role in the ability of a disease 
pathogen to survive and thrive in a new area. (For example, there is 
the added moisture that results from irrigation and fog, as in the 
coastal California growing areas, and the summer monsoon season that 
occurs in both Arizona and southern California.) The omission is never 
mentioned, so neither is the uncertainty this omission represents.
    Response: The plant hardiness zone map is used in the discussion of 
Risk Element #1, ``Climate-Host Interaction,'' as an objective means of 
specifying the extent of the potential range of the pest. We agree that 
it may be appropriate, as suggested by the commenter, to introduce 
relative humidity and rainfall as factors for consideration at this 
stage. However, the addition of those factors at this stage would have 
the effect of further limiting the potential range of the pest under 
consideration to areas even smaller than temperature zones, as the pest 
would be restricted to areas with appropriate ranges of multiple 
factors (temperature, rainfall, and relative humidity), rather than 
just one factor (temperature). That being said, the role of moisture is 
in fact considered in the risk assessment, contrary to the commenter's 
assertion that it was not. Specifically, Risk Element #3, ``Dispersal 
Potential,'' considers ``whether natural factors (e.g., wind, water, 
presence of vectors) facilitate dispersal'' as one of the three items 
examined when evaluating whether a pest has the potential to disperse 
(or, to use the commenter's terminology, ``survive and thrive'') after 
introduction into a new area.
    Comment: Sweet orange scab is rated medium for its host range 
potential yet it is not known to infect genera of Rutaceae other than 
Citrus species. Citrus black spot is rated high for its dispersal 
potential (capable of movement over 10 km per year), yet the scientific 
data, and the data sheet provided, indicate that this fungus only 
spreads short distances under natural conditions. Long-distance 
dispersal is attributed to the artificial movement of citrus leaves and 
nursery stock, both of which are beyond the scope of the risk 
assessment. If this assessment is correct, the 150-meter buffer 
provision in the proposed program should be reexamined.
    Response: Our understanding of this comment is that the commenter 
is pointing out that: (1) The rating we assigned for the host range 
potential of sweet orange scab was too high and (2) the rating we 
assigned for the dispersal potential of citrus black spot may have been 
too high, and if that is the case, the 150-meter buffer zone may be too 
large. We agree that Elsinoe australis (sweet orange scab) could have 
received a rating of ``low'' for host range potential and, as a result, 
sweet orange scab could have only been rated as ``medium''--not 
``high''--for its consequences of introduction. Similarly, Guignardia 
citricarpa (citrus black spot) could have been rated as ``medium'' for 
dispersal potential, and as a result, citrus black spot could have been 
rated as ``medium''--not ``high''--for its consequences of 
introduction. Although our original rating of ``high'' for the 
dispersal potential of citrus black spot may have been somewhat 
conservative, we believe that the 150-meter buffer zone provision is 
still an appropriate measure to protect production groves from 
neighboring properties that are not participating in the export 
program.
    Comment: Black spot is apparently on a wide range of other host 
plants. The risk of movement of Guignardia citricarpa on latently 
infected fruit and its ability to establish in a new area on various 
other hosts (i.e., not citrus) is underrated.
    Response: Guignardia citricarpa is morphologically identical to 
another Guignardia sp. that is latent in citrus and many other hosts. 
However, the identified host range of Guignardia citricarpa is limited 
to commercially grown Citrus spp. except for sour orange (C. aurantium) 
and its hybrids. Given the identified host range of Guignardia 
citricarpa, we believe that the risks presented by Guignardia 
citricarpa were appropriately rated in the risk assessment.
    Comment: The likelihood of introduction is estimated using 
probabilistic scenario analysis. Here, uncertainty is addressed in the 
probability distributions, but these distributions were in turn based 
upon a number of assumptions that are not explained. Among other 
criteria, pest risk assessments must contain sufficient detail and 
identify all sources of uncertainty in data extrapolation in order to 
be open to evaluation and review. It is for this reason that the FAO 
Guidelines for Pest Risk Analysis require that the analysis or 
assessment clearly state the sources of information and the rationales 
used in reaching decisions regarding the phytosanitary measures 
proposed.
    Response: Our risk assessment was conducted with strict adherence 
to the FAO guidelines. As explained in the risk assessment on p. 28, we 
estimated model inputs ``using the best available data and expert 
judgment as our basis.'' In those cases where data were available, we 
identified those data and the role they played in the development of 
our distributions. When data were not available, we used additional

[[Page 37633]]

information provided by our experts to arrive at estimates that 
reflected what we considered to be appropriate levels of uncertainty, 
and the distributions were derived to reflect those estimates; in those 
cases, the role of expert judgment or expert information in arriving at 
the estimates was acknowledged. We believe, therefore, that our risk 
assessment clearly states the sources of information and the rationales 
used in reaching decisions regarding the phytosanitary measures 
proposed as required by FAO.
    Comment: Although some background information was provided, it 
would have been extremely helpful to include some additional 
information within or accompanying the pest risk assessment. This would 
include a complete review of current pest status of citrus black spot 
and sweet orange scab in Argentina and in the four States; the trip 
reports for any and all site visits; all survey methods and results; 
and a complete discussion of Argentina s current and proposed control, 
harvesting, and packing procedures.
    Response: All of the information cited by the commenter is either 
in the public domain or is part of the rulemaking record, which was 
made available to the commenter. We do not believe that it would be 
feasible or even necessary to reproduce the entire public record in the 
risk assessment.
    Comment: APHIS has not adequately considered the risk of 
infestation and infection originating in residential areas.
    Response: The risk of infestation/infection in residential areas 
was considered in the risk assessment as part of input probabilities P6 
(fruit transported to suitable habitat), P7 (pest finds/pathogen 
reaches suitable host), and P8 (pest/pathogen able to complete life 
cycle). Those input probabilities considered both commercial production 
areas as well as residential areas.
    Comment: The mitigation scenarios for the fruit flies and citrus 
canker are estimated against the systems approach proposed for citrus 
black spot and sweet orange scab; there is no analysis provided for the 
efficacy of the direct mitigation measures proposed for these pests. 
For the fruit flies, it would be more relevant to provide the 
supporting data evidencing the effectiveness of the post-harvest cold 
treatment. For citrus canker, it would be more appropriate to show how 
this program meets the requirements for designation of a pest free 
area.
    Response: It is not the case that ``the mitigation scenarios for 
the fruit flies and citrus canker are estimated against the systems 
approach proposed for citrus black spot and sweet orange scab.'' The 
risk presented by each pest was analyzed individually with respect to 
pertinent mitigation measures. In fact, we state on page 32 of the risk 
assessment that the baseline treatments of washing, waxing, and dipping 
the fruit (for diseases) ``are expected to have only a minor effect on 
fruit flies.'' Our estimates do not include any reduced fruit fly risk 
from these treatments. As shown in Table 7 on p. 35 of the risk 
assessment, there are only two differences between the risk model 
inputs for the baseline (no specific mitigations) and the proposed risk 
mitigation program. That is, two of the nodes were affected by the 
proposed program. The first affected node is P5 (pest survives post-
harvest treatment). As described on p. 32, all of the reduced 
likelihood of fruit fly survival with the proposed program comes 
directly from the cold treatment for fruit flies:

    USDA has an approved cold treatment schedule for both Ceratitis 
capitata, Treatment T107(a), and Anastrepha fruit flies other than 
A. ludens, Treatment T107(c) (PPQ, 1992). The treatment schedule 
allows different temperature/time combinations to be used. For 
example, T107(a) allows 32 deg. F (or below) for 10 days as well as 
36 deg. F (or below) for 16 days. Treatment schedules were based on 
demonstrated efficacy of probit 9 (99.9968 percent) mortality. This 
corresponds to a survival rate of 0.00003 (0.003 percent). We 
represented survival as a lognormal distribution with a mean of 
0.0001 and a standard deviation (sd) of 0.00011. A sd of 0.00011 was 
chosen because the resulting distribution has a mode (peak of the 
distribution) at 0.00003.

    The other node that is different is P8 (pest able to complete life 
cycle). As explained on p. 33 of the risk assessment, we estimated that 
this value would be slightly lower as a result of the cold treatment 
for fruit flies. The reduced risk from fruit flies under the proposed 
program results from the cold treatment for fruit flies, and not from 
the treatments applied for the diseases of concern.
    Regarding citrus canker, three main components are considered in 
the establishment and subsequent maintenance of a pest free area: 
Systems to establish freedom, phytosanitary measures to maintain 
freedom, and checks to verify freedom has been maintained. Argentina 
established its freedom from citrus canker, as stated on page 36 of the 
pest risk assessment, through 4 years of comprehensive specific surveys 
with negative results as well as general surveillance for canker in the 
field and in published literature. Argentina continues to maintain area 
freedom through phytosanitary measures outlined on pages 27 and 36 of 
the pest risk assessment document. These phytosanitary measures include 
restrictions on the movement and planting of citrus nursery stock in 
the free area and domestic quarantine controls at airports and roads 
servicing the area. Continuing canker surveys, field and packinghouse 
inspections, and the requirement for a phytosanitary certificate help 
verify that area freedom is maintained.
    Comment: The probability estimate for ``harvested fruit is infected 
with citrus black spot and sweet orange scab'' is based on limited 
field survey data provided by Argentina. For example, treatment tests 
for grapefruit were performed on young trees in 1994 only, i.e., trees 
known not to show symptoms with or without fungicidal treatment. The 
1994-95 treatment data provided are for oranges only, and the age of 
the orchard trees is not provided. There were no data provided for 
lemons, the most susceptible citrus for citrus black spot infection. No 
treatment data were provided for sweet orange scab.
    Response: We acknowledged in the risk assessment that the survey 
data provided by Argentina was limited. In the discussion of node P1, 
``Harvested fruit is infected,'' we stated that ``our estimates * * * 
were based on limited field survey data provided by Argentina and 
expert information provided by scientists familiar with citrus 
production in Argentina and/or the pathogen.'' Because the field survey 
data were limited, we used additional information provided by our 
experts to arrive at estimates of these probabilities that reflected 
what we considered to be appropriate levels of uncertainty, and the 
distributions were derived to reflect those estimates.
    Comment: The probability estimate for ``pathogen not detected at 
harvest'' is based solely on expert information that the fruit pickers 
would be able to find and cull diseased fruit. It does not provide any 
discussion regarding the latency period of citrus black spot symptom 
expression, nor that symptom expression does not occur at all in fruit 
from trees younger than 12 years. Yet, it does ironically assume in the 
mitigation scenario, based on a program that suppresses symptom 
expression, that this activity would result in fewer citrus black spot 
infected fruit escaping detection.
    Response: In that latent infections would not be visible to pickers 
during harvest, we do not believe that it is necessary for the 
probability estimate for P2 (pathogen not detected at harvest) to 
provide a discussion regarding the latency period of citrus black spot 
symptom expression or the lack of symptom expression in all fruit from

[[Page 37634]]

trees less than 12 years old. Rather, the issues of latency and lack of 
symptom expression are considered in, and factored into, the 
probability estimates provided in P3 (pathogen not detected at packing 
house inspection) and P4 (pathogens survive post-harvest treatment). 
With regard to the last sentence of the comment, the systems approach 
is not, as the commenter states, a ``program that suppresses symptom 
expression.'' Rather, as we have stated elsewhere in this document, the 
treatments and cultural practices required by this rule are designed to 
prevent fruit from becoming infected in the first place. Those 
requirements are the basis for the risk assessment's expectation that 
``more rigorous export standards and reduced frequency of latent 
infection would result in fewer [citrus black spot] diseased fruit 
escaping detection.''
    Comment: The probabilistic estimate for ``pathogens survive post-
harvest treatment'' predicts that these minimal treatments would have a 
deleterious effect on the survival of both sweet orange scab and citrus 
black spot causal pathogens. What this estimate does not state is that 
this node only applies to pathogen spores that may be found 
contaminating the surface of the fruit and that the fruit at that point 
is resistant to infection.
    Response: It is correct that mature fruit is not susceptible to new 
infection and that the post-harvest treatment is intended to render 
nonviable any spores contaminating the surface of the fruit. This is 
reflected in the risk assessment's discussion of node P4, ``Pathogen 
survives post-harvest treatment,'' where we stated that ``[w]e assumed 
that the additional treatments [i.e., the chlorine dip] included in the 
proposed export program would further reduce the survival rate of the 
[sweet orange scab] pathogen'' and that ``[f]or our mitigated scenario 
we assumed that the chlorine dip would have an additional deleterious 
effect on the survival of the [citrus black spot] fungus.'' As noted 
elsewhere in this document, these post-harvest treatments are mainly to 
prevent post-harvest decay.
    Comment: In section 8.f, ``Inputs, Sweet orange scab, citrus black 
spot and citrus canker,'' the probabilistic estimate for ``fruit 
shipped to a suitable habitat'' is based solely on the percentage of 
geographical area that supports cultivation of citrus. Yet, in fact, 
this node would be more accurate if estimates were based on population 
densities, as fruit is going to be shipped based upon a target market, 
not geography. Then, a comparison should be made relative to the 
population percentage found within the citrus growing areas. As it is 
estimated now, this node is particularly likely to be grossly 
underestimated. The probabilistic estimate for ``pathogen reach 
suitable host'' is based on an assumption that the initial inoculum 
source was introduced into an orchard setting. In fact, it is much more 
likely that the inoculum will initially be introduced into an urban 
setting. As a result, this node is another one that is particularly 
likely to be grossly underestimated. This probability node, along with 
the one above, should be recalculated more appropriately.
    Response: We disagree with the commenter's statement that the 
probabilistic estimate for ``fruit shipped to a suitable habitat'' is 
likely to be grossly underestimated. With the large citrus markets 
throughout the United States, we have no reason to believe that our 
estimate of 5 percent (percentage of imported fruit that will be 
shipped to areas where citrus can survive) is too low or too high, nor 
have we received any specific information from any commenter that would 
allow us to change our estimate. (Note: Tables 8-10 on pp. 44-46 of the 
risk assessment correctly list our estimate as 5 percent, and this is 
the value used for the calculations. The text on p. 41 incorrectly 
states this value as 9 percent). While it is accurate to state that 
fruit will be shipped based on markets rather than geography, one 
cannot dispute the link between geography and suitable habitat. The 
ability of an area to support a pest population is a function of 
climate and the availability of host material, and not population 
density.
    Similarly, the commenter's statement that ``the probabilistic 
estimate for `pathogen reach suitable host' is based on an assumption 
that the initial inoculum source was introduced into an orchard 
setting'' is inaccurate. We can find no statement in the risk 
assessment that could lead the commenter to this conclusion. We stated 
in the risk assessment:

    All three pathogens analyzed are essentially restricted to 
citrus hosts (or closely related species). Suitable habitat for 
these organisms necessarily corresponds to the range of their citrus 
hosts. Consequently, we considered the citrus growing regions of the 
continental United States to be ``suitable habitat.'' We estimated 
the percentage of the area of the contiguous 48 States that supports 
the growth of citrus species.

    This percentage of the area of the contiguous 48 States that 
supports the growth of citrus species includes all areas where citrus 
fruit can be produced, including ``backyard trees'' in urban, suburban, 
or rural settings, or any other areas where citrus plants can survive 
and produce fruit, as well as commercial citrus-production areas. 
However, citrus is a subtropical plant and can only survive and produce 
fruit in a small portion of the continental United States. Accordingly, 
we do not agree with the commenter's statement that both nodes are 
grossly underestimated and need to be recalculated.
    Comment: The probabilistic estimate for ``pathogen able to complete 
disease cycle'' in particular should evaluate the effect of the systems 
approach, i.e., it should provide a measurement of the level of 
infection and an estimation as to risk from latent or suppressed 
symptom expression. It should also include a discussion of the role of 
pycnidiospores in disease establishment and episode development. 
Although citrus black spot epidemics tend to be caused by the 
ascospores produced on dead leaves, the pycnidiospores from fruit are 
quite capable of being the source of introduction of the disease. The 
risk assessment should give more careful consideration to the 
pathogenicity of the pycnidiospores and should consider the possibility 
that citrus black spot could become established in the United States 
through pycnidiospores infecting residential citrus.
    Response: Our understanding of the commenter's suggestion that 
``[t]he probabilistic estimate for `pathogen able to complete disease 
cycle' * * * should evaluate the effect of the systems approach, i.e., 
it should provide a measurement of the level of infection and an 
estimation as to risk from latent or suppressed symptom expression'' is 
that the commenter believes that the intended effect of the systems 
approach is to suppress the symptoms of citrus black spot and, on the 
basis of that belief, that we should estimate the percentage of fruit 
that will be latently infected and provide an estimate of the risk 
presented by that latently infected fruit. As we have stated elsewhere 
in this document, we disagree with the commenter's assertion that the 
goal of the systems approach is simply to suppress symptoms; rather, 
the systems approach is intended to prevent infection in the first 
place, provide for the detection of infection if it should occur, and 
prevent the entry of infected fruit into the United States. That being 
said, this node of the risk assessment (P8: Pathogen able to complete 
disease cycle) is assumed to be an independent event and, as such, 
begins with the assumption that the pest, in some form, has reached a 
suitable habitat and a

[[Page 37635]]

suitable host, including residential citrus. The node then describes 
``our estimate of the likelihood that these pathogens would, having 
reached a host plant, be able to infect that plant and complete the 
disease cycle.'' Thus, we believe that the risk assessment does in fact 
provide the estimation of risk sought by the commenter in the first 
part of her comment.
    In the second part of her comment, the commenter suggests that this 
node of the risk assessment ``should also include a discussion of the 
role of pycnidiospores in disease establishment and episode 
development.'' In our discussion of this node in the risk assessment, 
we stated that we ``took into account the type of infectious propagule 
produced by each of the three pathogens and the environmental and 
physiological requirements for host plant susceptibility and successful 
disease progression'' and later, specifically with regard to citrus 
black spot, that:

    The epidemiology of [citrus black spot] is influenced by the 
availability of inoculum, the environmental requirements for 
infection, the growth cycle of the host and the age of the fruit in 
relation to its susceptibility. Ascospores formed on dead leaves on 
the orchard floor form the main source of inoculum, however pycnidia 
on out of season or late hanging fruit can also serve as sources of 
rain splashed inoculum. Spores are released during rainfall and 
during irrigation. Except for lemons, leaf infections seldom occur. 
The critical period for infection starts at fruit set and lasts for 
4 to 5 months. Symptom development is hastened by rising 
temperatures, high light intensity, drought and poor vigor.

    Given the above discussion, we believe that we did give due 
consideration in the risk assessment to the pathogenicity of the 
pycnidiospores and the possibility that citrus black spot could become 
established in the United States through pycnidiospores infecting 
residential citrus. Our estimates of the risk presented by 
pycnidiospores are supported by the American Phytopathological 
Society's (APS) Compendium of Citrus Diseases (Whiteside, J.O., 
Garnsey, S.M. and Timmer, L.W., 1988, APS Press, American 
Phytopathological Society, St. Paul, MN. 80 pp.), which is cited 
repeatedly in the risk assessment. That publication states: 
``Pycnidiospores formed on dead leaves on the ground can reach the 
susceptible fruit only by the splashing of raindrops, and they are not 
considered an important source of inoculum.'' The pycnidiospores play a 
role in short distance water-dispersal of this disease. They may be 
produced on symptomatic, late-hanging fruit or on dead, decaying leaves 
on the orchard floor. Pycnidiospores from fallen leaves are very 
unlikely to reach fruit because they are solely waterborne. 
Pycnidiospores from late-hanging, symptomatic fruit can infect fruit 
that is in physical contact with the infected fruit or that is hanging 
below the symptomatic fruit, if the fruit are susceptible and 
environmental conditions appropriate. This agrees with the findings of 
McOnie (McOnie, K.C., 1964, ``Speckled blotch of citrus induced by the 
citrus black spot pathogen Guignardia citricarpa,'' Phytopathology 54: 
1488-1489), who concluded that ascospores are the major infective 
bodies and that spores of the asexual stage (i.e., pycnidiospores) are 
unimportant in producing fruit infections.
    Comment: The pest risk assessment concluded that the pest risk 
potential, minus the mitigation measures, is high for the fruit flies 
and sweet orange scab and medium for citrus black spot; citrus canker 
is not mentioned. No conclusions are expressed for the pest risk 
potential as mitigated by the proposed program. In any case, sufficient 
information necessary to assess the efficacy of the proposed systems 
approach for sweet orange scab and citrus black spot is not available 
within the proposed rule, the supporting pest risk assessment, or other 
documentation provided.
    Response: The pest risk potential of an organism, which can be 
viewed as a constant, is not affected by mitigating measures, which is 
why the risk assessment expressed no conclusions for the pest risk 
potential as mitigated by the proposed program. Rather, it is the 
likelihood of introduction that will be affected by the mitigating 
measures, and we did provide our conclusions for the likelihood of 
introduction as mitigated by the proposed program. Citrus canker is not 
mentioned because fruit will be imported only from the citrus-canker-
free area of Argentina. With regard to the efficacy of those mitigating 
measures, we believe that the data supplied by Argentina and the 
reports of APHIS personnel who conducted the site visits in Argentina, 
which are all part of the rulemaking record and were made available to 
the commenter, as well as the information contained in the scientific 
literature cited in the risk assessment, provided sufficient 
information to support the risk assessment and its conclusions relating 
to the risk reductions afforded by the mitigating measures required by 
this rule.
    Comment: In the risk assessment, APHIS states that it evaluated 
only pests that can ``reasonably be expected to follow the pathway, 
i.e., be included in commercial shipments of citrus.'' But the pathway 
contains more than just commercial shipment, and much of the protection 
estimated in the risk assessment for the diseases and pests evaluated 
comes from other components of the pathway. What should matter is not 
the probability of traversing the pathway as far as commercial 
shipment, but the probability of completing the whole pathway. The 
probability required for ``reasonably be expected'' appears to be 
extremely high compared with the required levels of protection. It is 
plausible that for other pests or diseases, other parts of the pathway 
are not of low probability. In that case, the risk assessment has not 
included sufficient pests.
    Response: In stating that the pathway consists of ``more than just 
commercial shipment'' and that protection may be afforded by ``other 
components of the pathway,'' it appears that the commenter is confusing 
the pathway itself with the mitigation measures applied to fruit in the 
pathway. The only pathway ``opened'' by this rule, and thus the only 
pathway appropriately considered in a risk assessment supporting this 
rule, is the commercial shipment of citrus fruit from Argentina to the 
continental United States. Other pathways (e.g., backyard fruit 
smuggled by airline passengers or placed in the mail) would exist with 
or without this rule, and thus did not fall within the scope of the 
risk assessment prepared for this rule. Commercial shipment is the 
whole pathway, and not merely a distinct stop along the pathway as the 
commenter suggests when he speaks of ``traversing the pathway as far as 
commercial shipment.'' In our risk assessment, the commercial shipment 
pathway for citrus fruit begins in the Argentine production area and 
ends in the continental United States in the ultimate consumer's trash 
can or compost pile, and this entire pathway was considered when 
assessing pest risk. The risk assessment lists all pests of citrus in 
Argentina, and all pests that can reasonably be associated with this 
pathway were analyzed in detail.
    Comment: The desired result of a Monte Carlo analysis should be 
carefully defined, whereas the risk assessment has no stated, well-
defined, goal. In our opinion, the goal that would provide the most 
useful information would be an estimate (and its uncertainty) of the 
average annual likelihood that the importation of Argentine citrus 
fruit will result in a pest outbreak in the United States. If this is 
the intended goal of the analysis,

[[Page 37636]]

APHIS must reconsider its use of any distributions that reflect year-
to-year variability. The distribution for the number of shipments of 
fruit that will be shipped to the United States was constructed ``to 
allow for variation in the frequency of shipments that might result 
from variation in production, frequency of shipments that are cleared 
for shipment, and variation in market demands in the United States.'' 
If the intended goal is to estimate an average likelihood of a pest 
outbreak, APHIS should ignore year-to-year variability in this value 
and instead construct a distribution that accounts only for uncertainty 
in the value for the average number of shipments that will be shipped 
to the United States. The same would apply for any other year-to-year 
variabilities included in the probability estimates, unless they were 
correlated. No explicit mention is made of such variabilities in the 
discussions of the other probability estimates, but the discussion of 
these estimates is inadequate. If there are correlations, such as that 
explicitly discussed in section 8.e P8 of the risk assessment, then 
such correlations have to be taken into account. One way to do so would 
be to incorporate the year-to-year variability together with the 
correlations in the modeling. Each iteration of the Monte Carlo 
assessment would then require a nested loop that averaged over multiple 
years in order to obtain the long-term average.
    Response: We disagree with the commenter's statement that the risk 
assessment has no stated, well-defined goal. The overall purpose of our 
risk assessment is stated in the first sentence of that document, i.e. 
``* * * to examine plant pest risks associated with the importation 
into the United States of fresh citrus fruit grown in certain areas of 
Argentina.'' Similarly, with regard to our use of Monte Carlo 
simulation methods to account for uncertainty in estimating 
probabilities, we stated the following in the first paragraph of 
section 8, Likelihood of Introduction (the only section of the risk 
assessment in which Monte Carlo simulation methods were used): ``For 
the pests listed in Table 6, we estimate the likelihood of introduction 
using a quantitative method referred to as `probabilistic risk 
assessment' or `probabilistic scenario analysis.' The purpose of a 
probabilistic risk assessment is to estimate the likelihood of an 
undesirable outcome (bad event). The bad event is represented by the 
endpoint of the risk model, i.e., introduction of a quarantine pest. 
Our method has four basic components: Scenario analysis, development of 
a mathematical model, estimation of input values for the likelihood 
model, and Monte Carlo simulation * * *.'' Thus, the purpose of the 
Monte Carlo portion of the risk assessment is also stated clearly, 
i.e., to estimate the likelihood that quarantine pests will be 
introduced.
    The goal suggested by the commenter--to provide ``an estimate (and 
its uncertainty) of the average annual likelihood that the importation 
of Argentine citrus fruit will result in a pest outbreak in the United 
States''--is a reasonable approximation of our stated goal with a 
slightly different endpoint. As explained in the risk assessment, 
``introduction'' of a pest means entry and establishment (i.e., 
reproducing, self-sustaining population of the pest). Pest outbreak is 
one possibility for the next step if we were to continue our scenario. 
We have used pest outbreak as our endpoint in previous risk 
assessments. However, in this risk assessment, we chose pest 
introduction as our endpoint. Use of pest introduction as the endpoint 
is more conservative (more pest exclusionary) than using pest outbreak. 
Estimates of the likelihood of outbreak would be lower than estimates 
of introduction because additional events would have to occur before 
the introduction would lead to an outbreak.
    The commenter also states that ``APHIS should ignore year-to-year 
variability in this value and instead construct a distribution that 
accounts only for uncertainty in the value for the average number of 
shipments that will be shipped to the United States.'' These remarks 
are premised on the belief held by some risk assessors that variability 
must be dealt with separately from uncertainty in all cases; however, 
the utility of this approach in all cases has not been demonstrated. In 
the case of our risk assessment, we believe that separating other forms 
of uncertainty from variability (i.e., year-to-year) would obscure, 
rather than illuminate, the issue. Commercial shipments of citrus from 
Argentina have never entered the United States; there are no data that 
would allow us to characterize the expected year-to-year variability in 
quantity imported. Although the actual number of shipments would vary 
on a year-to-year basis, the data do not exist to characterize that 
variability. There is considerable uncertainty regarding the quantity 
of shipments. That is why we used a normal distribution that is not 
bounded above or below the mean.
    Finally, with regard to the commenter's suggestion that we 
incorporate year-to-year variability together with correlations in the 
modeling, we did consider the implications of possible correlations 
among the nodes, but we determined that there were not any correlations 
that would affect the calculations in the Monte Carlo simulation.
    Comment: APHIS uses a simple multiplicative mathematical model to 
estimate the frequency of pest outbreaks in the United States. The 
estimated number of shipments of citrus fruit is multiplied by eight 
probability distributions to arrive at the final distribution for the 
likelihood of a pest establishing itself in the United States. If each 
stage of the process were truly independent of all preceding stages, 
and if it were certain that all fruit would pass through each stage of 
the process, then this would be a simple, accurate model to describe 
the likelihood of an exotic pest establishing itself in the United 
States. However, we do not believe that each stage is independent of 
the all preceding stages, nor do we believe that it is certain that all 
fruit will pass through each stage of the process. The risk 
assessment's mathematical model should take into account the 
correlation of the stages and potential for the failure of fruit to 
pass through all those stages.
    Response: We believe that the commenter has misinterpreted the risk 
model as a graphical representation of the risk mitigation process, 
which it is not. The steps in our model are consecutive--for example, 
fruit must be harvested before it can be taken to the packinghouse--
which could give the impression of dependence, but the risks examined 
at each step are independent; the risks examined in one node do not 
have a direct impact on the risks examined in the next. Although 
certain of the risk mitigation steps are represented in the risk model, 
the model accounts for other steps (e.g., biological) that are 
independent of human activities. For example, node P7 (figure 2 on page 
30) is stated as ``pest locates suitable host.'' Clearly, this is not a 
risk mitigation step that can be skipped, it is a representation of the 
probability that a pest will find host material should it enter the 
United States. This probability is not correlated with the other nodes. 
The scenario should be viewed according to the description in the risk 
assessment:

    First, we use the method of scenario analysis to conceptualize 
the events (referred to as nodes) that must occur before the 
endpoint or ``bad event'' (e.g., introduction of Anastrepha 
fraterculus or Elsinoe australis) can occur. Scenario analysis 
provides a conceptual framework for assessing and managing risk. 
Before the quarantine pest can

[[Page 37637]]

be introduced, all of the events shown in the model must occur.

    Regarding the commenter's statement ``however, we do not believe 
that each stage is independent of the all preceding stages,'' we 
disagree and believe the nodes are independent; it is not possible to 
address this comment more specifically without further information from 
the commenter about which nodes he believes are correlated with others. 
We have discussed the basis for our belief in the independence of the 
nodes elsewhere in this document and address the issue in the addendum 
that is available from the person listed under FOR FURTHER INFORMATION 
CONTACT.
    Regarding the commenter's statement ``nor do we believe that it is 
certain that all fruit will pass through each stage of the process,'' 
we would point out that the probabilities assigned to each node that 
represents a risk mitigation step relate directly to a ``failure'' of 
that particular step (e.g., pest not detected, pest survives 
treatment), thus the possibility of failure in each of the stages was 
considered in the risk assessment. Further, this rule requires that 
only fruit that passes through each stage of the process may be 
approved for entry into the United States. SENASA inspectors will be 
present at each stage to supervise, confirm, and document the 
successful application of each of the required mitigations, and a 
phytosanitary certificate issued by SENASA confirming that the fruit 
has been produced in accordance with the requirements of this rule must 
accompany each shipment of fruit exported to the United States.
    Finally, the commenter states that we used our model to estimate 
the frequency of pest outbreaks, but, as noted in our response to the 
previous comment, that is not the case. As shown in Figure 2 on page 30 
of the risk assessment, the endpoint of our risk model for the 
likelihood of introduction was ``pest establishes.'' International 
guidelines for pest risk analysis (FAO 1996, as referenced in the risk 
assessment) define introduction as pest entry plus establishment.
    Comment: APHIS selected an 18-kg box of fruit as the ``risk unit'' 
for the risk assessment and bases all estimates of probability on this 
unit. This is not appropriate for all steps, perhaps any step, in the 
analysis. For the first four stages of the pathway defined by the risk 
assessment (i.e., until the fruit is boxed at the packinghouse), the 
fruit are acted on independently of the boxes in which they will be 
placed. Moreover, the processes of storage, sorting, and packing occur 
in such a way that the fruit become fairly well randomized. Thus if 
p<INF>1</INF>p<INF>2</INF>p<INF>3</INF>p<INF>4</INF> are the ``per 
fruit'' probabilities designated as P1, P2, P3, and P4 on a ``per box'' 
basis in the risk assessment, then if 
p<INF>1</INF>p<INF>2</INF>p<INF>3</INF>p<INF>4</INF> are independent 
(but see below), the probability for a box containing n fruit to be 
infection-free after the fourth stage is 1-(1-
p<INF>1</INF>p<INF>2</INF>p<INF>3</INF>p<INF>4</INF>) \n\. But this 
cannot in general be written as the product P1P2P3P4 (as is done in the 
risk assessment) where P1 through P4 are independent, and it cannot 
even be so approximated if the product 
p<INF>1</INF>p<INF>2</INF>p<INF>3</INF>p<INF>4</INF> is reasonably 
large, as certainly occurs in the unmitigated situation. The natural, 
indeed the only, unit for consideration is the individual fruit. Using 
individual fruit will also allow straightforward analysis of the 
experiments that have been or can be performed to test efficacy of 
various treatments or actions.
    Response: As noted elsewhere in this document, we believe that a 
box of fruit is the most appropriate risk unit. No one unit is perfect 
for each node; prior to packing there is mixing of the fruit from an 
orchard. Once the fruit are packed, they are no longer independent of 
each other, and it is boxes, and not individual fruit, that will be 
shipped to--and, in all likelihood, remain in--specific destinations in 
the United States. Even though no one unit is perfect for each node, we 
decided that it would be most transparent, defensible, and correct to 
use a consistent risk unit throughout the model. The primary problem 
perceived with using individual fruit as the risk unit was the 
different size of the various fruit being considered (i.e., lemons, 
oranges, and grapefruit). Separate modeling for each type of fruit 
would have complicated the assessment significantly and needlessly; the 
expert group did not believe that separate modeling would improve the 
accuracy of the risk estimates, especially given the inherent 
uncertainties in the input parameters.
    As explained in the risk assessment (section 8.e.F1, p. 29), in 
each step of the scenario, the probabilities were estimated for one box 
of fruit. The commenter asserts:

    Thus if p<INF>1</INF>p<INF>2</INF>p<INF>3</INF>p<INF>4</INF> are 
the ``per fruit'' probabilities designated as P1, P2, P3 and P4 on a 
``per box'' basis in the risk assessment, then if 
p<INF>1</INF>p<INF>2</INF>p<INF>3</INF>p<INF>4</INF> are independent 
(but see below) the probability for a box containing n fruit to be 
infection-free after the fourth stage is 1-(1-
p<INF>1</INF>p<INF>2</INF>p<INF>3</INF>p<INF>4</INF>) \n\. But this 
cannot in general be written as the product P1P2P3P4 (as is done in 
the risk assessment) where P1 through P4 are independent, and it 
cannot even be so approximated if the product 
p<INF>1</INF>p<INF>2</INF>p<INF>3</INF>p<INF>4</INF> is reasonably 
large, as certainly occurs in the unmitigated situation.

    We believe that assertion is inappropriate because it mixes units, 
first assuming a per-fruit probability, then a per-box probability. We 
were consistent throughout the risk assessment and used per-box 
probabilities for each node.
    Comment: To correctly model the mitigated situation, more 
information should be presented about exactly what happens when citrus 
black spot or sweet orange scab is detected on fruit destined for the 
United States. Is the entire shipment prohibited from entering the 
United States? What about other shipments en route from the same grove? 
These do not appear to have been accounted for in the probability 
distributions for the risk assessment. The proposed regulations require 
that the grove be removed from the export program for the duration of 
the growing season if citrus black spot or sweet orange scab is 
detected upon any required inspection, including inspection at the port 
of first arrival. Would the removal of such groves from the export 
program affect any of the distributions in the risk assessment? It 
certainly affects the structure of the overall probability model.
    Response: As described in the proposed rule and noted by the 
commenter, should any of these diseases be detected on fruit destined 
for the United States, the entire shipment will be rejected and the 
grove will be eliminated from the program for the remainder of the 
shipping season. These events--the rejection of shipments and the 
elimination of groves--can be viewed as successful applications of the 
systems approach and, as such, contribute to the risk reductions 
estimated in our risk assessment. Because the probabilities assigned to 
each node that represents a risk mitigation step relate directly to a 
``failure'' of that particular step (e.g., pest not detected, pest 
survives treatment), our explicit focus was on failures rather than on 
successful applications of the systems approach. Those successes were, 
however, inherently reflected and accounted for in the appropriate 
probability distributions in the risk assessment.
    Comment: APHIS makes no attempt to account for the number of fruit 
in a box that are affected or for the number of pests affecting each 
fruit. Certainly, if several pieces of fruit in a given box were 
infested with fruit flies, the probability of the pest establishing 
itself in the United States as a result of the contaminated box would 
be much higher than if only one fruit was infected, as is explicitly 
acknowledged in section 8.e P8 of the risk assessment.

[[Page 37638]]

Because the ranges for these variables are large (ranging from zero to 
the maximum number of fruit in a box and from zero to a large number of 
pests per box), accounting for variability in the number of infested or 
infected fruits per box and for the number of pests per fruit (or box) 
could have a large impact on the results of the risk assessment.
    Response: As stated in the risk assessment (section 8.e P1, p.29), 
we considered the possibility that more than one fruit in a box might 
be infested with fruit flies (``Specifically, this node represents the 
probability of one or more individual fruit in a box being infested by 
any of the four species of fruit flies.'').
    However, because the likelihood that any individual fruit will be 
infested is low (mode of distribution = 0.00009), and because the fruit 
are mixed thoroughly prior to packing, the likelihood that multiple 
fruit within a single box will be infested is considerably smaller than 
0.00009. As indicated in the quote above, our estimates accounted for 
this possibility.
    Regarding multiple larvae, the most likely way (virtually the only 
way) that one of these fruit fly species could become established as a 
result of the importation of infested fruit is if there are multiple 
larvae in a particular fruit. A reasonable consideration of this 
situation leads to the conclusion that unless multiple larvae are 
present, it would be nearly impossible for a breeding pair to form. 
Thus, multiple larvae infesting a given fruit was the primary factor in 
our estimate. In addition, it should also be remembered that this rule 
will require all susceptible fruit to be treated according to a 
treatment schedule with a documented efficacy of 99.9968 percent.
    Comment: APHIS states, ``The nodes in our scenario (risk model) 
represent independent events that must all take place before an 
introduction can occur.'' However, it is not sensible to believe that 
the eight stages considered in the APHIS risk assessment are truly 
independent, or that the diagram (Figure 2 of the risk assessment) 
adequately represents the process of importation of citrus fruit. The 
model used in the assessment, which consists solely of independent 
stages, appears to have been selected to agree with APHIS's ``Detailed 
Description of the PPQ Pathway-Initiated Qualitative Commodity Pest 
Risk Assessment, Version 4.1'' for qualitative assessments. However, 
these guidelines are incorrect, even for a qualitative risk assessment. 
It may not be possible to construct such a linear sequence of steps to 
adequately represent the movement of a commodity--a more complex 
diagram may be necessary. Moreover, even if it is possible to construct 
such a sequence of such steps, it is incorrect to make estimates 
independently for each step. What is required are the conditional 
probabilities for subsequent steps, based on the prior steps in the 
sequence.
    Response: We consider it completely reasonable, given the 
parameters of the model, that all eight nodes are independent. Indeed, 
the model was constructed with the express purpose of constructing a 
model with independent nodes (events), and an expert review of the 
model conducted by the Harvard Center for Risk Analysis reported in the 
journal Risk Analysis (Gray et al., 1998) has validated our model and 
its assumption of independence. Without specific details from the 
commenter as to where and how dependencies might affect the model and 
its outcome, it is not possible to address this comment in detail 
except to repeat our statement that they are independent. Our model 
provides a framework for estimating risk, and we (and others, as noted 
above) believe the guidelines are valid. The model we selected has 
proven itself over the years, and for several commodity/pest 
combinations, to be an efficient means of estimating this type of risk. 
While we acknowledge that there are alternative ways of estimating this 
type of risk, we do not believe that using a different model would 
result in a substantively different outcome.
    The risk model (scenario) was not, as stated by the commenter, 
offered to represent the process of importation of citrus fruit. The 
process was explained in the proposed rule, and details of the proposed 
risk mitigation program were listed in the risk assessment on pp. 26-
28. Nor was our risk scenario offered to represent each mitigation 
measure in the proposed program; rather, it represents ``independent 
events that must all take place before an introduction can occur.'' The 
frequency of shipments/number of boxes (F1) and four of the eight nodes 
(P4, P6-P8) are not affected by risk mitigation measures. P1 is 
affected by standard and special pest control activities, P2 and P3 
represent inspections for pests, and P5 represents a variety of 
treatments depending on host and pest.
    The commenter asserts that the model appears to have been selected 
to agree with APHIS' guidance for performing qualitative risk 
assessments, when in fact our baseline scenario (risk model) for these 
risk assessments was developed before our qualitative process; the 
qualitative process is based on the probabilistic scenario. The 
commenter continues by stating: ``However, these guidelines are 
incorrect, even for a qualitative risk assessment. It may not be 
possible to construct such a linear sequence of steps to adequately 
represent the movement of a commodity--a more complex diagram may be 
necessary. Moreover, even if it is possible to construct such a 
sequence of such steps, it is incorrect to make estimates independently 
for each step.'' As stated above, the scenario was never intended to 
represent movement of a commodity. As we explained in the risk 
assessment, the nodes in our scenario represent independent events that 
must all take place before an introduction can occur. Regarding the 
commenter's statement that ``a more complex diagram may be necessary,'' 
we disagree. We believe that the events described in the risk model are 
necessary and sufficient for pest introduction. The commenter also 
states that ``What is required are the conditional probabilities for 
subsequent steps, based on the prior steps in the sequence.'' 
Conditional probabilities would be inappropriate because the nodes are 
independent.
    Comment: APHIS' failure to account for human error and failure 
modes that could result in skipping one or more of the eight stages in 
its model is the most significant structural error in the assessment. 
It is inconceivable that 1.2 million boxes per year of fruit could all 
be treated forever according to the risk mitigation program without a 
single mistake. Some stages of the systems approach are likely to be 
omitted at times through negligence, accident, or design. Since some of 
the steps greatly reduce pest survival (assuming the pest traverses the 
step), even small probabilities for omission of such steps must be 
included in the analysis. APHIS should have used fault tree analysis in 
its assessment to evaluate the areas where failure can occur.
    Response: All of the estimates for model inputs that are affected 
by human activities (P1 through P4) are based at least in part on a 
consideration of human error. For example, the most obvious reason that 
a pest would not be detected at harvest (P2) or during packing (P3) 
would be an insufficient inspection (i.e., human error). The 
possibility of human error in fungicide applications is considered in 
P1 and the failure of post-harvest treatments is considered in P4. The 
other nodes are based either on marketing decisions (F1, P6) or pest 
biology (P5, P7-8). We do not believe that fault tree analyses are 
required in areas where failure can occur, as all of the nodes in our 
model that have a human component represent a ``failure'' of the 
system.

[[Page 37639]]

    Comment: APHIS attempts to account for human error in some stages 
of the model, but ignores it in other stages. When constructing a 
distribution for sweet orange scab infection rates, APHIS claims to 
account for the nature of the sweet orange scab fungus and the 
possibility of human error in fungicide applications. However, it is 
impossible for us to review the appropriateness of the distribution 
constructed by APHIS' experts because APHIS does not describe in detail 
how it accounts for the possibility of human error.
    Response: The direct data we had available when preparing this 
distribution were limited, and we explicitly acknowledged that in the 
risk assessment. As noted by the commenter, we recognized that human 
error (e.g., the improper or incomplete application of the fungicidal 
sprays) would limit the effectiveness of this aspect of the program. 
However, there are no objective criteria that one can use to move from 
recognizing that there is the possibility of human error in fungicide 
application to an estimate of how much human error there is likely to 
be. There is no database that can be used to predict the frequency or 
severity of human error in fungicide applications, and little or no 
direct experimental evidence exists from which one can derive estimates 
for the effects of human error. We recognized, therefore, that there 
would necessarily be a large element of uncertainty in our estimates of 
potential human error, which we considered along with the biology of 
sweet orange scab in estimating disease incidence; that uncertainty is 
evident in the fact that the experts agreed that the disease incidence 
might range from 0.1 to 30 percent. We believe that the distribution we 
constructed appropriately accounts for the uncertainty in our estimates 
of the effects of human error.
    Comment: APHIS takes no account of the possibility of failure modes 
associated with the cold treatment for fruit flies. Treatment schedules 
for fruit flies are based on a demonstrated survival rate of 0.00003. 
This survival rate is the mode of the distribution selected to 
characterize the probability that fruit flies will survive cold 
treatment. If any boxes of fruit escape cold treatment (as will almost 
certainly happen for a small fraction of the 1.2 million boxes), the 
chance of fruit fly survival increases dramatically (by a factor of 
33,000) for those boxes. Failure modes could easily be incorporated 
into the analysis by adding a Bernoulli function or a Dirac delta 
function to steps that could accidentally be skipped.
    Response: The process of research and development for establishing 
commodity treatments is well documented in the scientific literature. 
Before any treatment is accepted, confirmatory tests must be completed 
to simulate treatments under actual treatment conditions. When fruit 
are treated, monitoring devices are placed to record the conditions of 
the treatment. Before fruit are allowed entry, the treatment record is 
verified to ensure that the fruit were treated according to the 
treatment schedule. If the fruit were not treated according to the 
schedule, they would be denied entry. This requirement directly 
addresses the possibility of failures in the application of the cold 
treatment.
    Comment: The principal failure of the risk assessment with respect 
to the probability distributions is the failure to cite any credible 
data underlying their selection, and the failure to provide any 
documentation on their derivation. Where some studies are cited to 
provide a basis for the derivation, APHIS provides only vague 
references. Examination of the rulemaking record turns up summary data 
from various studies in Argentina that may correspond to those 
references, but there is no way a reviewer can be absolutely certain. 
No analyses of the studies are provided or referenced in the risk 
assessment or the rulemaking record, so the basis of the risk 
assessment estimates for mean values and variability or uncertainty 
cannot be evaluated. It is clear, however, that the entire risk 
assessment fails to distinguish variability and uncertainty.
    Response: The probability density functions (PDF's) used by APHIS 
in the Argentine citrus and other assessments are what Hoffman and 
Kaplan refer to as ``subjective probability distributions'' in a recent 
article in Risk Analysis, An International Journal (``Beyond the Domain 
of Direct Observation: How to Specify a Probability Distribution that 
Represents the `State of Knowledge' about Uncertain Inputs,'' Vol. 19, 
No. 1, 1999, pp.131-134). They are subjective precisely because no 
direct evidence existed to allow construction of a objective 
probability distribution. As emphasized by Hoffman and Kaplan, this is 
the norm in probabilistic risk assessment.
    In no case were data available that could be used to directly 
specify a PDF, that is, data that represented results of studies that 
provided an estimate of the parameter with associated information 
regarding the range of values, variability or uncertainty in the data, 
and the shape of the distribution. ``Risk assessment does not 
legitimately focus on filling the information gaps, but rather on 
making a decision in the absence of information,'' (Orr, et al., 1994). 
Although doing a risk assessment under these conditions may be 
considered unacceptable by non-practitioners, the only way to complete 
this type (and most types) of risk assessment is to make the best 
estimate possible based on whatever indirect information is available. 
In most cases, there were no indirect data either (results of 
experiments conducted to test a particular hypothesis). However, we 
relied on the best available scientific information and, in virtually 
every case, reliable data and information existed that related to the 
parameter for which an estimate was needed. For example, although there 
may be no data per se regarding the likelihood that Xanthomonas 
axonopodis would be ``. . . able to complete disease cycle'' (P8) 
following entry into the United States on fruit for consumption, there 
is a wealth of scientifically valid data and information, and 
conclusions in scientific papers, that demonstrate that the likelihood 
is extremely low. Although we did not, in all cases, explicitly link 
sources of information to the PDF's in which the information was used, 
our knowledge of each of the insect pests and diseases is summarized in 
the pest data sheets contained in the risk assessment's appendices and 
our sources of information are cited in each pest data sheet and in 
section III (References) of the risk assessment. Additional information 
regarding the construction of each of the distributions is contained in 
the addendum to the risk assessment that is available from the person 
listed under FOR FURTHER INFORMATION CONTACT.
    Regarding the statement that ``it is clear, however, that the 
entire risk assessment fails to distinguish variability and 
uncertainty,'' we call the commenter's attention to section 8.c where 
we stated:

We were uncertain about the input values for the likelihood model. 
This is typical for risk assessments. Uncertainty in the estimated 
values may arise from (among other things):
    <bullet> natural variation over time
    <bullet> natural variation from place to place
    <bullet> data gaps or unconfirmed data
    <bullet> relationships among multiple components in a node.

    This statement documents the fact that we considered both 
variability and uncertainty. While it is true that we did not model 
variability or uncertainty separately, doing so is not a common 
practice, and this approach is useful only in certain circumstances. 
While this approach may provide more detailed information, it is not a 
given

[[Page 37640]]

that additional detail can necessarily be equated with greater 
accuracy. In the case of this particular risk assessment--and virtually 
any plant pest risk assessment--separating variability from other forms 
of uncertainty would constitute overinterpretation of available data.
    Comment: The risk assessment states that all the distributions are 
based on the professional judgment of the team of entomologists who 
developed the risk assessment. That professional judgment appears to 
have been based on research or actual data in only a few instances. 
APHIS certainly must have access to data from inspections and from 
previous infestations of pests in the United States. The use of such 
data would result in much more credible distributions than those 
derived solely from professional judgment. It is possible, even likely, 
that distributions based solely on professional judgment (i.e., without 
reliance on data) are wildly inaccurate, placing the reliability of the 
analysis in serious question.
    Response: We did indeed use those data whenever they were 
available, and they were cited in several locations (e.g., Alfieri et 
al., 1994; Brown et al., 1988; Gould, 1995; etc.). The distributions 
were not based solely on professional judgment, i.e., ``without 
reliance on data'' as suggested by the commenter. But for many of the 
nodes, no direct data existed to provide estimates for the input 
distributions, and professional judgment informed by the ``indirect'' 
sources of information available (e.g., scientific literature regarding 
a particular pest, interception records, etc.) was used according to 
international standards and accepted practice.
    Comment: In no case does APHIS discuss the decision criteria used 
to select the type of probability distribution (normal, lognormal, 
beta), let alone why only these three particular distribution types 
were used. In most cases (such as in the construction of distributions 
for fruit fly and citrus canker incidence, the probability that a pest 
is detected at harvest, the probability that the pest is detected in 
the packinghouse, the probability that the pest survives shipment, 
etc.), no justification beyond ``expert judgment'' is given for the 
parameters selected to characterize the distributions. While we 
recognize that extensive data originally may not have been available to 
characterize, such deficiencies should have been recognized very early 
in the process and further studies carried out to fill in the gaps in 
data.
    Response: In addition to the three distribution types identified by 
the commenter, we also estimated several nodes using another type of 
probability distribution, truncated lognormal. Distributions were 
chosen to reflect the current state of scientific knowledge. We 
explained the nature of each distribution chosen; in fact, we provide a 
separate section for each distribution. The explanations can be found 
in section 8.e., with titled subparts for each node (probability 
distribution) used for the fruit fly simulation, and section 8.f., with 
titled subparts for each probability distribution used for the three 
diseases. We provided justification for our choice of distribution in 
many, but not all, cases. For example, in the discussion of the choice 
of distribution to represent the likelihood that fruit fly larvae will 
survive post-harvest treatment (section 8.e P5) we state:

    Treatment schedules were based on demonstrated efficacy of 
probit 9 (99.9968 percent) mortality. This corresponds to a survival 
rate of 0.00003 (0.003 percent). We represented survival as a 
lognormal distribution with a mean of 0.0001 and a standard 
deviation (sd) of 0.00011. A sd of 0.00011 was chosen because the 
resulting distribution has a mode (peak of the distribution) at 
0.00003.

    In this case, although we did not offer a discussion of why a 
lognormal distribution was used, since ``there is a significant body of 
work that shows a particular family of distributions to match the 
variability in the type of variable in question'' (D. Vose, in press), 
insect response to treatments such as this is distributed lognormally. 
The statistical procedure (probit analysis) that led to the probit 9 
estimate (referred to above and in the risk assessment) is based on the 
assumption that response is distributed lognormally. This phenomenon 
and the lognormal distribution lies at the heart of this branch of 
science and is documented in the scientific references provided in the 
risk assessment. Additional information regarding the selection of 
distribution types, including those not discussed in detail in the risk 
assessment, is contained in the addendum to the risk assessment that is 
available from the person listed under FOR FURTHER INFORMATION CONTACT.
    Comment: Some justification needs to be provided for the estimates 
in the risk assessment for situations in which some data are available. 
For example, APHIS acknowledges that field and laboratory research has 
been performed on fruit fly infestations in commercial citrus 
production, yet it does not specify how (or even if) this research was 
used to derive the fruit fly infestation distribution, beyond stating 
that the entomologists working on the risk assessment used their 
professional judgment. Neither risk assessment nor the rulemaking 
record contains any documentation of either the evidence used or the 
methodology used to codify that evidence as probability distributions.
    Response: Our knowledge of each of the insect pests and diseases, 
which, given the lack of directly applicable data in many cases, played 
an important role in the formulation of our estimates, is summarized in 
the pest data sheets contained in the risk assessment's appendices, and 
our sources of information are cited in each pest data sheet and in 
section III (References) of the risk assessment. Where direct 
information was available, that information was identified; the same 
holds true for the use of expert judgment in arriving at our estimates. 
The addendum to the risk assessment that is available from the person 
listed under FOR FURTHER INFORMATION CONTACT identifies, for each node, 
the direct information and expert information that was available and 
provides a discussion of how the available information was used in the 
construction of the distribution.
    With regard to the commenter's specific example, we had no direct 
evidence of what the past, present, or future fruit fly infestation 
levels may be in Argentina. But regardless of where citrus is produced, 
we are confident that our distribution, which was based on expert 
judgment informed by experience with fruit flies and by information 
gleaned from numerous cited sources, reflects the entire realm of 
possibilities. As stated in section 8.e P1 of the risk assessment:

    The minimum infestation rate used in the calculations was 
0.000535 (e.g., one infested lemon per 280,400 lemons). The maximum 
infestation rate sampled for calculations was 0.495 (e.g., half of 
all boxes or one infested grapefruit per every 100 grapefruit).

    Thus, because of our uncertainty, we used a distribution providing 
values representing infestation levels from where the pest is nearly 
nonexistent (one lemon out of 280,400) to an infestation level that 
would stop production (half of all boxes infested).
    Comment: The number of boxes of fruit that will be shipped to the 
United States from Argentina is estimated as 1.2 million 18-kg boxes of 
fruit per year. This information was provided by citrus industry 
representatives in Argentina. From this single piece of data, APHIS 
constructed a normal distribution with a mean of 1.2 million and a 
standard deviation of 200,000 to represent the frequency of citrus 
shipments each year. APHIS states that this distribution was

[[Page 37641]]

constructed to allow for variation in the frequency of shipments that 
might result from variations in production, the frequency of shipments 
cleared for export, and market demands in the United States. Quite 
apart from the question as to whether a year-to-year variability is the 
correct statistic to evaluate in this context, APHIS does not specify 
how it arrived at a standard deviation of 200,000--APHIS presents no 
evidence whatsoever, nor provides any methodology. It is certainly 
possible to provide a plausible methodology for obtaining some value 
for variability; for example, basing it on distributions for the U.S. 
importation of citrus fruit from other countries, or on distributions 
for other exports from Argentina, or even citrus exports to countries 
other than the United States. Moreover, this annual variability may not 
be required, and should certainly not be used in the risk assessment as 
APHIS has used it.
    Response: While it is true that this situation could have been 
analyzed in greater detail, conducting the suggested analysis would 
represent overinterpretation of available data. We believe that the 
suggested analysis would obscure the situation, provide a false sense 
of security, and probably lead to a less accurate estimate.
    In constructing this distribution, the expert group started with 
the point estimate of 1,200,000 boxes per year supplied by Argentina; 
the group then considered whether it was reasonable to assume central 
tendency. The group agreed that the point estimate from Argentina was 
the best available estimate, but that values both above and below 
1,200,000 were possible (i.e., the distribution should demonstrate 
central tendency around 1,200,000). The group discussed a variety of 
factors that could affect the number of boxes imported, e.g., variation 
in harvest, variation in U.S. demand, unanticipated costs of the export 
program leading to less interest by growers, unanticipated success from 
the exporters' point of view leading to greater interest by growers, 
etc. There were, however, no data available that would allow us to 
estimate the effects these factors would have on the number of boxes 
shipped. Thus, the standard deviation of 200,000 chosen by the expert 
group represents uncertainty and not, as the commenter suggests, 
variability per se, in the model. (As noted in a recent paper published 
in the journal Risk Analysis (Gray et al., 1998), ``[k]nowledge of 
variability must be based on empirical estimates, otherwise it is 
another source of uncertainty.'')
    With no information suggesting any particular distribution type, 
the group believed that a normal distribution was most reasonable 
(i.e., symmetrical uncertainty around the mean/mode/median). They 
agreed that although the actual number of boxes imported would almost 
certainly be other than exactly 1,200,000 per year, they had no 
legitimate reason to believe it would be higher as opposed to lower or 
vice versa, or what the year-to-year variability would be. Using the 
software package Risk View <SUP>TM</SUP> (Palisade Corp., Newfield, NY) 
and trial and error, the group specified the (standard deviation) value 
that provided what they considered to be appropriate positions for the 
5th and 95th percentile values in the distribution.
    Comment: In section 8.f. P1 of the risk assessment, APHIS 
identifies data for sweet orange scab and citrus black spot infection 
rates in Argentina. It claims that limited field surveys indicate that 
39 percent of sampled trees in control plots (untreated) bear fruit 
with evidence of sweet orange scab. The distribution constructed by 
APHIS for sweet orange scab infection is a beta distribution with a 
mean probability of 0.5 that a box of produce is infected. How is 
APHIS's distribution related to the infection rates in field surveys? 
Why does APHIS select a beta distribution to characterize this 
probability? How does APHIS arrive at the two parameters necessary to 
characterize the beta distribution? There is no information in the risk 
assessment or the rulemaking record to support the constructed 
distributions. Similarly, APHIS cites the results of field surveys for 
citrus black spot as finding 14 percent and 82 percent of sampled fruit 
infected with citrus black spot in 1994 and 1995, and 56 percent of 
sampled trees infected in 1996. APHIS goes on to say, ``Our expert 
information predicted that the incidence of citrus black spot, on a per 
box basis, in untreated groves would range from a minimum of 10 percent 
to a maximum of 100 percent with a most likely value of 50 percent.'' 
APHIS then proceeds to construct a beta distribution with a mean of 60 
percent and a mode (most likely value) of 67 percent. Again, there is 
no information in the rulemaking record or the risk assessment to 
indicate how this distribution incorporates either the results of the 
field surveys or the expert information.
    Response: As stated in the risk assessment document, ``our 
estimates * * * were based on limited field survey data provided by 
Argentina and expert information provided by scientists familiar with 
citrus production in Argentina and/or the pathogen.'' Because the field 
survey data were limited, our expert estimates of these probabilities, 
which were informed by the body of scientific knowledge cited in the 
references and summarized in the pest data sheets, reflected what we 
considered appropriate levels of uncertainty, and the distributions 
were derived to reflect those estimates.
    The experts relied on professional judgment to construct 
probability density functions that accurately represented their 
understanding of the available information. For both citrus black spot 
and sweet orange scab, the experts, after discussing available 
scientific and other information, identified the general shape of the 
distributions that were needed to account for all identified or assumed 
variation and uncertainty. In both cases, the experts agreed on a beta 
distribution, and discussions ensued to establish the parameters of the 
chosen distributions. The experts used an iterative process in 
conjunction with the software program Risk View <SUP>TM</SUP> (Palisade 
Corp., Newfield, NY) to provide instant feedback on the shape and 
statistics associated with any particular set of parameters. This was 
largely trial and error, and the experts succeeded in producing beta 
distributions that represented the group's understanding of the 
available information. The experts used a consensus approach. The 
distributions captured the full range of variability and uncertainty 
considered essential by all experts, even though they may have 
represented more uncertainty than was felt necessary by any single 
expert.
    Comment: The rulemaking record contains some information on the 
field surveys performed in Argentina, in the form of a very short 
summary of some results of those field surveys. However, the record 
omits crucial information required to interpret these summary results, 
including the protocols used for the field surveys; complete, written 
scientific documents describing the surveys and their results; and the 
contemporaneous field notes that should have been taken during the 
surveys. Despite this lack of information, we believe that APHIS' 
interpretation of the results is incorrect, as applied in its risk 
assessment. Adding up the results of the 1996 field results, in which 5 
fruit per tree were sampled from each of 300 randomly selected trees, 
gives:

[[Page 37642]]



------------------------------------------------------------------------
                             Number of trees (out of 300 in each case)
   Number of  infected   -----------------------------------------------
     fruit per tree        Sweet orange scab in    Citrus black spot in
                                  oranges                 lemons
------------------------------------------------------------------------
               0                      181                     133
               1                       95                      78
               2                       22                      46
               3                        2                      25
               4                        0                      15
               5                        0                       3
------------------------------------------------------------------------

    (For this analysis, we do not distinguish Elsinoe australis from 
Elsinoe fawcettii.)
    The incidence of infection (per fruit) was 9.67 percent for sweet 
orange scab in oranges and 21.3 percent for citrus black spot in 
lemons. APHIS apparently took the fraction of trees infected to be 
equal to the number of trees with observed infected fruit divided by 
the total number of trees (119/300=39.7 percent for sweet orange scab 
in oranges, 167/300=55.7 percent for citrus black spot in lemons). This 
is incorrect, however, since not all fruit on each tree were examined. 
It is clear that not all fruit are infected even on an infected tree, 
so sampling 5 fruit per tree will likely yield zero fruit infected from 
quite a few infected trees.
    A simple approach to analyzing these experimental data is to assume 
some probability for a tree to be infected, and then to assume that all 
the fruit on an infected tree have an equal probability for infection 
(while those on uninfected trees have zero probability for infection). 
For sweet orange scab in oranges, this leads to a best estimate for the 
fraction of trees infected of 97.7 percent, and the observations are 
entirely consistent with (and statistically indistinguishable from) 100 
percent infection. In that case, with 9.67 percent fruit infected, we 
would expect to see almost exactly the pattern of detections (per tree) 
actually observed (it is just a binomial distribution of infections). 
For citrus black spot in lemons, the best estimate for the fraction of 
trees infected is about 64 percent, with 33 percent of the fruit 
infected on an infected tree (note that 0.64  x  0.33=0.21, the 
observed fraction of fruit infected), using the same simple model.
    The simple model used here leads to binomial statistics, although 
it is clear in the case of citrus black spot that there is actually 
more variability than the binomial distribution would predict. It is 
not difficult to postulate a more plausible model with the higher 
variability expected because of differences between geographic areas, 
groves, or field conditions. Accurate evaluation of the variability 
requires more field data, and is required for an adequate scientific 
evaluation of the Argentine situation.
    Response: We acknowledged that the information we initially 
provided to this commenter did not reflect the entire body of data that 
was used to support the proposed rule. However, as we also noted, we 
did forward additional documentation to the commenter following the 
close of the comment period in response to the commenter's FOIA 
request. We understand that the commenter is reviewing that additional 
documentation, and we have stated our willingness to thoroughly 
consider, and address as appropriate, any new scientific information 
that comes to light as a result of that review that has a material and 
significant bearing on this rulemaking proceeding.
    With regard to the commenter's argument that APHIS' interpretation 
of the results was incorrect, there are several ways to interpret and 
use the data presented by the commenter to support his argument. 
However, we believe that the analysis suggested by the commenter is 
based on invalid assumptions. Specifically, although it would be 
inadvisable to ``assume some probability for a tree to be infected,'' 
it would be a critical error ``to assume that all the fruit on an 
infected tree have an equal probability for infection''; this is known 
to be false. That is why the five fruit were sampled from the area of 
the trees where infected fruit were most likely. It would also be an 
error to assume that on trees where none of the five sampled fruit were 
infected, all fruit were not infected. With a sample of five fruit, it 
was known that not all infected trees were identified. That is one of 
the reasons why even though infected fruit were found on only 39.7 
percent of the sampled trees, the mode and mean of our estimate (input 
distribution) was higher (50 percent). The commenter also does not 
account for the fact that our risk unit was a box of fruit, not an 
individual fruit or entire tree. This is discussed further in the 
response to the next comment.
    Comment: From the description in section 8.f P1 of the risk 
assessment, APHIS appears to believe that the fraction of boxes 
infected is in some simple way related to the fraction of trees 
infected, since the only discussion of the former immediately follows 
the estimate of the latter in such a way as to suggest such a 
connection. There is no other discussion in either the risk assessment 
or the rulemaking record, and the values adopted by APHIS are very 
similar. This is incorrect however. The final shipping boxes are not 
filled from individual trees, but in the packinghouse after processes 
that will substantially mix fruit from multiple trees. To a good 
approximation, fruit will be randomized during harvesting, storage, and 
the packing process, so that a given box will be packed with fruit from 
a random selection of trees. For sweet orange scab in oranges, the 
probability for no fruit in a box to be infected would thus be about 
(1-0.0967)<SUP>100</SUP> for 100 fruit per box, or 3.8  x  
10<SUP>-5</SUP> if the structure of APHIS's model were correct. That 
is, the probability for an infected box of oranges (i.e., a box 
containing one or more infected fruit) in the base case for sweet 
orange scab is about 99.9962 percent. For citrus black spot in lemons, 
a similar calculation shows that the probability for a box of lemons 
(150 per box) to be infected in the base case is about 1-2.5  x  10-16, 
which is 100 percent for all practical purposes, under the same 
assumptions. In fact, the structure of APHIS's model is not correct, so 
these calculations are somewhat awry. One cannot follow a ``box'' of 
fruit through from harvest to packing, since the box is not constructed 
until after many processes that operate on individual fruit 
(independent of which box they finally end up in) and may affect the 
probability of infection. Thus estimating probabilities ``per box'' at 
this stage is itself a futile exercise. A better approach is to 
evaluate on a ``per fruit'' basis throughout the risk assessment.
    Response: The commenter states that it is incorrect to believe that 
the fraction of boxes infected is in some simple way related to the 
fraction of trees infected. We agree that there is no way to go 
directly from a sample of trees (with a sample of fruit taken from each 
tree) to either a per-fruit or per-box estimate. However, we believe 
that the sample, which is indicative of the overall infection rate in 
the grove for the year in which the sample was taken, can be used as a 
starting point for an estimate of the per-box infection rate. That 
being said, our estimates were made with the knowledge that factors 
existed that argued for both (1) a lower per-box infection rate (i.e., 
not all fruit on a tree with infected fruit are infected) and (2) a 
higher grove infection rate (i.e., not all sampled trees with infected 
fruit tested positive). This is one of the reasons that even though 
sweet orange scab-infected fruit were found on 39.7 percent of the 
sampled trees, the mode and mean of our estimate was higher (50 
percent).
    As stated in the risk assessment, ``Our expert information 
predicted disease incidence, on a per box basis, to range from a 
minimum of 1 percent to a maximum of 90 percent with a most likely 
value of 50 percent.'' However, because of the uncertainty in the

[[Page 37643]]

information, and because of the uncertainty of the experts regarding 
the per-box infection rate, we specified a distribution that allowed 
values for infection rates across the entire range of probabilities 
from 0 through 1 (100 percent). For sweet orange scab, we characterized 
our baseline estimate for the likelihood harvested fruit was infected 
(P1) with a beta (3.5, 3.5) distribution (see Table 8 of the risk 
assessment). With this distribution, although the most likely value was 
50 percent, values up to and including 100 percent were possible. The 
maximum value actually used for calculations was 0.9773+, i.e., 97.7 
percent. We made our estimates according to international guidelines 
for plant pest risk assessments, which have been endorsed by the United 
States, and are consistent with common practice in risk assessment as 
reported by Hoffman and Kaplan (1999, see reference above). We used 
available data and professional judgment to represent the data in the 
terms needed for the risk assessment.
    With regard to our use of ``per-box'' probabilities, we have stated 
previously in this document that we believe that our selection of the 
box, rather than individual fruit, as the risk unit is appropriate. 
Once the fruit are packed, they are no longer independent of each 
other, and it is boxes, and not individual fruit, that will be 
shipped--to and, in all likelihood, remain in--specific destinations in 
the United States. Even though no one unit is perfect for each node, we 
decided that it would be most transparent, defensible, and correct to 
use a consistent risk unit throughout the model. The primary problem 
perceived with using individual fruit as the risk unit was the 
different size of the various fruit being considered (i.e., lemons, 
oranges, and grapefruit). Separate modeling for each type of fruit 
would have complicated the assessment significantly and needlessly; the 
expert group did not believe that separate modeling would improve the 
accuracy of the risk estimates, especially given the inherent 
uncertainties in the input parameters.
    Comment: For citrus black spot, some additional data are available 
from the earlier small field experiments described in the rulemaking 
record. However, these were not field surveys as claimed by APHIS in 
the risk assessment (for example, the sampled trees were not selected 
at random), but rather the control side of experiments apparently 
designed to examine the effectiveness of fungicides; again no 
protocols, scientific documentation, field notes, or analyses are 
included in the rulemaking record. These small samples showed incidence 
per fruit of 0/432, 0/432 and 41/216 (19 percent) for grapefruit, and 
36/252 (14 percent) and 207/252 (82 percent) for oranges. The first and 
last pairs of these samples were from the same plot in different years. 
The APHIS characterization of these surveys in the risk assessment 
omitted entirely the results in grapefruit. The results, although not 
field surveys, do illustrate the possibility of no observed infection 
even without fungicidal treatments, and the high variability from place 
to place and year to year.
    Response: As noted by the commenter, the data we used were obtained 
through experiments using treated and untreated control plots. It is 
also the case that the risk assessment did not explicitly cite the 
grapefruit data reviewed by the commenter (which is available in the 
additional documentation that may be obtained from the person listed 
under FOR FURTHER INFORMATION CONTACT). That being said, it is clear 
from the available information that citrus black spot, as is the case 
with many diseases, is more prevalent in some years than in others. For 
this reason it is entirely possible that in some years no infection 
would be observed even if fungicides were not applied. The disease can 
be variable from place to place and year to year. This fact is not 
relevant to the efficacy of the systems approach, which is designed to 
mitigate the risk during years in which disease is likely.
    Comment: In the risk assessment, APHIS makes estimates for the 
probability of infection when the mitigation measures are taken. There 
is some confusion over the precise meaning assigned to the various 
mitigation measures that may substantially affect infection 
probabilities. Although APHIS does not provide any indication of its 
approach (either citation or methodology) for estimating post-
mitigation infection probabilities, simple analyses of the Argentine 
data on citrus black spot suppression by copper oxychloride treatment 
are possible, as shown in the following example.
    In those experiments, assume that the probability for a control 
(untreated) fruit to be infected is p (different in each experiment and 
from season to season), and that treatment with one application of 
copper oxychloride multiplies that probability by a factor R (different 
for each treatment type, and hopefully less than unity, to have an 
effective treatment), with two applications reducing it by 
R<INF>2</INF> (one could, and should, test this latter assumption). 
Assume binomial responses (e.g., because all fruit are equally likely 
to be infected, and treatment is equally effective on all fruit), and 
use binomial likelihood methods. We can then estimate p and R from the 
available data, together with the uncertainty on R, if desired. For 
grapefruit, two of the three available experiments show no responses at 
all, so they are useless for estimation of R. For oranges, we could 
test whether two applications really reduced the incidence equally in 
each application; inspection of the data shows that this is certainly 
plausible.
    Applying this simple model to the single useful experiment on 
grapefruit gives a maximum likelihood estimate (MLE) for R of 1.15 for 
the 1.8 percent treatment, and 0.31 for the 3.6 percent treatment. Thus 
two applications of 3.6 percent might reduce the rate 10-fold and three 
applications 33-fold. However, the uncertainty is large. This 
experiment shows no effect of the 1.8 percent treatment.
    For oranges, the MLE for R is 0.22 for 1.8 percent and 0.20 for 3.6 
percent, so that two applications of 3.6 percent might reduce the 
infection rate 24-fold, and three applications 118-fold. Notice that a 
24-fold reduction from the control group rate of 36/252 is entirely 
consistent with the observed 0/252 in the 93-94 season when two 
applications were made.
    Such analyses could be extended in various ways. For example, in 
this model the R values for 1.8 percent are significantly different for 
grapefruit and oranges, but for 3.6 percent they are not significantly 
different. The MLE for the combined value (for 3.6 percent) is 0.25, so 
that the model prediction for two applications is a 16-fold reduction 
in disease rate, and for three applications a 128-fold reduction. With 
so few experiments, and none available for analysis with three 
applications (versus one and two), one cannot test the model hypothesis 
that each application simply reduces the disease rate by a similar 
amount. Apparently, more experiments were in fact performed, but the 
rulemaking record reports only summary results that cannot be 
interpreted without much more information.
    This analysis indicates the paucity of the data available in the 
rulemaking record. For grapefruit, the one available experiment on the 
effectiveness on citrus black spot of 1.8 percent copper oxychloride 
treatment shows it to be ineffective, although it is almost as 
effective as 3.6 percent on citrus black spot on oranges.
    Response: The commenter offers an alternative way to consider the 
estimated efficacy of mitigation

[[Page 37644]]

treatments. However, the approach is complex and highly speculative, 
and in our estimation represents an overinterpretation of available 
data, which, as the commenter notes and we acknowledged in the risk 
assessment, were limited. Copper oxychloride is a well established 
treatment for citrus black spot and sweet orange scab. Our estimates 
concerning the efficacy of these mitigation treatments are based on 
expert interpretation of results that have been obtained in a variety 
of studies on the control of these diseases (for example, as referenced 
in Whiteside et al., 1988, as cited in the risk assessment).
    Comment: Only one experiment reported in the rulemaking record 
addresses the effectiveness of copper oxychloride treatment on citrus 
black spot in lemons. While it apparently showed that the treatment was 
effective, there were no details on the protocols adopted 
(concentrations, number of applications, experimental procedures, and 
so forth), although a naive calculation indicates that the incidence 
was reduced more than 100-fold (approximately 95 percent confidence 
limit). In another document there are two figures labeled ``Chemical 
control (Santa Clara-Jujuy),'' apparently for treatments in the 1993-94 
and 1994-95 seasons, that appear to correspond to suppression of citrus 
black spot in Eureka lemons, but there is no explanation of the origin 
of the data used in those two figures. APHIS should identify which 
treatments were applied in the tested groves and describe the level of 
disease in the region near the tested groves. Similarly, the 
effectiveness of copper oxychloride treatment for sweet orange scab is 
only demonstrated in one experiment (on oranges) in the rulemaking 
record, but the experimental protocols are not reported (number of 
treatments, concentrations, application rates, experimental procedures, 
and so forth). It is possible that some of this mitigating effect may 
be due to other simultaneous measures, such as cleaning of the orchard 
floors; however, in the absence of experimental protocols, this cannot 
be determined. Moreover, the available evidence is insufficient to 
adequately characterize that effect. For a defensible estimate of the 
effect of copper oxychloride treatments on citrus black spot and sweet 
orange scab, APHIS must have experimental data demonstrating its 
effectiveness under varying conditions, in different areas, and for 
different fruit. Furthermore, APHIS must provide details of its 
analyses demonstrating effectiveness, and must show the connection 
between the experimental data and the distribution used in the risk 
assessment.
    Response: As we have recognized in numerous instances in this 
document, there is not always a one-to-one correlation between the 
experimental data, which is limited in some cases, and the 
distributions used in the risk assessment. In this case, our estimates 
on the effectiveness of the copper oxychloride treatment, which is the 
treatment that was applied in the tested groves, are derived not solely 
from evidence supplied by Argentina but also from reports in the 
scientific literature (e.g., as reported by Whiteside et al., 1988, 
cited in the risk assessment). These reports represent results that 
demonstrate the effectiveness of copper oxychloride in reducing disease 
incidence under varying conditions, in different areas, and for 
different fruit, even in areas where the level of disease is high.
    Comment: The risk assessment (8.f. P4) states that it is assumed in 
the baseline that the fruit ``treatments may include, but are not 
limited to, washing fruit in a detergent bath, waxing and fungicide 
dips.'' It is not clear how much more extensive the proposed treatment 
program is, since the proposed treatment program could be described in 
exactly the same fashion as the baseline (although washing in detergent 
is not prescribed). The risk assessment (8.f. P4) also states that 
``the only post-harvest treatment for pathogens that is specifically 
prescribed in the proposed export program is a fruit dip in 200 ppm 
sodium hypochlorite (bleach) for 2 minutes.'' Actually, the preamble 
and proposed rule prescribe other specific treatments (immersion in 
orthophenilphenate of sodium, spray with imidazole, and application of 
2-4 thiazalil benzimidazole and wax) that are specifically for 
treatment for pathogens (although this may depend on one's definition 
of ``pathogen'' in this context).
    Response: The fact that the proposed treatment program examined in 
the risk assessment did not take into account the other specific 
treatments (immersion in orthophenilphenate of sodium, spray with 
imidazole, and application of 2-4 thiazalil benzimidazole and wax) that 
were described in the proposed rule and required by this rule can be 
attributed to the fact that the risk assessment was completed before 
the proposed rule was fully developed. However, it is clear that 
considering those treatments in the mitigated scenario in section 8.f. 
P4 of the risk assessment would have resulted in a higher risk 
reduction rating for the post-harvest mitigations, thus lowering the 
overall risk, which we already considered to be very low.
    Comment: APHIS's assumptions that sweet orange scab-infected fruit 
is removed with 89 percent probability at harvest (mean value for both 
baseline and mitigation program), while citrus black spot-infected 
fruit is removed at harvest with mean 50 percent probability (baseline) 
and 89 percent probability (mitigation program), cannot be supported by 
any available evidence. We see three problems with this assumption:
    <bullet> The incidence data used to support this are largely, if 
not totally, post-harvest incidences for latent disease, not field-
apparent incidence of disease in unharvested fruit. Any probability for 
detection during harvesting is apparently already incorporated in such 
values.
    <bullet> APHIS has assumed that pickers in Argentina make an 
attempt to cull blemished/diseased fruit, but our information indicates 
that pickers in Argentina do not cull fruit; rather all picked fruit is 
sent to the packinghouse for sorting there.
    The entire object of chemical and other treatment is suppression of 
disease. The disease infections in the export groves should be latent 
at the time of picking, as evidenced by the data provided by the 
Argentines, so that there is no visible evidence of disease in 
harvested fruit. It should therefore be physically impossible for the 
pickers to detect latent disease.
    With a reduced incidence at harvest, in the case of citrus black 
spot probably of entirely latent infections, there is no evidence that 
infected fruit is more likely to be removed by harvesters. At minimum, 
APHIS needs to document harvesting practices and obtain experimental 
evidence for removal probabilities at harvest. Such experiments would 
be very straightforward, since they simply involve random sampling of 
unharvested trees followed by sampling of fruit harvested in the normal 
course of events (and preferably also of the fruit, if any, that is 
culled by the harvesters). These should have been incorporated in 
experimental protocols at an early stage of experiment planning.
    Response: The commenter states that we used incidence data to 
support our estimates regarding the removal of diseased fruit in P2, 
``Pathogen not detected at harvest.'' This statement is incorrect. 
While data on disease incidence did affect our estimates for the 
likelihood that fruit are diseased in P1, ``Harvested fruit is 
infected,'' we indicated in the risk assessment (section 8.f P2, p.36-
38) that our estimates for P2

[[Page 37645]]

were based on a variety of factors, including ``the nature of the 
disease symptoms, the skill of the picker in recognizing diseased fruit 
and the quality standards employed by a given grove in culling diseased 
fruit.'' Because sweet orange scab symptoms are easily seen during 
harvest, our estimates were based on a higher (compared to citrus black 
spot) degree of confidence that sweet orange scab-infected fruit will 
be identified and removed at harvest. The commenter also states that 
the ``entire object of chemical and other treatment is suppression of 
disease.'' This statement, which we understand to be referring to 
citrus black spot, is also incorrect. As we have stated elsewhere, the 
object of the field treatments is the prevention of the disease, and 
not merely the suppression of symptoms. Latent infections of citrus 
black spot would not be observed, which is why our baseline estimate 
that this disease will be missed is higher. However, the systems 
approach will reduce the likelihood of latent infections, thus 
decreasing the likelihood that diseased fruit will be missed.
    Comment: APHIS provides estimates for the probability of detection 
of sweet orange scab and citrus black spot at packinghouse inspection. 
Again, no evidence is provided to support its estimates of 82 percent 
(mean: baseline) and 95 percent (mean: mitigation program) probability 
of detection of sweet orange scab, or with 74 percent (mean: baseline) 
and 95 percent (mean: mitigation program) probability of detection of 
citrus black spot. Factored into these estimates, according to APHIS, 
was the 20-day preharvest sampling and incubation of a small fraction 
of fruit.
    The very existence of the 20-day preharvest sampling and incubation 
program ensures that the detection probability at this stage is 
correlated with the incidence of citrus black spot or sweet orange 
scab, since the detection probability is higher for higher incidences. 
Thus, the structure of the risk assessment model is incorrect. It is 
important also to note that the detection probability is correlated 
with the actual incidence, not with the probability of citrus black 
spot or sweet orange scab. The structure of the model has to be 
adjusted to account for this. In a Monte Carlo analysis, for example, 
the simplest way is to ensure that the detection probability at this 
stage depends correctly on the incidence in the particular Monte Carlo 
sample.
    APHIS provides no documented evidence for the effectiveness of 
packinghouse inspections in either the risk assessment or the 
rulemaking record. The Argentines provided experimental data on the 
effectiveness of ``post-harvest treatments'' or ``post-harvest assays'' 
that presumably assessed all events occurring at the packinghouse, but 
again, because of the failure to provide protocols, experimental 
details, scientific reports, and field notes in the risk assessment or 
elsewhere, we cannot decipher what ``post-harvest treatments'' or 
``post-harvest assays'' means. We believe that all the ``post-harvest 
treatments'' or ``post-harvest assays,'' perhaps including any 
inspections, have essentially no effect on the incidence of latent 
infections of citrus black spot. Should it be necessary to evaluate the 
effect of packinghouse inspection, as distinct from further 
packinghouse treatment, the experimental procedure would be 
straightforward, since all that is required is sampling of fruit prior 
to and after such inspection (and preferably, also, sampling of 
rejected fruit).
    Response: The commenter's statement that ``The very existence of 
the 20-day preharvest sampling and incubation program ensures that the 
detection probability at this stage is correlated with the incidence of 
citrus black spot or sweet orange scab, since the detection probability 
is higher for higher incidences'' is incorrect. The packinghouse 
inspection and our estimates regarding the likelihood of detecting 
pests during this inspection are independent of both the 20-day 
preharvest sampling protocol and the results of that sampling. If any 
disease is detected as a result of the 20-day preharvest sampling, none 
of the fruit from that grove can be shipped to the United States. The 
only fruit that will be inspected and subsequently shipped to the 
United States are fruit from groves where the 20-day preharvest 
sampling resulted in a finding of no disease. The 20-day preharvest 
sampling that would be conducted to detect the presence of citrus black 
spot in the grove was accounted for in the risk model in P1, the 
likelihood that harvested fruit is infected. This sample must be taken 
from all groves that would ship fruit to the United States.
    The commenter's statement that ``[i]t is important also to note 
that the detection probability is correlated with the actual incidence, 
not with the probability of citrus black spot or sweet orange scab'' is 
likewise incorrect. The likelihood that diseased fruit will be detected 
during packing is not related to disease incidence. Although the number 
of times that diseased fruit are detected is related to disease 
incidence (i.e., more disease, more detections), the likelihood that 
diseased fruit will be detected is not correlated with disease 
incidence.
    In stating ``APHIS provides no documented evidence for the 
effectiveness of packinghouse inspections in either the risk assessment 
or the rulemaking record,'' the commenter is correct. These 
packinghouse inspections have not yet been conducted. Our estimates are 
based on examinations of citrus packinghouses in Argentina, experience 
with inspections and culling in citrus packing operations, direct 
knowledge of the etiology of these diseases, and familiarity with the 
symptoms of these diseases.
    Comment: APHIS estimates the effect of post-harvest treatments on 
citrus black spot survival (on a per-box basis, which itself may not be 
appropriate) as giving a mean survival of 0.64 in the baseline 
situation, and a mean of 0.50 under the mitigation program. APHIS 
appears to have ignored the results of experiments apparently designed 
to test the effects of post-harvest treatments. Since APHIS does not 
document how it arrived at its estimates, it is impossible to tell 
whether it examined these data. There are no APHIS analyses of the data 
in the risk assessment or the rulemaking record, but the assumptions in 
the risk assessment for probability distributions appear to be 
contradicted by these data.
    Response: The ``results of experiments'' referred to by the 
commenter are found in Argentine document Nota S.P. No. 338, which 
contains a summary of experiments to test the efficacy of post-harvest 
treatments on citrus black spot. Our analysis of that document 
indicates that the treatment effects were variable; compared to 
untreated controls, the proportion of treated fruit that developed 
black spot disease ranged from 30 to 100 percent. The primary 
difference between the treatments Argentina will use as part of its 
regular program (what we refer to as the baseline risk) and the 
treatments it will use as part of the program for exporting fruit to 
the United States (the proposed treatment program) is the sodium 
hypochlorite treatment. We did not ignore the results of the Argentine 
experiments, as the commenter asserts; rather, we believed that it 
would not be appropriate to assume that the difference in efficacy 
shown in the experiments, which compared treated to untreated fruit, 
would be the same as the difference in efficacy between the baseline 
scenario and the mitigation scenario examined in the risk assessment. 
This is because most of the treatments applied in the experiments cited 
by the commenter were,

[[Page 37646]]

appropriately, considered in the risk assessment's examination of the 
baseline risk, as those treatments are routinely applied by citrus 
producers in Argentina as part of their regular program. Therefore, as 
documented in the risk assessment (8.f P4), our estimates for the 
mitigated scenario focused on the degree of additional risk reduction 
offered by the sodium hypochlorite treatment, which we assumed would 
have an additional deleterious effect on the survival of the citrus 
black spot fungus. The increased level of efficacy of the mitigation 
program is modest, a probability of 0.50 that the fungus will survive 
treatment as opposed to a probability of 0.64 in the baseline scenario. 
The primary purpose of these treatments is to reduce post-harvest 
spoiling, not kill fungus diseases, and the main effect of the chlorine 
dip is to kill spores on the surface of the fruit.
    Comment: Since there is no information in the rulemaking record on 
the protocols for the experiments on the effectiveness of post-harvest 
treatments, nor any scientific documentation, we have to make some 
plausible assumptions in order to perform the simplest analysis. Assume 
that each experiment measures the disease rate in control and treated 
fruit, with the disease rate possibly differing in all the replicates 
of all the experiments. Assume that the post-harvest treatment alters 
the disease rate in the corresponding control by a fixed factor Q (by 
inspection, there is little difference within any set of replicate 
experiments; while one could and should formally test for equality, our 
simple analysis will forgo that testing for the sake of brevity). 
Assume that the same factor Q applies to all the experiments on a given 
fruit (again, this could and should be formally tested). Assume 
binomial distributions for infection, as would occur if the fruit were 
randomly chosen. Then the maximum likelihood estimates for Q are: 0.71 
(grapefruit), 1.16 (orange), and 0.92 (lemon).
    It should be noted that for this analysis, we have assumed that the 
detailed tables included in the rulemaking record and largely 
corresponding to the summaries provided by Argentina in Note S.P. 338, 
Annex III, are correct, and we have treated discarded fruit as though 
they were diseased. There are significant differences between those 
tables and the summaries presented by Argentina in Annex III in the 
descriptions of the number of fruit examined, and one table (Orange, 
Third Replicate) has the control and T2 groups transposed for all 
observations Rl, R2, R3, and R4. Once again, we are hindered by the 
absence of protocols, scientific documentation, and field notes from 
the rulemaking record. For example, whether discarded fruit should be 
analyzed as though infected depends on experimental details that are 
not presented within the rulemaking record, and even the summary tables 
in the record are inconsistent in their treatment of such discards. 
There are no comments by APHIS in either the risk assessment or the 
rulemaking record on these significant discrepancies.
    These experimental results indicate that the post-harvest 
treatments have little, if any, effect on latent infections of citrus 
black spot. It would be possible to find confidence limits and test for 
equality of effect, but the effort would be wasted given the tiny 
number of experimental conditions, and the likelihood for variation 
(beyond the assumed binomial randomness) with field conditions, fruit, 
and possibly experimental conditions. The results do, however, throw 
considerable doubt on the values used for Q in the risk assessment for 
citrus black spot (0.64, range 0.4 to 0.85).
    Response: In this comment, the commenter states in several places 
that there is no information in the rulemaking record on the protocols 
for the experiments on the effectiveness of post-harvest treatments for 
citrus black spot. In fact, the Argentine document to which the 
commenter refers, Note S.P. 338, states that ``[t]he results that 
appear in Annex III are the results of the assays that were carried out 
applying the methodology informed [sic] to APHIS in the `Protocol of 
Assays to Evaluate the Effectiveness of the Post-Harvest Treatments for 
the Control of Guignardia citricarpa in Citrus Produced in the North-
West of Argentina (NOA)' * *  *.'' That document, which is actually 
titled ``Assays to Test Effectiveness of the Postharvest Treatment for 
the Control of Guignardia citricarpa in Citrus Fresh Fruit Produced in 
Argentine Northwest Region (NOA),'' was provided to the commenter 
following the close of the comment period and is included in the 
material provided in the addendum to the risk assessment that may be 
obtained from the person listed under FOR FURTHER INFORMATION CONTACT.
    In discussing discrepancies that he believes exist among varies 
documents in the record, the commenter first states that the ``detailed 
tables,'' which are not identified in the comment, ``largely'' 
correspond to the summaries in Annex III of Note S.P. 338, and then 
states in the next sentence that there are ``significant differences'' 
between those tables and the summaries in Annex III. Without specific 
information as to where the differences occur, we are unable to provide 
the commenter with any clarification regarding possible discrepancies.
    The commenter concludes, as a result of the simple analysis set 
forth in his comment, ``that the post-harvest treatments have little, 
if any, effect on latent infections of citrus black spot.'' We 
acknowledged this in the risk assessment and recognized that the 
primary purpose of these treatments is to reduce post-harvest spoiling, 
not kill fungus diseases, and the main effect of the chlorine dip is to 
kill spores on the surface of the fruit. The expert information used in 
the risk assessment reflected the variability of the treatment data and 
the experts' uncertainty around those data. While assuming that the 
fungicidal and chlorine dips would have a deleterious effect on the 
viability of Guignardia citricarpa propagules, the experts recognized 
the latent nature of black spot infections. The germinating fungal 
spore forms an appressorium from which an infection peg penetrates the 
cuticle, and mycelium grows in between the cuticle and the epidermis 
where it may remain quiescent (Whiteside, 1988) and effectively 
protected from fungicidal treatments. However, the form in which the 
fungus remains after treatment (i.e., mycelium) can hardly be 
considered infective (McOnie, 1967). The experts predicted that between 
10 and 90 percent of infected boxes would survive post-harvest 
treatment with a most likely value of 50 percent.
    In our response to the previous comment, we discussed the data 
provided by Argentina on this subject and our analysis and 
interpretation of those data. As we noted in that response, we assumed 
that the addition of the sodium hypochlorite dip to the baseline post-
harvest treatments would have an additional deleterious effect on the 
survival of the citrus black spot fungus, but that the increased level 
of efficacy would be modest, reducing our estimate of the probability 
that the fungus will survive treatment from 0.64 (baseline) to 0.50 
(mitigated).
    Comment: For sweet orange scab, APHIS admits to having no efficacy 
data for the post-harvest treatments and provides no documentation of 
its method of reaching the values used in the risk assessment. 
Comparison with the citrus black spot case, where some data are 
available, leaves considerable doubt as to the adequacy of APHIS's 
methodology. In any case, it would be relatively straightforward to 
perform

[[Page 37647]]

efficacy studies using methodology similar to that used on citrus black 
spot, and there is no indication of why such studies have not been 
performed for sweet orange scab.
    Response: As noted by the commenter and in the risk assessment, no 
specific sweet orange scab efficacy data were available for the 
fungicidal activity of any of the individual post-harvest treatments 
that might be employed in the proposed export program. The incidence of 
sweet orange scab in a test sample of fruit subjected to the entire 
preharvest, harvest, and post-harvest export program was described in 
Argentine document 450/96 (September 30, 1996). In this survey, 300 
boxes of fruit were randomly chosen from a larger lot that had been 
subjected to the conditions of the export program. Ten fruit were 
collected from each of the 300 boxes and visually inspected for 
symptoms of sweet orange scab. None of the 3,000 total fruit examined 
expressed disease symptoms. However, the survey did not include 
controls and its design did not allow for the separation of the effects 
of field treatments, inspections, or post-harvest treatments. The data 
provided by this survey were nonetheless useful in illustrating the 
effectiveness of the measures required by the export program and, when 
combined with the considerations discussed in the next paragraph, led 
us to conclude that additional studies such as those suggested by the 
commenter would not be necessary for the purposes of our risk 
assessment.
    As we have noted elsewhere in this document and in the risk 
assessment, the only additional post-harvest treatment specifically 
required by the proposed export program (compared to the baseline) is 
the sodium hypochlorite dip. We assumed that the sodium hypochlorite 
dip--a treatment with widely recognized antifungal efficacy--would 
further reduce the survival rate of the sweet orange scab pathogen. An 
important consideration taken into account by our experts is the fact 
that, unlike citrus black spot, sweet orange scab lesions are erumpent 
and exposed on the surface of the rind. Thus, our experts believed that 
the sodium hypochlorite dip, along with the fungicidal treatments found 
in both the baseline program and the proposed export program, would be 
effective in killing any viable conidia on the surface of a pustule or 
contaminating the rind of fruit and may have some minor effect on sweet 
orange scab stomatic tissue.
    Comment: For citrus canker, APHIS cites literature efficacy studies 
on the effect of chlorine dips. However, the method by which 
probability distributions were assigned from this literature is 
undocumented.
    Response: The chlorine dip was only one factor considered when 
estimating the appropriate value for model inputs for this node (P4). 
The efficacy data on chlorine dips were considered along with other 
data and information, as cited on p.39 of the risk assessment:

    These treatments may include, but are not limited to, washing 
fruit in a detergent bath, waxing and fungicide dips. The only post-
harvest treatment for pathogens that is specifically prescribed in 
the proposed export program is a fruit dip in 200 ppm sodium 
hypochlorite (bleach) for 2 minutes.

    The probability distribution resulted from the expert judgment of a 
group of three plant pathologists familiar with treatment of commercial 
fruit for export, after consideration of all pertinent, available 
information. References for that information were provided in the risk 
assessment.
    Comment: The proposed rule calls for testing 320 fruit/200 ha, 
according to SENASA's randomized sampling protocol, a protocol that is 
not described in the proposed rule or the risk assessment. We believe 
that the presence of such a testing procedure alters the structure of 
the model that must be used for the risk assessment. It also appears 
that such a testing procedure is designed to fail--we believe that 
fruit with a startlingly high infection rate could pass through such a 
screen.
    From the information provided in the rulemaking record, total 
citrus production in northwestern Argentina appears to have been about 
20 tons/ha in 1989, indicating yields similar to those in California 
and Florida (20-40 tons/ha). The tree planting densities also appear 
similar (200 to 250 trees/ha). Thus, for lemons, at 150 fruit per 18-kg 
box (as assumed in the risk assessment), the lemon yield will be about 
170,000 to 340,000 per ha, and the total area required to produce the 
1,200,000 boxes examined in the risk assessment will be about 600 to 
1,000 ha.
    For the sake of argument, assume that Argentina sets up 20 groves 
each of 100 ha as potential U.S. export groves, and follows all the 
procedures of the proposed rule (and note that this is, at first sight, 
about twice the required area). A 100 ha grove might have a buffer zone 
of 69 ha, so that the total area of the grove plus buffer would be 169 
ha, calling for a sample of 270 fruit per grove+buffer (assuming that 
the buffer has to be sampled, but that is ambiguous in the proposed 
rule).
    Now suppose that all the fruit from all the proposed U.S. export 
groves are infected at a rate of 1 in 400 fruit (0.25 percent), which 
is fairly high, just 100 to 400 times lower than the unmitigated rate. 
The probability for no infected fruit in a random sample of 270 fruit 
is (1-0.0025)<SUP>270</SUP> = 0.5. Thus one could expect about 10 of 
the 20 groves to pass this test, providing the necessary area of 1,000 
ha, while the other 10 groves would be removed from the export program 
for this season. The next season, the same thing might happen, but with 
a different (random) set of 10 or so groves excluded, and 10 or so 
included. Examination of this scenario and its extensions shows that 
with suitable subdivision of the potential U.S. export acreage into 
groves, and acceptance that some groves each year will be randomly 
removed from the program, almost any infection rate in the fruit is 
possible under the sampling scheme suggested. That is, the sampling 
scheme is not effective at controlling the allowable infection rate.
    There is no need to postulate a deliberate effort to outwit the 
sampling scheme. It might prove economically advantageous for the 
citrus-producing region of northwestern Argentina to adopt all the 
procedures of the proposed rule for the entire citrus producing region, 
since such procedures may produce superior yields for many markets, not 
just the United States. Only a very small fraction of groves would have 
to meet the testing requirements to generate the suggested export 
volumes; and with the proposed sampling approach, these are likely to 
occur randomly even if the infection rates are higher than the 1-in-400 
fruit of the preceding example. It would be straightforward to design 
statistically adequate sampling and testing regimes to ensure that the 
overall infection rate of fruit from any grove is below any required 
value, and such schemes can be extended to account for nonuniform 
infection rates between groves, and even infection rates that vary 
within each grove, but there is no evidence in the record of any such 
attempt.
    Response: We disagree with the commenter's statement that a testing 
procedure that calls for a certain number of fruit to be collected from 
a defined area ``alters the structure of the model that must be used 
for the risk assessment.'' If the model we used in the risk assessment 
was a scenario tree model with branches that were based in some way on 
the outcome of the sampling, then the sampling protocol might have an 
impact on the structure of that model. In simple terms, the outcome of 
the sampling determines whether the fruit produced in an export grove 
will be considered in the export program, since the detection of 
disease

[[Page 37648]]

in a grove or buffer area as a result of the sampling will result in 
the elimination of the grove and the fruit it produces from the export 
program. Thus, the nature of the sampling protocol used for the export 
program does not affect the structure of the model because the sampling 
is outside the scope of the model; the risk model deals only with fruit 
from groves that have been cleared for participation in the program.
    In response to the comments regarding this sampling protocol, we 
are modifying the protocol for the 20-day preharvest sample and 
clarifying the basis and details of the sampling. The sampling protocol 
will be based on a statistically valid hypergeometric distribution. The 
``lot size,'' or population size, is equal to the number of trees in 
the grove and buffer area. We will set our desired level of detection 
as follows: We will sample enough trees to have a confidence level of 
at least 95 percent of detecting an infection rate of 1 percent or more 
of the trees. In preparing this protocol, we have assumed that there 
will be 250 trees per hectare, and we have assumed a maximum grove/
buffer area size of 800 hectares based on our available information. 
Given those two assumptions, we will require that 298 trees be sampled 
from each grove and buffer area (if an area to be sampled exceeds 800 
hectares, this rule provides that SENASA will contact APHIS, and APHIS 
will determine the number of trees to be sampled). The 298 trees must 
be selected at random. In order to increase the likelihood of detecting 
disease, the fruit must be sampled from portions of the trees that are 
mostly likely to have infected, symptomatic fruit (i.e. near the outer, 
upper part of the canopy on the sides of the tree that receive the most 
sunlight). We have set the number of fruit to be sampled from each tree 
(number of replicates) at four fruit per tree.
    Sampling 4 fruit from each of 298 trees will yield a sample size of 
1,192 fruit, which is somewhat less than what would result from 
sampling 800 hectares at the rate called for in the proposed rule (320 
fruit from each 200 hectares, i.e., 1,280 fruit). However, given that 
this new sampling protocol is based on a statistically valid 
hypergeometric distribution, we believe that it provides the 
``statistically adequate'' sampling regime called for by the commenter 
and, given its random selection of trees and focus on collecting fruit 
from those parts of the tree most likely to contain infected fruit, 
will, as suggested by the commenter, ``account for nonuniform infection 
rates between groves, and even infection rates that vary within each 
grove.''
    This sampling protocol will provide information regarding the 
disease status of farms wishing to be included in the program to export 
citrus fruit to the United States. Our risk model focuses on the risk 
to the United States of imported citrus fruit from farms in Argentina 
that are part of the official export program, i.e., farms that have 
already been certified for export to the United States. There are 
numerous risk mitigation measures in place, both as part of the regular 
risk mitigation program and the various special requirements of the 
U.S. export program. We believe that the testing and inspections 
required by this rule will ensure that fruit with a startlingly high 
infection rate does not enter the United States.
    Comment: The sampling of 320 fruit per 200 hectares shortly before 
harvest is an utterly insufficient sample size to be assured of 
detecting the presence of citrus black spot or sweet orange scab:
    <bullet> At an 8 m  x  5 m planting density, there would be 50,000 
trees/200 hectares; if 320 fruit are sampled, then 0.64 percent of all 
the trees would be sampled. If one assumes only 250 fruit are harvested 
per tree, then 0.00256 percent of the harvested fruit is sampled.
    <bullet> At a 10 m  x  5 m planting density, there would be 40,000 
trees/200 hectares; if 320 fruit are sampled, then 0.8 percent of all 
the trees would be sampled. If one assumes only 250 fruit are harvested 
per tree, then 0.0032 percent of the harvested fruit is sampled.

This sampling size is especially inadequate when one considers that 
disease incidence will be low due to the fungicide treatments. Further, 
the ability of a sampling program to detect, for example, citrus black 
spot, may depend upon the location of the trees sampled within the 
grove, the location of the samples on those trees, the age of the 
trees, etc. Sample size should be based on biometric principles that 
consider the characteristics of the disease, the incidence, and the 
level of precision desired to detect any present infections. APHIS 
should explain why the 320 fruit/200 hectares sample size was chosen 
and why it is appropriate for the desired purpose.
    Response: As explained in the response to the previous comment, the 
sampling protocol has been modified in this final rule to provide a 
statistically valid hypergeometric distribution that will provide for 
the sampling of enough trees to have a 95 percent confidence level of 
detecting an infection rate of 1 percent or more of the trees, and we 
have provided for four replicates per tree. The sampling system 
described in the proposed rule was the protocol offered by Argentina 
and was designed to be consistent with Argentina's existing monitoring 
system for citrus canker, which was based on a transect design.
    Comment: The probabilistic estimation for ``pathogen not detected 
at packinghouse inspection'' relies here on the results of the 20-day 
preharvest sampling results. But, this sampling consists of random 
collection of fruit at a rate of 320 fruit from each 200 hectares 
surveyed. No information on the statistical or biometrical validity of 
this sampling protocol is provided in the pest risk assessment or the 
proposed rule. Without this information, it is impossible to evaluate 
its impact as a safeguarding element, particularly as it relates to the 
mitigation scenario estimation.
    Response: As discussed in the responses to the previous comments, 
we have modified the sampling protocol that will be used to collect the 
fruit that will be subjected to laboratory analysis. Also, the 
commenter inaccurately states that ``the probabilistic estimation for 
`pathogen not detected at packinghouse inspection' relies here on the 
results of the 20-day preharvest sampling results.'' We understand, 
however, how the reader could reach that conclusion based on our 
statements on p. 38 in section 8.f P3 of the risk assessment, which may 
have given a false impression. To clarify, the packinghouse inspection, 
and our estimates regarding the likelihood of detecting pests during 
this inspection, are independent of both the 20-day preharvest sampling 
protocol and the results of that sampling. If any disease is detected 
as a result of the 20-day preharvest sampling, none of the fruit from 
that grove can be shipped to the United States. The only fruit that 
will be inspected and subsequently shipped to the United States are 
fruit from groves where the 20-day preharvest sampling resulted in a 
finding of no disease. The 20-day preharvest sampling, which would be 
conducted to detect the presence of citrus black spot in the grove and 
buffer area, was accounted for in the risk model in P1, the likelihood 
that harvested fruit is infected. Upon reconsideration, our estimates 
for this node should probably be considerably lower, given the rigor of 
the 20-day preharvest sample. This sample must be taken from all groves 
that ship fruit to the United States.

[[Page 37649]]

    Comment: Because we recognize that it is not practical to hold all 
harvested fruit for up to 3 weeks to detect latent symptoms, we suggest 
that the number of fruit examined in the 20-day preharvest sample be 
increased by at least tenfold to reduce the risk of disease 
introduction.
    Response: Because the sampling protocol required by this rule will 
provide for the sampling of enough trees to have a 95 percent 
confidence level of detecting an infection rate of 1 percent or more of 
the trees, and because the sampling protocol requires four fruit to be 
selected from each tree, with those fruit being chosen from the portion 
of the tree most likely to have infected fruit, there is almost no 
chance that infection could exist in a grove without infected fruit 
being included in the sample subjected to laboratory examination. 
Further, during the 20 days that the sampled fruit is in the 
laboratory, the fruit will be held under conditions that are ideal for 
the expression of symptoms in any infected fruit. Given those 
considerations, and given that the detection of symptoms in a single 
fruit will result in a grove being removed from the export program, we 
do not believe that a tenfold increase in the sample size is necessary.
    Comment: It is possible to design testing requirements that will 
reduce the failure rate below any given value under normal 
circumstances, but the risk assessment ought also to evaluate the 
effect of abnormal or unusual events. For example, the following need 
to be explicitly evaluated:
    <bullet> Failure to apply field control (copper oxychloride) 
treatment (e.g. through inadvertent failure to add the solution, etc.);
    <bullet> Failure of the field control treatment, even if applied;
    <bullet> Failure to include the chlorine dip in the treatment 
schedule;
    <bullet> Failure of the chlorine dip itself (e.g. inadvertent 
neutralization or failure to refresh or test);
    <bullet> Temporary or permanent failure of inspection machinery 
(e.g. through operator inattention);
    <bullet> Reintroduction of culled fruit (from harvest culling, if 
any, and/or packing plant inspection) into the product;
    <bullet> Infection through the use of the same packinghouse at 
different times for U.S. export and non-U.S. export fruit (e.g. by 
accidental inclusion of non-export fruit still in the packinghouse; or 
by infection carried on machinery); and
    <bullet> Infection through failure to disinfect tools, clothing 
etc. used in U.S. export groves after being used elsewhere.
    Response: Our entire model is a fault model; thus, it takes into 
account the kinds of events suggested by the commenter, e.g.:
    <bullet> Failures in the application or efficacy of field 
treatments are considered in the probabilities constructed for node P1, 
``Harvested fruit is infected'';
    <bullet> Failures in the application or efficacy of the chlorine 
dips are considered in the probabilities constructed for node P4, 
``Fungus survives post-harvest treatment'';
    <bullet> Inspection failures are considered in the probabilities 
constructed for P2, ``Pathogen not detected during harvest,'' and node 
P3, ``Pathogen not detected at packing house inspection.''
    As discussed in our responses to earlier comments, measures will be 
in place to prevent non-export fruit from being present in the 
packinghouses when any export fruit is present and we believe that it 
is unlikely that fruit could become infected as a result of coming in 
contact with packinghouse machinery or tools, clothing, etc. Finally, 
the risk mitigation program has a series of checks to confirm that the 
required steps have been taken.
    Comment: From the time the fruit leaves the packinghouse to the 
time it arrives at the U.S. port of entry, the only control system 
applied is the labeling on the boxes. APHIS has not evaluated the 
possibility for deliberate introduction of export-labeled boxes of 
untreated fruit in transit, for which there is presumably considerable 
economic incentive, nor for the possibility of misdirected, non-export-
labeled boxes containing infected fruit that are missed by U.S. port-
of-entry inspection.
    Response: The commenter states that there is ``presumably 
considerable economic incentive'' for the deliberate placement of 
nonprogram fruit in export-labeled boxes. We disagree, and would argue 
that there are actually economic disincentives for such actions. As 
stated in the proposed rule and in this final rule, the detection of 
citrus black spot or sweet orange scab during the course of any 
inspection or testing required by this rule will result in the grove in 
which the fruit was grown or is being grown being removed from the 
SENASA citrus export program for the remainder of that year's growing 
and harvest season, and the fruit harvested from that grove may not be 
imported into the United States from the time of detection through the 
remainder of that shipping season. Because citrus fruit from 
nonparticipating groves is more likely to be infected with citrus black 
spot or sweet orange scab than fruit grown in registered groves, we 
believe that it is unlikely that the growers and packers participating 
in the SENASA citrus export program (and incurring additional costs of 
production by doing so) would allow their entire export operation to be 
jeopardized by allowing potentially infected fruit from 
nonparticipating groves to be commingled with their export-quality 
fruit, especially given that Argentina already has strong domestic 
demand for its citrus and numerous well-developed export markets to 
which nonprogram fruit may be exported. In addition to that purely 
economic disincentive, SENASA inspectors will also be present in the 
groves and packinghouses during the growing, harvest, and shipping 
seasons to ensure that all requirements of the regulations are being 
observed.
    Regarding the possibility of misdirected, non-export-labeled boxes 
containing infected fruit being missed by U.S. port-of-entry 
inspection, we believe that it is unlikely that such misdirection would 
occur, given that this rule prohibits non-export fruit from being in 
the packinghouse when export fruit is present. That being said, the 
possibility of boxes containing infected fruit arriving in the United 
States is considered throughout the model. The model is a fault model 
and estimates the probability of pests entering the United States and 
becoming established. Each of these nodes are assumed to be independent 
events and, as such, begin with the assumption that pests, in some 
form, have infested or infected the fruit (P1), avoided detection (P2, 
P3), survived treatment (P4), survived shipment (P5), been shipped to a 
suitable habitat (P6), found a suitable host (P7), and will be able to 
complete the disease cycle (P8). As such, each of these nodes 
represents a ``fault'' in the system. One such fault that could lead to 
infected or infested fruit being inserted into the system includes 
boxes of fruit that are not part of the system being inserted into the 
system.
    Comment: Because the proposed rule does not include any 
safeguarding requirements on the fruit as it is moved from the grove to 
the packinghouse and from the packinghouse to the point of export, the 
risk assessment needs to include an evaluation of the probabilities for 
infection with citrus diseases or contamination with infected material 
(e.g. blown leaves, ascospores attaching to fruit or fruit boxes) 
during transport within Argentina. Examination of the transport system 
must include staging areas on the road and in port, and must take 
account of simultaneous movement of other fruit that has not been 
subject to the same

[[Page 37650]]

sanitary requirements as the U.S. export fruit.
    Response: Mature fruit is not susceptible to infection by citrus 
black spot or sweet orange scab, so the possibility of infection during 
transport is not relevant and, therefore, did not need to be considered 
in the pest risk assessment.
    Comment: APHIS estimates the fraction of the United States that is 
suitable habitat for fruit flies to be 10 to 15 percent, and the 
fraction of the United States that is suitable for sweet orange scab, 
citrus black spot, and citrus canker to be approximately 9 percent. 
From the text of the risk assessment, it appears that these values are 
simply a fraction of the area of the United States. A more appropriate 
value would be the probability that fruit will actually be shipped to 
an area with a suitable habitat. Such a distribution should take 
account of the population of the United States that lives in suitable 
habitats or current (or potential) shipping patterns for fresh citrus. 
The distribution should take account of the seasonal probability of 
shipping fruit to a citrus-growing region, and the correlation of this 
probability with the probability for pest survival.
    Response: We have no reason to believe that the analysis suggested 
by the commenter would result in a different distribution than the ones 
we used. As we noted in response to an earlier comment, with the large 
citrus markets throughout the United States, we have no reason to 
believe that our estimate of 5 percent (percentage of imported fruit 
that will be shipped to areas where citrus can survive) is too low or 
too high. Nor have we received any specific information from any 
commenter that would allow us to change our estimate. Further, we do 
not believe that human population density or shipping patterns for 
citrus fruit are relevant when one is considering whether or not an 
area provides a suitable habitat for an organism, as that suitability 
is more a function of climate and the availability of host material. 
The ability of an area to support a pest population exists regardless 
of the factors raised by the commenter.
    Comment: The U.S. segment of the pathway is identical in the risk 
assessment for the baseline and the mitigation program. The probability 
distributions appear to be pure guesswork by APHIS (so far as can be 
evaluated from the documentation in the risk assessment and proposed 
rule). There is no indication of the potential infection routes that 
were considered, nor of the use of any data either on prior infections 
elsewhere in the world or (except to a minor extent for fruit flies) on 
the population biology of the pests themselves.
    Response: There is no evidence, nor any reason to believe, that 
these diseases have ever been introduced by this pathway--i.e., 
commercial shipment of citrus fruit--or a similar pathway anywhere in 
the world. Every scientific reference--and the known biology of these 
diseases--indicates that other pathways are responsible for 
introductions that have occurred. Because our risk assessment focused 
on the commercial shipment pathway, it did not consider other pathways 
such as the smuggling of plant material and nursery stock, which is by 
far considered the most likely pathway for introduction in all known 
introductions with uncertain cause. Our estimates resulted from our 
consideration of a variety of potential infection routes, such as 
consumers discarding rinds or whole fruit in compost heaps in the 
vicinity of citrus trees on their property, and rinds or fruit 
discarded in orchards. The scope of our risk assessment and 
consideration of potential infection routes are discussed in greater 
detail in our response to the next comment.
    Comment: There are multiple potential pathways for pests to get 
into U.S. citrus areas or other areas of concern. Without 
documentation, it is impossible to evaluate whether APHIS has 
considered all of them in the risk assessment, and it is impossible to 
evaluate their relative importance. For example, citrus groves or 
backyard trees could be exposed to pests by a fruit or peel discarded 
by workers, trespassers, or passers-by; by peels placed in compost 
piles; by truck accidents scattering fruit; and by air dispersion of 
spores or contaminated material from ventilated trucks. Indeed, the 
probability of discarded fruit will be higher for sweet orange scab or 
citrus black spot infected fruit, since a consumer is more likely to 
discard fruit in which infection has become apparent. All these 
examples could readily be examined using event-tree modeling, using 
available data on consumption of raw fruit, human activity patterns, 
accident statistics, shipping statistics, and so forth. It should also 
be noted that most of the pathways by which infections might take hold 
in the United States are based on single fruit, not on boxes. Thus any 
quantitative risk assessment for these pathways would most readily (and 
possibly can only) be conducted on a ``per fruit'' basis, not on a 
``per box'' basis.
    Response: The purpose of the risk assessment, as stated in the 
first sentence of the risk assessment on p. 1, is ``* * * to examine 
plant pest risks associated with the importation into the United States 
of fresh citrus fruit grown in certain areas of Argentina.'' The 
document is a commodity-based risk assessment conducted to inform the 
decision of whether commercial citrus from Argentina should be 
enterable under a specific set of mitigation measures. It was not the 
purpose of the risk assessment to consider all the various pathways by 
which citrus pests could enter the United States. A plant pest risk 
assessment that considers all the different pathways by which a pest 
can enter an area, which is referred to as a pest-initiated risk 
assessment, would be the appropriate vehicle for conducting the types 
of analyses suggested by the commenter.
    That being said, the possibility that citrus groves or backyard 
trees could be exposed to the pathogen via discarded fruit or peel was 
considered in our risk assessment (P7, Pathogen reaches suitable host). 
We concluded that it is highly unlikely that infected fruit producing 
viable pycnidiospores will ever reach the United States. If this did 
occur and the fruit or peel was thrown in a compost heap, even under a 
backyard citrus tree, it would be highly unlikely that fruit in the 
tree could become infected. The pycnidiospores are only waterborne and, 
therefore, can only infect fruit when the inoculum source is in direct 
contact with or physically close to fruit on the tree, or if there was 
fruit positioned beneath the inoculum source so that the spores could 
drip onto that lower-hanging fruit. This also would assume that the 
environmental conditions were favorable for infection and that fruit 
were susceptible. Realistically, it would be difficult to infect U.S. 
fruit, even if infected fruit was purposely placed in the tree canopy. 
In greenhouse inoculation studies conducted by an APHIS scientist, it 
was necessary to place fungal cultures of citrus black spot directly on 
susceptible fruit and to keep the inoculum and fruit moist for nearly 7 
days. Even under these highly favorable conditions, not all inoculated 
fruit became infected. Thus, the likelihood of infection in the field, 
even by symptomatic fruit, is very low. Finally, we believe that our 
use of the box as the risk unit, as opposed to the individual fruit as 
the commenter suggests, is an appropriate choice. Retail boxes stay 
intact from the packinghouse until their point of final sale (e.g., a 
supermarket), and it is reasonable to assume that most or all of the 
fruit in a box would be used, and the remains

[[Page 37651]]

discarded, in the same general vicinity (e.g., town, neighborhood) as 
the point of final sale.
    Comment: For the U.S. segment of the pathway considered (including 
shipping), APHIS estimates the probability for citrus black spot 
outbreak to be about 10<SUP>-9</SUP> per infected 18-kg box (0.83 0.05 
x  0.005  x  0.000005), using the mean values for the distributions 
given in Table 9 of the risk assessment. The total U.S. consumption of 
fresh citrus fruit is about 25 lbs/person/yr, or 2.8  x  10<SUP>9</SUP> 
kg/yr, or 1.6  x  10<SUP>8</SUP> boxes/yr at 18 kg/box. Thus, APHIS is 
effectively suggesting that if the entire U.S. fresh citrus fruit 
supply were imported, and it was all infected at source (100 percent), 
the probability for a citrus black spot outbreak in the United States 
would be on the order of 0.16 per year. This is an unreasonable 
prediction, given the experiences elsewhere with citrus black spot 
infection. Note that the APHIS approach (on a ``per box'' basis) cannot 
apparently distinguish between 1 infected fruit per box, and 100 
percent infected fruit in a box, whereas these clearly pose different 
risks.
    Response: First, as explained in the response to the previous 
comment and elsewhere in this document, we believe that a box of fruit 
is an appropriate risk unit. Second, given the preponderance of 
evidence and expert opinion that long distance spread of Guignardia 
citricarpa via infected fruit is unlikely, and the dearth of documented 
cases of such spread, we believe that the probability calculated by the 
commenter is not unreasonable and our distributions, therefore, are 
appropriate. We offer the following citations from the scientific 
literature to support our conclusions:
    <bullet> ``Ascocarps of the pathogen have never been found on fruit 
and the pycnidiospores are not airborne. Therefore, disease spread is 
unlikely through the movement of infected fruit.'' (Whiteside, J.O.; 
Garnsey, S.M.; Timmer, L.W. 1988. St. Paul, MN: American 
Phytopathological Society. 80 p.).
    <bullet> ``The fungus can readily be carried on imported citrus 
fruits, but the risk of spread from these is relatively low.'' (Smith, 
I.M.; McNamara, D.G.; Scott, P.R.; Holderness, M.; Burger, B. 1997. 
Quarantine Pests for Europe. New York: CAB International. 1,425 p.).
    <bullet> ``Fruit cannot rate high as an effective source of 
inoculum (pathway) in international trade. Ascospores have never been 
found on fruit, but pycnidiospores are produced that are not 
airborne.'' (Santacroce, N.G. 1982. ``Guignardia citricarpa Kiely.'' 
Hyattsville, MD: USDA, APHIS, BASS. 7 p.)
    Comment: To provide a reliable risk assessment, APHIS must provide 
documentation according to the procedure of Kaplan (1992), which APHIS 
claims to have followed in preparing the risk assessment. First, this 
documentation must explicitly lay out the evidence upon which the 
probability distributions are based, including any disagreements 
between the experts. Second, it must show the reasoning leading from 
the evidence to the distributions. Third, APHIS should state the names 
of the experts involved, and the risk assessors involved. In several 
places throughout the risk assessment, there is confusion between the 
experts and the authors--or are they the same, and does this violate 
the spirit of Kaplan's approach? We suggest that if the experts and the 
risk assessors are the same people, then the spirit of Kaplan's 
approach requires a substantially larger effort to separately document 
the evidence and the line of reasoning taken in obtaining distributions 
from such evidence.
    Response: The reliability of a risk assessment depends on the 
extent to which it accurately represents the actual risk. We agree, 
however, that it is important to document the basis of a risk 
assessment so that readers can make judgments about the validity of the 
information in the risk assessment. That is why we provided extensive 
information and references concerning the scientific information that 
formed the basis of our risk assessment. The information, scientific 
data, and evidence used to estimate the appropriate input values 
(distributions) was cited in the 162 scientific references, 13 
regulatory references, and supporting documents cited in the risk 
assessment. Specifics about how this information was interpreted and 
used is provided in the discussions for each of the nodes in our model 
(sections 8.e. and 8.f.) and in the pest data sheets prepared for, and 
presented in, the risk assessment (Appendices I through VII). The three 
authors of the document are listed on the cover sheet. Tables 7 through 
10 list the 72 node estimates used to conduct the Monte Carlo portion 
of the risk assessment. Each estimate consists of a distribution type 
and estimates for the distribution parameters. The exact list of 
experts used to estimate each of the 72 distributions varied from node 
to node. However, section IV of the risk assessment (``Preparation, 
Consultation and Review,'' pp. 58-59) lists the 21 experts (including 
the three authors) within and outside USDA who were consulted during 
production of the risk assessment. While the three authors did, in some 
cases, double as both risk assessors and experts, we believe that the 
review provided by the remaining 18 listed experts who were consulted, 
as well as the State regulatory personnel and others who reviewed the 
risk assessment in its draft form, preclude the lending of any undue 
weight to the opinions of the authors when it was necessary for them to 
act in both capacities.
    Comment: The FAO ``Guidelines for Pest Risk Analysis'' provide that 
risk assessments must be well documented: ``A risk assessment [pest 
risk analysis] should be sufficiently documented so that when a review 
or a dispute arises, the risk assessment will clearly state the sources 
of information and the rationales used in reaching a management 
decision regarding phytosanitary measures taken or to be taken'' (FAO, 
International Standards for Phytosanitary Measures, adopted November 
1995 by the 28th Session of the FAO Conference, p. 20). In contrast to 
the FAO requirements, however, the 1997 risk assessment does not 
disclose the sources of much of the data relied upon, the basis for a 
number of assumptions relied upon, nor the names of particular experts 
who were looked to for estimates that are used in the risk assessment.
    Response: The commenter states that we did not disclose the sources 
of much of the data relied upon, but we believe that we thoroughly 
documented our sources of information in section III of the risk 
assessment (References) and in the references listed at the end of each 
of the pest data sheets provided as appendices.
    The commenter states that we did not disclose the basis for a 
number of assumptions relied upon, but we did provide a narrative 
discussion of how we arrived at probabilities used in each of the nodes 
for each of the pests of concern (fruit flies and diseases). While the 
information we provided for each node may not have contained the level 
of detail that the commenter appears to believe would have been 
appropriate, we did attempt to describe how we arrived at each of our 
estimates in those discussions rather than simply reporting our 
estimates in table form. Additional information regarding the 
construction of our distributions is provided in the addendum to the 
risk assessment that may be obtained from the person listed under FOR 
FURTHER INFORMATION CONTACT.
    The commenter states that we did not disclose the names of 
particular experts who were looked to for estimates that

[[Page 37652]]

are used in the risk assessment, but section IV of the risk assessment 
(Preparation, Consultation, and Review) lists the names of each of the 
entomologists, botanists, plant pathologists, agriculturalists, plant 
virologists, and information specialists who participated in the 
preparation of the assessment, as well as the names of the APHIS and 
State personnel who were consulted during the preparation of the 
assessment and who reviewed drafts of the assessment. As can be seen by 
the Argentine citrus risk assessment and our previous risk assessments, 
it has not been our normal practice to explicitly tie individual 
experts to the estimates provided for specific nodes; we will, however, 
consider doing so in future risk assessments.
    Comment: Variability represents known heterogeneity of a quantity. 
Uncertainty represents lack of knowledge about that quantity that could 
be better characterized with further research and/or measurement. 
Variability and uncertainty should be considered separately in a Monte 
Carlo risk assessment, so that one can identify the sources of the 
spread in the resulting distribution. A final risk distribution might 
be interpreted very differently if the source of most of the spread 
were uncertainty than if the source were true variability in the input 
parameters. The APHIS risk assessment focuses primarily on uncertainty, 
with a smaller emphasis on variability, but APHIS makes no distinction 
between the two in its risk assessment calculations. Moreover, APHIS 
seems to confuse the two when it states, ``Uncertainty in the estimated 
values may arise from natural variation over time, natural variation 
from place to place, data gaps or unconfirmed data, [and] relationships 
among multiple components in a node.'' Many of the distributions 
presented in the risk assessment are claimed to be uncertainty 
distributions for probabilities, but since the methods used to elicit 
these distributions are not specified, we cannot evaluate whether the 
distinctions between variability and uncertainty were maintained during 
the elicitation. The object of the risk assessment is not adequately 
specified with respect to variability and uncertainty, but the most 
logical interpretation would exclude year-to-year variability as being 
of great interest. However, such year-to-year variability is explicitly 
included in at least one distribution incorporated in the assessment.
    Response: As noted in a recent paper published in the journal Risk 
Analysis (Gray et al., 1998) and cited in response to a previous 
comment, [k]nowledge of variability must be based on empirical 
estimates, otherwise it is another source of uncertainty. With the 
exception of one or two nodes, data providing an estimate of 
``variability (as it) represents known heterogeneity of a quantity'' do 
not exist for these parameters. Accounting separately for variability 
and other forms of uncertainty in this risk assessment would constitute 
overinterpretation of available data. Overinterpretation of available 
data would most likely lead to risk estimates that are less, rather 
than more, accurate.
    Comment: APHIS states that the risk analysis computer software 
package @Risk for Excel (Palisade Corp., Newfield, NY) is used to run 
the Monte Carlo Analysis. However, APHIS does not state which version 
of this software was used, in what spreadsheet package, nor where to 
find technical details of the software that are necessary to critically 
evaluate the adequacy of this software for the assessment. The 
spreadsheet itself is not included in the risk assessment or in the 
rulemaking record. To ensure reproducibility of the analysis, APHIS 
should at least document which version of @Risk was used, and should 
provide a copy of the spreadsheet used for the analysis. We have 
reservations that even this is sufficient, since required technical 
details of @Risk are not publicly available. These include such 
important details as the algorithm used to generate (pseudo) random 
numbers. Other software packages with similar capabilities make 
technical details available.
    Response: We used @Risk for Excel, version 3.5c, to run the 
analysis. We did not supply the ``required technical details of @Risk'' 
because we believed that sufficient information--i.e., all the 
technical information the software company has chosen to make publicly 
available was provided in the @Risk documentation. We concluded that 
including the spreadsheets would provide no new information; the risk 
model (i.e., the calculations used) is completely described and 
adequately represented in Figure 2 (p. 30) and section 8.b. (p. 28) of 
the risk assessment, and all input values used in all spreadsheets are 
completely specified in Tables 7 through 10. The spreadsheets 
themselves may be obtained from the person listed under FOR FURTHER 
INFORMATION CONTACT.
    Comment: Although the primary focus of the risk assessment is, as 
it should be, on pests that affect or are present on Argentine citrus 
crops, the citrus fruit itself is not the only item that will be 
imported. The fruit will be packed in crates or boxes and shipped on 
pallets. The North American Plant Protection Organization (NAPPO) has 
recognized that a large percentage of wood dunnage or packing materials 
moving in international trade is composed of low quality, inexpensive 
wood products that may contain quarantine pests. The structure of the 
model used by APHIS does not allow problems such as this to be 
addressed in the risk assessment.
    Response: APHIS recognizes the plant pest risk presented by solid 
wood packing materials and has separate regulations in 7 CFR 319.40-
3(b) that address these risks. Further, on January 20, 1999, we 
published in the Federal Register (64 FR 3049-3052, Docket No. 98-057-
1) an advance notice of proposed rulemaking soliciting public comment 
on how to amend our regulations on the importation of logs, lumber, and 
other unmanufactured wood articles to decrease the risk of solid wood 
packing material (e.g., crates, dunnage, wooden spools, pallets, 
packing blocks) introducing exotic plant pests into the United States. 
We are currently reviewing the information received in response to that 
notice and are preparing a risk assessment and other documentation 
regarding the issue.
    Comment: The eighth step in the risk assessment (pest able to 
complete its life cycle) is likely to be the most uncertain of all, 
certainly for the diseases, since so little is known of the population 
biology of these diseases. For fruit flies, APHIS clearly recognizes 
that a problem exists, but its attempt to take account of it (section 
8.e. P8) is unfortunately incorrect and inadequate. It seems likely 
that a better incorporation of concepts from population biology would 
almost certainly change the model used in the risk assessment, at least 
for the final step(s).
    Response: Much is known about the population biology of the 
diseases and fruit flies, and we believe that we took into account all 
the pertinent aspects of the known biology of these plant pests in our 
estimates for P8 for both the diseases and fruit flies. For the 
diseases, we considered the type of infective propagules produced by 
the pathogens and the environmental and physiological requirements for 
host plant susceptibility and successful disease progression. For fruit 
flies, we estimated the probability of an outbreak, per infested lot of 
fruit fly host material, for infested lots delivered to suitable 
habitats using data on the known number of Anastrepha outbreaks from 
1990 through 1996 and estimates of the number of infested lots entering 
favorable habitats in the United States.

[[Page 37653]]

The paper that forms the basis of those estimates (Miller et al. 1996, 
cited in the risk assessment) was subjected to international review by 
scientists conducting research on the population biology of fruit 
flies. Thus, we believe that we did incorporate concepts from 
population biology in our estimates for P8 for each of the diseases and 
fruit flies, and do not believe that there are any pertinent aspects of 
the known biology of these plant pests that were not considered in the 
risk assessment.
    Comment: The most difficult and least certain parts of the pathway 
(the U.S. segment) are common to the mitigated and unmitigated 
scenarios. It seems unlikely that incorporation of details of 
population biology would make as large a difference for diseases as it 
might for fruit flies, since it is unlikely that interactions between 
fungal spores or colonies are as substantial as between individual 
fruit flies. In such circumstances, it may be useful to perform a 
differential analysis of the risks for diseases that will isolate just 
the effects of the mitigation measures. In this case, a differential 
analysis would stop at the calculation of the probability for infected 
fruit to enter the United States, and so emphasize the relative effect 
of the mitigation measures. This procedure has the effect of removing 
the substantial uncertainties in the rest of the pathway from 
consideration, since such uncertainties would be common to both 
mitigated and unmitigated scenarios (unless, for some reason, there 
were correlations connecting the Argentine and U.S. segments of the 
pathways).
    Response: Separate analyses were performed for the fruit flies and 
the diseases. International guidelines, and APHIS interests, dictate 
that the likelihood estimate of primary interest is the likelihood of 
introduction, not the likelihood of entry. Nonetheless, it is possible 
to calculate our estimates for the likelihood of entry using the 
information provided in the risk assessment. Estimates for the 
likelihood of entry could be obtained by using P5 as the endpoint of 
the simulation and the values provided in Tables 7 through 10. 
Regarding the issue of a differential analysis, it is not clear how 
conducting a differential analysis to emphasize the relative effect of 
the mitigation measures would aid APHIS' decisionmaking process. We 
must consider the risk posed by the entire pathway. The decision of 
whether to proceed with the rulemaking process is based on the risk 
presented by the entire pathway.
    Comment: In the current assessment, the known total mitigation 
effect for citrus black spot (ratio of infection rates for fruit at the 
U.S. in the unmitigated versus mitigated scenarios) is controlled 
solely by the effect of the copper oxychloride treatment, and might 
amount to a factor of 50 to 200-fold under the conditions of the 
experiments available in the record. No evidence has been presented in 
the record for any mitigating effect of the other proposed steps, and 
there is evidence indicating a lack of effect for the post-harvest 
treatments. The full system tests are entirely consistent with such 
minimal effects, given the detection limits of those tests. Moreover, 
there is no evidence that good results could be achieved consistently 
over time, with fruit from different areas, with grapefruit, or with 
different varieties of lemons and oranges. This minimal and relatively 
unproved mitigation effect might be compared with the much higher and 
well-proved 30,000-fold (probit 9) mitigation effect afforded against 
fruit flies by cold treatment, although the absolute probability for 
subsequent infection in the United States must also be taken into 
account.
    Response: It is not true, as stated by the commenter that ``the 
known total mitigation effect for citrus black spot (ratio of infection 
rates for fruit at the U.S. in the unmitigated versus mitigated 
scenarios) is controlled solely by the effect of the copper oxychloride 
treatment.'' Although the copper oxychloride treatment is the primary 
risk mitigation measure against citrus black spot, other measures that 
will have a mitigating effect on citrus black spot were identified and 
discussed in the risk assessment; these measures are required by this 
rule and thus will be applied consistently over time. Specifically, the 
removal of debris prior to bloom is also an effective mitigation 
measure in that it reduces inoculum present in the grove. Additionally, 
the harvest and packinghouse culling reduces the likelihood that 
diseased, symptomatic fruit will be shipped. It is correct that the 
post-harvest treatments have little effect on citrus black spot. With 
the inclusion of the 20-day preharvest incubation to detect latent 
infection, whereby observation of a single infected fruit will remove 
the entire grove from the export program for the entire year, the 
overall systems approach results in a substantial risk reduction. Our 
estimates of the risk reduction afforded by all these measures, and our 
use of supporting data and expert judgment in arriving at those 
estimates, are set forth in the risk assessment.
    The commenter concludes by contrasting the 30,000-fold mitigating 
effect of cold treatment for fruit flies with the smaller (50- to 200-
fold) effect of the mitigating measures for citrus black spot. Taken on 
its face, this comparison would seem to indicate that the mitigating 
measures for citrus black spot leave something to be desired in terms 
of their ability to reduce the risk presented by that disease. However, 
as is clearly presented in table 11 of the risk assessment, the 
baseline (unmitigated) risk presented by citrus black spot is far lower 
than that presented by fruit flies (in the mean, 1 chance in 28,653 for 
citrus black spot versus 1 chance in 7.4 for fruit flies). Thus, even 
with the comparatively more modest mitigating effect of the citrus 
black spot measures, the risk estimated for citrus black spot in the 
mitigated scenario is still lower than that estimated for fruit flies 
(in the mean, 1 chance in 3.2 million for citrus black spot versus 1 
chance in 350,000 for fruit flies).
    Comment: APHIS does not have guidelines for performing quantitative 
pest risk assessments. While such guidelines can, in many cases, be 
restrictive and prevent development of better approaches, they can also 
serve a useful purpose by preventing common errors. In view of the 
myriad problems with the risk assessment, APHIS should consider 
developing quantitative guidelines, in consultation with experts in 
probabilistic risk assessment, to prevent similar problems in future 
quantitative assessments.
    Response: APHIS has published very specific guidelines for 
qualitative plant pest risk assessments (USDA 1995, ``Pathway-Initiated 
Pest Risk Assessment: Guidelines for Qualitative Assessments, version 
4.0,'' USDA-APHIS-PPQ, Riverdale, MD). The only difference between the 
methods described in that document and our probabilistic assessments is 
section 8, where we estimate the likelihood of introduction. APHIS has 
not published a separate document describing the methods it uses to 
estimate the likelihood of introduction when using probabilistic 
methods. Although our methods have evolved slightly with each 
probabilistic assessment as we obtain comments, our methods have 
remained fairly consistent and clearly illustrated. Additionally, the 
methods we used in the present risk assessment are clear. Our process 
was created in consultation with world leaders in the field of 
probabilistic risk assessment, and our process has indeed been 
subjected to extensive peer review by experts in probabilistic risk 
assessment. Subsequent reviews by experts have been very favorable and 
have led to several improvements in our process.

[[Page 37654]]

Although improvements will be made following the present risk 
assessment, we have not been made aware of any significant errors that 
require significant changes in our methods.

Risk Assessment--``Principles of Good Practice''

    The following comments were generated by a commenter who evaluated 
the risk assessment against 14 principles of good practice for Monte 
Carlo risk assessment outlined by Burmaster and Anderson (1944). APHIS 
is familiar with this publication, has referred to it often, and has 
used it along with other similar works as a guide when conducting 
probabilistic risk assessments. However, this particular work 
represents only one set of suggestions and does not represent an 
``industry standard.'' Despite that, as indicated in the individual 
responses below, our methods are consistent with many of the 
suggestions listed by the commenter. Below, we have presented each 
principle and the accompanying critique provided by the commenter, and 
each is followed by APHIS' response. Further, as discussed in the 
introductory note to the previous section of this document (``Risk 
Analysis''), additional documentation regarding the information or data 
used as the basis for the risk assessment's conclusions is contained in 
an addendum to the risk assessment that may be obtained from the person 
listed under FOR FURTHER INFORMATION CONTACT.
    Show all formulas used in the risk assessment. We do not agree with 
the structure of the model used in the risk assessment. However, the 
only formula used in the APHIS risk assessment is the simple 
multiplicative formula used to calculate the likelihood of pest 
establishment. This formula is simple and, while not presented 
algebraically, is presented in Figure 2 and adequately described in the 
text. However, Figure 2 is illegible, even in the electronic version of 
the report available on the Internet, due to the extremely low 
resolution of the image file. No better copy is available anywhere in 
the risk assessment or in the rulemaking record.
    Response: As indicated by the commenter, our risk assessment is 
quite transparent. We explained in extensive detail how we conducted 
our risk assessment, and we and our peer reviewers have found the 
structure of our model to be appropriate and correct. We apologize if 
the commenter had difficulty downloading material from our web site and 
we would be happy to provide additional copies of our model. APHIS 
regularly supplies paper copies of the risk assessment to anyone 
requesting a copy.
    Calculate and present point estimates of risk. APHIS does not 
calculate a point estimate of the risk of infestation; however, this 
principle is not necessarily applicable to a plant pest risk 
assessment. In a human health risk assessment, such a point estimate 
provides a point of comparison for the results of the Monte Carlo 
analysis with standard analyses that are familiar. In a plant pest risk 
assessment, a point estimate would be somewhat less useful since 
quantitative point estimates are as unfamiliar as probabilistic 
estimates, and so may not be necessary.
    Response: We agree with the commenter's sense that point estimates 
are not a necessary element of a plant pest risk assessment, which is 
why we did not calculate a point estimate of the risk of infestation.
    Present the results from sensitivity analyses to identify inputs 
suitable for probabilistic treatment. APHIS does not perform 
sensitivity analyses or analyze inputs to determine how given variables 
affect the predicted risk. As mentioned previously, many of the 
distributions used in the risk assessment are not based on measured 
data. A sensitivity analysis could be used to help focus data 
collection on the most important variables. Additionally, such an 
analysis could identify variables that drive the risk assessment in two 
senses: (1) Variables that account for the magnitude of the predicted 
risks and (2) variables that account for the range of the predicted 
risks. Understanding which variables drive the resulting risk 
distribution in these two senses is key to interpreting the results of 
the risk assessment and focusing future research.
    Response: We did perform sensitivity analyses as part of the final 
step of the probabilistic analysis of the proposed mitigation program; 
as the earlier steps in the risk assessment were not probabilistic, 
sensitivity analyses were not performed on those earlier steps. 
Further, because sensitivity analyses are not particularly useful with 
a simple, linear, multiplicative model of the type used in the risk 
assessment, they were not discussed in the risk assessment. If the 
commenter is interested, our sensitivity analyses are part of the 
documentation contained in the supplemental information that is 
available from the person listed under FOR FURTHER INFORMATION CONTACT.
    The commenter suggests that sensitivity analysis could be used to 
help focus data collection on the most important variables, but that 
was not the purpose of the risk assessment. Rather, the purpose of the 
risk assessment was to estimate the risk associated with a particular 
proposed program, and not to aid in the design of a new program.
    The commenter also suggests that: ``Additionally, such an analysis 
could identify variables that drive the risk assessment in two senses: 
(1) Variables that account for the magnitude of the predicted risks and 
(2) variables that account for the range of the predicted risks. 
Understanding which variables drive the resulting risk distribution in 
these two senses is key to interpreting the results of the risk 
assessment and focusing future research.'' Regarding item (1), the risk 
assessment discusses mitigations that reduce risk, and it provides 
estimates of the likelihood of pest introduction with and without the 
system of risk mitigations. The various input parameters do not 
represent sources of risk per se, they represent events that must occur 
before a pest can be introduced; some of them represent specific risk 
mitigations (e.g., P5, cold treatment for fruit flies), not sources of 
risk, while others reflect the biology of the organism and are not 
sources of risk (e.g., P7, pest locates suitable host). The sources of 
risk are identified in the hazard identification section of the 
assessment (Sections 4-6).
    Regarding item (2), the sensitivity analyses we conducted do in a 
sense identify ``variables that account for the range of the predicted 
risks,'' but the commenter's wording does not reflect the purpose, 
outcome, or use of the risk assessment. The risk assessment does not 
deal with a ``range of predicted risks.'' The probabilistic portion of 
the risk assessment estimates, for four separate pests, the likelihood 
of introduction given importations with no specific risk mitigations 
(the baseline scenario) and with a specific set of mitigations (the 
proposed program). However, our sensitivity analyses do indeed identify 
those variables that account for the largest amount of uncertainty in 
the output (the estimated likelihood of pest introduction). As noted 
earlier, with the type of model used in the risk assessment (i.e., 
simple, linear, and multiplicative), that information can be obtained 
by examination of the input parameters (Tables 7-10).
    Restrict the use of probabilistic techniques to issues of 
regulatory importance. The APHIS risk assessment is restricted to the 
issue of regulatory importance, i.e., the likelihood that exotic pests 
imported with Argentine produce will establish themselves in the United 
States. There are few enough parameters in the model that probabilistic 
techniques can be used on

[[Page 37655]]

all. A more realistic model (e.g. including failure modes and 
correlations) might, however, be too complex for such an approach 
(particularly using the chosen software).
    Response: We agree that our model is appropriate to the task at 
hand. We disagree that a more complex model would necessarily be more 
realistic; thus, we see no reason to needlessly complicate our model.
    Provide detailed information on the input distributions selected. 
APHIS presents the parameters necessary to characterize the 
distributions used in the risk assessment. It also, and unnecessarily, 
presents the mean, mode, standard deviation, 5th percentile, and 95th 
percentile of most distributions, at great length and repetitively in 
the text. This allows an informed reader to reproduce the calculations. 
APHIS, however, provides very little additional information about the 
distributions it selected. It presents no graphs of the distributions 
used in the assessment. Very little justification is provided for the 
choice of distributions in the report beyond ``expert judgment,'' so 
that even knowledgeable persons cannot reproduce the full analysis. For 
some distributions, APHIS identifies data that can be used to support 
the distribution (such as for sweet orange scab incidence), but offers 
no justification for the type of distribution selected and no 
description of how the data are used to construct the distribution.
    Response: We agree that the information we provided was sufficient 
to allow an informed reader to reproduce our calculations. We did not 
present graphs for a variety of reasons, not the least of which is that 
graphs would be redundant. However, an informed reader could produce 
graphs of our distributions using the information provided in the risk 
assessment. We believe we included sufficient information about the 
generation of our input distributions in the narrative descriptions 
that are provided in the risk assessment for each of the input values 
(F1, P1 through P8) used in our likelihood model. If the commenter is 
interested, expanded explanations regarding our selection of input 
distributions are part of the documentation contained in the 
supplemental information that is available from the person listed under 
FOR FURTHER INFORMATION CONTACT.
    Show how the input distributions capture and represent both the 
variability and the uncertainty in input variables. APHIS makes no 
effort to distinguish between variability and uncertainty, and offers 
no discussion of their separate contributions to the results of the 
analysis. The roles played by uncertainty and variability in the risk 
assessment depend on the goal of the analysis. If the goal of the 
analysis is to estimate a distribution for the average annual 
likelihood that an infestation will occur in the United States, 
uncertainty will play a larger role in the analysis than variability. 
Year-to-year variability may be intentionally ignored in the analysis 
because the analysis would not be focusing on variations in the 
likelihood of an infestation from year to year. If, instead, the goal 
of the analysis is to generate a distribution of the likelihood that 
each box of fruit will cause an infestation, year-to-year variability 
may play a much larger role. The goal of the analysis should be more 
clearly defined, and APHIS should include a discussion of the roles of 
uncertainty and variability in the analysis.
    Response: The approach suggested here is relatively new and is 
appropriate only in certain situations. In other situations, such as 
the present risk assessment, it is not clear that better results would 
be obtained. In fact, using this approach would require a significant 
overinterpretation of available data and would most likely lead to risk 
estimates that are less, rather than more, accurate. When making a 
decision about whether to allow importation of a particular commodity, 
whether uncertainty in the estimate results from variability or other 
forms of uncertainty may not matter. The primary consideration is the 
value of the risk, not the shape of the output distribution.
    The purpose of our analysis is closer to the first of the possible 
goals suggested by the commenter (``to estimate a distribution for the 
average annual likelihood that an infestation in the United States'') 
than it is to the second (``to generate a distribution of the 
likelihood that each box of fruit will cause an infestation''). 
Specifically, in section 8 of the risk assessment, we state: ``The 
purpose of a probabilistic risk assessment is to estimate the 
likelihood of an undesirable outcome (bad event). The bad event is 
represented by the endpoint of the risk model, i.e., introduction of a 
quarantine pest.''
    Use measured data to inform the choice of input distributions 
whenever possible. As noted above, most of APHIS's distributions are 
based on expert judgment. The risk assessment includes little 
discussion of the reasoning behind the selection of distribution type 
and the parameters used to characterize the distributions. In some 
cases, APHIS identifies available data, but it is not clear how these 
data are used in the construction of the distribution.
    Response: We did, in fact, use measured data whenever possible to 
inform our choice of input distributions when preparing the risk 
assessment. Ideally, existing data would provide the basis for direct 
estimation of model inputs; however, when conducting probabilistic 
assessments to inform decisions regarding importation of agricultural 
commodities, scientific experiments have not, except in rare cases, 
been conducted that provide data that represent ``direct evidence'' for 
risk assessments. In fact, results are seldom provided that can even be 
used as indirect model inputs. As we made clear in the risk assessment, 
all available data were reviewed and professional judgment then used to 
represent the available information. Because most of our commodity risk 
assessments are conducted to support decisions that must be made within 
relatively narrow time frames, research programs can seldom be designed 
and conducted to provide data specifically for the assessments 
(although in the present case, the United States required Argentina to 
design and conduct additional experiments that were completed before 
completion of the risk assessment). Beyond directly applicable measured 
data, USDA bases the estimates needed for its probabilistic commodity 
risk assessments on pest interception records, the known biology of the 
organism being assessed (or the known biology of related taxa) as 
represented in the scientific literature, expert judgment based on 
laboratory experience with the pest or related organisms, expert 
judgment based on field experience with the pest or related organisms, 
expert judgment based on experience conducting commodity inspections at 
ports of entry or in the exporting country, and experience working with 
export programs and export-quality commodities.
    Discuss the methods and report the goodness-of-fit statistics for 
any parametric distributions that were fit quantitatively to measured 
data. It is not clear from the text of the report whether APHIS 
actually fits distributions to any real data. No goodness-of-fit 
statistics are reported in the assessment. There is no discussion of 
any relation between the cited experts' estimates of minimum, maximum, 
and mode, and the parameters of the distributions, nor is such a 
relation self-evident. If the data fitting algorithms in @Risk were 
used to fit distributions to data, the procedure should be clearly 
described in the text.

[[Page 37656]]

    Response: The only situation where goodness-of-fit statistics are 
appropriate was for the distribution used to characterize fruit fly 
survival with the cold treatment. We did not conduct goodness-of-fit 
tests because they were completed as part of the scientific research 
conducted during establishment of the treatment protocol.
    Discuss the presence or absence of moderate to strong correlations 
between input variables. The APHIS report assumes that each of the 
eight steps in the model is independent from all other steps. It is 
unlikely that the eight steps are truly independent. Whether or not 
strong correlations exist, APHIS should discuss the possibility that 
correlations exist and estimate the effects of such correlations on the 
results of the analysis.
    Response: We did consider the possibility of correlations among the 
various nodes. As we reported in the risk assessment, we are confident 
that the nodes are independent, given the model and values used. Our 
analyses detected no correlations. Our conclusion that the nodes are 
independent resulted from both prior and ad hoc considerations, as well 
as model outputs.
    Provide detailed information and a graph for each output 
distribution. APHIS presents the mode, median, mean, and 95th 
percentile of the output distributions for each pest under the baseline 
import program and assuming the presence of a pest mitigation program. 
APHIS does not provide a graph for any of the output distributions.
    Response: We have frequently considered whether we should include 
graphical representations of our output distributions. We have 
repeatedly reached the conclusion that it is neither necessary nor 
important to do so. In fact, we believe it could serve to obscure our 
findings.
    Perform probabilistic sensitivity analyses for all key inputs to 
distinguish the effects of variability from the effects of uncertainty 
in the inputs. APHIS does not perform any sensitivity analyses to 
identify the inputs with the greatest contributions to the output 
distribution. As discussed previously, APHIS makes no attempt to 
distinguish the effects of variability from those of uncertainty.
    Response: We always conduct sensitivity analyses as part of our 
probabilistic risk modeling, and did so for the Argentine citrus risk 
assessment; contrary to the commenter's assertion, those analyses did 
indeed indicate those inputs that contributed the greatest amount of 
uncertainty to the output. (Those analyses are part of the 
documentation contained in the supplemental information that is 
available from the person listed under FOR FURTHER INFORMATION 
CONTACT.) A sensitivity analysis addresses the relationship between 
variation in the input parameters and variation in the output. 
Specifically, the analysis quantifies the degree of correlation between 
variation in individual input parameters and the output parameter. The 
value of these coefficients does not, however, indicate the amount of 
uncertainty in an input parameter. Because of the type of model we used 
(i.e., simple, linear, and multiplicative), the values represent the 
magnitude of the uncertainty (as represented by the standard deviation 
of the input distribution) relative to the mean of the input 
distribution.
    The commenter suggest that sensitivity analysis can be used to 
distinguish the effects of variability from the effects of uncertainty 
in the inputs, but we do not believe that is possible. When data are 
available to allow analysts to distinguish variability from other 
sources of uncertainty, variability and other forms of uncertainty can 
be accounted for, and modeled, separately. This is accomplished by 
having separate inputs for variability and other forms of uncertainty 
in the input parameters. However, in this particular case (as in the 
majority of probabilistic risk assessments), the available information 
did not allow us to model variability separately from other sources of 
uncertainty. A sensitivity analysis cannot change this fact and cannot 
provide us with the ability to distinguish the effects of variability 
from the effects of other sources of uncertainty.
    In a simple, linear, multiplicative model of the type used in the 
Argentine citrus assessment, the sensitivity analysis reflects little 
more than the ``coefficient of variation'' of the input parameters. The 
coefficient of variation is obtained by dividing the standard deviation 
of the distribution by the mean. Parameters with relatively large 
amounts of variation relative to their mean will have a relatively high 
``sensitivity coefficient'' and will have a ``larger impact'' on the 
output. Another way of stating this is that the output is most 
sensitive to those input parameters about which the experts were most 
uncertain. Thus, with this type of model, the sensitivity analysis 
reflects uncertainty in the input parameters. Tables 7 through 10 
reveal those parameters about which the experts were most uncertain 
(P1, P5, P6, P7, P8, depending on pest and scenario); thus these are 
the parameters that had the ``biggest impact'' on the output. The 
values for both the standard deviation and the mean were provided in 
the tables of input values (Tables 7 through 10), so the information 
necessary to obtain the coefficient of variation was available in the 
risk assessment. As the sensitivity analysis provides information that 
is already available in Tables 7 through 10, we believed that little if 
any additional information would have been provided by reporting the 
sensitivity analysis in the risk assessment.
    Regarding distinguishing the effects of variability and 
uncertainty, as stated above, we have not encountered many situations 
where we had sufficient, directly applicable data to provide separate 
estimates for variability and other forms of uncertainty. Thus, to 
conduct such an analysis would constitute overinterpretation of 
available data.
    Investigate the numerical stability of the output distribution. 
APHIS does not investigate the numerical stability of either the 
central moments of the output distribution (such as the mean and 
standard deviation) or the tails of the output distribution. 
Additionally, APHIS provides no discussion of the sensitivity of the 
upper tails of the output distribution to the tails of the input 
distributions. One option for investigating the numerical stability of 
the output distribution is to calculate the uncertainty for the mean 
and the 5th and 95th percentiles of the distribution. A second option 
would be to perform a larger run (e.g., 50,000 iterations instead of 
10,000) and to compare the distributions.
    Response: The @Risk software we used automatically monitors 
convergence ``to help monitor the stability of the output distributions 
created during a simulation'' (@Risk software documentation: @Risk 
Advanced Risk Analysis for Spreadsheets, 1997, Palisade Corporation, 
Newfield, NY). That documentation states that the statistics monitored 
on each output distribution are the average percent change in 
percentile values (0 to 100 percent, in 5 percent steps), the mean, and 
the standard deviation. Thus, we monitored the stability during all 
simulations. Although @Risk simulations can be run with an ``automatic 
shutoff'' option that is triggered when the output distribution has 
reached stability, and despite the fact that the distributions reached 
stability before completing all 10,000 iterations, we completed 10,000 
iterations on each simulation. Prior to conducting the Argentine citrus

[[Page 37657]]

assessment, APHIS conducted informal investigations of the number of 
simulations needed to reach stability with our simple, linear, 
multiplicative models. We found that in some cases that running 1,000 
iterations was not sufficient to reach stability, so we increased the 
number of iterations in our simulations to 10,000. In the Argentine 
citrus risk assessment, 10,000 iterations was found to be sufficient to 
reach stability.
    While considering out response to this comment, we re-ran our 
simulations with 10,000 iterations (as done in the assessment) and then 
with 50,000 iterations as suggested by the commenter. We used the same 
random number generator seed. Results were the same with 10,000 
iterations and not significantly different with 50,000 iterations. For 
example, with the fruit fly program (as opposed to baseline) 
simulation, the 95th percentile value with 10,000 iterations was 1.07 
x  10<SUP>-5</SUP> (0.0000107) and with 50,000 iterations the 95th 
percentile value was 1.08  x  10<SUP>-5</SUP> (0.0000108). Another 
example with the same simulation is for the 90th percentile value, the 
value with 10,000 iterations was 5.80  x  10<SUP>-6</SUP> (0.00000580) 
and with 50,000 iterations was 5.61  x  10<SUP>-6</SUP> (0.00000561); 
thus, the 90th percentile value (part of the upper tail) was lower 
(less risk) with more iterations. Because the 90th and 95th percentile 
values can be considered representative of the upper tail (upper 
estimate for the likelihood of pest introduction), we offer this as an 
indication of the stability of the upper tail. The purpose of 
conducting a probabilistic assessment is to try a range of values to 
see how the output changes. When the experts constructed the input 
distributions, all necessary uncertainty regarding the inputs was 
captured and the simulations included calculations based on the upper 
tails of all nine distributions.
    Present the name and statistical quality of the random number 
generator used. APHIS does not present any information about the random 
number generator used for the risk assessment. We assume that the 
random number generator provided with @Risk was used in the assessment, 
but as mentioned previously, the version of @Risk that was used in the 
assessment is not specified. Even if this was the random number 
generator used, more information should be provided, such that a reader 
of the risk assessment could determine the quality of the random number 
generator without purchasing @Risk.
    Response: In section 8.d of the risk assessment, we stated that ``a 
computer program randomly selects a value from each of the input 
probability distributions. * * * We use the risk analysis computer 
software package @Risk for Excel (Palisade Corp., Newfield, NY, USA) to 
run our simulations.'' As noted previously, we used version 3.5c of 
that program. We did not supply additional information regarding 
@Risk's random number generator because we concluded that sufficient 
information was provided in the @Risk documentation.
    Discuss the limitations of the methods and the interpretation of 
the results. APHIS offers neither a discussion of the limitations of 
the methods used in the risk assessment nor an interpretation of the 
results. APHIS does not acknowledge any sources of bias in the risk 
assessment and does not discuss how additional research or measurements 
might be able to improve the analysis.
    Response: The purpose of our risk assessment was to inform a 
decision regarding the enterability of commercial citrus from Argentina 
under a specific risk mitigation program. We improve our risk 
assessment process as needed, and it was not our purpose to discuss the 
evolution of our risk assessment process as part of this or any other 
plant pest risk assessment. An interpretation of our results and 
specific recommendations are provided on p. 48 in the section titled 
``Conclusion: Pest Risk Potential and Phytosanitary Measures.'' In that 
section we stated that without mitigations, there is a high likelihood 
that one or more of the analyzed pests will be introduced. Regarding 
the proposed risk mitigation measures, we state that ``an appropriate 
level of protection from introduction of plant pests with shipments of 
commercial citrus from Argentina requires strict adherence to risk 
mitigation measures such as those analyzed in this assessment,'' i.e., 
the proposed risk mitigation measures provide an appropriate level of 
protection. With regard to the commenter's statement regarding a 
discussion of the ability of additional research or measurement to 
improve the risk assessment, it is the very nature of risk assessment 
to deal with incomplete information--otherwise, the risk assessment 
would be rendered unnecessary. We believe that the available 
information is sufficient to support the efficacy of the measures 
required by this rule and our analysis of the risks associated with 
Argentine citrus.

Economic and Other Analyses

    Comment: The proposed rule's economic analysis states that 
Argentine citrus would enter the U.S. market at a time when few lemons 
are produced by U.S. growers. This is not true. The California lemon 
industry has invested heavily in developing specialized lemon trees 
that are harvested year round. Moreover, although the peak of the 
California harvest comes from March to June, the fruit is capable of 
being stored for 90 to 120 days without loss of color, flavor, or 
quality. Hence, the great majority of California lemons are sold into 
the summer marketplace at the very time Argentina intends to export 
fruit.
    Response: The proposed rule's economic analysis was not focused on 
lemon production alone, as the commenter suggests. Rather, our 
consideration of the domestic citrus market was more general. 
Specifically, we stated in the proposed rule that ``* * * domestic 
shipments of citrus fruit are at their lowest during the months of 
July, August, and September, dropping to approximately 3.5 to 5 percent 
of average annual shipments * * *. Since the peak production period for 
citrus in Argentina is from May to October, the entry of Argentine 
fresh citrus fruits would likely peak during these months, which 
represent the most likely window of opportunity for Argentine imports 
to enter the U.S. market * * *. Importers and brokers would likely 
benefit from the entry of Argentine citrus fruit into the U.S. market 
because they would be able to provide quality fruits during the months 
when domestic production is lowest.'' That discussion in the proposed 
rule was intended to illustrate the complementary nature of production 
in the northern and southern hemispheres, and not to discount the 
potential presence of domestically produced fruit in the marketplace.
    Comment: The economic analysis prepared for the proposed rule 
provides an inaccurate representation of the potential economic effects 
of imported Argentine citrus by: (1) Assuming that oranges, grapefruit 
and lemons are in the same product market, i.e., that they are perfect 
substitutes in both production and consumption and that a pound of 
imported oranges has the same impact on lemon prices as does a pound of 
imported lemons; (2) asserting that there is very little U.S. citrus 
production during the summer months when most Argentine exports occur 
and that few U.S. citrus producers would, therefore, be affected; (3) 
assuming that the composition of citrus imports (oranges, grapefruit, 
or lemons) does not alter the

[[Page 37658]]

impact of imports; (4) ignoring the multiplier effects of fresh citrus 
sales; and (5) assuming that marketing margins are constant and that 
price changes at the producer and wholesale levels are transmitted 
immediately to the retail level.
    Response: The commenter's statements numbered 1, 3, 4, and 5 are 
addressed in our final economic analysis set forth in this final rule 
under the heading ``Executive Order 12866 and Regulatory Flexibility 
Act.'' With regard to point number 2, we noted in the response to the 
previous comment that our economic analysis did not discount the 
presence of domestically grown fruit in the marketplace during the 
summer months. Rather, we stated that because Argentina exports most of 
its fresh fruit during the summer months, those imports would not 
compete with the peak production season in the United States (late 
fall, winter, and early spring), which would limit--not eliminate--the 
impact on U.S. producers, exporters, and importers of citrus. In 
several places, including both the introduction and conclusion of our 
analysis, we explicitly recognized that the magnitude of the economic 
effect of Argentine citrus would depend on the additional Argentine 
supply, the U.S. supply and demand for citrus, and price conditions in 
the rest of the world, and concluded that the larger the share of 
Argentine imports, relative to U.S. domestic supply, the larger the 
U.S. producer losses and the larger the U.S. consumer gains. We did 
not, as the commenter suggests, assert that only a few U.S. producers 
would be affected by Argentine citrus imports.
    Comment: The economic analysis prepared for the proposed rule fails 
to recognize that the growth in Argentine citrus exports has been and 
will continue to be concentrated in fresh lemons and that there are 
significant amounts of lemons now being processed that could be 
diverted to the fresh export market, since the price paid for lemons 
for processing is usually much lower than for fresh use. There is, 
therefore, the potential that fresh lemon imports from Argentina during 
the summer months could likely range from 40 to 100 million pounds, and 
not the 10 to 50 million pounds examined in the analysis.
    Response: The economic analysis did recognize the growth in 
Argentine citrus production and, since that growth is predominantly in 
the lemon sector, implicitly recognized the concentration on fresh 
lemons noted by the commenter. Indeed, it was the growth in Argentine 
citrus production levels that served as the basis for our estimates of 
potential imports of Argentine citrus into the United States, as we 
expect that Argentina will maintain its well-established export markets 
in Europe, given the substantial investment that they have made to 
cultivate those markets and the inadvisability of developing a heavy 
dependence on a single market such as the United States. With regard to 
the diversion of lemons from the processing market to the fresh market, 
we acknowledge that fresh lemons bring higher prices than lemons for 
processing, but one must also consider that the costs of production 
will be higher for those groves producing fresh lemons for the U.S. 
export market in light of this rule's requirements for additional 
phytosanitary measures during the growing and packing process and the 
costs of transporting fresh lemons versus the costs of transporting 
concentrated lemon juice and essential oils. With these considerations 
in mind, we do not believe that a significant diversion of lemons from 
the processing market to the fresh market is likely.
    Comment: Section 603 of the Regulatory Flexibility Act requires 
agencies to prepare and make available for comment an initial 
regulatory flexibility analysis in connection with any proposed rule. 
The purpose of the analysis is to assess the impact of the proposed 
rule on small entities. While APHIS correctly recognizes that 96 
percent of U.S. citrus fruit farms are small entities, it nonetheless 
states that ``this action would not have a significant economic impact 
on a substantial number of small entities.'' We do not understand how 
APHIS could conclude that the approval of citrus imports, some of which 
will be in direct competition with domestic growers, would not have a 
significant economic impact on a significant number of those small 
growers. Thus, APHIS must prepare the analysis required by 5 U.S.C. 
603, including the preparation of an analysis of significant 
alternatives. Even if APHIS concludes that no significant alternative 
exists which can accomplish the stated objectives and minimize the 
impact on small growers, this discussion must still be set forth in the 
proposed rule.
    Response: In the economic analysis provided in the proposed rule, 
we identified 17,898 farms producing citrus in the United States and 
stated that 96 percent (17,182) of those farms were small entities with 
gross sales of less than $500,000. The remaining 4 percent (716) of 
those farms had gross sales of more than $500,000 and thus were not 
considered small entities under the applicable Small Business 
Administration criteria. In the scenario we examined in which 50 
million pounds of Argentine citrus entered the United States (the 
largest import volume of the five scenarios considered), we stated that 
the expected loss to producers would be $36.674 million. When spread 
evenly across the 17,898 producers identified, that would amount to a 
loss of $2,049 per farm. However, we also noted in our analysis that 
the 4 percent of producers who are not small entities owned 66 percent 
of the total citrus-growing acreage. If the expected losses are 
weighted to the relative shares of citrus-producing acreage, the 17,182 
small entities could expect to bear a collective loss of $12,469,160 
(i.e., $36.674 million multiplied by 0.34), which amounts to $726 per 
small farm. Under section 605(b) of the Regulatory Flexibility Act, the 
requirements of section 603 do not apply to any proposed or final rule 
if the head of the agency certifies that the rule will not, if 
promulgated, have a significant economic impact on a substantial number 
of small entities. Thus, our statement in the proposed rule that ``this 
action would not have a significant economic impact on a substantial 
number of small entities'' was the Administrator's certification of 
this minimal effect, as required by section 605(b).
    Comment: There is no evidence in the proposed rule that APHIS 
prepared an environmental impact assessment of the rule, which should 
have been prepared in order for APHIS to comply with the requirements 
of the National Environmental Policy Act (NEPA). APHIS' NEPA 
implementing regulations in 7 CFR 372.5(b)(1) require the preparation 
of such a report. If either the Medfly, various species of Anastrepha, 
or possibly other pests were to enter the United States via Argentine 
fruit and become established, a significant, and perhaps widespread 
spraying program would be required. We submit that APHIS is obligated 
to consider this possibility, and prepare, at a minimum, an 
environmental impact assessment if such an event were to occur.
    Response: For the proposed rule, those issues were considered in 
the risk assessment in section 7 (Consequences of Introduction: 
Economic/Environmental Importance) of chapter II (Risk Assessment). An 
environmental assessment was not prepared for the proposed rule because 
APHIS previously decided, in accordance with our NEPA implementing 
regulations in 7 CFR 372.5(c), to classify future amendments to 7 CFR 
part 319 as categorically excluded actions not requiring the 
preparation of an

[[Page 37659]]

environmental assessment. However, in December 1998, following the 
publication of the proposed rule, our review and consideration of the 
comments that had been received by that time led us to prepare an 
environmental assessment that addresses the concerns raised by the 
commenter. That environmental assessment, as well as a finding of no 
significant impact based on the information presented in the 
environmental assessment, may be obtained by contacting the person 
listed under FOR FURTHER INFORMATION CONTACT.
    Comment: APHIS has failed to prepare a civil rights impact analysis 
to analyze the impact of the proposed rule, if adopted, on various 
minority groups. The potential for the rule to lead to a significant 
loss of jobs for one or more ethnic groups must be considered.
    Response: We did in fact prepare a civil rights impact assessment 
for the proposed rule. It may be obtained by contacting the person 
listed under FOR FURTHER INFORMATION CONTACT.

Miscellaneous

    In addition to the changes discussed previously in this document, 
we are also amending two other sections of the fruits and vegetables 
regulations to correct outdated and erroneous references to several 
sections of the regulations, including Sec. 319.56-2f, which will be 
the location of this rule's provisions regarding the importation of 
grapefruit, lemons, and oranges from Argentina.
    Specifically, paragraph (e) of Sec. 319.56a, ``Administrative 
instructions and interpretation relating to entry into Guam of fruits 
and vegetables under Sec. 319.56,'' refers to ``the provisions of 
Secs. 319.56-2d and 319.56-2f to 319.56-2m, inclusive,'' but all of 
those sections, with the exception of Sec. 319.56-2d, have been removed 
or redesignated since the time the regulations in Sec. 319.56a became 
effective in 1959. Therefore, we are amending Sec. 319.56a(e) so that 
it accurately reflects the locations of those remaining sections of the 
regulations to which it originally referred.
    Similarly, we are amending Sec. 319.56-2i to remove a reference to 
Sec. 319.56-2f that dates back to when that section contained 
provisions regarding the importation of Manila mangoes from Mexico. In 
1995, Sec. 319.56-2f was removed and reserved and its provisions 
regarding the importation of oranges, grapefruit, and mangoes from 
Mexico were integrated into the table contained in Sec. 319.56-2x. 
Section 319.56-2i should have been amended at that time to reflect the 
removal of Sec. 319.56-2f, but was not. Further, the inclusion of 
mangoes from Mexico on the list of commodities in Sec. 319.56-2x that 
may be imported subject to treatment in accordance with the PPQ 
Treatment Manual means that it is no longer necessary to include 
provisions regarding Mexican mangoes in Sec. 319.56-2i. Therefore, we 
are amending Sec. 319.56-2i by removing the reference to Mexico from 
the title of the section, eliminating paragraph (a)(2), and removing 
the reference to Sec. 319.56-2f from paragraph (b).
    Therefore, for the reasons set forth in the proposed rule and in 
this document, we are adopting the provisions of the proposal as a 
final rule with the changes discussed in this document.

Effective Date

    This is a substantive rule that relieves restrictions and, pursuant 
to the provisions of 5 U.S.C. 553, may be made effective less than 30 
days after publication in the Federal Register.
    Argentina has demonstrated in accordance with international 
standards that the citrus-growing areas of the States of Catamarca, 
Jujuy, Salta, and Tucuman are free from citrus canker. Further, we 
believe that the phytosanitary requirements contained in this rule to 
prevent the introduction of other plant pests will reduce the risks 
posed by the importation of grapefruit, lemons, and oranges to a 
negligible level. Given these considerations, we believe that it is no 
longer necessary to prohibit the importation of grapefruit, lemons, and 
oranges from Argentina.
    Immediate implementation of this rule is necessary to provide 
relief to those persons who are adversely affected by restrictions we 
no longer find warranted. This rule requires that certain measures be 
taken in order for grapefruit, lemons, and oranges to be imported into 
the continental United States, including measures that must be applied 
early in the growing season. Making this rule effective immediately 
will allow plant health authorities and interested producers in 
Argentina to initiate the required measures as the growing season 
begins in order for their fruit to be eligible for export to the 
continental United States during the 2000 shipping season. Therefore, 
the Administrator of the Animal and Plant Health Inspection Service has 
determined that this rule should be effective less than 30 days after 
publication.

Executive Order 12866 and Regulatory Flexibility Act

    This rule has been reviewed under Executive Order 12866. The rule 
has been determined to be significant for the purposes of Executive 
Order 12866 and, therefore, has been reviewed by the Office of 
Management and Budget.
    This rule amends the citrus fruit regulations by recognizing a 
citrus-growing area within Argentina as being free from citrus canker. 
This rule also amends the fruits and vegetables regulations to allow 
the importation of grapefruit, lemons, and oranges from the citrus 
canker-free area of Argentina under conditions designed to prevent the 
introduction into the United States of two other diseases of citrus, 
sweet orange scab and citrus black spot, and other plant pests. These 
changes will allow grapefruit, lemons, and oranges to be imported into 
the continental United States from Argentina subject to certain 
conditions.
    The entry of Argentine fresh citrus fruits into the continental 
United States can be expected to place additional competitive pressure 
on domestic producers and on exporters from other countries who 
currently market fresh citrus fruits in the United States. The net 
benefits of this rule are likely to be positive, where consumers would 
benefit from lower prices while producers would likely bear the primary 
losses.

Analysis

    This analysis, which also serves as our cost-benefit analysis, 
considers the potential economic effects on domestic producers and 
consumers of citrus of allowing the importation of fresh citrus fruits 
from Argentina into the continental United States. Since entry of 
Argentine citrus to the continental United States will take place in 
three stages, the study focuses on citrus production, price and 
potential economic effects of this rule on consumers and producers 
during each stage. The major effects considered are losses to domestic 
producers and gains to consumers due to decreased prices resulting from 
increased volume. The magnitude of the impact will depend on the size 
of additional Argentine supply, the U.S. supply and demand for citrus, 
and price conditions in the rest of the world. Because Argentina 
already has well-established international markets, particularly in 
Europe, potential additional Argentine supply to the United States 
would likely be limited. After brief overviews of U.S. and Argentine 
production and import/export status and a discussion of prices, we 
evaluate the impact of increased imports from Argentina on the U.S. 
lemon, orange, and grapefruit markets.
    The data sources used for the analysis include: USDA, National 
Agricultural

[[Page 37660]]

Statistics Service (NASS) production statistics; the 1997 Census of 
Agriculture; USDA, Economic Research Service, ``Foreign Agricultural 
Trade of the United States''; USDA, Agricultural Marketing Service, 
marketing information; USDA, Foreign Agricultural Service, ``Annual 
Citrus Report''; and United Nations, Food and Agricultural 
Organization, production and trade statistics. A complete bibliography 
of the sources used in this analysis is available from the person 
listed under FOR FURTHER INFORMATION CONTACT.

U.S. Citrus Industry

Citrus production

    The United States produced 30,270 million pounds of grapefruit, 
lemons, and oranges (citrus henceforth) in 1996, with a value of $2.4 
billion. Four States--Arizona, California, Florida and Texas--accounted 
for about 98 percent of the grapefruit, lemon, and orange farms and 
more than 99 percent of the acreage in 1997 (the latest census year).
    As shown in Table 1, in 1997 there were 4,410 farms in the four 
main citrus-producing States that produced grapefruit, 1,978 that 
produced lemons, and 13,133 that produced oranges. Approximately 97 
percent of these fruit farms (Standard Industrial Classification 0272) 
had gross sales of less than $500,000 and thus are considered to be 
small entities according to the Small Business Administration size 
standards (13 CFR 121.601). These small citrus farms accounted for less 
than 34 percent of the total citrus growing acreage, while the 
remaining 3 percent of citrus farms (i.e., those with annual gross 
sales of $500,000 or more) accounted for about 66 percent of the 
acreage.

                                Table 1.--Farms by State and Type of Citrus, 1997
----------------------------------------------------------------------------------------------------------------
                                                     Grapefruit              Lemons                Oranges
                                               -----------------------------------------------------------------
                     State                                   Small                 Small                 Small
                                                Number of   entities  Number of   entities  Number of   entities
                                                  farms       (%)       farms       (%)       farms       (%)
----------------------------------------------------------------------------------------------------------------
Arizona.......................................        159        100        154         95        266         98
California....................................      1,279         97      1,824         93      5,640       98.5
Florida.......................................      2,549         97  .........  .........      6,893       96.2
Texas.........................................        423         97  .........  .........        334         99
                                               -----------------------------------------------------------------
    Total farms...............................      4,410  .........      1,978  .........     13,133  .........
----------------------------------------------------------------------------------------------------------------
Source: USDA/NASS, Census of Agriculture 1997. Note the United States Summary includes farms that may be
  producing more than one type of citrus and thus reports fewer farms than when farms are added up by States.

    Oranges, grapefruit, and lemons account for about 95 percent of the 
total U.S. citrus production. The 1996 value of U.S.-produced oranges 
was $1.82 billion; grapefruit, $289 million; and lemons, $261 million. 
Table 2 below shows the end use of grapefruit, lemons, and oranges for 
the United States (1993/94 to 1997/98 average). As the table shows, the 
share of processed fruit is greater than that diverted to the fresh 
export market or fresh domestic market.

 Table 2.--End Use of Citrus in the United States: Average of 1993/94 to
                                 1997/98
------------------------------------------------------------------------
                                               Percentage to:
                                  --------------------------------------
              Fruit                             Fresh fruit
                                      Export       market     Processing
------------------------------------------------------------------------
Grapefruit.......................         18.6         28.7         52.7
Lemons...........................         14.4         36.8         48.8
Oranges..........................          5.4         14.7        79.9
------------------------------------------------------------------------
Source: USDA/ERS, Fruit and Tree Nuts: Situation Outlook Yearbook, FTS-
  287, October 1999.

    Production for the fresh orange, grapefruit, and lemon markets 
accounted for about 25.2 percent of total citrus production or 
approximately 8,662 million pounds in 1997/98. The share of citrus 
fruits destined for the fresh market varied by State and by fruit. 
Table 3 below shows fresh utilized production, fresh fruit share, and 
distribution by State.

              Table 3.--Fresh Production and Share by State and Type of Citrus, 1993/94 to 1997/98
----------------------------------------------------------------------------------------------------------------
                                                Grapefruit                Lemons                  Oranges
                                         -----------------------------------------------------------------------
                  State                      Fresh       Fresh       Fresh       Fresh       Fresh       Fresh
                                            utilized     fruit      utilized     fruit      utilized     fruit
                                          production*  share (%)   production  share (%)   production  share (%)
-----------------------------------------------------------------------*-----------------------*----------------
Arizona.................................          56          68         168          59          84          87
California..............................         400          68         807          50       3,700          78
Florida.................................       1,904          42  ...........  .........         940           5
Texas...................................         250          70  ...........  .........          69         77
----------------------------------------------------------------------------------------------------------------
* Fresh utilized production is in millions of pounds.
Source: USDA/ERS, Fruit and Tree Nuts: Situation Outlook Yearbook, FTS-287, October 1999.


[[Page 37661]]

    As can be seen from Table 3, the fresh market accounted for about 
87 percent of the oranges, 68 percent of the grapefruit, and 59 percent 
of the lemons produced in Arizona; about 78 percent of the oranges, 68 
percent of the grapefruit, and 50 percent of the lemons produced in 
California; about 5 percent of the oranges and 42 percent of the 
grapefruit produced in Florida; and 77 percent of the oranges and 70 
percent of the grapefruit produced in Texas.
    The annual average consumption of oranges, grapefruit, and lemons 
in the United States has stayed at around 21.7 pounds per person (12.6 
pounds of oranges, 6.5 pounds of grapefruit, and 2.4 pounds of lemons), 
1977 to 1997, with a variability of about 10 percent. Fresh citrus 
fruits are marketed throughout the year, most heavily between October 
and May. Table 4 shows the marketing seasons for the fruits, by State.

                              Table 4.--Marketing Seasons by Fruit and State, 1999
----------------------------------------------------------------------------------------------------------------
              Fruit                        State                             Marketing season
----------------------------------------------------------------------------------------------------------------
Grapefruit.......................  Arizona.............  November 1 to July 31.
                                   California..........  November 15 to October 30.
                                   Florida.............  September 10 to July 31.
                                   Texas...............  October 1 to May 30.
Lemons...........................  Arizona.............  August 15 to March 1.
                                   California..........  August 1 to July 31.
Oranges..........................  Arizona.............  November 1 to August 31.
                                   California (Navels).  November 1 to June 15.
                                   California            March 15 to December 20.
                                    (Valencias).
                                   Florida (Early and    October 1 to April 15.
                                    midseason).
                                   Florida (Valencia)..  February 1 to July 31.
                                   Texas...............  September 25 to May 15.
----------------------------------------------------------------------------------------------------------------
Source: USDA, NASS, Citrus Fruits 1999 Summary, September 1999.

    Domestic shipments of citrus fruit are at their lowest during the 
months of July, August, and September (the distribution of oranges 
drops to approximately 6.4 percent of average annual shipments, 
grapefruit to 0.7 percent, and lemons to 16.3 percent). U.S. citrus 
exports are also at their lowest during these months. Citrus imports 
are also widely distributed throughout the year, but with above-average 
imports during July, August, and September (about 29 percent). 
Wholesale prices follow the same seasonal supply patterns, as they are 
lower during peak production months--October to May--and higher during 
summer months from June to September. Since the peak production period 
for citrus in Argentina is from May to October, the entry of Argentine 
fresh citrus fruits will likely peak during these months, which 
represent the most likely window of opportunity for Argentine imports 
to enter the U.S. market. The annual average terminal market wholesale 
price in 1996 in major U.S. cities was approximately 40 cents per pound 
for oranges, 29 cents per pound for grapefruit, and 43 cents per pound 
for lemons. (The average monthly wholesale prices were estimated from 
Terminal Market Prices by cities for January to December 1996; USDA/
AMS, Fruit and Vegetable Market News.)
    Importers and brokers will likely benefit from the entry of 
Argentine citrus fruit into the U.S. market because they will be able 
to provide quality fruits during the months when domestic production is 
lowest. Consumers will be able to obtain a wide choice of fresh citrus 
throughout the year and will not need to wait for the peak domestic 
production season or switch to non-citrus fruits.

Citrus Trade

    Foreign markets play an increasingly important role for U.S. 
producers, accounting for approximately 29 percent of the 1996 annual 
fresh citrus fruit sales. The total value of the U.S. fresh grapefruit, 
lemon, and orange exports was approximately $659 million in 1996. In 
terms of value, oranges accounted for 43.9 percent of citrus exports, 
grapefruit for 38.1 percent; and lemons for 18 percent. The United 
States is a net exporter of citrus fruits. Imports of fresh grapefruit, 
lemons, and oranges were valued at about $26.7 million in 1996; by 
value, about 5.4 percent of imports were grapefruit, 10.1 percent were 
lemons, and 84.5 percent were oranges.
    A few countries accounted for the bulk of the U.S. fresh citrus 
export market. In Asia, Japan (46 percent), Hong Kong (10.4 percent), 
the Republic of Korea (3 percent), and Taiwan (3 percent) together 
accounted for approximately 62.4 percent of total U.S. exports. Next, 
exports to Canada were about 25 percent. In Europe, France (3.3 
percent), The Netherlands (2.9 percent), and the United Kingdom (1 
percent) are the major importers. The United States, as noted above, is 
not a major importer of fresh citrus fruits. Major suppliers are 
Australia (67 percent), Mexico (13 percent), and Chile (6.2 percent); 
these countries together supplied about 86 percent of U.S. fresh citrus 
imports in 1996.
    U.S. fresh orange exports increased at an average growth rate of 
4.2 percent between 1985 and 1996; fresh grapefruit exports increased 
by 3.7 percent during that same period. In contrast, exports of lemons 
declined by an average rate of 1.1 percent between 1985 and 1996.
    Citrus imports to the United States increased at an average annual 
growth rate of 10 percent between 1985 and 1996. Imports are heaviest 
during the months when U.S. production and shipments are lowest. There 
is also a reciprocal window of opportunity for U.S. producers to step 
in during the months when production is low in countries of southern 
hemisphere. At present, the United States is exporting approximately 
$100,000 worth of citrus fruit to Argentina and importing none.

Argentine Citrus Industry

Production

    Argentina produced an annual average of 3,104 million pounds of 
grapefruit, lemons, and oranges between 1985 and 1996. Of this, about 
1,632 million pounds is from three States: Jujuy, Salta, and Tucuman. 
(The fourth State affected by this rule--Catamarca--has little to no 
commercial citrus production.) Table 5 shows the end use of the three 
fruits in Argentina.

[[Page 37662]]



       Table 5.--End Use of Citrus in Argentina, 1996-1998 Average
------------------------------------------------------------------------
                                                Percentage to:
                                     -----------------------------------
                Fruit                                Fresh
                                        Export       fruit    Processing
                                                    market
------------------------------------------------------------------------
Grapefruit..........................          13          69          18
Lemons..............................          18          15          67
Oranges.............................          11          71         18
------------------------------------------------------------------------
Source: USDA/FAS, Argentina Citrus Annual Report 1999, No. AR9034.

    A greater proportion of grapefruit and oranges is consumed 
domestically as fresh fruit, while a larger proportion of lemon is 
industrially processed.
    The annual rate of increase in Argentine citrus production between 
1985 and 1996 is attributable mostly to a 4.7 percent increase in lemon 
production. For the other citrus varieties, the growth rate was much 
less (0.7 percent for oranges and 0.4 percent for grapefruit). Export 
growth rates during this period were 15.4 percent for lemons, 4.1 
percent for oranges, and 0.7 percent for grapefruit.

Citrus Trade

    Argentina is one of South America's major exporters of grapefruit, 
lemons, and oranges. It exported 638 million pounds of those varieties 
in 1996 and an average of 470 million pounds per year between 1992 and 
1996 (433, 334, 445, 500, and 638 million pounds per year, 
respectively). Most of that fruit went to Europe, which accounted for 
nearly 87 percent of exports. Major destinations included The 
Netherlands (52 percent), France (14 percent), Spain (8 percent), the 
United Kingdom (10 percent), and Russia (8 percent). Smaller importers 
of Argentine citrus include Portugal, Belgium, Germany, Hong Kong, and 
Saudi Arabia. Since the majority of the U.S. fresh citrus exports went 
to the Far East, the United States and Argentina appear to be serving 
distinct markets. Imports of fresh citrus accounted for only about 0.06 
percent of the utilized total Argentine citrus supply.
    Argentina can be expected to maintain its well-established export 
markets, which, as noted in the previous paragraph, are mainly in 
Europe. Exports to the United States would provide another potential 
outlet for the Argentine citrus industry.

Wholesale Terminal Market Prices

    Fresh citrus fruit wholesale prices are lower in Argentina than in 
the United States. Average wholesale prices in Argentina for fresh 
grapefruit, oranges, and lemons were 17, 18, and 17 cents per pound, 
respectively, in 1996. These are lower than the average U.S. wholesale 
price of 29, 40, and 43 cents per pound of the respective fresh fruits 
for the same period. However, the Argentine wholesale prices do not 
reflect the additional costs that exporting these fruits to the United 
States would entail; i.e., overland transport cost from northwestern 
Argentina to the south-central coast, the sea freight rate, cold 
treatment, and the tariff rates, which add about 15 to 20 cents per 
pound to the average Argentine wholesale price. In addition, even 
before their fruit is exported to the United States, participating 
groves will incur added production costs in meeting the requirements of 
this rule. These requirements include grove cleaning, grove treatment, 
visual survey of groves 20 days prior to harvest, sampling and 
laboratory examination of fruit from the grove and buffer area, 
registered technicians at each packinghouse to verify the origin of 
fruit coming in, and sodium hypochlorite dipping prior to packing. 
These additional requirements are expected to add about 3 to 5 cents 
per pound to costs. Thus, by the time the fresh citrus from Argentina 
arrives at U.S. ports, the gap in prices will be narrower.

Effects on Producers and Consumers

    This section of the analysis examines the potential economic 
effects on U.S. producers and consumers of allowing fresh lemons, 
oranges, and grapefruit from Argentina to enter the U.S. market. 
Because of our conclusion that the importation of Argentine citrus 
poses a negligible pest risk, we do not believe that it is necessary to 
evaluate the costs of pest introduction in this analysis.
    This analysis is based on expected additional exports of these 
fruits by Argentina.\1\ As noted previously, the entry of Argentine 
citrus fruit into the continental United States will be phased in over 
three stages. In the first stage (the 2000 and 2001 shipping seasons), 
the fruit will be authorized entry into 34 non-citrus-producing, non-
buffer States; in the second stage (the 2002 and 2003 shipping 
seasons), the fruit may enter the original 34 States plus an additional 
10 buffer States; and in the final stage (beginning with the 2004 
shipping season), the fruit may enter all areas of the continental 
United States.
    A partial equilibrium economic surplus framework is used in this 
analysis to consider the benefits and the costs of this rule. Potential 
producer losses and gains to consumers are quantified for each citrus 
product in terms of changes in producer and consumer surplus resulting 
from increased imports from Argentina. This analysis measures the 
direct effects of this rule on domestic producers of oranges, 
grapefruit, and lemons. Indirect and induced effects on income, output, 
and employment are not considered.
    To simplify the analysis, supply and demand curves are assumed to 
be linear and the supply shift is assumed to be parallel. We use point 
estimates for the elasticities of supply and demand, average annual 
prices, and estimates of annual U.S. production and annual Argentine 
exports in the analysis. We assume U.S. and Argentine citrus are 
substitutes for one another. Seasonality in their production, 
consumption, and distribution are ignored.
---------------------------------------------------------------------------

    \1\ Producers and exporters in Argentina would not have the 
flexibility to make adjustments from domestic sales to exports or 
from processing to fresh, at least not within a single season. The 
rule essentially requires growers to commit their groves to the U.S. 
export market before a tree ever blooms, given that they must 
register with SENASA prior to the start of the growing season and 
begin applying specific phytosanitary measure (e.g., grove cleaning, 
field treatments) very early in the season. A non-registered grove 
that normally produces fruit for the Argentine domestic fresh or 
processing market could not, in response to high U.S. prices, simply 
decide to begin shipping fruit to the United States. It is possible 
that a profitable shipping season in the U.S. market for Argentine 
export could lead additional Argentine growers to enter into the 
export program for the following year. Historical export growth is a 
good indicator of what could happen. The recent growth in lemon 
exports is used to estimate Argintina's fresh lemon exports to the 
United States.
---------------------------------------------------------------------------

    To estimate the total exports of oranges, lemons, and grapefruit 
that could be expected to result from this rule, we use State- and 
fruit-specific 1995 production data from three of the four eligible 
Argentine States--Jujuy, Salta, and Tucuman. Because export levels for 
Argentine citrus fruit have been subject to marked fluctuations over

[[Page 37663]]

time, a simple semi-log model is used to estimate the growth rate of 
exports of each of the three fresh fruits. Exports to the United States 
are then calculated by assuming that Argentina would maintain its 
current exports to the rest of the world and divert its incremental 
export to the United States.
    Exports from Argentina will depend to a large extent on whether 
Argentine citrus will be price competitive with U.S. citrus. Table 6 
shows the average annual prices in Argentina, plus shipping and 
additional costs imposed by the rule, and U.S. prices. While seasonal 
prices can vary substantially from the average, we believe that the 
averages provide some sense of the incentives for Argentine citrus 
exports to the United States. Price differentials for the three citrus 
commodities indicate that Argentine lemons will be able to compete 
effectively with U.S. lemons. It is less likely that oranges and 
grapefruit from Argentina will have the same competitive advantage and, 
therefore, it is less likely that they will be exported to the United 
States.

                              Table 6.--Estimates of Price Differentials for Citrus
----------------------------------------------------------------------------------------------------------------
                                                                    Per-pound price  (dollars)
                                                ----------------------------------------------------------------
                                                                                          Price of
                     Fruit                        Argentina    Transport    Additional   Argentine     Price of
                                                  wholesale       cost      costs due     fruit in    U.S. fruit
                                                    price                    to rule        U.S.
----------------------------------------------------------------------------------------------------------------
Grapefruit.....................................          .17      .15-.20      .03-.05      .35-.42          .29
Oranges........................................          .18      .15-.20      .03-.05      .36-.43          .40
Lemons.........................................          .17      .15-.20      .03-.05      .35-.42          .43
----------------------------------------------------------------------------------------------------------------

Lemons

    Using a 5-year average (1992/93 through 1996/97) of U.S. 
consumption, production plus imports minus exports, we estimated U.S. 
domestic consumption of lemons to be 728 million pounds. The average 
price is $0.43 per pound. There are very few published elasticity 
estimates available. Published estimates from quantity-dependent models 
for lemon demand elasticity are not available, but Ferguson and Carman 
find an elasticity of demand for lemon of -0.44 in an unpublished 
study. Another study yielded an elasticity of supply for lemons greater 
than zero (Kinney et al., 1987, p.9, equation 6). Estimation by various 
data points, using acreage and per-acre revenue data in Tables 9 and 6, 
respectively, of Kinney et al. yields elasticities of supply for lemons 
between 0.04 and 0.17. In our analysis we use the -0.44 estimate for 
the elasticity of demand and assume an elasticity of supply equal to 
0.09.
    Because export levels for Argentine lemons have been subject to 
marked fluctuations over time (e.g., increases of 73 percent in 1994, 
17 percent in 1995, 49 percent in 1996, and almost 10 percent in 1997 
and decreases of 55 percent in 1986, 15 percent in 1989, and 25 percent 
in 1993), the quantities of fruit considered in this analysis are based 
on growth rates in Argentina's fresh lemon exports to the rest of the 
world. As discussed above, a simple semi-log model was used to estimate 
the growth rate of lemon exports between 1985 and 1998. The results 
show that lemon exports increased at the rate of 15 percent during that 
period. Using 1994-1998 average exports from the eligible Argentine 
States, 293.6 million pounds, as a baseline number, the total expected 
increase in exports would be 44.04 (293.6  x  0.15) or, rounding, 44 
million pounds.
    We assume that the elasticities, the quantity of the domestic 
lemons produced and consumed, and the quantity of Argentine lemons 
imported would not change over the 3-stage phase-in period.
    Estimated results of introducing imported fresh lemons from the 
Argentine States of Jujuy, Salta, and Tucuman into the U.S. market are 
as shown in Tables 7, 8, and 9. Because the price differential between 
Argentine lemons and U.S.-produced lemons shown in Table 6 appears to 
be sufficient to make export of lemons profitable to Argentine 
exporters, we estimate the impacts on consumers and producers 
considering three scenarios for each phase of the rule's 
implementation. The three scenarios examine the impact of 60 percent, 
80 percent, and 100 percent of the 44-million-pound increase in lemon 
exports being shipped to U.S. markets.
    We assume that the elasticities and the quantity of Argentine 
lemons imported would not change over the 3-stage phase-in. Our point 
of comparison in each stage is the absence of lemon imports from 
Argentina. In other words, the analysis at each stage assumes the same 
level of domestic production and consumption and the same price prior 
to importation of Argentine lemons. We have made no attempt to assess 
the incremental effects of the rule over the 3-stage phase-in period 
and, furthermore, it is not appropriate to compare the impacts of the 
various stages or to sum across the stages to obtain a total effect.
    Table 7 provides an analysis of expected impacts during Stage 1, 
including percent change in price, percent change in quantity, 
resultant producer losses, consumer benefits, and net benefits, for 
each diversion scenario. Stage 1 allows for importation of citrus into 
34 States. These States account for approximately 60 percent of fresh 
lemon consumption in the United States, about 437 million pounds.

  Table 7.--The Importation of Fresh Lemons From Argentina to Approved
                            States (Stage 1)
------------------------------------------------------------------------
                                   Percentage of average Argentine lemon
                                     export growth diverted to the U.S.
                                                  market:
                                  --------------------------------------
                                        60           80          100
------------------------------------------------------------------------
Imports (millions of pounds).....         26.4         35.2           44
Percent change in price..........        -11.4        -15.2          -19
Percent change in quantity.......        -1.03        -1.37        -1.71

[[Page 37664]]

 
Decrease in producer surplus           -22.251      -29.616      -36.957
 (millions of dollars)...........
Increase in consumer surplus            22.926       30.817       38.833
 (millions of dollars)...........
Net benefit (millions of dollars)        0.675        1.201        1.876
------------------------------------------------------------------------

    As Table 7 shows, during the first stage producer losses could 
potentially range between $22.251 million and about $36.957 million, 
while consumer gains could range between $22.926 million and $38.33 
million. The net benefits, therefore, would be between $675,000 and 
about $1.876 million.
    In Stage 2, Argentine imports will be shipped to 44 States, which 
account for 72.4 percent of lemon consumption, approximately 527 
million pounds. Table 8 shows that the expansion in Stage 2 will yield 
about the same results as Stage 1.

  Table 8.--The Importation of Fresh Lemons From Argentina to Approved
                            States (Stage 2)
------------------------------------------------------------------------
                                   Percentage of average Argentine lemon
                                     export growth diverted to the U.S.
                                                  market:
                                  --------------------------------------
                                        60           80          100
------------------------------------------------------------------------
Imports (millions of pounds).....         26.4         35.2           44
Percent change in price..........       -9.452      -12.602      -15.753
Percent change in quantity.......       -0.851       -1.134       -1.418
Decrease in producer surplus           -22.270      -29.651      -37.011
 (millions of dollars)...........
Increase in consumer surplus            22.830       30.647       38.567
 (millions of dollars)...........
Net benefit (millions of dollars)        0.560        0.996        1.556
------------------------------------------------------------------------

    Table 9 presents the results for the third stage, when fresh lemons 
imported from Argentina are allowed in all areas of the continental 
United States.

   Table 9.--The Importation of Fresh Lemons From Argentina (Stage 3)
------------------------------------------------------------------------
                                   Percentage of average Argentine lemon
                                     export growth diverted to the U.S.
                                                  market:
                                  --------------------------------------
                                        60           80          100
------------------------------------------------------------------------
Imports (millions of pounds).....         26.4         35.2           44
Percent change in price..........        -6.84        -9.12        -11.4
Percent change in quantity.......        -0.62        -0.82        -1.03
Decrease in producer surplus            -21.35       -28.44       -35.52
 (millions of dollars)...........
Increase in consumer surplus             21.74        29.13        36.59
 (millions of dollars)...........
Net benefit (millions of dollars)         0.39         0.69         1.07
------------------------------------------------------------------------

    As shown in Table 9, both producer losses and consumer gains during 
this final period would be slightly less than during the previous two 
stages, as Argentine imports would compete with the entire domestic 
fresh supply. Producer losses in this scenario range between $21.35 
million and $35.52 million, while consumer gains are between $21.74 
million and $36.59 million. The net benefits would thus be between 
$390,000 and $1.07 million.
    One of the commenters who responded to our proposed rule stated 
that in Argentina, 30 percent of lemon acreage is due to begin bearing 
during the next 5 years, thus annual production of lemons will increase 
significantly. This commenter reported that estimated lemon production 
increased 240 million pounds from 1996 to 1997 and concluded that 
within 5 years, Argentine citrus exporters, with an established 
distribution network, could very easily export 100 to 200 million 
pounds or more of fresh lemons to the United States during the summer 
months, a much larger export level than was considered in the proposed 
rule's economic analysis.
    With regard to current increases and potential suitable land for 
future expansion of lemon groves in Argentina, both planted acres and 
harvested acres have increased from their 1996 levels. Planted acreage 
increased from 76,763 acres to 102,698 acres in 1998, while harvested 
acreage increased from 69,854 acres to 95,095 acres. As can be seen, 
harvested acres accounted for about 92.6 percent of the planted acreage 
in 1998. For 1999, acres planted are forecasted to increase to 106,210 
acres, while harvested acres are forecasted to decline to 93,860 acres 
as older groves are replaced by younger, non-fruit-bearing trees. Over 
90 percent of the planted acreage is being harvested, and about 5 
percent of new plantings are replacement plantings. If these expansions 
continue and if weather conditions are favorable, Argentina will have a 
much larger potential to export more fresh lemons to all countries,

[[Page 37665]]

including the United States. (USDA/FAS, Argentina Citrus Annual Reports 
for 1997 [AR7043], 1998 [AR8032], and 1999 [AR9034], U.S. Embassy, 
Buenos Aires, Argentina; Randall J. Hager, Agricultural Attache, Office 
of Agricultural Affairs, U.S. Embassy, Buenos Aires, August 1999, 
personal communication; and Mariano Ripari, Agricultural Attache, 
Embassy of Argentina, Washington DC, August 1999, personal 
communication).
    Whether this expansion will continue, and how it will affect the 
United States, depends not only on the availability of suitable land in 
Argentina and the capital to convert that land to lemon groves, but 
also on many other factors such as production costs, relative world 
prices for fresh lemons, U.S. prices, the exchange rates for major 
currencies, changes in consumer taste for fresh lemons, growth in the 
demand for fresh lemons in other countries that are already importing 
from Argentina, the opening of other potential markets (e.g., new 
markets for Argentine lemons are opening in the Far East), and the 
profitability of alternative land use. Since inclement weather can 
affect both the quantity and quality of fresh lemons, there is added 
uncertainty in predicting Argentina's fresh lemon export capacity. For 
example, although production increased from about 1,905 million pounds 
in 1997 to 2,260 million pounds in 1998, this did not translate to 
large export levels for fresh lemons. Instead, exports declined from 
388 million pounds to 344 million pounds, as fresh lemons were diverted 
for processing due to rainy weather that caused poor quality.
    Table 10 shows an import of 100 million pounds of fresh lemon to 
the United States would result in price decline of about 26 percent and 
producer loss of about $80 million. However, consumer benefit would be 
about $86 million dollars, yielding a net benefit of about $5.57 
million. We do not expect this level of lemon imports from Argentina to 
be realized.

Table 10.--Impact in the United States of Larger Argentine Lemon Exports
                          to the United States
 [Price elasticity of demand is -0.44 and price elasticity of supply is
                                  0.09]
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Potential exports to the United States (millions of pounds)         *100
Percent change in price....................................       -25.92
Percent change in quantity**...............................        -2.33
Decrease in producer surplus (millions of dollars).........       -80.19
Increase in consumer surplus (millions of dollars).........        85.76
                                                            ------------
    Total surplus (millions of dollars)....................        5.57
------------------------------------------------------------------------
*Less than perfectly inelastic supply.
**This decrease in quantity may be due to diversion of fresh lemons to
  the processing sector as the price of fresh lemons declines.

    Increased ability to export will translate to sales only if there 
is a comparable market demand for fresh lemons. Over the last several 
years, per capita consumption (between 2.54 and 2.90 pounds per person) 
has remained stable, with very small variability (a mean of 2.7 pounds 
per person and a standard deviation of 0.12 pounds per person). U.S. 
consumption of fresh lemons over the last 3 years has declined from 
766.3 million pounds (peak amount in 1995/96) to 747.9 million and 
675.8 million pounds in 1996/97 and 1997/98, respectively (USDA/ERS, 
``Fruit and Tree Nuts: Situation and Outlook Report,'' October 1999, 
p.74). Most available estimates for the price elasticity of demand for 
fresh lemon are below -0.5, implying that the demand for fresh lemons 
is price inelastic. This means that for every 1 percent decrease in 
their price, the demand for fresh lemons would increase by less than 
0.5 percent. Given an estimated price elasticity of -0.44, a 100-
million-pound increase in supply of fresh lemons would require a price 
decrease of about 26 percent. In other words, for a large quantity of 
fresh lemons to be absorbed, the price of fresh lemons has to decrease 
substantially. If 100 million or more pounds of fresh lemons were to be 
imported from Argentina, the negative effect on domestic producers 
would be much larger than predicted under the importation scenario of 
44 million pounds. Consumer benefits would still outweigh producer 
losses. Since such a large influx of fresh lemons would require a large 
price decline to be absorbed, it would not be profitable for Argentina 
to export fresh lemons in such large quantities to the United States.

Oranges

    Using a 5-year average (1992/93 through 1996/97) of U.S. 
consumption, production plus imports minus exports, we estimated U.S. 
domestic consumption of oranges to be 3,479 million pounds. The average 
price is $0.40 per pound. As with lemons, there are very few published 
elasticity estimates available. The two studies most often referred to 
are by Huang (1993) and Thompson et al. (1990) and relate to oranges 
and grapefruit. Huang provides estimates both for Marshallian and 
Hicksian demand systems. The results of the Marshallian demand system 
are reported and used here--a demand elasticity of -0.849 for oranges. 
Thompson, et al. estimate -0.719 for the demand elasticity for oranges. 
A recent study showed that the elasticity of supply for California 
oranges was 0.149 (Villezca-Becerra and Shumway 1992). In our analysis, 
we use the -.849 estimate made by Huang for the elasticity of demand 
and assume an elasticity of supply equal to 0.149.
    Similar to lemons, our estimate for Argentine orange exports to the 
United States are based on growth rates in Argentina's fresh orange 
exports to the rest of the world. As above, a simple semi-log model was 
used to estimate the growth rate of orange exports between 1985 and 
1996. The results show that orange exports increased at the rate of 4.1 
percent during that period. Using 1992-1996 average exports from the 
Argentina, 171 million pounds, as a baseline number and assuming the 
share of exports from the eligible Argentine States would continue to 
be 26.59 percent, the total expected increase in exports would be 1.86 
million pounds (171  x  0.2659  x  .041) or, rounding, 2 million 
pounds.
    Table 11 reports the potential effects of orange imports from 
Argentina during the first, second, and third stages of the import 
program. We believe the price differential between U.S. and Argentine 
oranges illustrated in Table 6 suggests that a lower proportion of 
Argentine orange exports will be diverted to the United States. 
Therefore, we assume a 20 percent diversion of the 2 million pounds of 
the expected increase in Argentine exports, or 400,000 pounds. Table 11 
shows that price decreases as the volume of imported oranges increases, 
given domestic supply in the approved States during every stage.

[[Page 37666]]



 Table 11.--The Importation of Fresh Oranges from Argentina to Approved
 States for Stages 1 through 3, assuming 20 percent of average Argentine
                orange export diverted to the U.S. market
------------------------------------------------------------------------
                                                   Stage
                                  --------------------------------------
                                        1            2            3
------------------------------------------------------------------------
Imports (millions of pounds).....          0.4          0.4          0.4
Percent change in price..........        -0.04        -0.03       -0.012
Percent change in quantity.......       -0.003       -0.003       -0.002
Decrease in producer surplus           -0.3019      -0.3019     -0.16032
 (millions of dollars)...........
Increase in consumer surplus            0.3019       0.3019      0.16033
 (millions of dollars)...........
Net benefit (millions of dollars)       0.0000       0.0000     0.00001
------------------------------------------------------------------------
Note: The utilized supply for Stage 1 is 2,089 million pounds for
  approved States; for Stage 2 it is 2,518 million pounds.

Consumer gains in every stage are approximately equal to producer 
losses.

Grapefruit

    Using a 5-year average (1992/93 through 1996/97) of U.S. 
consumption, production plus imports minus exports, we estimated U.S. 
domestic consumption of grapefruit to be 1,602 million pounds. The 
average price is $0.29 per pound. As with lemons, there are very few 
published elasticity estimates available. The two studies most often 
referred to are by Huang (1993) and Thompson et al. (1990) and relate 
to oranges and grapefruit. Huang provides estimates both for 
Marshallian and Hicksian demand systems. The results of the Marshallian 
demand system are reported and used here--a demand elasticity of -0.455 
for grapefruit.
    Thompson, et al. estimate -0.523 for the demand elasticity for 
grapefruit. A recent study showed that the elasticity of supply for 
California grapefruit was 0.409 (Villezca-Becerra and Shumway 1992). In 
our analysis we use the -0.455 estimate made by Huang for the 
elasticity of demand and assume an elasticity of supply equal to 0.409.
    Similar to lemons and oranges, our estimate for Argentine 
grapefruit exports to the United States are based on growth rates in 
Argentina's fresh grapefruit exports to the rest of the world. As 
above, a simple semi-log model was used to estimate the growth rate of 
grapefruit exports between 1985 and 1996. The results show that 
grapefruit exports increased at the rate of 1 percent during that 
period. Using 1992-1996 average exports from the Argentina, 79.72 
million pounds, as a baseline number and assuming the share of exports 
from the eligible Argentine States would continue to be 51.22 percent, 
the total expected increase in exports would be 0.41 million pounds 
(79.72  x  0.5122  x  0.01).
    Given the price advantage possessed by U.S. producers of grapefruit 
(see Table 6), we believe that it is highly unlikely that Argentine 
grapefruit will be marketed in the United States.
    However, if we perform an analysis of the impact of grapefruit 
imports similar to the analysis done for oranges and lemons, we find 
that there is not a significant effect on either U.S. producers or 
consumers. On the basis of the growth rate of grapefruit production in 
Argentina, which was less than 1 percent, the maximum that could be 
diverted would be about 410,000 pounds. This amount, when compared to 
about 1,603 million pounds of domestic supply of fresh grapefruit in 
the United States, is very small. As a result, price would decrease by 
only about 0.03 percent with 100-percent diversion in Stage 3. 
Producers losses and consumer gains both would be around $137,600, 
yielding a net benefit of zero.

Conclusion

    Overall, the estimated net economic effects of this rule are 
positive. There is a direct relationship between producer losses and 
consumer gains on the one hand and the quantity of imports on the other 
hand. Therefore, the larger the share of imports from Argentina, 
relative to U.S. domestic supply, the larger the U.S. producer losses 
and the larger the U.S. consumer gains. In all cases, consumer gains 
are equal to or slightly outweigh grower losses.
    As seen in Tables 7 through 11, the entry of fresh citrus fruits 
from Argentina into U.S. markets would induce producer losses and 
consumer gains. The greatest effect would be due to importation of 
lemons because the price differential between domestic fresh lemons and 
Argentine lemons may be largest. The expected lemon imports from 
Argentina would represent a larger proportion of the U.S. domestically 
available fresh lemon volume compared to that for fresh oranges and 
grapefruit.
    Overall, considering all three stages of the import program, fresh 
lemon prices could potentially decrease between 6.84 percent and 19 
percent. Producers would possibly lose between $21.35 million and 
$36.96 million, while consumers would potentially gain between $21.74 
million and $38.83 million annually as the result of importing fresh 
lemons from Argentina, yielding a net benefit of between $390,000 and 
$1.876 million. In all cases, consumer gains slightly outweigh grower 
losses.
    The extent of any actual decrease in prices would depend to a great 
degree upon the size of the price elasticity of demand, the magnitude 
of the change in supply, and the size of the baseline price. For lower 
price elasticities, both losses and gains would be higher. Since fresh 
fruit exports from Argentina, especially of oranges and grapefruit, are 
not expected to be large, they are not expected to change citrus fruit 
production and consumption patterns in the United States.
    Because Argentina's peak season of production complements the U.S. 
low season of production (particularly for oranges and grapefruit) and 
vice versa, this rule should have a positive effect for consumers. U.S. 
prices during the months of June through September are higher than the 
annual average. The effect would vary by commodity, with the largest 
effect on lemon prices. As a result of the highest expected additional 
fresh lemon supply, the average lemon price in the United States would 
decrease by as much as 19 percent (in Stage 1), from 43 cents per pound 
to about 34.83 cents per pound. Orange prices would decline by as much 
as 0.04 percent (in Stage 1), from 40 cents per pound to 39.98 cents 
per pound. The effect on grapefruit prices is even more insignificant.
    In addition, it is important to note that the analysis implicitly 
assumes the worst-case scenario because the partial equilibrium 
analysis does not allow for substitution among producers. If the price 
of fresh citrus fruits decreases significantly, then the producers may 
choose to channel their products to overseas markets or to processing

[[Page 37667]]

markets. Under those scenarios, the decrease in prices expected to 
result from this rule would be less than that estimated in this 
analysis, resulting in less of a decrease in producer surplus.
    This rule would have a net positive effect on the overall economy, 
since consumer benefits would be slightly higher than producer losses. 
The increased potential for trade and facilitation of flow of goods 
will benefit the welfare of both countries. These trading relationships 
benefit numerous sectors in the U.S. national economy. Increased trade 
in these sectors have dual benefits. Those employed are also consumers 
of fresh citrus fruit. Since fresh citrus fruits are normal goods, with 
positive income elasticities, increased jobs, outputs, and income in 
those sectors can also mean increased consumption of citrus products.
    The only significant alternative to this rule would be to make no 
changes in the regulations; i.e., to continue to prohibit the 
importation of grapefruit, lemons, and oranges from Argentina. We have 
rejected that alternative because we believe that Argentina has 
demonstrated that the citrus-growing areas of the States of Catamarca, 
Jujuy, Salta, and Tucuman are free from citrus canker and because we 
believe that the systems approach offered by Argentina to prevent the 
introduction of other plant pests reduces the risks posed by the 
importation of grapefruit, lemons, and oranges to a negligible level.
    Under these circumstances, the Administrator of the Animal and 
Plant Health Inspection Service has determined that this action will 
not have a significant economic impact on a substantial number of small 
entities.

Executive Order 12988

    This final rule allows the importation of grapefruit, lemons, and 
oranges from Argentina under certain conditions. State and local laws 
and regulations regarding grapefruit, lemons, and oranges imported 
under this rule are preempted while the fruit is in foreign commerce. 
Grapefruit, lemons, and oranges are generally imported for immediate 
distribution and sale to the consuming public and will remain in 
foreign commerce until sold to the ultimate consumer. The question of 
when foreign commerce ceases in other cases must be addressed on a 
case-by-case basis. No retroactive effect will be given to this rule, 
and this rule does not require administrative proceedings before 
parties may file suit in court challenging this rule.

National Environmental Policy Act

    An environmental assessment and finding of no significant impact 
have been prepared for this rule. The assessment provides a basis for 
the conclusion that the importation of grapefruit, lemons, and oranges 
under the conditions specified in this rule will not present a risk of 
introducing or disseminating plant pests and would not have a 
significant impact on the quality of the human environment. Based on 
the finding of no significant impact, the Administrator of the Animal 
and Plant Health Inspection Service has determined that an 
environmental impact statement need not be prepared.
    The environmental assessment and finding of no significant impact 
were prepared in accordance with: (1) The National Environmental Policy 
Act of 1969 (NEPA), as amended (42 U.S.C. 4321 et seq.), (2) 
regulations of the Council on Environmental Quality for implementing 
the procedural provisions of NEPA (40 CFR parts 1500-1508), (3) USDA 
regulations implementing NEPA (7 CFR part 1b), and (4) APHIS' NEPA 
Implementing Procedures (7 CFR part 372).
    Copies of the environmental assessment and finding of no 
significant impact are available for public inspection at USDA, room 
1141, South Building, 14th Street and Independence Avenue SW., 
Washington, DC, between 8 a.m. and 4:30 p.m., Monday through Friday, 
except holidays. Persons wishing to inspect copies are requested to 
call ahead on (202) 690-2817 to facilitate entry into the reading room. 
In addition, copies may be obtained by writing to the individual listed 
under FOR FURTHER INFORMATION CONTACT.

Paperwork Reduction Act

    In accordance with section 3507(d) of the Paperwork Reduction Act 
of 1995 (44 U.S.C. 3501 et seq.), the information collection or 
recordkeeping requirements included in this final rule have been 
approved by the Office of Management and Budget (OMB). The assigned OMB 
control number is 0579-0134.

List of Subjects

7 CFR Part 300

    Incorporation by reference, Plant diseases and pests, Quarantine.

7 CFR Part 319

    Bees, Coffee, Cotton, Fruits, Honey, Imports, Incorporation by 
reference, Nursery Stock, Plant diseases and pests, Quarantine, 
Reporting and recordkeeping requirements, Rice, Vegetables.

    Accordingly, we are amending title 7, chapter III, of the Code of 
Federal Regulations as follows:

PART 300--INCORPORATION BY REFERENCE

    1. The authority citation for part 300 continues to read as 
follows:

    Authority: 7 U.S.C. 150ee, 154, 161, 162 and 167; 7 CFR 2.22, 
2.80, and 371.2(c).


    2. In Sec. 300.1, paragraph (a), the introductory text is revised 
to read as follows:


Sec. 300.1  Materials incorporated by reference.

    (a) Plant Protection and Quarantine Treatment Manual. The Plant 
Protection and Quarantine Treatment Manual, which was reprinted 
November 30, 1992, and includes all revisions through May 2000, has 
been approved for incorporation by reference in 7 CFR chapter III by 
the Director of the Office of the Federal Register in accordance with 5 
U.S.C. 552(a) and 1 CFR part 51.
* * * * *

PART 319--FOREIGN QUARANTINE NOTICES

    3. The authority citation for part 319 continues to read as 
follows:

    Authority: 7 U.S.C. 150dd, 150ee, 150ff, 151-167, 450, 2803, and 
2809; 21 U.S.C. 136 and 136a; 7 CFR 2.22, 2.80, and 371.2(c).


Sec. 319.28  [Amended]

    4. In Subpart--Citrus Fruit, Sec. 319.28 is amended as follows:
    a. In paragraph (a)(1), by adding the words ``Argentina (except for 
the States of Catamarca, Jujuy, Salta, and Tucuman, which are 
considered free of citrus canker),'' immediately after the word 
``Seychelles,''.
    b. In paragraph (a)(2), by adding the words ``(except as provided 
by Sec. 319.56-2f of this part)'' immediately after the word 
``Argentina''.
    c. In paragraph (a)(3), by adding the words ``(except for the 
States of Catamarca, Jujuy, Salta, and Tucuman, which are considered 
free of Cancrosis B)'' immediately after the word ``Argentina''.


Sec. 319.56a  [Amended]

    5. In Sec. 319.56a, paragraph (e), the first sentence is amended by 
removing the words ``and 319.56-2f to 319.56-2m, inclusive,'' and 
adding the words ``, 319.56-2e, 319.56-2g, 319.56-2k, 319.56-2l, and 
319.56-2p'' in their place.

    6. In Subpart Fruits and Vegetables, a new Sec. 319.56-2f is added 
to read as follows:

[[Page 37668]]

Sec. 319.56-2f  Administrative instructions governing importation of 
grapefruit, lemons, and oranges from Argentina.

    Fresh grapefruit, lemons, and oranges may be imported from 
Argentina into the continental United States (the contiguous 48 States, 
Alaska, and the District of Columbia) only under permit and only in 
accordance with this section and all other applicable requirements of 
this subpart.
    (a) Origin requirement. The grapefruit, lemons, or oranges must 
have been grown in a grove located in a region of Argentina that has 
been determined to be free from citrus canker. The following regions in 
Argentina have been determined to be free from citrus canker: The 
States of Catamarca, Jujuy, Salta, and Tucuman.
    (b) Grove requirements. The grapefruit, lemons, or oranges must 
have been grown in a grove that meets the following conditions:
    (1) The grove must be registered with the citrus fruit export 
program of the Servicio Nacional de Sanidad y Calidad Agroalimentaria 
(SENASA).
    (2) The grove must be surrounded by a 150-meter-wide buffer area. 
No citrus fruit grown in the buffer area may be offered for importation 
into the United States.
    (3) Any new citrus planting stock used in the grove must meet one 
of the following requirements:
    (i) The citrus planting stock originated from within a State listed 
in paragraph (a) of this section; or
    (ii) The citrus planting stock was obtained from a SENASA-approved 
citrus stock propagation center.
    (4) All fallen fruit, leaves, and branches must be removed from the 
ground in the grove and the buffer area before the trees in the grove 
blossom. The grove and buffer area must be inspected by SENASA before 
blossom to verify that these sanitation measures have been 
accomplished.
    (5) The grove and buffer area must be treated at least twice during 
the growing season with an oil-copper oxychloride spray. The timing of 
each treatment shall be determined by SENASA's expert system based on 
its monitoring of climatic data, fruit susceptibility, and the presence 
of disease inoculum. The application of treatments shall be monitored 
by SENASA to verify proper application.
    (6) The grove and buffer area must be surveyed by SENASA 20 days 
before the grapefruit, lemons, or oranges are harvested to verify the 
grove's freedom from citrus black spot (Guignardia citricarpa) and 
sweet orange scab (Elsinoe australis). The grove's freedom from citrus 
black spot and sweet orange scab shall be verified through:
    (i) Visual inspection of the grove and buffer area; and
    (ii) The sampling of 4 fruit from each of 298 randomly selected 
trees from each grove and buffer area covering a maximum area of 800 
hectares. If the area to be sampled exceeds 800 hectares, SENASA must 
contact APHIS for APHIS' determination as to the number of trees to be 
sampled. The sampled fruit must be taken from those portions of the 
trees that are mostly likely to have infected, symptomatic fruit (i.e. 
near the outer, upper part of the canopy on the sides of the tree that 
receive the most sunlight). The sampled fruit must be held in the 
laboratory for 20 days at 27  deg.C, 80 percent relative humidity, and 
in permanent light to promote the expression of symptoms in any fruit 
infected with citrus black spot.
    (c) After harvest. After harvest, the grapefruit, oranges, or 
lemons must be handled in accordance with the following conditions:
    (1) The fruit must be moved from the grove to the packinghouse in 
field boxes or containers of field boxes that are marked to show the 
SENASA registration number of the grove in which the fruit was grown. 
The identity of the origin of the fruit must be maintained.
    (2) During the time that any grapefruit, lemons, or oranges from 
groves meeting the requirements of paragraph (b) of this section are in 
the packinghouse, no fruit from groves that do not meet the 
requirements of paragraph (b) of this section may enter the 
packinghouse. A packinghouse technician registered with SENASA must 
verify the origin of all fruit entering the packinghouse.
    (3) After arriving at the packinghouse, the fruit must be held at 
room temperature for 4 days to allow bruises or other fruit damage to 
become apparent.
    (4) After the 4-day holding period, bruised or damaged fruit must 
be culled and the fruit must be inspected by SENASA to verify its 
freedom from citrus black spot and sweet orange scab. The fruit must 
then be chemically treated as follows:
    (i) Immersion in sodium hypochlorite (chlorine) at a concentration 
of 200 parts per million for 2 minutes;
    (ii) Immersion in orthophenilphenate of sodium;
    (iii) Spraying with imidazole; and
    (iv) Application of 2-4 thiazalil benzimidazole and wax.
    (5) Before packing, the treated fruit must be individually labeled 
with a sticker that identifies the packinghouse in which they were 
packed and must be inspected by SENASA to verify its freedom from 
citrus black spot and sweet orange scab and to ensure that all stems, 
leaves, and other portions of plants have been removed from the fruit.
    (6) The fruit must be packed in clean, new boxes that are marked 
with the SENASA registration number of the grove in which the fruit was 
grown and a statement indicating that the fruit may not be distributed 
in Hawaii, Guam, the Northern Mariana Islands, Puerto Rico, the U.S. 
Virgin Islands, or in any State (each of which must be individually 
listed) into which the distribution of the fruit is prohibited pursuant 
to paragraph (g)(1) or (g)(2) of this section.
    (d) Phytosanitary certificate. Grapefruit, lemons, and oranges 
offered for entry into the United States from Argentina must be 
accompanied by a phytosanitary certificate issued by SENASA that states 
the grapefruit, lemons, or oranges were produced and handled in 
accordance with the requirements of paragraphs (a), (b), and (c) of 
this section and that the grapefruit, lemons, or oranges are apparently 
free from citrus black spot and sweet orange scab.
    (e) Cold treatment. Due to the presence in Argentina of 
Mediterranean fruit fly (Medfly) (Ceratitis capitata) and fruit flies 
of the genus Anastrepha, grapefruit, lemons (except smooth-skinned 
lemons), and oranges offered for entry from Argentina must be treated 
with an authorized cold treatment listed in the Plant Protection and 
Quarantine Treatment Manual, which is incorporated by reference at 
Sec. 300.1 of this chapter. The cold treatment must be conducted in 
accordance with the requirements of Sec. 319.56-2d of this subpart.
    (f) Disease detection. If, during the course of any inspection or 
testing required by this section or Sec. 319.56-6 of this subpart, or 
at any other time, citrus black spot or sweet orange scab is detected 
on any grapefruit, lemons, or oranges, APHIS and SENASA must be 
notified and the grove in which the fruit was grown or is being grown 
shall be removed from the SENASA citrus export program for the 
remainder of that year's growing and harvest season, and the fruit 
harvested from that grove may not be imported into the United States 
from the time of detection through the remainder of that shipping 
season.
    (g) Limitations on distribution. The distribution of the 
grapefruit, lemons, and oranges is limited to the continental United 
States (the 48 contiguous States, Alaska, and the District of 
Columbia.). In addition, during the 2000 through

[[Page 37669]]

2003 shipping seasons, the distribution of the grapefruit, lemons, and 
oranges is further limited as follows:
    (1) During the 2000 and 2001 shipping seasons, the fruit may be 
distributed in all areas of the continental United States except 
Alabama, Arizona, Arkansas, California, Colorado, Florida, Georgia, 
Louisiana, Mississippi, Nevada, New Mexico, Oklahoma, Oregon, Texas, 
and Utah.
    (2) During the 2002 and 2003 shipping seasons, the fruit may be 
distributed in all areas of the continental United States except 
Arizona, California, Florida, Louisiana, and Texas.
    (3) For the 2004 shipping season and beyond, the fruit may be 
distributed in all areas of the continental United States.
    (h) Ports of entry. The grapefruit, lemons, and oranges may enter 
the United States only through a port of entry located in a State where 
the distribution of the fruit is authorized pursuant to paragraph (g) 
of this section.
    (i) Repackaging. If any grapefruit, lemons, or oranges are removed 
from their original shipping boxes and repackaged, the stickers 
required by paragraph (c)(5) of this section may not be removed or 
obscured and the new boxes must be clearly marked with all the 
information required by paragraph (c)(6) of this section.

(Approved by the Office of Management and Budget under control 
number 0579-0134)

    7. Section 319.56-2i, including the section heading, is revised to 
read as follows:


Sec. 319.56-2i  Administrative instructions prescribing treatments for 
mangoes from Central America, South America, and the West Indies.

    (a) Authorized treatments. Treatment with an authorized treatment 
listed in the Plant Protection and Quarantine Treatment Manual will 
meet the treatment requirements imposed under Sec. 319.56-2 as a 
condition for the importation into the United States of mangoes from 
Central America, South America, and the West Indies. The Plant 
Protection and Quarantine Treatment Manual is incorporated by 
reference. For the full identification of this standard, see Sec. 300.1 
of this chapter, ``Materials incorporated by reference.''
    (b) Department not responsible for damage. The treatments for 
mangoes prescribed in the Plant Protection and Quarantine Treatment 
Manual are judged from experimental tests to be safe. However, the 
Department assumes no responsibility for any damage sustained through 
or in the course of such treatment.

    Done in Washington, DC, this 8th day of June 2000.
Bobby R. Acord,
Acting Administrator, Animal and Plant Health Inspection Service.
[FR Doc. 00-14851 Filed 6-9-00; 10:00 am]
BILLING CODE 3410-34-U